Journal articles on the topic 'Heifer calves'
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1
Furniss, S. J., A. Stroud, H. Barrington, S. P. J. Kirby, J. P. Wray, and P. Dakin. "The effect of dam’s parity on the first lactation performance of dairy heifers." Proceedings of the British Society of Animal Production (1972) 1986 (March 1986): 102. http://dx.doi.org/10.1017/s0308229600016093.
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Whether they are planning to calve for the first time at two or three years old Many farmers choose to serve their maiden dairy heifers (animals not previously served, (M. A. F. F. 1985)) with a beef breed recognised for giving easier calvings .Often the heifer breeding programme is not well supervised and it is a matter of convienience to use a resident beef bull.There are however,considerable advantages to serving heifers with dairy bulls including an increased number of heifer calves for selection or the ability to serve older, nature cows (animals that have commenced at least their first lactation (M. A. F. F. 1985))with a continental beef breed giving large calves of higher market value. Because heifers tend to be calved as a group they provide a batch of calves which can be concentrated upon, easing management and improving control over performance.If heifers are served by bulls of as higher genetic merit as would normally be used on cows then increased genetic turnover will raise the genetic index in the younger dam which should be reflected in her daughter’s performance.
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Cônsolo, Nara, Jasper Munro, Stéphanie Bourgon, Niel Karrow, Alan Fredeen, Janel Martell, and Yuri Montanholi. "Associations of Blood Analysis with Feed Efficiency and Developmental Stage in Grass-Fed Beef Heifers." Animals 8, no. 8 (August 2, 2018): 133. http://dx.doi.org/10.3390/ani8080133.
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Proxies for feed efficiency, such as blood-based indicators, applicable across heifers varying in genetic makeup and developmental state are needed. Assessments of blood analytes and performance were made in heifer calves and pregnant heifers. Residual feed intake, a measure of feed efficiency, was used to categorize each population of heifers as either efficient or inefficient. Efficient heifer calves had lower mean cell hemoglobin, greater lymphocyte count, and fewer segmented neutrophils at the end of the test compared to inefficient calves. Efficient pregnant heifers had greater counts of lymphocytes with fewer segmented neutrophils at the end than inefficient pregnant heifers. Efficient heifer calves exhibited higher specific immunoglobulin M than inefficient calves. Throughout the test, efficient heifer calves had elevated potassium and phosphorus, and reduced alkaline phosphatase (ALP) compared to inefficient heifers. Efficient pregnant heifers showed greater ALP, non-esterified fatty acids and creatinine, but lower cholesterol and globulin than inefficient pregnant heifers. Levels of red and white blood cells, creatine kinase, cholesterol, glucose, potassium and phosphorus were higher in heifer calves compared with pregnant heifers. There is potential for blood analytes as proxies for feed efficiency; however, it is necessary to consider the inherent associations with feed efficiency and heifers’ developmental stage.
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Elliott, Lisa M., Joe L. Parcell, and David J. Patterson. "Determination of the Value of Minimum Sire Accuracy Traits." Journal of Agricultural and Applied Economics 45, no. 2 (May 2013): 259–75. http://dx.doi.org/10.1017/s1074070800004739.
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Using Missouri Show-Me-Select Replacement Heifers Inc. sale data, this article uses hedonic modeling to assess the marginal implicit values of physical and genetic characteristics, expected performance characteristics of calves, and market factors to bred heifer price. In 2008, a higher quality standard, known as Tier II, was created combining minimum expected progeny difference (EPD) accuracies for a heifer's sire with previous heifer standards. Heifer characteristics and market factors as well as yearling and carcass weight EPDs were found to significantly influence heifer price. Results suggest that Tier II heifers receive a premium compared with traditional Show-Me-Select heifers.
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Coleman, Lucy, Natalia Martín, Penny Back, Hugh Blair, Nicolás López-Villalobos, and Rebecca Hickson. "Low Birthweight Beef Bulls Compared with Jersey Bulls Do Not Impact First Lactation and Rebreeding of First-Calving Dairy Heifers—A Case Study in New Zealand." Dairy 3, no. 1 (January 27, 2022): 87–97. http://dx.doi.org/10.3390/dairy3010007.
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Dairy heifers in New Zealand are typically naturally mated by Jersey bulls to produce low-value non-replacement offspring sold for slaughter a few days after birth. Producing a beef-sired calf from a dairy heifer will increase the value of these calves for beef production but may compromise the subsequent career of the animals, in terms of milk production, rebreeding success, health, or survival of the heifer. This study aimed to determine the impact of low birthweight Angus and Hereford bulls versus breed-average Jersey bulls on the reproduction and production traits of first-calving dairy heifers. The experiment included 304 heifer-calf pairs over 2 years. Calves sired by Angus and Hereford bulls were 3.5–4.4 kg and 3.7–6.8 kg heavier than Jersey-sired calves and had a 4.2% and 9.3% incidence of assistance at birth for normally presented calves over the 2 years, respectively. No normally presented Jersey-sired calves were assisted. There was no difference in body condition score, pre-calving live weight, milk production, pregnancy rate, inter-calving interval, re-calving day, and 21-day re-calving rate of heifers mated to the different breeds of bulls. The results indicate that the Angus and Hereford bulls with low birthweight and high direct calving ease estimated breeding values (EBV) can be used to produce calves of greater value than Jersey-sired calves without impacting dairy heifer production. However, a small increase in assistance at calving could be expected.
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Keane, M. G., and M. J. Drennan. "Growth and Carcass Composition of Implanted and Non-Implanted Heifers and Steers Reared Together." Proceedings of the British Society of Animal Production (1972) 1986 (March 1986): 23. http://dx.doi.org/10.1017/s0308229600015348.
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The national cow herd consists of 1.64m dairy and 0.43m beef cows. They produce a total of 1.76m reared calves annually. Of these 0.42m heifers go as herd replacements, leaving 0.46m heifers and 0.88m males available for beef production. There is a 2:l ratio of males to femaies in the population of calves available for beef production. Also, there are few straightbred dairy heifer calves available and the mean birth date of heifer calves for beef production is later than that cf males. The objectives of the present experiment were (i) to compare the performance and carcass composition of non-implanted and implanted heifers and steers and (ii) to compare the carcass composition of serially slaughtered non-implanted and implanted heifers.Sixty tour (48 female and 16 male) Spring born Hereford x Friesian calves (initial live-weight 45 kg) were purchased and reared on milk replacer and concentrates. After 81 days they were blocked on weight and assigned from within sex type to 8 treatment groups.
6
Newman, J. A., S. D. M. Jones, M. A. Price, and B. C. Vincent. "Feed efficiency in once-calved and conventional systems of heifer beef production." Canadian Journal of Animal Science 73, no. 4 (December 1, 1993): 915–30. http://dx.doi.org/10.4141/cjas93-093.
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A total of 120 crossbred heifers (initial weight = 270 ± 3 kg) were used in a project to evaluate a once-calved-heifer system of beef production. They were reared on a cereal silage–grain diet and, beginning at an average age of 385 d, exposed during a 6-wk breeding period to bulls of breeds chosen for calving ease. Ninety-six heifers reared calves to weaning. The calves were weaned and the heifers were slaughtered 3, 5 or 7 mo after calving, and the feed conversion efficiency of these treatment groups was compared with that of a similar group of 32 heifers slaughtered at 457 d of age after a conventional feeding program. Feed conversion calculations included the combined cow–calf unit for heifers that had reared a calf and were based on weaning-day and end-of-test (27 Sept.) endpoints. During the post-calving period, the late-weaned cow–calf units tended to be more efficient to the point of weaning, but the early-weaned ones were significantly more efficient if the calf's performance from weaning to the end of test was considered. From the start of test to the weaning endpoint, conventionally reared heifers were significantly more efficient than early-weaned once-calved heifers on many of the bases studied. To the end-of-test endpoint, however, they did not differ significantly (e.g., 411.4 ± 20.5, vs. 402.1 ± 29.0, 441.0 ± 29.0 and 460.2 ± 29.0 MJ DE kg−1 lean product weight for conventionally reared vs. 3-, 5- and 7-mo-weaned once-calved heifers). These results suggest that animals in a once-calved-heifer system of beef production can utilize digestible energy as efficiently as those in a conventional system if conception failure and calf losses can be controlled. Key words: Beef production, heifers once-calved, feed efficiency
7
Rigby, I. "Once-bred heifer systems." Proceedings of the British Society of Animal Production (1972) 1989 (March 1989): 8. http://dx.doi.org/10.1017/s0308229600010096.
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Major changes are taking place in the UK beef industry, as a result of the reduction in dairy cow numbers due to milk quotas. Similar reductions are taking place throughout Europe and have resulted in a strong export market for UK calves. Consequently in 1988 there were 800,000 fewer calves available for beef production than there were when quotas were introduced. This downward trend is forecast to continue and by 1990 the EEC will no longer be self-sufficient for veal and beef.At times of calf shortages the concept of once-bred heifer beef (producing one calf out of a heifer otherwise destined for slaughter as clean beef, and then slaughtering her shortly after calving) has been considered as a way of generating extra calves and meeting the shortfall. Historically low fertility in young heifers, and high levels of dystokia have limited the commercial uptake of the technique. In addition returns have been low because heifers that have produced a calf are not eligible for Variable Beef Premium payments and, being unfamiliar with this type of slaughter animal the meat trade has regarded tham as cull cows and paid a reduced price.
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Gordon, I. "Modern techniques for enhancing reproduction in suckler cattle systems." Proceedings of the British Society of Animal Production (1972) 1989 (March 1989): 6. http://dx.doi.org/10.1017/s0308229600010072.
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For those involved in suckler cattle systems, there are likely to be several new opportunities for increasing production efficiency in the years ahead. As a result of recent developments in embryo production technology the future is likely to see embryo transfer being used on an increasing scale and eventually taking over from artificial insemination as a major factor influencing the production of beef calves. Sex control techniques, applied to sperm or to embryos, are likely to be of particular value in making bull calves available for twinning or heifer calves for once-bred heifer production systems. The paper examines the various possibilities for applying reproductive technology in enhancing fertility, controlling oestrus and ovulation, inducing twin births, increasing the efficiency of once-calved heifer production systems,in the application of cloning techniques and the use of recombinant DNA technology.
