Journal articles on the topic 'Heifer calf'
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Umar Paputungan, Lentji Rinny Ngangi, and Wapsiaty Utiah. "Factors affecting calf parturition of the Ongole grade beef heifers." Open Access Research Journal of Life Sciences 3, no. 2 (June 30, 2022): 077–82. http://dx.doi.org/10.53022/oarjls.2022.3.2.0052.
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Serious economic losses due to calf or heifer increasing mortality during parturition, the normal calving period without human interference was urgently needed. The most important internal factor influencing calving difficulty was Calf birth weight (CBW). Other external factors considered to contribute calving difficulty were heifer live weight (HLW), heifer body length (HBL), and heifer chest girth (HCG), calf parturition durability (CPD) representing linear CBW. Objective of this study was to estimate above factor mostly affecting calving difficulty of Ongole Grade heifers mated by artificial insemination method. Study was involving 126 Ongole Grade heifers at the artificial insemination center of North Sulawesi province, Indonesia. Data on HLW, HBL, HCG, CPD and CBW were collected from 126 heifers at ages of two to three years old. All linear body measurements were included as independent variables in multiple regression equation affecting dependent variable of CBW in the models using statistical datasheet of Microsoft Office Excel 2007. Results showed that HCG, HBL and CPD as independent variables can be recommended to predict CBW representing internal factor of Ongole Grade heifers in the multiple regression model as follows: Calf birth weight (Y in kg) = 26.871 + 0.0033 heifer body length (X1 in cm) – 00.0255 heifer chest girth (X2 in cm) + 0.032 calf parturition durability (X3 in minute) with determination coefficient (R2) of 0.91.
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Nickles, Kirsten, Alejandro E. Relling, Alvaro Garcia-Guerra, Francis L. Fluharty, and Anthony J. Parker. "87 Beef Heifers Housed in Muddy Environmental Conditions Lose Body Weight and Body Condition but Meet Gestational Requirements for Fetal Growth." Journal of Animal Science 99, Supplement_3 (October 8, 2021): 46. http://dx.doi.org/10.1093/jas/skab235.081.
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Abstract Beef heifers experience an exponential increase in energy requirements during late gestation. Heifers must simultaneously grow a fetus, reach mature body weight, and prepare for their first lactation. In spring calving herds, these energy demands coincide with environmental stressors. Future climate projections for the Midwest predict increased winter rainfall, creating muddy conditions. It is likely that muddy conditions increase heifer energy requirements. The increased energy requirements, if not met, may compromise growth of the heifer and fetus. The objectives of this experiment were to evaluate the effects of muddy conditions on heifer body weight (BW), body condition score (BCS), and calf birth weight. Eighteen Angus heifers (n = 9/treatment) were paired based on initial BW. One heifer from each pair was assigned to either the mud (MUD) or control (CON) treatment. Heifers in the CON treatment were housed in pens with sawdust, and heifers in the MUD treatment were housed in pens with mud (20.3 ± 7.6 cm). Heifers were housed individually, and each pair received the same dietary allowance based on the CON heifer’s BW for maintenance, growth, and gestation. From day 196 to 266 of gestation, heifers were weighed and assigned a BCS weekly. Data were analyzed as a randomized complete block design with repeated measurements (SAS 9.4). On day 196 of gestation, heifers were similar in BW and BCS (P > 0.05). By day 266, MUD heifers weighed 43.5 kg less than CON heifers (P < 0.01) and were assigned a BCS of 4.3 compared with CON heifers that were a BCS of 6.1 (P < 0.01). Calf birth weight was not different (P = 0.21). Heifers in both treatments were able to maintain fetal growth, however, MUD heifers did not meet their energy requirements and had decreased BW and BCS compared with the CON heifers.
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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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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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Kim, Na Yeon, Seong Jin Kim, Se Young Jang, Hye Jin Seong, Yeong Sik Yun, and Sang Ho Moon. "Characteristics of vocalisation in Hanwoo cattle (Bos taurus coreanae) under different call-causing conditions." Animal Production Science 59, no. 12 (2019): 2169. http://dx.doi.org/10.1071/an17698.
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The present study provided basic data regarding cattle farming on the basis of animal welfare, by using Hanwoo cattle (Bos taurus coreanae) vocalisations. We collected and analysed cattle-vocalisation data during situations that commonly occur during cattle farming (steer handling call, n = 130; heifer handling call, n = 418; heifer oestrus call, n = 454; heifer feed-anticipation call, n = 124; calf introduction call, n = 212) at a Hanwoo cattle farm and investigated differences in vocalisation parameters (call duration, call intensity, fundamental frequency, first formant, second formant, third formant, fourth formant) according to the type of call. Regarding call duration, intensity and first formant, the heifer oestrus call was significantly (P < 0.05) longer than were the other calls. The calf introduction call was the second longest in duration and first formant. Regarding fundamental frequency, the steer handling call was significantly higher than were the other calls (P < 0.05), with the heifer oestrus call being the lowest by a significant amount (P < 0.05). Regarding the second and third formants, the feed-anticipation call had a significantly higher frequency than did the other calls (P < 0.05). Regarding the fourth formant, the steer and heifer handling calls showed the highest frequency levels by a significant margin (P < 0.05). The calf introduction and heifer oestrus calls scored the lowest for the third formant and fourth formant (P < 0.05). Ultimately, vocalisation-parameter analysis of Hanwoo in different situations enabled the classification of an auditory communication system on the basis of their physiological and emotional states. Such vocalisation research data can be used for animal welfare and to enable more advanced and precise cattle farming.
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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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Spence, S. A., S. A. Spence, A. C. Woodhead, and A. C. Woodhead. "The relationship between management practices and estimated weight for age of Friesian heifers in north-eastern New South Wales." Australian Journal of Experimental Agriculture 40, no. 3 (2000): 357. http://dx.doi.org/10.1071/ea98135.
