Academic literature on the topic 'Heifer calf'

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.

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.

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.

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

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.

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.

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.

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.

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.

Pregnancy loss and calf death can cost dairy producers more than $230 million annually. While methods involving nutrition, climate, and health management to mitigate pregnancy loss and calf death have been developed, one potential influence that has not been well examined is the reproductive microbiome. I hypothesized that the microbiome of the reproductive tract would influence heifer fertility and calf gut microbial development. The objectives of this dissertation were: 1) to examine differences in phenotypes related to reproductive physiology in virgin Holstein heifers based on outcome of first insemination, 2) to characterize the uterine microbiome of virgin Holstein heifers before insemination and examine associations between uterine microbial composition and fertility related phenotypes, insemination outcome, and season of breeding, and 3) to characterize the various maternal and calf fecal microbiomes and predicted metagenomes during peri-partum and post-partum periods and examine the influence of the maternal microbiome on calf gut development during the pre-weaning phase. In the first experiment, virgin Holstein heifers (n = 52) were enrolled over 12 periods, on period per month. On -3 d before insemination, heifers were weighed and the uterus was flushed. Flush pH and glucose concentration were measured. Blood was collected from coccygeal vessels on d -3, 15, 18, 21, 24, 27, and 30 relative to insemination and serum progesterone concentration was measured. Ultrasound measurements of dominant follicle diameter and corpus luteum volume. Insemination outcome was determined on d 30 using ultrasound and pregnancy was checked on d 42, 56, 70, and 84. Heifers were clustered based on outcome of insemination at d 30 (not pregnant, NP30, n = 24; pregnant, PS30, n = 28), d 84 (not pregnant, NP84, n = 24; pregnant but lost before d 84, PL84, n = 2; successfully pregnant through d 84, PS84, n = 26). Differences in phenotypes were assessed based on insemination outcome at d 30 and d 84. Weight was greater in NP30 heifer than PS30 heifers. Progesterone was greater in PS30 and PS84 heifers than NP30 or NP84 heifers on d -3 and 18 to 30 and CL volume was greater in PS30 and PS84 heifers than NP30 and NP84 heifers on d 21 and 30. To summarize, traits related to pregnancy maintenance were different in virgin Holstein heifers based on first insemination outcomes and might be able to be used to predict heifer reproductive performance. Uterine flushes were examined in a subset of heifers (n = 28) based on insemination outcome and period. This subset was also clustered based on season (spring, n = 3; summer, n = 12; fall, n = 8; winter, n = 5). From this subset of heifers, DNA was extracted from uterine flush and 16S amplicons of the V4 region underwent 250 paired-end sequencing via Illumina NovaSeq 6000. Filtered reads were clustered into operational taxonomic units using a 97% similarity and assigned taxonomy using the SSURNA Silva reference version 132. Alpha and beta diversity were measured and differences in alpha and beta diversity measurements were analyzed based on insemination outcome at d 30 or d 84 and season of breeding. Differential abundance analyses were performed at the phylum and genus taxonomic ranks based on insemination outcome at d 30 or d 84 and season of breeding. Bacterial richness was reduced in PL84 heifers than NP84 and PS84 heifers and reduced in heifers bred in spring than those bred in other seasons. Bacterial community structure was different based on insemination outcome at d 30 and d 84 using unweighted Unifrac distances and was different based on season of breeding using weighted Unifrac distances. We observed an increase of Bacteroidetes in PS30 and PS84 heifers compared to NP30 and NP84 heifers. Ureaplasma and Ruminococcus had an increased abundance in PS30 and PS84 heifers than NP30 and NP84 heifers, while Afipia and Gardnerella had an increased abundance in NP30 and NP84 heifers than PS30 and PS84 heifers. Prevotella and Ruminococcus had a reduced abundance in summer bred heifers than winter bred heifers. Proteobacteria had a moderate negative correlation with -3 d progesterone (rp = -0.42) and Actinobacteria had a moderate negative correlation with fetal growth rate (rp = -0.66). Uterine microbiome of virgin Holstein heifers differed based on insemination outcomes and season of breeding and might be a new phenotype to indicate heifer fertility. In the second experiment, multiparous Holstein cows (n = 12) were placed in individual box stalls 14 d before expected calving. Sterile swabs were used to collect samples from the posterior vagina of the dam approximately 24 h before calving, dam feces, dam oral cavity, and colostrum within 1 h after calving, and cotyledonary placenta within 6 h after calving. Calves (n = 12; bulls = 8, heifers = 4) were isolated immediately after parturition to prevent environmental contamination. Colostrum was fed to calves using a clean bottle that was assigned to the calf for the duration of the study. Calves were individually housed for 60 d until weaning. Sterile swabs were used to collect calf fecal samples at birth, 24 h, 7 d, 42 d, and 60 d of age. A subset of calf-dam pairs (n = 6; bulls = 3, heifers = 3) were selected and DNA was extracted from all samples. Amplicons covering V4-V5 16S rDNA regions were generated using extracted DNA and sequenced using 300 bp paired end sequencing via Illumina MiSeq. Sequences were aligned into operational taxonomic units using the 97% Greengenes reference database. Spearman correlations were performed between maternal and calf fecal microbiomes. Negative binomial regression models were created for genera in calf fecal samples at each time point using genera in maternal microbiomes. Metagenomes were predicted, collapsed into gene pathways and differences in predicted metagenomes were analyzed within STAMP (Statistical Analysis of Metagenomic Profiles). We determined that Bacteroidetes dominated the calf fecal microbiome at all time points (relative abundance ≥ 42.55%) except for 24 h post-calving, where Proteobacteria were the dominant phylum (relative abundance = 85.10%). Colostrum and placenta had low diversity within samples and clustered independently from fecal samples. Each maternal microbiome was a significant predictor for calf fecal microbiome during at least 2 time points. Genes for infectious disease and neurodegenerative disease were greater in colostrum and 24 h calf fecal samples compared to other samples. Results indicated that no one maternal microbiome was a major influence on calf fecal microbiome inoculation and development. Instead, calf fecal microbial development stems from various maternal microbial sources. Overall, the reproductive microbiome was predictive of heifer pregnancy outcomes and calf fecal microbial development. The virgin heifer uterine microbiome could be used to predict fertility and adaptation to heat stress, but further research including a larger group of pregnancy loss is needed. Maternal microbiomes from the reproductive tract, colostrum, oral cavity, and feces could all be used to predict calf microbial development, but more research including other maternal microbiomes and environmental microbial contributions is needed. However, the results from this dissertation indicate reproductive microbiome composition is a trait that might be predictive of dairy cattle performance.
Doctor of Philosophy
The ability of a cow to become pregnant and a calf to thrive after birth are crucial to successful dairy farm operations. Recent evidence in humans has shown bacteria in the reproductive tract can influence maternal fertility and the bacterial community of newborns, an indicator of early health. This same relationship might exist in dairy cattle. I propose that specific traits related to fertility and the bacterial community in the reproductive tract of dairy cattle influences their ability to become pregnant and influences the bacterial community developing in calves after their birth. In my first experiment, I collected samples of uterine fluid from cattle that had never been pregnant before the first time they would be bred. I also collected blood samples before and after breeding to measure hormone levels as well as measurements of portions of reproductive tract using an ultrasound. Using a specific portion of DNA that is similar across all bacteria, I identified the bacterial community in the collected uterine fluid. Cattle were grouped based on breeding outcome (not pregnant, pregnant but lost, or kept pregnancy) and season of breeding. Differences in various traits and bacterial communities were examined based on breeding outcome and season. I found that traits like hormone levels in the blood and size of structures on the reproductive tract, and uterine bacterial community all differed based on breeding outcome. We also found that uterine bacterial community also differed based on season of breeding. These results could be used to predict if a cow will become pregnant before they are ever bred, but more research is needed. In our second experiment, we collected samples from the reproductive tract, milk, mouth, and feces of cows immediately after they gave birth. We then collected samples from their calves right at birth as well as at various time points during their early life. Using the same section of DNA used during the first experiment, we identified the bacterial community composition from the various maternal and calf samples. We then identified correlations between maternal and calf bacteria and used a mathematical model to see if the maternal bacteria could predict bacteria in the calf. We found that the various maternal bacteria could predict calf bacteria throughout the calves early life. While an experiment using a larger group of cows and calves is needed, our results indicate that the maternal bacteria could be used to predict calf bacteria and may help determine which calves are more likely to become sick than others. Overall, we found that the bacteria in the reproductive tract could be used to predict ability to become pregnant and calf bacterial development. The incorporation of this bacterial community as a trait on farms could help reduce pregnancy loss and calf illness, but further research examining how the bacteria interact with the animal is needed.