9
LOSINGER, WILLARD C., and A. JUD HEINRICHS. "Management practices associated with high mortality among preweaned dairy heifers." Journal of Dairy Research 64, no. 1 (February 1997): 1–11. http://dx.doi.org/10.1017/s0022029996001999.
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In a national survey of US dairy operations, 1685 dairy operations reported 47057 new dairy heifers (either births or acquisitions) and 4427 deaths (9·4%) of preweaned dairy heifer calves over a 3 month period. Stepwise logistic regression was used to identify management practices associated with high mortality among preweaned heifers in dairy operations where at least three dairy heifer calves were born alive or moved on to the operation. Analysis was done twice: once by separating all operations by size into high or low mortality; again using only operations with <2 and >10% mortality to eliminate dairy operations with intermediate levels of mortality from the comparisons. Results were similar. Dairy operations in the West were more likely to fall in the high mortality category than dairy operations in the rest of the country. In addition, the following dairy operation characteristics were associated with high death levels in both models: rolling herd average milk production <7710 kg, preweaned heifers placed in groups of seven or more, a male having primary responsibility for the care and feeding of preweaned heifers, calves not receiving hay or other roughages until >20 d old, calves fed on mastitic or antibiotic milk after colostrum and calves not given whole milk after colostrum.
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Kerby, Mike, Tom Clarke, Tom Angel, and Kythé Mackenzie. "The use of fixed time artificial insemination programmes for the use of sexed semen in block calving dairy heifers." Livestock 26, no. 3 (May 2, 2021): 124–30. http://dx.doi.org/10.12968/live.2021.26.3.124.
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In seasonal block calving herds reproductive efficiency can have a significant impact on productivity and profitability. Within this it is key that the nulliparous heifers calve down promptly in the block, and if these heifers can have heifer calves it will expediate genetic gain. There is extensive research into the conception rates of differing protocols and the literature is reviewed to support the choice of protocol used in the subsequent case study. The case study uses a 6-day progesterone protocol with two injections of prostaglandin F2α and sexed semen; it demonstrated acceptable conception rates as well as the variability that can occur between different bulls' semen straws. Finally, the case study assesses the costs and benefits of the synchronisation programme and concludes a cost benefit of £88.55 per heifer.
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Baruselli, Pietro S., Carlos A. Rodrigues, Roberta M. Ferreira, José Nelio S. Sales, Flávia M. Elliff, Laísa G. Silva, Mariana P. Viziack, Luana Factor, and Michael J. D’Occhio. "Impact of oocyte donor age and breed on in vitro embryo production in cattle, and relationship of dairy and beef embryo recipients on pregnancy and the subsequent performance of offspring: A review." Reproduction, Fertility and Development 34, no. 2 (2022): 36. http://dx.doi.org/10.1071/rd21285.
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Genomic selection combined with in vitro embryo production (IVEP) with oocytes from heifer calves provides a powerful technology platform to reduce generation interval and significantly increase the rate of genetic gain in cattle. The ability to obtain oocytes with developmental competence from calves has been recognised for more than 60years. There is renewed interest in the potential of this reproductive technology as the beef and dairy industries seek to identify and multiply animals that satisfy consumer demand for efficient utilisation of natural resources, with minimal environmental impact and high product quality. Heifer calves show a good follicular response to FSH stimulation and oocytes can be recovered by ovum pick-up (OPU). However, the efficiency of OPU/IVEP remains lower for calves compared with peripubertal heifers and cows, in both indicus (Zebu, Bos indicus) and taurus (Bos taurus) breeds. Indicus cattle generally have more follicles, yield a greater number of oocytes, and have a better IVEP outcome, compared with taurus cattle. The treatment of prepubertal heifers with bovine somatotrophin (bST) and propylene glycol before OPU/IVEP has yet to show a major improvement in embryo production. Holstein (taurus) dairy heifers derived from different reproductive technologies (AI, MOET, OPU/IVEP) showed a similar age at puberty and first-lactation milk production. OPU/IVEP Holstein embryos transferred to beef or dairy cows likewise yielded heifers with the same performance. The gains in productivity that can be achieved with strategic use of OPU/IVEP in heifer calves make this a relevant and highly important reproductive technology in cattle breeding. Ongoing optimisation of the technology is needed for the potential of OPU/IVEP in young donors to be fully realised.
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Evans, A. C. O., and N. C. Rawlings. "Effects of a long-acting gonadotrophin-releasing hormone agonist (Leuprolide) on ovarian follicular development in prepubertal heifer calves." Canadian Journal of Animal Science 74, no. 4 (December 1, 1994): 649–56. http://dx.doi.org/10.4141/cjas94-094.
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We studied the effects of reducing gonadotrophin secretion on ovarian follicular development in young prepubertal heifer calves. Calves received a GnRH agonist (n = 5, 15 mg of Leuprolide acetate, i.m.) or carrier (n = 5) at 8 and 12 w of age. Starting at 8 and 34 w of age, ovarian follicles were monitored daily for 17 d, and at 10, 15, 25 and 35 w of age, blood samples were collected every 15 min for 12 h for measurement of serum concentration of LH and FSH. GnRH agonist treatment did not affect the age and body weight at puberty (P > 0.05). Agonist treatment suppressed follicle numbers and in two heifers follicle emergence (growth above 4–5 mm) was blocked immediately. In three agonist-treated heifers, follicle emergence was blocked after one extended wave of follicular growth. At 34 w of age the pattern of ovarian follicular growth did not differ between groups but oestradiol secretion was lower in agonist-treated heifers. During agonist treatment basal and mean concentrations of FSH, and LH and FSH pulse amplitude were decreased but basal LH concentrations increased (P < 0.05). At 25 and 35 w of age some rebound in gonadotrophin secretion was seen.We concluded that disrupting gonadotrophin secretion in young prepubertal heifer calves by GnRH agonist treatment, suppressed ovarian follicular growth but that a rebound in gonadotrophin secretion prevented long term-effects on sexual development. Key words: Follicle stimulating hormone, gonadotrophin-releasing hormone, heifer calves, luteinising hormone ovarian follicles
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Ismail, Zuhair, and Mohammad Muhaffel. "Dairy calf and replacement heifer mortality on a single intensively managed dairy farm in Jordan: A 3-yearlong study (2016-2018)." Open Veterinary Journal 12, no. 6 (2022): 944. http://dx.doi.org/10.5455/ovj.2022.v12.i6.21.
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Background: Pre-weaning dairy calf and replacement heifer mortality represents significant economic loss, limits genetic improvement and growth of the herd and indicates poor management and animal welfare status on the farm. Aim: Currently, the rates and causes of dairy calf and replacement heifer mortality in Jordan are not known. Therefore, the objective of this study was to determine the incidence rates and causes of mortality of pre-weaning calves and replacement heifers in Jordan. In addition, the age and seasonal distribution of mortality are determined in the study. Methods: Data extracted from the farm management record software over 3 years (January 2016 to December 2018) were used in this study. Calf-specific data included the day and month of birth, and sex. Health-related data included age at death, necropsy findings, laboratory findings if available, and the presumptive diagnosis. Descriptive analysis was performed to determine the 3-year overall mortality rate as well as the yearly mortality rate in pre-weaning calves and replacement heifers using excel spreadsheets of Microsoft Word 10. Results: Only female calves (n= 724) born alive during the study period were used in the analysis. The overall calf mortality rate was 8.9% with a yearly rate ranging between 5.9% to 12%. The majority of deaths occurred in calves less than 50 days of age with an average age of 17 days. There was a seasonal pattern for calf mortality with the majority of deaths occurred during the colder months of the year (December, January, February, March). The highest number of pre-weaning calves died because of enterotoxemia (39%) and pneumonia (30%). Other causes of calf mortality were abomasal ulcer (8%), enteritis (6%), septicemic salmonellosis (5%), meningitis (4%), rumen drinkers (3%), aspiration pneumonia (3%), septic arthritis (1%), and omphalitis (1%). The overall 3-year heifer mortality rate was 4%. The average age of dead heifers was 8 months (range 3 months to 23 months). The highest number of heifers died because of neurologic disease (37%) and enterotoxemia (33%). Other causes of heifer mortality were abomasal ulcer (11%), enteric salmonellosis (7%), chronic rumen tympany (7%), and chronic pneumonia (4%). Conclusion: Data presented in this study are essential to construct and implement effective preventative health programs and improve farm management practices to reduce calf and heifer losses.
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Vedovatto, Marcelo, Elizabeth Palmer, Juliana Ranches, Miguel Miranda, Vinícius Gouvêa, John Arthington, João Vendramini, and Philipe Moriel. "163 Effects of pre- and post-partum supplementation of molasses/urea with or without methionine fortification on growth performance of primiparous cows and their offspring." Journal of Animal Science 97, Supplement_1 (July 2019): 58. http://dx.doi.org/10.1093/jas/skz053.131.
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Abstract The present study evaluated the performance of calves born from primiparous cows offered pre- and post-partum supplementation of sugarcane molasses/urea added or not with DL-methionine hydroxyl analog. On d 0 (~56 d before calving), 36 Brangus heifers were stratified by BW and BCS (345 ± 4.7 kg; 2 yr of age), and randomly allocated into 1 of 12 bahiagrass pastures (3 heifers and 1.2 ha/pasture). Treatments were randomly assigned to pastures (4 pastures/ treatment) and consisted of no supplementation (NOSUP) or supplementation of molasses/urea (7.2 kg DM/heifer/ wk; 75% TDN, 20% CP; DM basis) with (MOL+) or without (MOL-) fortification with 105 g/heifer/wk of methionine (Alimet, Novus International Inc., Romance, AR) from d 0 until all heifers within each pasture calved. Total weekly amount of molasses/urea (and methionine for MOL+ heifers) was divided by 2 and offered on Tuesdays and Wednesdays. After all cows calved, all pairs were fed 12.7 kg/cow/wk of molasses/urea (DM basis) and grazed a single bahiagrass pasture until calf early-weaning (d 147). Calves received a soybean hull-based supplement at 3.5% of BW (DM basis) and ad libitum stargrass hay from d 154 to 201. Calving date and cow BCS on d 44 did not differ between MOL+ and MOL- (P ≥ 0.50), but both groups calved at greater BCS than NOSUP cows (P ≤ 0.008). However, cow BCS on d 147 and pregnancy percentage on d 288 did not differ among treatments (P ≥ 0.27). Calf birth BW did not differ among treatments (P ≥ 0.21), but ADG from birth to d 201 was greater for MOL+ and MOL- vs. NOSUP calves (P ≤ 0.05). Therefore, pre- and post-partum supplementation of sugarcane molasses/urea improved cow BCS at calving and calf postnatal growth compared with no supplementation. Supplemental methionine did not further enhance cow and calf growth performance
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Hogan, Lindsay A., Michael R. McGowan, Stephen D. Johnston, Allan T. Lisle, and Kylie Schooley. "Suckling Behaviour of Beef Calves during the First Five Days Postpartum." Ruminants 2, no. 3 (August 15, 2022): 321–40. http://dx.doi.org/10.3390/ruminants2030022.