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The weight of 2659 Friesian heifers was measured electronically on 41 farms in north-eastern New South Wales during autumn 1992. The 41 producers involved were surveyed on their heifer management practices. The relationship between liveweight and age was determined from these measurements. This provided a base line against which improvement in heifer weight for age could be measured subsequent to a planned extension program. In 1992, 2 management practices were found to be associated with significantly higher weights for age. These were feeding more than 1 kg of concentrate to heifers prior to weaning and grazing heifers on fertilised pasture between weaning and 12 months of age. An extension program promoting improved heifer management was conducted, using adult learning principles, from 1992 until 1995. Nineteen of the 41 farms were revisited in winter 1997 when the heifers were again measured and management practices surveyed. Heifer weight for age had increased by a small but significant amount between 1992 and 1997. Management changes which occurred between 1992 and 1997 were: increased vaccination rates; decreased use of antibiotic injections for treating calf illnesses; increase in feeding over 1 kg of concentrate per day to preweaned heifers; and increased use of silage to feed weaned heifers. There was also a decreased percentage of producers who considered calf diseases to be a problem. Between 1992 and 1995, 14 farmers began monitoring their heifers regularly, either by measuring weight electronically or by using a weigh tape.
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Fallon, R. "Calf and Heifer Rearing." International Journal of Dairy Technology 59, no. 1 (February 2006): 53–54. http://dx.doi.org/10.1111/j.1471-0307.2006.00225.x.
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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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Shah, Nadeem, Manisha Sethi, Pratyush Kumar, Tushar K. Mohanty, Mukesh Bhakat, Raju K. Dewry, Debajyoti Sarkar, Vinod K. Gupta, and Aye Soe. "Selection of Heifers and Breeding Bulls for Reducing Calving Difficulties in the First Calvers: An Overview." Indian Journal of Veterinary Sciences and Biotechnology 17, no. 02 (April 10, 2021): 01–08. http://dx.doi.org/10.21887/ijvsbt.17.2.1.
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Calving difficulty is associated with cow mortality, calf loss, veterinary and labor costs, and causes delayed return to estrus and lower conception rate. Dystocia is common in heifers, and the frequency decreases with the increasing age of the cow. Farmers need to consider both genetics and management factors in an attempt to reduce dystocia. Calf birth weight, the pelvic area of the dam and their interrelationships are major determinants of dystocia. The weight of the calf is governed by genetic, environmental and management factors. Genetic factors include sex, length of gestation, breed, inbreeding, and genotype. Non-genetic factors include age and parity of the dam, nutrition of the dam during various phases of gestation, and environmental temperature and humidity. Dystocia management must begin with a selection of heifer for mating with respect to the body weight of heifers, body condition score (BCS) and dam’s pelvic area should be considered before heifer selection. Not only heifer selection but sire selection using an estimated breeding value for calving ease should also be considered to lessen the dystocia rate in a herd. A combination of culling heifers with small pelvic areas and using bulls reported to be calving ease sire may reduce dystocia significantly. Apart from all these factors, genomic selection for reducing calving difficulties is a new tool for dystocia management.
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Schatz, T. J., and M. N. Hearnden. "Heifer fertility on commercial cattle properties in the Northern Territory." Australian Journal of Experimental Agriculture 48, no. 7 (2008): 940. http://dx.doi.org/10.1071/ea08057.
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The performance of heifers at their first (maiden heifers) and second matings (first lactation heifers) was recorded between 2003 and 2008 to establish current heifer fertility levels on 14 commercial cattle properties in the Northern Territory (NT). Pregnancy rates in maiden heifers (joined first at ~2 years of age) were generally adequate (>75%) to produce enough pregnant replacement breeders. Pregnancy rates in first lactation heifers were often very low (<20%) due to the low liveweight of heifers between calving and weaning. However on properties where first lactation heifers were in good condition at this time, pregnancy rates were high (>70%). Calf loss between pregnancy diagnosis and weaning in first lactation heifers was often high (>30%). The average of the calf loss figures from all the herds studied was 22%.
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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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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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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
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Basarab, J. A., M. G. Colazo, D. J. Ambrose, S. Novak, D. McCartney, and V. S. Baron. "Residual feed intake adjusted for backfat thickness and feeding frequency is independent of fertility in beef heifers." Canadian Journal of Animal Science 91, no. 4 (December 2011): 573–84. http://dx.doi.org/10.4141/cjas2011-010.
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Basarab, J. A., Colazo, M. G., Ambrose, D. J., Novak, S., McCartney, D. and Baron, V. S. 2011. Residual feed intake adjusted for backfat thickness and feeding frequency is independent of fertility in beef heifers. Can. J. Anim. Sci. 91: 573–584. This study examined the effects of residual feed intake (RFI), RFI adjusted for off-test backfat thickness (RFIfat) and RFI adjusted for off-test backfat thickness and feeding event frequency (RFIfat & activity) on heifer fertility and productivity. Beef heifers (n=190) were monitored for individual daily feed intake and feeding event activity over 108–112 d using the GrowSafe System® and assessed for age at puberty based on plasma progesterone concentration. Individual animal daily feed intake, feeding event activity and off-test backfat thickness were then used to calculate RFI, RFIfat and RFIfat & activity and group heifers as either negative ([−], RFI<0.0) or positive ([+], RFI≥0.0) for RFI. Heifers averaged 298 kg (SD=34) in body weight, were 276 days of age (SD=19) at the start of test, grew at 0.90 kg d−1 (SD=0.21), consumed 7.62 kg DM head−1 d−1 (SD=0.84) and had a feed conversion ratio of 8.93 (SD=2.43). Age (351 d, SD=43) and weight (367.3 kg, SD=45.0) at puberty were similar between [−] and [+] RFI heifers, but age at puberty was delayed in [−] RFIfat (P=0.04) and RFIfat & activity (P=0.08) heifers compared with [+] RFIfat and RFIfat & activity heifers. Efficient or [−] RFI heifer exhibited a lower pregnancy (76.84 vs. 86.32%, P=0.09) and calving rate (72.63 vs. 84.21%, P=0.05) compared with [+] RFI heifers. These differences were partially removed in [−] RFIfat and completely removed in [−] RFIfat & activity compared with their [+] RFI counterparts (pregnancy rate, 80.85 vs. 82.29%, P=0.80; calving rate, 75.53 vs. 81.25%, P=0.34). No differences were observed between efficient and inefficient heifers in calving difficulty, average calving date, age at first calving, calf birth weight, calf pre-weaning ADG, calf weaning weight and heifer productivity. However, [+] RFI heifers exhibited a 1.9-fold higher calf death loss compared with [−] RFI heifers (11.11% vs. 5.71%, P=0.24). This difference was more pronounced in [+] RFIfat and [+] RFIfat & activity heifers, which exhibited 2.2-fold (11.84% vs. 5.33%, P=0.15) and 3.0-fold (12.66% vs. 4.17%, P=0.06) higher calf death loss compared with [−] RFI heifers. There was no relationship of RFI adjusted for backfat thickness and feeding activity on fertility traits indicating that backfat thickness and feeding activity may be associated with feed intake and should be considered when selecting heifers for improved feed efficiency.