The variability in calf management can change the physiological state of the calf as they are weaned or attain puberty. It is up to the producer to ensure that the calves develop properly to meet their expected needs on the farm. While there are guidelines from the NRC in place, there is a substantial range in the amount of protein and fat that a calf can be fed. This physiological state can be reflected in the proteins produced in tissues, the expression of gene regulatory pathways, or even the microbes present in the gut. The purpose of this study was to examine how an increase in dietary energy in milk replacer of pre-weaned Holstein heifers impacts the microbial profile of the rumen as well as the transcriptome in tissues related to growth and metabolism. Our hypothesis was that pre-weaned Holstein heifers on milk replacer diets with lower dietary energy will have a different rumen microbiome composition and a different transcriptome in growth related tissues. Holstein heifer calves (n = 36) were assigned randomly to 1 of 2 milk replacer diets: restricted (R; 20.9% CP, 19.8% Fat; n = 18) or enhanced (E; 28.9% CP, 26.2% Fat; n = 18). Calves were euthanized and rumen fluid was collected at pre-weaning (8 wks; n = 6) or post-weaning (10 wks; n = 6). Liver (L), adipose (A), and longissimus dorsi (LD) tissues were collected at pre-weaning (8 wks; n = 12). Average daily gain (ADG) and gain-to-feed ratio (G:F) were calculated for each calf. Analysis of ADG and G:F was performed using a PROC GLM in SAS with diet as the main effect; E calves had increased ADG and G:F compared to R calves. For rumen samples, libraries were constructed from extracted DNA and DNASeq was conducted using a paired-end analysis at 100 bp using Illumina HiSeq 2500. Operational taxonomic unit (OTU) clustering analysis was conducted using the 16s rRNA Greengenes reference. A PERMANOVA analysis was conducted in R to determine OTU populations for age and treatment. There was no difference in microbiome composition between pre-weaning and post-weaning calves (P = 0.761). Microbiome composition differed between E and R calves (P < 0.001). Bacteroidetes and Firmicutes represented the most abundant phyla for both E and R calves. Enhanced calves had 49.4% (5141 reads) Bacteriodetes and 36.4% (3789 reads) Firmicutes; whereas, R calves had 31.6% (2491 reads) Bacteriodetes and 41.1% (3236 reads) Firmicutes. For L, A, and LD samples, libraries were constructed from extracted RNA for RNA-Seq analyses. RNA-Seq analysis was performed using CLC Genomics Workbench and the Robinson and Smith Exact Test was used to identify differentially expressed genes between diets. There were 238 differentially expressed genes in A, 227 in LD, and 40 in L. Of the differentially expressed genes, 10 appeared in at least 2 tissues. PANTHER was used to identify functional categories of differentially expressed genes. The majority of genes were associated with metabolic processes (A = 112, 26.7%; L = 16, 32.0%; LD = 81, 34.0%) or cellular processes (A = 93, 22.1%; L = 13, 26.0%; LD = 73, 30.7%). In E calves, upregulated genes included those regulating NADH dehydrogenation (LD = 17, A = 5; i.e. ND1, ND4), gluconeogenesis (LD = 2, A = 6; i.e. ALDOB, PCK2), and cell proliferation (LD = 2, A = 3; i.e. GADD45A, CDKN1A). There was a difference in both the transcriptome and rumen microbiome of calves fed differing levels of dietary energy. The calves on the R diet had a rumen microbial composition more similar to a younger calf, while the composition of E calves was more similar to a mature calf. The change in regulation of genes involved in the cell cycle and ATP synthesis in response to dietary energy could explain the change in ADG between diets. Because the R calves appeared to have stunted development of their microbiomes and an expression profile similar to oxidative stress, it is possible that the R diet did not meet the nutritional requirements of that calves.
Master of Science