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Observations of 17 heifer-calf pairs were collected over the first 5 days postpartum (p.p.) to study nursing and maternal behaviour of beef cattle. Cattle were managed in a 6 ha paddock and heifer–calf interactions were determined from both regular visual observations and video recordings. Of 17 potential calves, one was stillborn and 3 died in the first 5 days p.p. associated with dystocia and congenital malformation. Four further potential neonatal calf mortality risks were identified, which included poor calving site selection (n = 1), calf misadventure (n = 1), heifer-calf separation (n = 3) and mismothering (n = 3), with each resulting in distress, physical exhaustion of the calf and impaired nursing. There was marked variation between heifers in the expression of optimal maternal behaviours, with only 39% classified as ‘good’ mothers. Dam terminated nursing bouts were 27% shorter in duration than calf terminated nursing bouts; 29% of heifers terminated nursing bouts at least 50% of the time. Only 68% of observed suckling interactions were considered effective. On average, the nursing behaviour lasted 7.0 min, with sucking making up 54% of the total nursing time, the sucking rate was 2.0 sucks/s, and the calves performed 7.5 teat-switches, 2.4 butts and 0.9 teat-strips per min of nursing. In 67% of nursing interactions, the calves sucked on all four teats. By three days p.p., all calves developed a clear, consistent suckling pattern. Prior to this, the calves had shorter nursing bouts, spent less time nursing and manipulating the udder, paused more, switched teats and butted less, and had a slower sucking rate. The behaviour of some calves (i.e., low teat fidelity and high levels of milk stimulation behaviours) suggested that their dam milk availability was low. This study has quantified early post-partum nursing behaviour of neonatal beef calves and highlighted dam and calf behaviours that may adversely affect milk intake and, therefore, impact calf survival.
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Ceja, Guadalupe, Jacquelyn P. Boerman, Rafael C. Neves, Nicholas S. Johnson, Jon P. P. Schoonmaker, Matthew W. Jorgensen, and Jay S. Johnson. "PSI-2 A procedure for urine collection in pre-weaned heifer calves." Journal of Animal Science 99, Supplement_3 (October 8, 2021): 277. http://dx.doi.org/10.1093/jas/skab235.508.
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Abstract Urine collection is a useful tool to analyze intestinal permeability in cattle for research and diagnostic purposes. However, urine sampling techniques often rely on total waste collection, which reduces the ability to perform more frequent sampling and obtain accurate and sterile urine volumes. A potential alternative is urethral catheters, which have been used in cows and weaned heifers. However, urethral catheters have not been thoroughly tested in pre-weaned dairy heifer calves. The study objective was to develop a urethral catheter placement procedure in pre-weaned heifer calves for continuous and accurate urine collection. Fifteen Holstein heifer calves had catheters placed at 8 ± 2 days (37.5 ± 3.38 kg BW) and 40 ± 2 days (59.3 ± 5.38 kg BW) of age. During the procedure, calves were individually housed (1.87 m2/calf) and restrained. The vulva was cleaned using betadine and 70% ethanol and then a sterile, lubricated 8.9 cm speculum was inserted into the vagina. A sterile guidewire (145 cm x 0.89 cm) was inserted into a lubricated sterile 10 FR catheter. The catheter was inserted into the urethral opening (~5–7 cm into vagina), guided into the bladder, and the catheter balloon was filled with water (10 mL). The guide wire was removed, and urine flow confirmed correct placement before a 4 L urinary drainage bag was attached to the catheter. Individual calf health observations were made twice over a 24-hour period and included vaginal discharge, bleeding, redness or inflammation, and tissue discharge in the urine. Occurrence rate was determined using PROC FREQ in SAS 9.4. Regardless of catheterization timing, bleeding and tissue discharge occurred at a rate of 3.33% ± 0.18, and vaginal discharge and inflammation occurred at a rate of 6.70% ± 0.25. In summary, this procedure is a viable method for total urine collection in pre-weaning heifer calves.
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Rawlings, N. C., J. P. Kastelic, A. C. O. Evans, P. M. Bartlewski, A. P. Beard, R. K. Chandolia, and S. J. Cook. "Plasma concentrations of cortisol and progesterone during the period of reproductive development in beef and dairy heifers." Animal Science 75, no. 2 (October 2002): 281–88. http://dx.doi.org/10.1017/s1357729800053030.
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AbstractThe plasma concentrations of cortisol and progesterone during reproductive maturation in the heifer calf were examined. Six beef heifer calves were handled and bled every 2 weeks (control), 30 were left unhandled (naive). At 13, 21, 30, 39 and 47 weeks of age, a different group of naive heifers and the control heifers were bled every day for 5 days (puberty seen at 57·4 (s.e. 1·3) weeks). Thirty-nine dairy heifer calves were allocated to seven groups to receive adrenocorticotropic hormone (ACTH) at either 4, 7, 9, 16, 26, 36 or 46 weeks of age (puberty expected around 43 weeks of age). Plasma concentrations of cortisol increased at 21, 30 and 39 weeks of age in frequently handled and naive beef heifers; the increase was greater at these ages in the naive beef heifers (age and treatment P < 0·01). No age trend was apparent for plasma concentrations of cortisol and progesterone prior to ACTH injections (t = 0) in frequently handled dairy heifers. Adrenal progesterone secretion did not change with age in beef heifers, but naive beef heifers had greater plasma concentrations than frequently handled beef heifers. ACTH induced cortisol release in dairy heifers as early as 4 weeks of age (P < 0·05), but the response was greater in dairy heifers 16 weeks old and older (P < 0·05). A progesterone response to ACTH in dairy heifers was not seen until animals were 9 weeks old. It is concluded that as heifers mature reproductively, there is a parallel increase in the sensitivity of the adrenal gland to ACTH and handling stress.
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Stokes, Rebecca S., Frank A. Ireland, and Daniel W. Shike. "Influence of repeated trace mineral injections during gestation on beef heifer and subsequent calf performance." Translational Animal Science 3, no. 1 (October 9, 2018): 493–503. http://dx.doi.org/10.1093/tas/txy105.
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Abstract Commercial Angus heifers (n = 190; body weight (BW) = 315 ± 49.3 kg) were used to determine the effects of trace mineral injections during gestation on heifer and subsequent calf performance. Heifers received three previous subcutaneous trace mineral (Multimin 90 [MM]; n = 93) or sterilized physiological saline (CON; n = 97) injections approximately 90 d apart. These treatments were maintained and subsequent injections were given 205, 114, and 44 ± 26 d prepartum. Heifers were provided free-choice inorganic minerals. Heifer BW and body condition scores (BCS) were collected at trial initiation (296 ± 26 d prepartum) and 5- to 10-week intervals thereafter. Liver samples were collected at trial initiation, 5 and 176 ± 3 d postpartum from a subset of cows to determine trace mineral status. Milk production was assessed on 80 cow–calf pairs (40/treatment) at 71 ± 15 d postpartum. Cows were artificially inseminated (AI) 82 d postpartum and then exposed to bulls for 38 d. Data were reported from 174 calves (n = 87 calves/treatment). Calf liver samples were collected 5 and 147 ± 3 d postpartum to determine trace mineral status. Calf weaning BW was collected at 159 ± 26 d postpartum. Calf performance including calving date, birth BW, weaning BW, average daily gain (ADG), and health data were collected. Heifer BW and BCS did not differ (P ≥ 0.72) throughout the experiment. Multimin heifers tended (P = 0.08) to have greater initial liver Se and tended to have decreased (P = 0.08) initial liver Zn compared with CON. At calving, MM cows had increased (P ≤ 0.01) liver Cu and Se. There was no difference (P ≥ 0.47) in Julian calving date, calving percent, or unassisted births. Calf birth BW was lesser (P = 0.02) for MM than CON calves, and MM calves had greater (P = 0.03) liver Cu concentrations at birth than CON calves. Despite MM cows having increased (P < 0.01) milk production, calf weaning BW and ADG were not different (P ≥ 0.87). In addition, calf morbidity and mortality were not different (P ≥ 0.43) between treatments. Calf mineral status was not different (P ≥ 0.57) at the time of weaning regardless of treatment; however, MM cows had decreased (P = 0.03) liver Zn. Multimin cows had decreased (P = 0.05) AI pregnancy rates, yet there was no difference (P = 0.34) in overall pregnancy rate. Supplementing an injectable trace mineral during heifer development and gestation increased cow milk production and resulted in decreased AI pregnancy rates; however, there was no effect on overall pregnancy rates or preweaning calf health or performance.
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Demateis Llera, Federico, Claudina Vissio, María Paula Turiello, María Alejandra Herrero, and Alejandro José Larriestra. "Heifer management characterization in dairy herds from the west of Buenos Aires, Argentina." Brazilian Journal of Veterinary Research and Animal Science 58 (September 1, 2021): e178793. http://dx.doi.org/10.11606/issn.1678-4456.bjvras.2021.178793.