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Krasnova, Alexandra Yuryevna, Yuri Ivanovich Krasnov, Ivan Nikolaevich Krasnov, and Valentina Viktorovna Miroshnikova. "Dynamics of pneumatic drive of devices for udder massage of animals." Agrarian Scientific Journal, no. 8 (September 10, 2021): 95–99. http://dx.doi.org/10.28983/asj.y2021i8pp95-99.
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The paper presents the results of theoretical developments on the deformation of flexible shells of the executive bodies of the means of stripping, the assessment of their mechanical impact on the udder of the heifer and first-calf, the dynamics of the pneumatic drive of the executive bodies. The design and technological parameters of the devices for milking first-calf heifers and massaging the udder of heifers are justified, the set and duration of technological operations for animal milking and the economic efficiency of their implementation are determined.
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Wellnitz, Krista R., Cory T. Parsons, Julia M. Dafoe, Darrin L. Boss, Samuel A. Wyffels, Timothy DelCurto, and Megan L. Van Emon. "Influence of Heifer Post-Weaning Voluntary Feed Intake Classification on Lifetime Productivity in Black Angus Beef Females." Animals 12, no. 13 (June 30, 2022): 1687. http://dx.doi.org/10.3390/ani12131687.
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This study evaluated heifer post-weaning voluntary feed intake (g/kg BW) classification on performance and reproductive measures, as well as impacts on lifetime productivity of 519 commercial Angus beef females. Heifer post-weaning voluntary feed intake (g/kg BW) was calculated over 80 test days following weaning using GrowSafe units. Heifers were categorized based on voluntary feed intake (g/kg BW) as either low (<−0.50 SD from the mean), average (±0.50 SD from the mean), or high (>0.50 SD from the mean) within year. Cow body weight (BW) and body condition score (BCS) at breeding displayed an age effect (p < 0.001), with 2- and 3-year-old cows having lighter BW and lower BCS than 4-yr-old and older cows. Cow BW at weaning showed significance for age and intake (p < 0.001) with younger cows being lighter than older cows, while low intake classified females had greater BW at weaning compared to average and high intake females. Additionally, calf 205-d weights and calf weaning weights (p < 0.01) were significant for age with calves born from older cows weighing more than younger cows. Weaning weight ratio displayed a linear increase with increasing intake classification (p < 0.01). Heifer yearling BW was significant for intake (p < 0.01) with low and average intake heifer classifications having greater heifer yearling BW than cows that had high intake classification as a heifer. Age and intake classification did not impact (p ≥ 0.22) pregnancy status or AI conception. In summary, heifer post-weaning feed intake classification had only minor impacts compared to age effects on lifetime productivity of Angus beef females.
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Sinclair, K. D., and B. G. Lowman. "The effect of differing patterns of energy intake in mid and late pregnancy in maiden heifers." Proceedings of the British Society of Animal Production (1972) 1990 (March 1990): 122. http://dx.doi.org/10.1017/s0308229600019024.
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The sharp fall in dairy cow numbers which has occurred since the introduction of milk quotas in 1983 has seen a resurgence of interest in the suckler cow. As a result the June 1989 census revealed that the number of heifers under two years old destined for breeding was 6.1 percent up on the previous year. It therefore seems clear that over the next few years as the beef herd expands more emphasis is going to be placed on the young breeding heifer. Problems with breeding from young heifers are well known. However, current knowledge of the effects of pre partum nutrition on heifer and calf performance is incomplete. The purpose of this study was therefore to monitor the effects, of differing patterns of energy intake in mid and late pregnancy in maiden heifers.
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Callum, C., K. H. Ominski, G. Crow, F. Zvomuya, and J. A. Basarab. "Relationship between residual feed intake classification as a heifer and lifetime productivity of beef cattle." Canadian Journal of Animal Science 99, no. 1 (March 1, 2019): 191–201. http://dx.doi.org/10.1139/cjas-2018-0002.
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The effect of residual feed intake adjusted for backfat thickness (RFIfat) on heifer pregnancy rate and subsequent lifetime productivity was examined in 867 beef females that were ranked as low, medium, or high RFIfat. Age at first calving, weaning weight of first calf, and most probable producing ability for birth weight (MPPAbw) and weaning weight (MPPAww) were calculated to assess first parity heifer productivity. The effect of heifer RFI adjusted for backfat (RFIfat; n = 532) on subsequent lifetime cow productivity (n = 415) was calculated based on kg of calf weaned per cow bred per year. A total lifetime productivity measure (n = 218) were also calculated as total calf weaning weight (kg) output per cow culled. RFI rank had no significant effect on pregnancy rate, when adjusted for season and site differences (P = 0.33). No significant correlations (P < 0.05) were observed between MPPAww and RFI, RFIfat, RFI adjusted for backfat and feeding event frequency (RFIfat & activity), or age at first calving. A negative trend (P < 0.10) between RFI, RFIfat, and MPPAbw calculated from first parity pregnancy rate and production traits was no longer apparent when adjusted for RFIfat & activity. These results suggest that selection for low RFI replacement heifers has no impact on their first parity pregnancy rate and productivity or on subsequent cow productivity.
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Bennett, Gary L., John W. Keele, R. Mark Thallman, Warren M. Snelling, Harvey C. Freetly, and Larry A. Kuehn. "19 Mature size and other trait differences in cows selected for calving ease and growth." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 22–23. http://dx.doi.org/10.1093/jas/skaa278.041.