Forty four first-calf heifers were randomly selected to determine lactational and metabolic responses to high fat diets and isoacids. All heifers were allowed ad libitum consumption of a control diet for the first 2 weeks of lactation and then offered experimental diets Eor the next 4 weeks. Each 6 cows of twenty four were randomly assigned to 1) a control diet (C) with 35.2% corn silage, 14.4% alfalfa haylage and 50.4% concentrate (dry matter basis), 2) C with 2% calcium stearate (S) substituted for corn grain, 3) C with 2% tallow (T) for corn grain, and 4) C with 10% whole cottonseed (W) for corn grain, cottonseed meal and cottonseed hulls. The remaining 20 heifers were randomly assigned to diets C, S, T, and W, each with 4g/kg isoacids added (CI, SI, TI, and WI). Fat supplementation or isoacid addition did not affect milk production. Addition cf isoacid increased milk fat percentage, 4% fat-corrected milk, milk fat production (kg/day) and dry matter intake. Differences due tc isoacid were greatest when added to W. Increased milk lactose percentage and weight gain were evident in animal receiving WI compared to W ration. Fat supplementation depressed percentages cf milk fat, milk lactose and milk solids-not-fat. Milk protein percentage and somatic cell count were not affected by treatments. Plasma glucose,and glucose and epinephrine challenge parameters were not affected by diet. Peak plasma non-esterified fatty acid response to epinephrine injection, detected at 10 to 12 minites, was similar for C, S, T, and W. Concentrations of individual volatile fatty acids (VFA) and total VFA in rumen fluid were increased by fat supplements. Isoacid addition increased the amounts of isobutyrate and isovalerate; however, acetate and total VFA concentrations were decreased compared to CI when isoacids were added to high fat diets. The ratio of acetate to propionate was similar for all diets. Digestibilities cf dry matter, crude protein, and acid detergent fiber were not influenced by diet. The efficiency of energy utilization was highest for control diet. In conclusion, lactational, metabolic, and physiological responses to S, CI, and WI were favorable. Responses to W were lowest.
M.S.