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The replacement program in a dairy farm represents the second or third largest cost in a dairy operation. This study aimed to characterize and typify the practices related to the dairy heifer replacement program and describe the growth, development, and health parameters during this period in commercial dairy herds in Trenque Lauquen. A cross-sectional observational study was carried out, including 54 randomly selected dairy farms that were visited once to collect data about facilities and management through a semi-structured survey. Cluster and principal coordinates analysis were applied to classify the farms based on all variables collected, grouped in four main areas: pre-fresh cows, colostrum management, pre-weaning calf ’s management, and personnel. Additionally, growth, development, and health status were also recorded and described for calves and breeding heifers. Two similar-sized farm clusters were identified with differences in management and facilities in different areas of calves rearing. In one cluster there was a greater proportion of farms having a pre-fresh group, implementing appropriate health (colostrum, vaccination) and feeding management. Also, differences in personnel and technical support were relevant. The estimated body gain was 452 and 774 g/d for calves younger or older than 60 d of age, respectively. The age and weight farm averages in breeding heifers were 21.0 mo (range: 16.7-27.5) and 416.3 kg (range: 336.7-519.3), respectively. Diarrhea and respiratory affections were the major problems in pre-weaning calves and heifer rearing, respectively. The median mortality was 7.3, 7.6, and 2.9% at the calving, pre-weaning, and heifer rearing period, respectively. The results showed an improvement opportunity for producers, the design of precise and high impact programs that could lead to an improved replacement program.
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Padungtod, P., J. B. Kaneene, D. Jarman, K. Jones, R. Johnson, A. Drummond, Z. Duprey, and I. Chaichanapunpol. "Enteric parasitosis in northern Thailand dairy heifers and heifer calves." Preventive Veterinary Medicine 48, no. 1 (January 2001): 25–33. http://dx.doi.org/10.1016/s0167-5877(00)00179-3.
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Hamilton, D., RC Seirer, and JP Cook. "Effects of drought rations offered to lactating beef heifers on liveweight changes, milk production and composition, calf carcasses and cow fertility." Australian Journal of Experimental Agriculture 30, no. 6 (1990): 801. http://dx.doi.org/10.1071/ea9900801.
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Thirty-two early-summer-calving Angus heifers received 4 rations in early lactation for the last 92 days of drought and then grazed pasture. The aim was to produce calves suitable for slaughter at weaning (i.e. at about 11 months of age) and to maintain the usual calving rate of about 85% at the next calving. Variations on the control ration of 83% cracked wheat and 17% long oaten hay, plus minerals and vitamins, were 44% hay or additions of urea or sodium bicarbonate. The calves received 0.33 kg and later 0.66 kg of pasture hay/head.day. The nitrogen content of the respective rations was 19.3, 17.5, 24.3 and 19.3 g/kg of dry matter. The apparent digestibilities of the organic matter were 66, 68 and 88% for the pasture hay, oaten hay and cracked wheat, respectively. There was no acidosis, but the heifers would only consume at 80% of the intended level of 6.0 kg/head.day for the control ration. Heifer condition score, weight change and milk composition, and calf growth and milk consumption, did not differ (P>0.05) between treatments. The average daily liveweight changes during drought feeding were -0.51 kg for the heifers and +0.64 kg for the calves. There was a tendency to slower eating and fewer calves at the next calving with the urea and bicarbonate rations. The calves were all of slaughter condition at weaning, and on average 84% of the heifers calved at the next calving. The control ration appeared to contain adequate roughage and nitrogen for milk production. The heifers' energy requirement in relation to milk production and liveweight performance was as predicted by the common feeding standards. Feed consumption, although lower than intended and probably constrained by the mineral content of the diet, was adequate in heifers that were initially fat enough to tolerate prolonged weight loss.
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Vincent, B. C., S. D. M. Jones, L. E. Jeremiah, J. A. Newman, and M. A. Price. "Carcass characteristics and meat quality of once-calved heifers." Canadian Journal of Animal Science 71, no. 2 (June 1, 1991): 311–19. http://dx.doi.org/10.4141/cjas91-040.
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Three groups of once-calved (OCH) heifers were slaughtered following the weaning of their calves at 3 (OCH3, n = 32), 5 (OCH5, n = 33) and 7 (OCH7, n = 31) months postcalving. A fourth group of heifers was fed a silage/grain diet and slaughtered at 15 mo of age (C, n = 32). Alternate sides of each carcass were electrically stimulated (ES) at 475 volts for 1 min (20 pulses m−1, 60 Hz) at 45 min post-stunning. All left sides were dissected into fat, lean and bone and meat quality parameters recorded. Rib eye steaks were evaluated for palatability by a trained panel and for consumer acceptability after an aging period of 6 d. All OCH groups produced heavier carcasses with a higher level of marbling than the C group after adjustment of the data to a constant proportion of carcass fatness, but the proportional yields of lean and bone tissue were similar for all heifer groups. OCH groups produced meat that was darker with a lower drip loss and higher 45 min and 6 d pH than the C group. Consumer acceptability of rib eye steaks was similar for all heifer groups, but the OCH7 (oldest) group had a higher amount of connective tissue when evaluated by a trained panel than other heifer groups. Taste panel evaluations showed that ES increased meat tenderness and overall palatability and reduced the amount of connective tissue when compared to meat from unstimulated carcasses. ES also increased the consumer acceptability of tenderness by 14.3%, flavor by 5.6%, juiciness by 5.2% and overall palatability by 6.7% over meat from unstimulated carcasses. It was concluded that once-calved heifers could produce heavier carcasses of similar composition and meat with similar eating quality to conventionally managed nonpregnant feedlot heifers. Electrical stimulation improved the consumer acceptability of meat primarily through an improvement in meat tenderness. Key words: Beef, carcass, electrical stimulation, meat quality, once-calved heifers
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Hough, GM, and GJ Sawyer. "Aspects of heifer management which limit productivity on dairy farms in Western Australia: a survey." Australian Journal of Experimental Agriculture 33, no. 7 (1993): 833. http://dx.doi.org/10.1071/ea9930833.
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In 1989, a survey of 53 producers from the major dairy areas of the south-west of Western Australia was conducted to determine current management practices for dairy heifers and to identify of areas of heifer management which could be improved to increase overall farm productivity. Total farm size averaged 220 ha, with an average market milk quota of 699 L/day (50% of total milk produced). One-third of producers described their farm activity as dairying only. Some 116 calves were born per farm, with a year-round calving distribution. Calves were fed 5.4 L whole milk/day, with an average age at weaning of 13 weeks (range 5-26 weeks). Mortality recorded to 3 months of age was 4% and the most important health problem associated with calf rearing was scours. Of those properties with a health problem, 25% used antibiotics on a regular basis. All producers provided supplementary feed pre-weaning. In the period between weaning and mating, more than half the producers ran heifers on paddocks 3-80 km distant from the main farm, with hay the most common form of supplementary feed. Most dairy heifers were naturally mated to Hereford, Friesian, or Angus sires; hence, few heifers from first calvers were kept as dairy replacements. Average age at first calving was reported to be 30 months, with 1 in 9 heifers culled post-calving, generally for low milk production. The survey highlighted several aspects of heifer management with the potential to improve overall productivity of dairy farms in Western Australia. They include earlier weaning, strategic use of antibiotics to prevent the development of antibiotic resistance, greater use of artificial insemination, and a reduction in age at first calving.
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Camussone, Cecilia M., Ana I. Molineri, Marcelo L. Signorini, Verónica E. Neder, Carlos A. Vitulich, and Luis F. Calvinho. "Risk factors of S. aureus intramammary infection in pre partum dairy heifers under grazing conditions and molecular characterization of isolates from heifers and cows." Journal of Dairy Research 87, no. 1 (February 2020): 82–88. http://dx.doi.org/10.1017/s0022029919001018.
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AbstractThe aims of the research reported here were to identify potential risk factors associated with the presence of Staphylococcus aureus intramammary infection (IMI) in pre partum dairy heifers on 17 dairy farms from three provinces of Argentina and to characterize, at molecular level, isolates from those heifers and lactating cows from two selected herds. A total of 1474 heifers and 4878 lactating cows were studied. The prevalence of Staphylococcus aureus IMI in the heifers, heifers at quarter level and lactating cow mammary quarters was 14.41, 4.82, and 14.65%, respectively. Univariate analysis showed the key variables associated with S. aureus IMI presence in the heifers were: S. aureus IMI prevalence in cows of the lactating herd, the time calves stayed with their dam after birth, the calf rearing system, the place of rearing (own farm or other dairy farm) and fly control on the farm. None of the variables included in the multivariable analysis was associated with the presence of S. aureus IMI in the pre partum heifers, probably due to low variability among management practices used by the farms for rearing the heifer calves. At the molecular level, S. aureus isolates were grouped into three main PFGE clusters and several genotypes within the clusters. Isolates from mammary secretion of pre partum heifers and milk of lactating cows comprised different PFGE clusters in both herds, although two exceptions occurred. The absence of gene fnbpB, which codifies for a virulence factor protein involved in cell invasion by S. aureus, was significantly more frequent in pre partum heifer secretion isolates than in isolates from lactating cow milk. These results suggest that, under these management conditions, isolates from mammary secretions of pre partum heifers do not originate from the milk of lactating cows, but rather other sources to which the heifer is exposed.
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COHEN, R. D. H., B. D. KING, and E. D. JANZEN. "THE USE OF PROSTAGLANDIN F2α IN NATURALLY BRED BEEF HEIFERS." Canadian Journal of Animal Science 68, no. 4 (December 1, 1988): 1301–4. http://dx.doi.org/10.4141/cjas88-147.
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Heifers injected with prostaglandin F2α had significantly higher pregnancy and conception rates within 11 d of start of breeding than noninjected heifers; 56.9 vs. 45.5 pregnancy as a percent of heifers exposed (P < 0.05) and 74.1 vs. 58.2 conception as a percent of pregnant heifers (P < 0.005). Data were pooled for 422 heifers over 5 yr. However, there were no significant effects on calving distribution or weaning weights of their calves. Key words: Prostaglandin F2α, natural breeding, heifer, estrus synchronization
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Palmer, Elizabeth A., Francisco Peñagaricano, Marcelo Vedovatto, Rhaiza A. Oliveira, Sena L. Field, Jimena Laporta, and Philipe Moriel. "Effects of maternal gestational diet, with or without methionine, on muscle transcriptome of Bos indicus-influenced beef calves following a vaccine-induced immunological challenge." PLOS ONE 16, no. 6 (June 24, 2021): e0253810. http://dx.doi.org/10.1371/journal.pone.0253810.