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Abstract Cows selected for heifer calving ease and yearling weight might also show changes in other important traits. Cattle from select and control lines within 7 populations were selected for reduced heifer calving difficulty EPD (select) or for average birth weight EPD (control) and for identical yearling weight EPD (select and control). Heifers randomly sampled within sire and born in the 4th and 5th of 7 years of selection were retained until 6 years of age with culling for once open and health, but not for other performance. Both lines were bred to the same bulls for calves born during the 3 years post-selection. Select line heifers were 7% lighter (-2.6 ± 0.5 kg, P < 0.01) at birth and not different at weaning (0.2 ± 1.5 kg) or yearling ages (-2.1 ± 2.7 kg). Select cow mature weights estimated by Brody growth curves were 5.2% lighter (-32.9 ± 3.7 kg, P < 0.01) and heights were 2.2% shorter (-3.0 ± 0.7 cm, P < 0.01) than controls. Calf weaning weights were not different. Interactions between 1st calving select (bred to select bulls) and control heifers (bred to control bulls) vs. older cows (all bred to the same bulls) were significant for survival (P < 0.01) and calving assistance (P = 0.03). Select line heifers increased calf survival (86.8% vs. 70.9%) and had decreased calving assistance (16.4% vs. 39.3%), but differences in cows for these traits were negligible. Calves born per select cow exposed exceeded those born per control cow only for 2nd calving (7.1%, P = 0.04), possibly due to reduced calving difficulty as heifers. Selection for calving ease and yearling weight resulted in cows with smaller mature size and similar or better calving ease, calf survival, and calf weaning weight. USDA is an equal opportunity provider and employer.
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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.
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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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Morris, S. T., F. Y. Chan, N. Lopez-Villalobos, P. R. Kenyon, D. J. Garrick, and H. T. Blair. "Growth, feed intake and maternal performance of Angus heifers from high and low feed efficiency selection lines." Animal Production Science 54, no. 9 (2014): 1428. http://dx.doi.org/10.1071/an14220.
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Feed conversion efficiency is an important factor affecting profitability for cow-calf production systems. One method of characterising feed conversion efficiency is by calculating residual feed intake (RFI), the difference between measured and expected feed intakes. A high RFI value indicates low feed efficiency while a low RFI value indicates high feed efficiency. The present experiment used 49 Angus heifers sired by Angus bulls selected for high or low RFI. The progeny were bred on commercial farms and then transferred to Massey University at weaning at ~200 days of age. The heifers were weighed at ~30-day intervals and were mated at 15 months, calved at 2 years old and reared their calf to ~160 days of age. Each heifer had recorded its own liveweight gain (from its weaning to weaning of its first calf), herbage intake at 350 and 450 days of age using the n-alkane technique and maternal performance (calf production). These records were analysed to estimate the RFI of each heifer, and to determine differences in RFI between selection lines. There were no significant differences (P > 0.05) in liveweight or dry matter requirements between selection lines at Day 350, but differences were significant (P < 0.05) at Day 450 such that the high feed efficiency line were 24.6 kg heavier and required an extra 0.32 kg/head.day of herbage. There were no significant differences (P > 0.05) between the two lines in herbage intake or RFI measured at either Days 350 or 450. There were no differences (P > 0.05) in pregnancy rates, calf birth dates or birthweights, estimated 24-h milk production or calf weaning weights between the two lines. This experiment shows that beef cattle selected for low RFI have higher growth rates and heavier liveweights than cattle selected for high RFI; both lines had similar calf production at first breeding.
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Parcell, J. L., K. C. Dhuyvetter, D. J. Patterson, and R. Randle. "The Value of Heifer and Calf Characteristics in Bred Heifer Price1." Professional Animal Scientist 22, no. 3 (June 2006): 217–24. http://dx.doi.org/10.15232/s1080-7446(15)31097-4.
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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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Browning Jr., Richard, Emily G. Hayes, and Andrea S. Lear. "Spontaneous Appearance and Transmission of Polydactyly in Dexter Cattle." Case Reports in Veterinary Medicine 2020 (January 16, 2020): 1–5. http://dx.doi.org/10.1155/2020/6407847.
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A 3-yr-old Dexter cow and her yearling Dexter heifer calf exhibited polydactyly. Neither animal was linebred within 5 generations. This cow-calf pair represented the first reported occurrence of polydactyly in Dexter cattle in the US or abroad. Based upon external examination, the cow was classified as having a spontaneous unilateral case of polydactyly with an extra digit along the medial digit of the right front limb and the heifer was classified as having bilateral polydactyly because both front limbs exhibited an extra digit along the medial digit. Radiographic examination confirmed bilateral status of the heifer and revealed bilateral status of the cow. The front feet of the cow and heifer had extra bone formation consistent with an extra digit along the medial digit. Neither animal suffered from limited mobility to date or required hoof treatments. The cow produced a second calf from a different sire, a bull calf that did not appear polydactylous per external examination and was not examined radiographically. The two polydactylous animals will remain in the breeding herd to produce more study calves unless their fitness becomes compromised. Genetic aspects of the cases are discussed.
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Ott, Grace C., Rebecca K. Poole, Matt H. Poore, and Carrie L. Pickworth. "157 Impact of weaning strategy on heifer performance and reproductive development." Journal of Animal Science 97, Supplement_3 (December 2019): 153. http://dx.doi.org/10.1093/jas/skz258.314.
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Abstract Weaning is recognized as one of the most stressful times of a beef calf’s post-natal life. The objective of this study was to determine if weaning strategy impacts heifer development and reproduction. At 7 months of age, 96 predominantly Angus heifers at 2 locations were assigned to 1 of 3 weaning treatments: abrupt relocation of the calf on d0 (Abrupt, n = 32), fenceline contact starting on d0 prior to relocation of the calf on d7 (Fence, n = 33), and abrupt relocation of the calf on d84 (Late, n = 31). Calf weights, hip heights, and body condition scores (BCS) were collected to evaluate post-weaning performance. Reproductive tract scores (RTS; 0–5 scale, 5=most mature) were assigned every 54 days from d56 to d218. Heifers were synchronized using a 7-day CO-Synch + CIDR® protocol and artificially inseminated (AI) on d246. Data were analyzed using PROC MIXED of SAS with repeated measures. Statistical significance was determined at P ≤ 0.05. Late heifers were heavier at d28 and d56 than Abrupt and Fence (P < 0.05), but BW was similar across treatments starting at d84. Average daily gain (ADG) was greater for Late than Abrupt (0.39 and -0.03 kg/day respectively; P < 0.01) and tended to be greater than Fence (0.16 kg/day; P = 0.07) to d28; however, Late had lower ADG than Abrupt and Fence from d28-84 (0.66, 0.83, and 0.81 kg/day respectively; P < 0.05). No treatment differences were observed in BCS or hip height. Late tended to have greater RTS than Abrupt and Fence (2.54, 2.20, and 2.16 respectively; P ≤ 0.10) on d56, but there was no difference on or after d164. Fence tended to have greater AI conception rates than Abrupt and Late (66%, 44%, and 42% respectively; P ≤ 0.08). This data indicates there were initial performance differences based on weaning strategy, but this had minimal impact on heifer development.