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Maternal nutrition during gestation can cause epigenetic effects that translate to alterations in gene expression in offspring. This 2-year study employed RNA-sequencing technology to evaluate the pre- and post-vaccination muscle transcriptome of early-weaned Bos indicus-influenced beef calves born from dams offered different supplementation strategies from 57 ± 5 d prepartum until 17 ± 5 d postpartum. Seventy-two Brangus heifers (36 heifers/yr) were stratified by body weight and body condition score and assigned to bahiagrass pastures (3 heifers/pasture/yr). Treatments were randomly assigned to pastures and consisted of (i) no pre- or postpartum supplementation (NOSUP), (ii) pre- and postpartum supplementation of protein and energy using 7.2 kg of dry matter/heifer/wk of molasses + urea (MOL), or (iii) MOL fortified with 105 g/heifer/wk of methionine hydroxy analog (MOLMET). Calves were weaned on d 147 of the study. On d 154, 24 calves/yr (8 calves/treatment) were randomly selected and individually limit-fed a high-concentrate diet until d 201. Calves were vaccinated on d 160. Muscle biopsies were collected from the same calves (4 calves/treatment/day/yr) on d 154 (pre-vaccination) and 201 (post-vaccination) for gene expression analysis using RNA sequencing. Molasses maternal supplementation led to a downregulation of genes associated with muscle cell differentiation and development along with intracellular signaling pathways (e.g., Wnt and TGF-β signaling pathway) compared to no maternal supplementation. Maternal fortification with methionine altered functional gene-sets involved in amino acid transport and metabolism and the one-carbon cycle. In addition, muscle transcriptome was impacted by vaccination with a total of 2,396 differentially expressed genes (FDR ≤ 0.05) on d 201 vs. d 154. Genes involved in cell cycle progression, extracellular matrix, and collagen formation were upregulated after vaccination. This study demonstrated that maternal supplementation of energy and protein, with or without, methionine has long-term implications on the muscle transcriptome of offspring and potentially influence postnatal muscle development.
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Laflamme, L. F. "Effect of degree of fatness in yearling replacement beef heifers on lifetime performance." Canadian Journal of Animal Science 73, no. 2 (June 1, 1993): 295–301. http://dx.doi.org/10.4141/cjas93-032.
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A study was initiated to determine the long-term effect of weight and age at breeding in yearling beef heifers on lifetime performance. Thirty weaned replacement heifers in each of 3 yr were equally fed until breeding on one of three systems: (i) gain of 1 kg d−1 and bred at 350 kg (medium); (ii) gain of 1 kg d−1 and bred at 15 mo of age (high); or (iii) bred at 350 kg and 15 mo of age (low). The high group had an advantage (P < 0.05) in the number of calves produced or weaned, suggesting a greater persistency of production; however, the low group weaned heavier calves. The rearing treatments had no effect (P > 0.05) on the heifer mature weights or on the birth weights of the calves. Most of the differences detected were in the first 5 yr, at which time 50% of the heifers had already been culled. Key words: Beef heifers, rearing, lifetime performance
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Damiran, Daalkhaijav, Kathy Larson, Leah Pearce, Nathan Erickson, and H. A. Lardner. "Effects of Heifer Calving Date on Longevity and Lifetime Productivity in Western Canada." Sustainable Agriculture Research 7, no. 4 (July 30, 2018): 11. http://dx.doi.org/10.5539/sar.v7n4p11.
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The objective of this study is to determine the effect of calving early as a heifer on lifetime production in western Canada. This study evaluated the longevity and life time production data on 211 individual heifers (data gathered for 16 years) at the Western Beef Development Centre (WBDC), Saskatchewan. Heifers were classified as calving in the first (period 1; n= 87), second (period 2; n = 66), or third (period 3; n = 58) 21-day period of the calving season. For each subsequent calf born to the cow, calving period was reassigned in the same manner. The current study showed that the average life time number of calves weaned for heifers that calved in the 1st, 2nd, and 3rd 21-day period was 5.4 ± 0.32, 4.5 ± 0.37, and 4.2 ± 0.39, respectively. Retaining percentage rate of period 1 cows was 4.3-17.8 and 2.1-19.1% units greater than those of period 2 and period 3 cows, respectively. Period 1 heifers had the greatest life time produced total cumulative weaning weight (p <0.01) value of 1157 kg/cow, followed by period 2 and period 3 heifers, 947 and 841 kg/cow, respectively. Period 1 cows generated an additional $718 to $1077 in weaned calf revenues over their lifetime. This study suggested that, in western Canada, heifers that calved earlier had greater pregnancy rates, remained in the herd longer, and produced one more calf in their lifetime than those that calved in the later periods.
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EDRINGTON, TOM S., TODD R. CALLAWAY, ROBIN C. ANDERSON, and DAVID J. NISBET. "Prevalence of Multidrug-Resistant Salmonella on Commercial Dairies Utilizing a Single Heifer Raising Facility†." Journal of Food Protection 71, no. 1 (January 1, 2008): 27–34. http://dx.doi.org/10.4315/0362-028x-71.1.27.
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The objectives of the current research were twofold: (i) to determine the prevalence of multidrug-resistant (MDR) Salmonella in the various classes of dairy cattle and (ii) to determine if comingling of calves from multiple farms at a heifer feedlot serves as a transmission vector for Salmonella back to the dairy farm. Four large commercial dairies in the southwestern United States were sampled in October 2005 and again in March 2006. Fecal samples were collected from hutch calves, 12-and 24-month-old heifers, lactating cows, dry cows, and cattle in the sick-fresh pen and cultured with brilliant green agar supplemented with novobiocin (BGAnov) to estimate the overall Salmonella prevalence, or with tetracycline (BGAtet) to estimate MDR Salmonella. Antimicrobial susceptibility testing was conducted with the National Antibiotic Resistance Monitoring System (NARMS) testing panel, and a portion of the isolates were serotyped. Salmonella prevalence among groups ranged from 0 to 96% positive, with the highest incidence observed in the hutch calves and cattle in the sick-fresh pen. Twenty-eight different serotypes were identified with serotype Reading accounting for the majority of isolates cultured on BGAtet. Nearly all (100 of 103) isolates cultured on BGAnov and screened for antibiotic resistance were pan susceptible, whereas over one-half (64%) of the isolates cultured on BGAtet were MDR. Forty isolates displayed the ACSSuT resistance pattern, and 36 isolates displayed the MDR-AmpC pattern of the 72 isolates examined following culture on BGAtet. The incidence of Salmonella cultured on BGAtet was low (9%) in all heifers and only one MDR isolate was cultured (from a 12-month-old heifer), suggesting the risk of transmission of Salmonella from the heifer feedlot back to the dairy is low. Results of this research suggest the incidence of MDR Salmonella, found primarily in hutch calves and cattle in the sick-fresh pen, is low in comparison to the overall Salmonella prevalence.
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Paputungan, Umar, Manopo Jouke Hendrik, and Surtijono Edmundus Siswosubroto. "SELEKSI BOBOT BADAN INDUK DAN EVALUASI KESULITAN PARTUS ANAK (Dystocia) SAPI BALI HASIL PERSILANGAN PEJANTAN SAPI LOKAL UNGGUL SULAWESI UTARA." ZOOTEC 39, no. 2 (July 31, 2019): 486. http://dx.doi.org/10.35792/zot.39.2.2019.26221.
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BODY WEIGHT SELECTION AND EVALUATION OF CALVING DIFFICULTY (Dystocia) IN BALI BREED FEMALE CATTLE MATED WITH OUTSTANDING LOCAL BULL OF NORTH SULAWESI. Records on calving performances of 217 parental dams of Bali beef cattle breed including their calves were used to study calving difficulty of Bali beef cattle breed heifers and cows with experiencing in delivery of more than one generation of calving. The difficulties of calving were scored into calving difficulty scores of six scores, initiated at score 0 indicating normal calving to score 5 indicating the most difficult calving delivery requiring surgery. The parental heifers and adult cows as well as their calves grazed onto places within local grass pasture all days starting at 07.00 a.m. to 17.30 p.m. without supplementary feeds of concentrate as the main management system practiced by 104 farmers as the animal owners at rural areas. Differences of calving difficulties in both Bali beef cattle breed groups of heifers and cows were analyzed by nonparametric test of “The Mann-Whitney U test”, using ranks of data based on the incidence frequencies of calving difficulty scores. Data of calving difficulty scores of both Bali beef cattle breed heifer group and cow group were ranked in to the numerical rank initiated from the lowest to largest numerical order. The calculated z value in this study indicating the incidence frequencies of calving difficulty in heifer group was significantly higher than those in cow group. Frequencies of calving difficulty on the category score basis in Bali beef cattle breed heifer group were significantly higher compared with those in Bali beef cattle breed cow group. Low live weights and body dimensions of heifer group highly tended to experience in the incidence and severity of calving difficulty compared with those of cow group. Selection of heifers with relatively well developed body dimensions and live weight relative to expected calf birth weight would be recommended to reduce calving difficulty.Keywords: Bali beef cattle breed, dam and calf body measurements, calving difficulty
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Rutter, L. M., and P. A. Day. "Effects of a growth implant and age of dam on growth and fertility in heifer calves." Canadian Journal of Animal Science 74, no. 2 (June 1, 1994): 203–8. http://dx.doi.org/10.4141/cjas94-028.