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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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Morrill, J. L. "Dairy calf and heifer research at KSU." Kansas Agricultural Experiment Station Research Reports, no. 2 (January 1, 1990): 2–4. http://dx.doi.org/10.4148/2378-5977.3301.
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Winder, Charlotte B., Cathy A. Bauman, Todd F. Duffield, Herman W. Barkema, Greg P. Keefe, Jocelyn Dubuc, Fabienne Uehlinger, and David F. Kelton. "Canadian National Dairy Study: Heifer calf management." Journal of Dairy Science 101, no. 11 (November 2018): 10565–79. http://dx.doi.org/10.3168/jds.2018-14680.
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Uhrincat, Michal, Jan Broucek, Anton Hanus, and Peter Kisac. "Effect of Raising Dairy Heifers on Their Performance and Reproduction after 12 Months." Agriculture 11, no. 10 (October 7, 2021): 973. http://dx.doi.org/10.3390/agriculture11100973.
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The objective of this study was to test the hypotheses that a heifer’s growth, health, and reproduction after 12 months are impacted by rearing (feeding/housing) before weaning, their season of birth, and the father’s lineage. Fifty-one Holstein heifers, born during January–March (SB1), April–June (SB2), July–September (SB3), and October–December (SB4) and originating from four fathers, were assigned to one of the three rearing treatments: restricted suckling (RS), calf in a pen with the mother until the 21st day, sucking three times daily, then group pen (6 kg milk) to weaning; unrestricted suckling (US), calf in a pen with foster cows (6 kg milk) to weaning; and conventional rearing (CR), calf in a hutch until the 56th day, then group pen to weaning (milk replacer 6 kg). After weaning on the 84th day, heifers were kept in groups with the same ration. The growth of the live body weight (LBW), health, and reproduction were recorded. The LBW had a tendency to increase from the 360th to the 570th days in the US, and the reduced growth of the LBW was shown in the CR. Heifers of SB2 had the highest LBW at 570 days of age. The ages of the first insemination service and the conception varied significantly among the rearing groups. The results indicate that a heifer rearing method may have a significant impact on their later growth and fertility.
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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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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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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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Akanno, Everestus C., Graham Plastow, Carolyn Fitzsimmons, Stephen P. Miller, Vern Baron, Kimberly Ominski, and John A. Basarab. "Genome-wide association for heifer reproduction and calf performance traits in beef cattle." Genome 58, no. 12 (December 2015): 549–57. http://dx.doi.org/10.1139/gen-2015-0031.
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The aim of this study was to identify SNP markers that associate with variation in beef heifer reproduction and performance of their calves. A genome-wide association study was performed by means of the generalized quasi-likelihood score (GQLS) method using heifer genotypes from the BovineSNP50 BeadChip and estimated breeding values for pre-breeding body weight (PBW), pregnancy rate (PR), calving difficulty (CD), age at first calving (AFC), calf birth weight (BWT), calf weaning weight (WWT), and calf pre-weaning average daily gain (ADG). Data consisted of 785 replacement heifers from three Canadian research herds, namely Brandon Research Centre, Brandon, Manitoba, University of Alberta Roy Berg Kinsella Ranch, Kinsella, Alberta, and Lacombe Research Centre, Lacombe, Alberta. After applying a false discovery rate correction at a 5% significance level, a total of 4, 3, 3, 9, 6, 2, and 1 SNPs were significantly associated with PBW, PR, CD, AFC, BWT, WWT, and ADG, respectively. These SNPs were located on chromosomes 1, 5–7, 9, 13–16, 19–21, 24, 25, and 27–29. Chromosomes 1, 5, and 24 had SNPs with pleiotropic effects. New significant SNPs that impact functional traits were detected, many of which have not been previously reported. The results of this study support quantitative genetic studies related to the inheritance of these traits, and provides new knowledge regarding beef cattle quantitative trait loci effects. The identification of these SNPs provides a starting point to identify genes affecting heifer reproduction traits and performance of their calves (BWT, WWT, and ADG). They also contribute to a better understanding of the biology underlying these traits and will be potentially useful in marker- and genome-assisted selection and management.
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Sato, R., K. Yamada, Y. Shinozuka, H. Ochiai, and K. Onda. "Gas-filled urachal abscess with a pinging sound in a heifer calf." Veterinární Medicína 64, No. 8 (August 29, 2019): 362–66. http://dx.doi.org/10.17221/61/2019-vetmed.
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A 6-month-old crossbred of a Holstein and Japanese Black heifer calf weighing 95 kg presented with a history of intermittent abdominal distension and failure to thrive. The physical examination identified a pinging sound over the dorsal left flank. The abdominal radiography showed a huge gas-filled mass. The intravenous urography revealed no communication between the mass and the urinary bladder. Although the visual examination and palpation of the umbilicus did not reveal visible abnormalities, an umbilical disease was suspected because the animal exhibited poor growth, depression, and a hunched back posture. When the eschar adhering to the centre of the umbilicus was removed, the presence of a fistulous tract was revealed. The umbilical ultrasound examination revealed an intra-abdominal abscess and the fistulography demonstrated that the abscess communicated with the umbilicus. The abscess, compressing into the rumen, was observed by computed tomography. From these images, it was diagnosed as an umbilical cord remnant abscess and a definitive diagnosis of a urachal abscess was obtained by open abdominal surgery and the subsequent removal of the mass. The calf was discharged from the university hospital on day 14 after the operation. This case shows that a urachal abscess should be considered when a pinging sound is present, even if the animal exhibits no swelling or pain of the umbilicus.
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HERRIOTT, DONALD E., DALE D. HANCOCK, ERIC D. EBEL, LINDA V. CARPENTER, DANIEL H. RICE, and THOMAS E. BESSER. "Association of Herd Management Factors with Colonization of Dairy Cattle by Shiga Toxin-Positive Escherichia coli O157." Journal of Food Protection 61, no. 7 (July 1, 1998): 802–7. http://dx.doi.org/10.4315/0362-028x-61.7.802.
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Management factors in 36 Pacific Northwest dairy herds were evaluated for their association with the prevalence of Shiga toxin-positive Escherichia coli O157 (E. coli O157) in dairy cattle. The within-herd prevalence of E. coli O157 was estimated by bacteriological culture of fecal pat samples, collected monthly for 6 months (approximately 60 per visit), from heifer cattle. During the first visit to each farm, a management questionnaire was administered that covered a broad range of animal husbandry practices. On each subsequent visit, a brief questionnaire was administered to detect changes in management practices. A significantly higher prevalence of E. coli O157 was noted in herds that fed com silage to heifers compared to herds that did not feed com silage. More tentative associations of E. coli O157 prevalence were observed for weaning method, protein level of calf starter, feeding of ionophores in heifer rations, feeding of grain screens to heifers, and feeding of animal by-products to cows.
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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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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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Winslow, Christine M., Jason Wood, John N. Gilliam, and Melanie A. Breshears. "Congenital amelanotic melanoma in a crossbred heifer calf." Journal of Veterinary Diagnostic Investigation 29, no. 4 (April 19, 2017): 544–47. http://dx.doi.org/10.1177/1040638717706399.
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A large, pedunculated cutaneous mass protruding from the left flank fold and an enlarged left prefemoral lymph node were found on examination of a 3-d-old crossbred Aberdeen Angus heifer. The calf was asymptomatic aside from peripheral lymphadenopathy, and the mass, along with the left prefemoral lymph node, was surgically excised. Histologic examination of the mass and the lymph node revealed a homogeneous population of neoplastic cells that stained positively with immunohistochemical stains S100 and melan A, supporting a diagnosis of congenital amelanotic melanoma with nodal metastasis. Two months later, the calf became acutely recumbent and was euthanized after clinical examination revealed widespread metastasis. Gross autopsy revealed widely disseminated metastases that involved vertebral bodies, spinal cord, heart, kidneys, lungs, oral mucosa, multiple lymph nodes, and the marrow cavity of several long bones. Our case serves as a reminder that, although rare, congenital neoplasms occur in bovids and have the potential for aggressive, metastatic behavior.
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Wong, Agnes, Christina R. Wilson-Frank, Stephen B. Hooser, and Grant N. Burcham. "Chronic copper toxicosis in a crossbred heifer calf." Journal of Veterinary Diagnostic Investigation 32, no. 3 (February 28, 2020): 458–62. http://dx.doi.org/10.1177/1040638720908229.
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An 8-mo-old, crossbred, heifer calf was presented to the Heeke Animal Disease Diagnostic Laboratory with a history of ataxia and altered mentation. Grossly, the liver was diffusely yellow-orange, turgid, and exuded watery, thin blood on cut section. The cortex and medulla in both kidneys were diffusely and markedly dark brown to black. The urinary bladder was filled with dark red urine. Histologically, centrilobular hepatocellular degeneration was observed, but these sections lacked necrosis. In the kidney, numerous cortical tubules contained intraluminal bright eosinophilic fluid and red-orange granular casts that stained positive for hemoglobin with the Dunn–Thompson method. The gross and histologic lesions supported a high level of suspicion for copper toxicosis. Feed and water samples from the farm were submitted for mineral analysis. The copper concentration in the feed was 118 mg/kg, and the molybdenum concentration was 0.9 mg/kg. Chronic copper toxicosis is rarely reported in cattle. The gross lesions in our case are a departure from, although similar to, previously reported cases, including lack of histologic hepatocellular necrosis. Collectively, gross and histologic lesions were compatible with copper toxicosis in this calf, and copper concentrations in the feed samples suggest a feed-mixing error.
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Aysheshim Belay, Bekele. "The Effect of Housing and Waste Management Practice for Milk Production in Arba Minch Town, Gamo Zone, Ethiopia." International Journal of Current Research and Academic Review 9, no. 1 (January 20, 2021): 50–58. http://dx.doi.org/10.20546/ijcrar.2021.901.004.
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The objective of the study was to assess waste management practice of small holder dairy farms in Arba Minch town. The survey methodology was systematically purposive sampling using semi-structure questionnaires. Herd composition were observed lactating cows (15%), pregnant cow (10%), lactating and pregnant (20 %), heifer (10%) bull (10%) oxen (10%) male calf (10%) and female calf (15%). While in the sechaarea; lactating (20%), pregnant (10%), lactating and pregnant cow (25 %), heifer (10%) bull (5%) oxen (10%) male calf (10%) and female calf (10%). So in the study area most respondent holds lactating and pregnant cows. Respondent uses open barn, open camp and others. That not comfortable for animal. This covers (22%), (7.5%) and (2.5%) of respondent respectively. The major wastes are dung, urine (52.5%).Most respondent (95%) said that wastes affect animal, human, environment. It sometimes cause of complain with neighbors due to leaking of wastes and bad smell from the farm (82.5) and source some zoonotic disease, cough and etc.
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Moore, Mikayla F., Shane Gadberry, David Lalman, Frank White, Sara Linneen, and Paul A. Beck. "341 Meta-analysis of the Performance Responses of Replacement Heifers and Beef Cows to Monensin." Journal of Animal Science 99, Supplement_3 (October 8, 2021): 191–92. http://dx.doi.org/10.1093/jas/skab235.345.
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Abstract Performance benefits of monensin have been extensively studied in finishing and stocker cattle, but considerably less published work is available evaluating response to monensin supplementation in cow-calf production systems. Feed additives are more difficult to study in cow-calf production systems due to unstable diet characteristics and cow physiological state throughout the production cycle. This meta-analysis investigated the impacts of monensin on performance of extensively raised beef cow-calf and developing replacement heifers. The replacement heifer analysis was conducted with a maximum of 48 treatment means in 18 experiments. The mature cow analysis included 21 publications and 26 mean comparisons. The metaphor package (version 2.4-0; Viechtbauer, 2010) for R (version 4.0.3; www.r-project.org) was used to determine the overall effect size of monensin compared to a negative control. Each study’s n, means, and SEM or P-value was used to calculate the mean difference and estimate of within study variance for responses of interest. For replacement heifers, average daily gain (+0.03 ± 0.008 kg/d), feed efficiency (+0.013 ± 0.008 gain:feed), and percentage cycling before the breeding season (+15.9 ± 5.13%) were increased (P < 0.01), while dry matter intake (-4.3%) and age at puberty (-8.9 ± 1.48 d) were decreased (P < 0.01). Six studies reporting ad libitum forage intake for mature cows showed that monensin decreased (P = 0.008) DMI by 0.85 ± 0.322 kg/day. Six studies showed monesin increased (P = 0.01) milk yield 0.39 ± 0.15 kg/day by mature cows in early lactation. There were no differences in artificial insemination pregnancy nor total pregnancy for either the heifer or mature cow data sets. This analysis also indicates potential for use of monensin in beef cow production systems, but further research is needed to elucidate the effects on DMI and milk production in beef cows.