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A field trial was conducted to determine the effects of a growth implant on growth, pregnancy rate, calving difficulty and calf weaning weight in replacement beef heifers. Heifers were assigned equally to either a control (n = 43; no implant), Ralgro (n = 43) or Synovex-C (n = 42) treatment group based on age of dam and age and weight at the start of the trial (implantation at 45–90 d of age). Neither Ralgro nor Synovex-C enhanced heifer weight or average daily gain (ADG) from the start of the trial to weaning (approximately 7 mo of age), breeding, or pregnancy determination. At breeding, Synovex-C implanted heifers had greater pelvic area than controls while Ralgro implanted heifers were intermediate (control = 149.7, Ralgro = 154.7 and Synovex-C = 157.4 pooled SE of 2.2 cm2; P = 0.05). Pelvic dimensions were similar among treatments at pregnancy determination and there were no treatment effects on calving difficulty. Age of dam affected heifer weight (P = 0.0005) and ADG (P = 0.001) to weaning, with heifers from mature cows weighing more at weaning and having a higher ADG from the start of the study to weaning than heifers from either first- or second-calf cows. Post-weaning performance of heifers from first-calf cows was similar to heifers from mature cows while heifers from second-calf cows were lighter at breeding (P = 0.04) and had a lower ADG from weaning to breeding (P = 0.04). Age of dam did not influence pregnancy rate (P = 0.10), but more heifers from second-calf cows calved late in the calving season (≥ 64 d) compared with heifers from either first-calf or mature cows (P = 0.04). It appears from this field trial that use of a growth implant between 45 and 90 d of age neither enhanced growth nor impaired fertility in beef heifers bred as yearlings. It also appears that second-calf 3-yr-olds may need to be managed separately from the mature cow herd in order to optimize replacement heifer development. Key words: Bovine, replacement heifers, growth implant, age of dam, weight, pregnancy rate
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Yanich, T. V., M. A. Derkho, and A. A. Tegza. "The Hemostatic System and Its Variability during Pregnancy of Holstein Breed Animals." WSEAS TRANSACTIONS ON ENVIRONMENT AND DEVELOPMENT 18 (November 24, 2022): 1252–58. http://dx.doi.org/10.37394/232015.2022.18.117.
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Changes in the hemostaticsystem during pregnancy in heifers and heifer calves were studied, reference intervals for the thrombocytogram and the blood coagulation system during "physiological pregnancy" were established, the dependence of blood parameters on progesterone concentration and pregnancy trimester was assessed. The work was performed on heifer calves(pregnant) and heifers of the Holstein breed, from whom blood was taken for research. It was found that during pregnancy, the number of platelets and platelet crit in the thrombocytogram decreases by 3.36 and 3.62 times (P<0.05), but the number of large platelets increases by 39.87% (P<0.05). The clotting tendency of blood is determined by the variability of parameters associated with the fibrinogenesis process: thrombin time decreases by 19.88% (P<0.05) and the concentration of fibrinogen increases by 38.98% (P<0.05). This is facilitated by a decrease in antithrombin III level by 37.04%. The data obtained during a physiological pregnancy can be used as normative when assessing the condition of animals, which will allow timely to detect various abnormalities in the hemostatic system and to carry out appropriate preventive measures.
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FREDEEN, H. T., J. A. NEWMAN, A. K. W. TONG, and G. W. RAHNEFELD. "POSTWEANING GAIN AND FEED EFFICIENCY OF CROSSBRED BULLS, STEERS AND HEIFERS FROM CHAROLAIS, SIMMENTAL AND LIMOUSIN SIRES MATED TO HEREFORD, ANGUS AND SHORTHORN DAMS." Canadian Journal of Animal Science 69, no. 3 (September 1, 1989): 571–82. http://dx.doi.org/10.4141/cjas89-069.
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Postweaning gain and feed efficiency results are reported from an evaluation of crossbred calves sired by Charolais, Simmental and Limousin bulls and born to Hereford, Angus and Shorthorn cows in 48 herds located throughout the Canadian Prairie Provinces. Bull, steer and heifer calves were weaned at approximately 7 mo of age and transported to the Brandon or the Lacombe Research Stations where their performance was measured during a 112-d postweaning test period in which male calves were fed a high-energy feedlot diet and heifers were developed as breeding females on a lower energy diet. The data, which did not represent all sire breeds or sexes in all station years, were analyzed in eight separate data sets for gain and five for feed efficiency. Interpretation is based on paired comparisons of breed crosses within data set. In general, Limousin-sired male calves gained an average of 14.0 kg less than Charolais-sired and 9.6 kg less than Simmental-sired male calves from comparable dams, while Charolais-sired and Simmental-sired male calves performed equally. The same breed-of-sire pattern was apparent in heifer calves fed a lower energy diet, but the effects were smaller and were significant less often. Breed-of-dam effects were apparent for on-test weight, but not for gain during the test period. There were no consistent breed-of-sire differences in feed conversion ratio. The cost to the feeder of the slower gain exhibited by the Limousin-sired calves in this experiment could be offset by the lower calf purchase weight, depending on the premium, if any, paid on the price per kg for the lighter calves. Key words: Beef cattle, breed comparison, post-weaning growth, feed efficiency
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Sowers, CiCi A., Vinicius N. Gouvea, Michael L. Barnes, and Glenn C. Duff. "PSI-28 Effect of Pluronic-F68 fog solution on performance and morbidity of newly-received heifer calves." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 471. http://dx.doi.org/10.1093/jas/skaa278.821.
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Abstract Morbidity and mortality from bovine respiratory disease of newly-received feedlot cattle continues to be a problem for the feedlot industry. The objective of this study was to evaluate effects of utilizing a novel breathing treatment containing a non-ionic surfactant (Pluronic-F68) on performance and morbidity of high-risk calves during a 45-d receiving period. Angus/Angus-cross heifer calves (n = 240) were acquired in Delhi, LA and transported (14h) to the research facility. Heifers were allowed 21-h rest with access to water and RAMP® prior to processing. Heifers were sorted into 16 pens by processing order and randomized into one of two treatments: novel breathing treatment containing 6.25% Pluronic-F68 solution, 28.13% glycerin, and 65.62% water (FOG; n = 8 pens/treat and 15 heifers/pen) and control (CON; n = 8 pens/treat and 15 heifers/pen). Control heifers were held in an enclosed stock trailer for 10 min and followed by FOG heifers, during which time treatment was administered. The person responsible for identifying signs of morbidity was blinded to treatment assignments. Data were analyzed as a completely randomized design using MIXED (continuous) or GLIMMIX (binomial) models of SAS 9.4. Average daily gain was similar between treatments (P = 0.91). No differences were found in dry matter intake (P = 0.14) nor in feed efficiency (P = 0.58). There were no differences (P = 0.74) in final body weights. Morbidity was similar at first, second and third antimicrobial administration regardless of treatment (P ≥ 0.34). The number of antimicrobial treatments required or the management of BRD was similar between treatments (P = 0.72) There was no difference (P = 0.44) in mortality between FOG and CON groups. The Pluronic-F68 solution did not improve performance or reduce morbidity of newly received heifer calves; however, further research with a different concentration and/or duration of fogging may be warranted.
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Kerby, Mike J., and Keith Cutler. "Use of artificial insemination and oestrus synchronisation in beef herds." Livestock 27, no. 6 (November 2, 2022): 259–64. http://dx.doi.org/10.12968/live.2022.27.6.259.
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The use of artificial insemmination (AI) in beef herds has been increasing in the last two decades especially when used in conjunction with oestrus synchronisation (OS) protocols. The resultant improvement in reproductive efficiency has a significant impact on productivity and profitability, particularly in seasonal block calving beef herds. Within this it is key that the nulliparous heifers calve down promptly in the block, and if these heifers can have heifer calves it will expediate genetic gain. This article reviews the benefits of using AI and the OS programmes commonly used, including those involving prostaglandin F 2 alpha (PG) alone, progesterone-releasing devices either with PG or with gonadotropin-releasing hormone and PG or with additional equine chorionic gonadotropin. It also comments on the relatively new ‘7 and 7 Synch’ protocol as well as approaches to pre-synchronisation, non-cycling beef cows, late-calving beef cows and pre-pubertal heifers.
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Ilse, B. R., V. L. Anderson, D. S. Buchanan, K. G. Odde, G. P. Lardy, and K. A. Vonnahme. "Short Communication: Growth and attainment of puberty in calves from cows supplemented with linseed meal during late gestation and early lactation." Canadian Journal of Animal Science 92, no. 4 (December 2012): 443–47. http://dx.doi.org/10.4141/cjas2012-036.
Full textAbstract:
Ilse, B. R., Anderson, V. L., Buchanan, D. S., Odde, K. G., Lardy, G. P. and Vonnahme, K. A. 2012. Short Communication: Growth and attainment of puberty in calves from cows supplemented with linseed meal during late gestation and early lactation. Can. J. Anim. Sci. 92: 443–447. To test the objective that a linseed meal (LSM) supplement in beef cows during late gestation and early lactation would impact offspring growth performance, steer carcass composition, and attainment of puberty in heifer calves, multiparous beef cows received either LSM or a control supplement for the last 60 d of gestation (exp. 1; n=72) or during the first 60 d of lactation (exp. 2; n=91). In both experiments, birth weight, weaning weight, and ADG of calves were not affected (P>0.31) by LSM supplementation. There was no effect (P>0.09) of supplementation on carcass characteristics of steer progeny fed to market weight. In exps. 1 and 2, attainment of puberty in heifer calves was not influenced (P>0.58) by supplement type. Linseed meal supplementation during late gestation or early lactation does not appear to affect calf growth, onset of puberty in heifer calves, or steer carcass quality.
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Boadi, Dinah, and M. A. Price. "The effects of catch-up (compensatory) growth on reproductive performance of beef heifers." Canadian Journal of Animal Science 76, no. 4 (December 1, 1996): 523–29. http://dx.doi.org/10.4141/cjas96-079.
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Fifty-four heifer calves were allocated to five feeding/weaning treatments at birth in April/May 1990: 1) VEW (n = 11) dams feed-restricted for 3 mo before and 2 mo after calving; calves weaned in June onto gram-supplemented pasture and then into a drylot in October; 2) EW1 (n = 10) dams not restricted; calves weaned in August (unsupplemented pasture) into drylot in October; 3) EW2 (n = 10) dams not feed-restricted; calves weaned directly into drylot in August; 4) LW1 (n = 12) dams feed restricted for 3 mo before, but not after calving; calves weaned directly into drylot in October, 5) LW2 (n = 11): dams not restricted; calves weaned directly into drylot in October. The very early (VEW) and early (EW1, EW2) weaned heifers grew significantly slower than the later-weaned ones (LW1, LW2) from birth to September, and were still significantly lighter at 12–13 mo of age (May 1991). Recovery of liveweight-for-age was achieved by EW2 heifers by 18 mo and VEW and EW1 by about 23 mo of age. Early weaning treatments delayed age but not weight at first estrus (P < 0.05) yet the number of heifers conceiving and calving, and all associated reproductive data, including rebreeding success were unaffected by treatment (P > 0.05). Despite a delay in first estrus, reproductive efficiency and calving performance were not impaired by early feed restriction in heifers conceiving at 15 mo of age. Key words: Beef heifers, feed restriction, fertility, reproduction, catch-up growth
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Sowers, Consuelo A., Vinicius N. Gouvêa, Michael L. Barnes, and Glenn C. Duff. "Effect of Pluronic-F68 fog solution on performance and morbidity of newly received heifer calves." Translational Animal Science 4, Supplement_1 (December 1, 2020): S149. http://dx.doi.org/10.1093/tas/txaa124.