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Sinclair, K. D., J. Booth, and B. G. Lowman. "The effect of a short finishing period for weaned once-bred heifers prior to slaughter on carcass height and composition." Proceedings of the British Society of Animal Production (1972) 1989 (March 1989): 129. http://dx.doi.org/10.1017/s0308229600011193.
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Previous work carried out at Aberdeen to investigate the effect of varying the length of the suckling period post calving on heifer and calf performance has shown little difference in the carcasses of heifers slaughtered twelve weeks post calving compared to heifers slaughtered six weeks post calving (Lowman and Broadbent, 1988). These results further emphasise the nutritional demand for lactation and suggest that major improvements in carcass weight of calved heifers can only be obtained if they are weaned early or allowed an appropriate finishing period after weaning. An experiment was therefore set up to examine the effect of a short finishing period for weaned once-bred heifers prior to slaughter on carcass weight, composition and eating quality and to relate these findings to a group of non-pregnant heifers.
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Ziegler, Rob, Jacki Musgrave, T. L. Meyer, Rick N. Funston, Kathryn Hanford, James C. MacDonald, and Travis Mulliniks. "405 WS Young Scholar Talk MS I: The impact of cow size on cow-calf and post-weaning progeny performance in the Nebraska Sandhills." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 200–201. http://dx.doi.org/10.1093/jas/skaa278.370.
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Abstract Optimizing beef production system efficiency requires an understanding of genetic potential suitable for a given production environment. Therefore, the objectives of this retrospective analysis were to determine the influence of cow body weight (BW) adjusted to a common body condition score (BCS) of 5 at weaning influenced cow-calf performance and post-weaning steer and heifer progeny performance. Data were collected at the Gudmundsen Sandhills Laboratory, Whitman, NE, on crossbred, mature cows (n = 1,715) from 2005 to 2017. Cow BCS at calving, pre-breeding, and weaning were positively associated (P < 0.01) with greater cow BW. Increasing cow BW was positively associated (P < 0.01) with the percent of cows that conceived during a 45-d breeding season. For every additional 100-kg increase in cow BW, calf BW increased (P < 0.01) at birth (2.70 kg) and adjusted 205-d weaning BW (14.76 kg). Calf pre-weaning average daily gain (ADG) increased (P < 0.01) 0.06 kg/d for every additional 100-kg increase in cow BW. Heifer progeny BW increased (P < 0.01) post-weaning with every addition 100-kg increase in dam BW. Dam BW did not influence (P ≥ 0.11) heifer puberty status prior to breeding, overall pregnancy rates, or the percent of heifers calving in the first 21-d of the calving season. Steer initial feedlot BW (7.20 kg¬), reimplant BW (10.47 kg), and final BW (10.29 kg) increased (P □ 0.01) for every additional 100-kg increase in dam BW. However, steer feedlot ADG was not influenced (P > 0.67) by dam BW. Hot carcass weights of steers were increased (6.48 kg; P = 0.01) with every additional 100-kg increase in cow BW. In a hypothetical model using the regression coefficients from this study, total output (calf weaning and cull cow BW) would be 6,352 kg greater utilizing a 454 kg cowherd compared with a 554 kg cowherd. Overall, larger sized-cows within this herd and production system of the current study had increased reproductive performance and offspring BW; however, total production output and economic returns would be potentially greater when utilizing smaller-sized cows.
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Petrukhina, L. L. "Milk productivity of first-calf cows depending on the intensity of their breeding." Siberian Herald of Agricultural Science 51, no. 6 (January 4, 2022): 77–83. http://dx.doi.org/10.26898/0370-8799-2021-6-9.
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The paper presents the results of studies of milk productivity of black-and-white cows depending on the age of the first insemination and live weight at the first calving in the conditions of the Irkutsk region. The dynamics of heifer rearing by year, milk productivity of cows in the 1st and 3rd lactations depending on the intensity of their development has been studied. The experiment was conducted on farm materials from the Irkutsk Region using generally accepted zootechnical, analytical, variation and statistical research methods from 2016 to 2020. Live weight of heifers at all ages met the requirements of the elite and elite-record classes. Analysis of the data showed that the growth rate of the animals increased during 5 years (6.0%, 6.8, 2.3 and 4.8% respectively with a significant difference p ≥ 0.90). With the increased intensity of heifer rearing, an increase in milk yield over 305 days of the first lactation was observed. The highest milk production was noted in the 1st (5309-5476 kg) and 3rd (5418-5817 kg) lactations in cows with the first fruitful insemination at 13-14 months. The lowest 1st and 3rd lactation yields are obtained from cows inseminated at 20 months of age or older. Higher milk production in the first and third lactations was obtained from cows with a live weight at first calving of 541-550 kg, 551 kg and higher (5197-5164, 5436-5545 kg respectively). Less milk production was obtained from cows with a live weight at first calving of up to 500 kg (4567-5122, 4943-5009 kg). The results obtained make it possible to reveal the influence of the intensity of rearing heifers on the productive qualities of cows.
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Bennett, Gary L., Robert Cushman, Anthony K. McNeel, Eduardo Casas, and Timothy P. Smith. "PSVIII-30 Relationship of molecular breeding value for beef tenderness on heifer traits through weaning their first calf." Journal of Animal Science 97, Supplement_3 (December 2019): 266–67. http://dx.doi.org/10.1093/jas/skz258.542.