Full textAbstract:
Abstract: Morbidity and mortality from bovine respiratory disease (BRD) of newly received feedlot cattle continue to be problems for the feedlot industry. The objective of this study was to evaluate the effects of utilizing a novel breathing treatment containing a nonionic surfactant (Pluronic-F68) on performance and morbidity of high-risk calves during a 45-d receiving period. Angus/Angus-cross heifer calves (n = 240) were acquired in Delhi, LA, and transported (14 h) to the research facility. Heifers were allowed 21-h rest with access to water and RAMP prior to processing. Heifers were sorted into 16 pens by processing order and randomized by pen into one of two treatments: novel breathing treatment containing 6.25% Pluronic-F68 solution, 28.13% glycerin, and 65.62% water (FOG; n = 8 pens per treat and 15 heifers per pen) and control (CON; n = 8 pens per treat and 15 heifers per pen). Control heifers were held in an enclosed stock trailer for 10 min and followed by FOG heifers, during which time treatment was administered. The person responsible for identifying signs of morbidity was blinded to treatment assignments. Data were analyzed as a completely randomized design using MIXED (continuous) or GLIMIX (binomial) models of SAS 9.4. Average daily gain was similar between treatments (P = 0.91). No differences were found in dry matter intake (P = 0.14) nor in gain efficiency (P = 0.58). There were no differences (P = 0.74) in final body weights. Morbidity was similar at first, second, and third antimicrobial administration regardless of treatment (P ≥ 0.34). The number of antimicrobial treatments required or the management of BRD was similar between treatments (P = 0.72). There was no difference (P = 0.44) in mortality between FOG and CON groups. The Pluronic-F68 solution did not improve performance or reduce morbidity of newly received heifer calves; however, further research with a different concentration and/or duration of fogging may be warranted.
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Cilkiz, Kubra Z., Emilie C. Baker, Penny K. Riggs, Ronald D. Randel, David G. Riley, and Thomas Welsh. "PSVIII-39 Genome-wide DNA methylation alteration in prenatally stressed Brahman heifer calves with the advancement of age." Journal of Animal Science 97, Supplement_3 (December 2019): 263–64. http://dx.doi.org/10.1093/jas/skz258.537.
Full textAbstract:
Abstract This study investigated whether DNA methylation patterns changed over the first five yr of life within prenatally stressed (PNS) heifer calves compared to change within a Control group. Prenatal stress was induced by the transportation of pregnant Brahman cows for 2-hr periods at 60±5, 80± 5, 100±5, 120±5, and140±5d of gestation. White blood cells were sampled from the same 6 PNS heifer calves and 8 Control heifer calves at 28 d and 5 yr of age. The DNA methylation data were generated through Reduced Representation Bisulfite Sequencing. Based on results of mapping and bioinformatics analyses, 73,758 hypermethylated and 73,367 hypomethylated CpG sites, 375 hypermethylated and 377 hypomethylated CHG sites, 735 hypermethylated and 842 hypomethylated CHH (C = cytosine; G = guanine; H = either adenine, thymine, or cytosine) sites were obtained from 28-d-old PNS calves compared to when they had matured into 5-yr-old PNS cows (P ≤ 0.05). The 28-d-old Control heifer calves contained 53,005 hypermethylated and 57,103 hypomethylated CpG sites, 200 hypermethylated and 202 hypomethylated CHG sites, 439 hypermethylated and 535 hypomethylated CHH sites compared to when they matured into 5-yr-old Control cows (P ≤ 0.05). As DNA methylation of gene promoter regions is associated with reduced transcription activity, strongly hypermethylated and hypomethylated CpG sites located in promoter regions underwent Ingenuity Pathway Analysis. The top canonical pathways altered by strongly hypermethylated and hypomethylated CpG sites between 28-d-old and 5-yr-old PNS cows were 4-1BB Signaling in T Lymphocytes (P = 0.00169) and Transcriptional Regulatory Network in Embryonic Stem Cells (P = 0.000744). Mineralocorticoid Biosynthesis (P = 0.00901) and Transcriptional Regulatory Network in Embryonic Stem Cells (P = 0.000804) were the other top canonical pathways altered between 28-d-old and 5-yr-old Control cows. PNS calves appeared to develop an altered epigenome compared to Control group calves during the first five yr from birth.
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Moss, Angela R., and D. I. Givens. "Methane production from weaned dairy heifer calves." Proceedings of the British Society of Animal Science 1998 (1998): 54. http://dx.doi.org/10.1017/s1752756200597063.
Full textAbstract:
Agriculture is one of the major sources of methane in the UK and the major contribution is that from the ruminant animal. Most current inventories include emissions from growing and adult cattle and it has been assumed that the young calf contributes little to the methane flux. There is a dearth of information for young cattle (65-110 kg liveweight) and the objective here was to provide methane data for this group of ruminants to assist in improving the UK inventories for methane.
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Moss, Angela R., and D. I. Givens. "Methane production from weaned dairy heifer calves." Proceedings of the British Society of Animal Science 1998 (1998): 54. http://dx.doi.org/10.1017/s0308229600032670.
Full textAbstract:
Agriculture is one of the major sources of methane in the UK and the major contribution is that from the ruminant animal. Most current inventories include emissions from growing and adult cattle and it has been assumed that the young calf contributes little to the methane flux. There is a dearth of information for young cattle (65-110 kg liveweight) and the objective here was to provide methane data for this group of ruminants to assist in improving the UK inventories for methane.
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Vaz, Ricardo Zambarda, José Fernando Piva Lobato, and João Restle. "Influence of weaning age on the reproductive efficiency of primiparous cows." Revista Brasileira de Zootecnia 39, no. 2 (February 2010): 299–307. http://dx.doi.org/10.1590/s1516-35982010000200011.
Full textAbstract:
The effects of weaning age (90 days or 156 days) of female beef calves were evaluated on their subsequent performance from the beginning of the first pregnancy and the end of the second breeding season, at 22/24 months of age. During pregnancy, heifers were managed as a single group on Brachiaria brizantha cv. Marandu pasture; after calving, on bristle oats (Avena strigosa Schreb) and ryegrass (Lolium multiflorum Lam.); and on Brachiaria humidicula pasture during the second reproductive period. The characteristics studied were not influenced by calf weaning age. Heifers submitted to early or conventional weaning weighed 354.5 and 351.9 kg in the post-calving, and 363.4 and 359.2 kg when they weaned their calves. Average daily gain during the breeding season was 0.562 kg, and body condition score was 3.10 and 3.93 at the beginning and end of the experiment, respectively. Average calf birth and weaning weights were not influenced by dam weaning age, and were 28.7 ± 0.74; 86.5 ± 3.26 and 27.4 ± 0.92; 90.3 ± 4.04 kg, respectively, for dams submitted to early or conventional weaning. Dystocia, calving, birth, and weaning rates were not different between weaning ages, with mean values of 29.5; 95.3; 77.3 e 73.4%. Conception rates were 47.9% in the initial third and 40.8% in the second third versus 11.3% in the final third of the breeding season. Heifer average age at conception was 438 and 434 days for early weaning and conventional weaning. Pregnancy rates and production efficiency estimates at calving and calf weaning were not affected by heifer weaning age. Heifer early weaning did not affect their subsequent performance until the end of the second breeding season, at 22/24 months of age.
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Guterbock, Walter M. "The impact of BRD: the current dairy experience." Animal Health Research Reviews 15, no. 2 (October 29, 2014): 130–34. http://dx.doi.org/10.1017/s1466252314000140.
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AbstractThe primary source of data on bovine respiratory disease (BRD) prevalence in US adult dairy cattle is producer surveys, which estimate that 2.4–2.9% of cattle are affected. This estimate appears low when compared to calculations based on limited data regarding on-farm deaths due to BRD and the number of carcasses at slaughter with severe BRD. These calculations indicate that approximately 3% of dairy cows die on farm or go to slaughter with severe BRD. Not included in these data are cows that are treated for BRD and retained. The primary manifestation of BRD on dairy farms is in calves. Nationwide surveys have estimated that 12.4–16.4% of preweaned dairy heifer calves are affected with BRD, and 5.9–11% of calves are affected after weaning. More detailed prevalence studies have generally included a limited number of small farms, with limited calf age range studied. All studies relied on producer diagnosis. Prevalence in these studies ranged from 0 to 52%, with many cases occurring before weaning, and with BRD being associated with increased calf death rates. BRD affects heifer growth. It appears to have a small effect on age at first calving, and some studies have shown small effects on performance and herd life after calving. First lactation performance of heifers depends on many factors that can obscure the effects of calfhood BRD.
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King, B. D., R. D. H. Cohen, S. McCormac, and C. L. Guenther. "Maternal factors and the prediction of dystocia in beef heifers." Canadian Journal of Animal Science 73, no. 2 (June 1, 1993): 431–35. http://dx.doi.org/10.4141/cjas93-045.