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Abstract Selection for beef carcass traits using SNP may have off-target effects on reproduction. Composite cattle (MARC III) were selected for SNP affecting beef tenderness. Selection increased minor allele frequency of a polymorphism in calpastatin (CAST) and changed frequencies of three common haplotypes in µ-calpain (CAPN1) towards 0.33 resulting in heifers of all 18 (3 CAST × 6 CAPN1) genotypes. The minor allele frequency for a diacylglycerol O-acyltransferase 1 (DGAT1) polymorphism was also increased but was not expected to affect beef tenderness. About 60 heifers were retained over 3 years (N = 187). Retention was based on representing the entire genotypic distribution. Contemporary steers from the population were harvested and measured for meat tenderness using slice shear force. Steer data were used to predict molecular breeding values (MBVSSF; 0.0 to 4.1 kg) for the heifers based on CAST and CAPN1. Traits were analyzed with linear covariates for MBVSSF and number of DGAT1 K alleles (0, 1, or 2), fixed effects appropriate for the trait, and random sire of heifer effects. A 1.0 kg increase in heifer MBVSSF was associated (P ≤ 0.05) with 5.6 ± 2.8 d earlier puberty and a 0.73 ± 0.36 kg increase in birth weight of their first calf. Pregnancy rates were not affected but would have had to exceed 5 to 6 % per kg MBVSSF to be significant. A larger experiment would be needed to detect differences that are smaller but still economically important. Regression coefficients for DGAT1 were significant for pre-calving hip height (0.78 ± 0.37 cm) and 26-mo weight (7.2 ± 3.6 kg). Within the precision of this experiment, selecting for more tender MBVSSF or for DGAT1 appears to have little negative effect on economically important traits in heifers but may increase age at puberty. USDA is an equal opportunity provider and employer.
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Baumgaertner, Friederike, Sarah R. Underdahl, Kacie L. McCarthy, Ana Clara B. Menezes, Wellison Jarles da Silva Diniz, Alison K. Ward, Kevin K. Sedivec, et al. "187 Effects of energy supplementation during early gestation in beef heifers on body weight, concentrations of IGF-1, and calf characteristics." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 163–64. http://dx.doi.org/10.1093/jas/skaa278.299.
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Abstract Objectives were to evaluate effects of early gestation energy supplementation on heifer body weight (BW), IGF-1 concentrations, and calf characteristics. One-hundred Angus-based heifers (initial BW = 371.1 ± 3.9 kg) were estrous synchronized, bred to female-sexed semen, then randomly assigned to either a basal diet to achieve 0.20 kg/d (CON, n = 50) or a basal diet plus supplemental energy to achieve 0.75 kg/d gain (SUPP, n = 50) for 84 d. The CON diet consisted of 37% corn silage, 53% prairie hay, and 10% distillers dried grain with solubles (DDGS). The SUPP diet was 29% corn silage, 41% prairie hay, 5% DDGS, and 25% corn/PurinaAccuration Range Supplement 33 blend. Heifers were individually fed via Insentec feeders (Insentec Marknesse, The Netherlands), with bi-weekly feed delivery adjustments to achieve targeted gains. After d 84, heifers were managed as a single group on pasture, then in a dry lot until parturition. A total of 46 heifers gestated female pregnancies to term (n = 23 CON and n = 23 SUPP). Body weights and blood samples were collected on d 0, 42, 84, 162, 234, 262, and at parturition. By design, SUPP heifers were 55.4 kg heavier (P < 0.0001) than CON at d 84. Weight divergence remained throughout gestation, with SUPP heifers being 41.5 kg heavier at parturition (P < 0.0001). For SUPP, IGF-1 concentrations were greater throughout gestation (P = 0.003). Fetal size, as measured by ultrasound, was not affected by treatment at d 42 (P = 0.50), 63 (P = 0.35), or 84 (P = 0.20); however, calves from SUPP dams were 2.1 kg heavier (P = 0.03) and had larger chest circumference (P = 0.05) at birth compared with CON. Early gestation nutrition impacted heifer BW and IGF-1 concentrations throughout gestation, and clearly impacted in utero fetal growth.
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Fernandez, Rachel, Kasey A. Elder, John F. Odhiambo, Kiana Green, Rachel Dunn, and Derrick Coble. "81 Effects of Hurricane-Related Stress During Gestation on Replacement Heifer (Bos Taurus) Development in a Limited-Resource Beef cow-Calf System." Journal of Animal Science 100, Supplement_3 (September 21, 2022): 38–39. http://dx.doi.org/10.1093/jas/skac247.075.
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Abstract In a limited resource cow-calf operation, obtaining puberty in heifers is one of the main concerns for long-term productivity. Although nutritional factors have a large role in heifer development, environmental factors are sometimes overlooked until a catastrophic event such as a hurricane occurs. For this project, two heifer groups, born in the same herd at different intervals, were compared: Group 1(experienced catastrophic hurricane event in 3rd trimester of their fetal development) and Group 2 (no adverse event during gestation). The groups were weighed four similar time points during development: at 12 months of age (Period 1, pre-pubertal), 13-14 months (Period 2, puberty), pre-breeding (Period 3), and at the end of breeding (Period 4). The blood cortisol, glucose, and progesterone concentrations were compared between the groups during their pre-pubertal period. Group comparisons were performed using mixed procedures of SAS. Data are presented as means ±SEM. Group mean differences were declared significant at P < 0.05. We observed a significant (P < 0.01) Group by Period effect on heifer body weight (655.2± 14.2 vs. 747.3 ±15.4, for Groups 1 and 2, respectively). Overall, Group 1 was lighter than Group 2 in periods 1 and 2, but there was no difference thereafter. There were significant group differences in glucose (60.5± 8.8 vs 95.3±11.5, mg/dL for groups 1 and 2 respectively, P< 0.01) and progesterone (62.2±12.6 vs 124.0± 13.8, pg./mL for groups 1 and 2, respectively, P< 0.01). However, there was no significant difference in cortisol concentrations (P< 0.48). Therefore, catastrophic weather events such as hurricanes that are common throughout the world might have a negative impact on heifer development, as observed in this project. This observation warrants further investigation. Funding agency: USDA- NIFA CBG #2021-38821-34599
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Galeotti, M., S. Belluzzi, D. Volpatti, M. L. Bergonzoni, E. D'Agaro, and L. A. Volpelli. "Evaluation of mast cells in calf and heifer uteri." Theriogenology 48, no. 8 (December 1997): 1301–11. http://dx.doi.org/10.1016/s0093-691x(97)00372-5.
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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.