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Stepwise discriminant analysis was used to determine maternal factors associated with dystocia in 564 2-yr-old heifers bred to bulls with below breed average birth weights. Calf birth weight (n = 556) was consistently the most significant (P < 0.001) factor correlated (R2 = 0.31) with dystocia. Other significant (P < 0.001) factors were weight at breeding (n = 376) and calving (n = 559; R2 = 0.11 for both traits). Other factors considered were age at breeding (n = 446), pelvic area at breeding (n = 112) and pregnancy evaluation (n = 297), heifer birth weight (n = 564), gestation length (n = 467) and age at calving (n = 559) but none were significant (P > 0.05). Heifers requiring caesarian section were heaviest (P < 0.05) at breeding and their calves were heaviest (P < 0.05) at birth. Unassisted heifers were heavier at calving (P < 0.05) than assisted heifers. It was concluded that none of the factors examined in this study was a reliable predictor of dystocia in beef heifers but that heifers should be bred at 75–80% of their expected calving weight to reduce the risk of dystocia. Key words: Dystocia, heifer, discriminant analysis
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Zhang, Shengchao, Sibtain Ahmad, Yuxia Zhang, Guohua Hua, and Jianming Yi. "Long Intergenic Non-Coding RNAs in the Mammary Parenchyma and Fat Pad of Pre-Weaning Heifer Calves: Identification and Functional Analysis." Animals 11, no. 5 (April 28, 2021): 1268. http://dx.doi.org/10.3390/ani11051268.
Full textAbstract:
Enhanced plane of nutrition at pre-weaning stage can promote the development of mammary gland especially heifer calves. Although several genes are involved in this process, long intergenic non-coding RNAs (lincRNAs) are regarded as key regulators in the regulated network and are still largely unknown. We identified and characterized 534 putative lincRNAs based on the published RNA-seq data, including heifer calves in two groups: fed enhanced milk replacer (EH, 1.13 kg/day, including 28% crude protein, 25% fat) group and fed restricted milk replacer (R, 0.45 kg/day, including 20% crude protein, 20% fat) group. Sub-samples from the mammary parenchyma (PAR) and mammary fat pad (MFP) were harvested from heifer calves. According to the information of these lincRNAs’ quantitative trait loci (QTLs), the neighboring and co-expression genes were used to predict their function. By comparing EH vs R, 79 lincRNAs (61 upregulated, 18 downregulated) and 86 lincRNAs (54 upregulated, 32 downregulated) were differentially expressed in MFP and PAR, respectively. In MFP, some differentially expressed lincRNAs (DELs) are involved in lipid metabolism pathways, while, in PAR, among of DELs are involved in cell proliferation pathways. Taken together, this study explored the potential regulatory mechanism of lincRNAs in the mammary gland development of calves under different planes of nutrition.
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Bagg, R., G. Vessie, J. Wilson, and P. Dick. "Comparison of the effects of monensin and decoquinate on feed intake and growth performance in dairy calves up to weaning age." Canadian Journal of Animal Science 80, no. 4 (December 1, 2000): 721–23. http://dx.doi.org/10.4141/a00-063.
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Holstein heifer calves (88) received 50 mg kg−1 of feed containing either monensin or decoquinate for 42 d prior to weaning. There were no significant differences between treatments in feed intake, weight gain or height gain, suggesting that monensin and decoquinate have equivalent effects on these parameters in pre-weaned dairy calves. Key words: Monensin, decoquinate, dairy calves
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Malau-Aduli, Aduli Enoch Othniel, Razaq Oladimeji Balogun, John Roger Otto, Sumita Verma, Maduka Wehella, and David Jones. "Novel Encapsulated Calcium Butyrate Supplement Enhances On-Farm Dairy Calf Growth Performance and Body Conformation in a Pasture-Based Dairy Production System." Animals 10, no. 8 (August 8, 2020): 1380. http://dx.doi.org/10.3390/ani10081380.
Full textAbstract:
The effect of supplementing neonatal heifer calves with varying levels of ECAB on pre-weaning growth performance was investigated. Post-weaning growth was also measured, to determine any carry-over effect of pre-weaning supplementation of ECAB. Forty-eight heifer calves (7 ± 0.4 days old, average liveweight of 39.3 ± 5.3 kg) were utilized in a complete randomised experimental design, comprising 16 calves per pen, randomly allocated to one of the following three treatments: (1) Basal commercial calf starter mix without ECAB (Control); (2) control plus 4 kg/ton of ECAB (Low); and (3) control plus 6 kg/ton of ECAB (High). Calves were group-fed ad libitum for 77 days (11 weeks, pre-weaning period) with free choice access to water and 5.5 L of milk per head per day through an automated feeder. Calves were weighed weekly during the pre-weaning period, after which all calves were then weaned onto the same ryegrass pasture as one group. At approximately 9 months of age, calves were weighed to estimate post-weaning body weight gain. During the pre-weaning period, average daily dry matter feed intake was similar for 4 kg/ton and 6 kg/ton calves (649 g versus 688 g, respectively) and both were greater than that of the control calves (382 g). Average daily gain (ADG) was significantly higher for 4 kg/ton calves compared to 6 kg/ton calves or control calves (0.83 ± 0.03 kg, 0.74 ± 0.03 kg and 0.71 ± 0.03 kg, respectively; p = 0.0001). Similarly, 4 kg/ton calves had significantly increased chest girth (95.9 ± 0.7 cm), withers height (88.9 ± 0.5 cm), body length (82.9 ± 0.6 cm), and body condition score (1.99 ± 0.12) compared to 6 kg/ton calves (93.4 ± 0.7 cm, 87.4 ± 0.7, 81.5 ± 0.6 cm, and 1.67 ± 0.10, respectively) or control calves (92.9 ± 0.7 cm, 88.2 ± 0.5 cm, 80.1 ± 0.6 cm, and 1.30 ± 0.08, respectively). There was significant treatment × week interaction for all pre-weaning growth parameters. Breed differences were detected but there was no treatment × breed interaction. Post-weaning, 4 kg/t calves and 6 kg/t calves had significantly higher ADG compared to control calves (0.80 ± 0.03 kg, 0.85 ± 0.03 kg versus 0.70 ± 0.03 kg, respectively; p = 0.0047). It is concluded that under the conditions of this study, supplementing heifer calves with ECAB during pre-weaning period resulted in improved growth performance and there appears to be a post-weaning carry-over effect.
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Carroll, Jeffery A., Nicole C. Burdick Sanchez, John D. Arthingon, Corwin D. Nelson, Aimee L. Benjamin, Filiz T. Korkmaz, David E. Kerr, and Phillip A. Lancaster. "In utero exposure to LPS alters the postnatal acute-phase response in beef heifers." Innate Immunity 23, no. 1 (November 21, 2016): 97–108. http://dx.doi.org/10.1177/1753425916678472.
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The potential effect of prenatal LPS exposure on the postnatal acute phase response (APR) to an LPS challenge in heifers was determined. Pregnant crossbred cows were separated into prenatal immune stimulation (PIS) and saline groups (Control). From these treatments, heifer calves were identified at weaning to subsequently receive an exogenous LPS challenge. Sickness behavior scores (SBS) were recorded and blood samples were collected at 30-min intervals from −2 to 8 h and again at 24 h relative to the LPS challenge. There was a treatment × time interaction for the change in vaginal temperature (VT) such that the change in VT was greater in Control than PIS from 150 to 250 min, yet it was greater in PIS than Control from 355 to 440 min and from 570 to 1145 min. There was also a treatment × time interaction for SBS such that scores were greater in Control than PIS at 0.5 h, yet were greater in PIS than Control from 2.5 to 4 h post-LPS. There was a tendency for a treatment × time interaction for serum concentrations of IL-6, which were greater in PIS than Control heifers from 5.5 to 6 h and from 7 to 8 h post-challenge. Thus, a single exposure to LPS during gestation can alter the postnatal APR to LPS in heifer calves.
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Bertenshaw, C., and P. Rowlinson. "The influence of positive human-animal interaction during rearing on the approach behaviour of young dairy heifers." Proceedings of the British Society of Animal Science 2001 (2001): PC09. http://dx.doi.org/10.1017/s1752756200006530.
Full textAbstract:
Modern management of dairy heifers leads to lack of familiarisation with humans. Consequently when the dairy heifer calves and enters the milking herd in close contact with humans whom she innately fears, her productivity and welfare are at risk. The rearing period has potential for shaping the heifers experiences of people prior to the regular contact of milking where productivity can suffer and behaviour be disruptive. This experiment was to determine if positive treatment reduced fear of humans and if so if heifers generalise this response to other humans. The results will be used in further analysis relating to subsequent measures of behaviour, production and welfare associated with milking.
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Trott, Josehine F., Amy E. Young, Bret R. McNabb, Xiang Yang, Thomas F. Bishop, and Alison L. Van Eenennaam. "19 Comparative Evaluation of Human-edible Animal Products Derived from Offspring of Genome Edited and Control Cattle." Journal of Animal Science 99, Supplement_3 (October 8, 2021): 11–12. http://dx.doi.org/10.1093/jas/skab235.020.
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Abstract Risk assessments of genetically modified (GM) animals include evaluating whether milk and meat derived from the GM animal is as nutritious to humans and/or animals as traditionally-bred animals. The underlying assumption of this comparative approach is that traditionally-bred animals have a well-established history of safe use. The goal of this project was to provide empirical data on the development and nutritional composition of animal products derived from the offspring of a genome edited dairy bull, homozygous for the dominant PC Celtic POLLED allele. The bull was crossed with horned Hereford (HH) cows (pp) to obtain five male and one female heterozygous hornless (RC) calves. Hereford, Angus and Holstein bulls were also bred to Hereford cows to produce five HH calves, two polled Angus/Hereford (AH) calves, and three horned Holstein/Hereford (HO) calves (with 25% genetic identity to the hornless offspring), respectively as contemporary controls. Weights were recorded at 8 months, 1 year and slaughter (n = 9–16). Following calving, individual quarters of the RC heifer (RC.calf1), one HO heifer (HO.calf2), two horned HH heifers, and one contemporaneous hornless AH cow (3113) were milked at varying timepoints during the first seven weeks of lactation. Meat samples were collected from the 6 hornless RC calves and 3 horned HO comparator offspring after slaughter. Proximate analysis was conducted for meat and milk samples. Cattle that inherited a POLLED allele from the genome-edited bull showed no differences in their overall growth (Figure 1) or meat composition (Figure 2) when compared to contemporary controls. Milk composition varied between animals and by days in milk (DIM), although values were within the normal range reported in peer-reviewed literature (Figure 3). Bovine milk composition is known to be influenced by breed, nutrition, parity, and DIM, making it difficult to obtain appropriate comparators in experiments with a limited number of GM animals.