Replacement heifer rearing is critical for the future of the dairy operation, especially to improve genetic merit and maintain herd size. A replacement heifer from the day she is born to the day she calves herself is generally a 2-year investment without potential income. A myriad of options exists on how to manage, fed, and ultimately raise replacement heifers. This study quantifies the costs associated with replacement heifer management decisions from birth to calving related to housing, labor, feed and health. The heifer rearing period can be broken into pre and post weaning sections to allow for more understanding the variation of these different biological time periods. Variation can influence the investment per day and breakdown of resources required from a dairy producer. Total heifer raising cost varied broadly across all management scenarios in our study, with feed and labor consistently representing over 60% of the total cost. After determining the true cost on an individual farm, or providing developed assumed cost for a change in management, producers can better manage current expenses and be more prepared for future investment.

Neonatal nutrition may influence performance in later life in many species; however, there have been a few studies of this phenomenon in cattle. Determining if there are direct and residual effects of nutrition during the first 60 days of life may help optimise lifetime productivity. Underfeeding reduces calf weaning weight and delays puberty, which reduces the potential lifetime productivity of the dairy heifers. As well as repercussions on calf health, growth and welfare; many studies in human suggest that underfeeding of the newborn is a major risk factor for metabolic diseases in the adult. The aims of this study were to investigate the performances of Holstein heifers that were fed increased milk replacer compared to restricted volumes during their early life and to determine the impact of this on key performance indicators of these animals as future potential the best cows in the herd. Thus, a total of eighty eight heifers were included in this study, which forty seven heifers were in Group A (ad libitum milk replacer fed group) and forty one heifers were in Group R (restricted milk replacer fed group). They were enrolled 8 weeks prior to predicted calving based on artificial insemination dates of pregnancies confirmed by per rectum ultrasound examination of the uterus and 282 days of gestation period. The body weight, body condition score, withers and loin height, heart and belly girth, crown to rump length and hock fetlock length were recorded from 8 weeks prior to predicted calving until 30 weeks of postpartum. Blood samples were collected for β-hydroxybutyrate (BHB) concentration measurements and milk samples were collected for pregnane profiles analysis. Data on physical measurements (heifers and calves), pregnane profiles, reproductive parameters, BHB concentration values, health parameters, milk yield and milk components were analysed. The MilkBot parameters were used to describe the lactation curve between the 2 groups. There was no large effect of different pre-weaning feeding strategies during early life of heifers on their growth, fertility, health, milk yield and day old calf performances between Group A and Group R during first lactation period. There were no differences in MilkBot parameters; estimated scale, decay, persistence, peak milk and peak day between the 2 groups. However, several significant findings were observed; heifers in Group A had higher milk protein percentage and higher in somatic cell counts (SCC). Meanwhile, heifers in Group R had higher number of delayed ovulation type 1 (DOV1) profile, higher incidence of subclinical ketosis (SCK) and higher in estimated ramp. Another finding was heifers produced more milk following birth of a bull calf regardless of groups.

Effects of weaning on metabolic profiles and hepatic IGF-1 mRNA of beef dams (Trial 1), and diet effects for early-weaned (EW) steers on response to an infectious bovine herpesvirus-1 (BHV-1) challenge (Trial 2) were investigated. Trial 1 treatments were arranged in a 2 x 2 factorial and included 14 heifers and 14 cows assigned randomly to one of two treatment regimens: EW (average age of 114 ± 13 d) or normal-weaned (NW, average age of 197 d). Heifers with calves EW experienced a greater increase (parity x weaning; P = 0.02) in BW over heifers with calves NW, but no change in BW due to weaning was observed for cows (P > 0.71). Early weaning (vs. NW) increased (P < 0.05) body condition (BC) and change in BC of all dams. No parity x weaning or parity x weaning x d interactions (P > 0.14) were observed for serum IGF-1, NEFA, or urea nitrogen (SUN). A parity x d interaction (P < 0.05) for hepatic IGF-1 mRNA, serum IGF-1, and SUN was observed, but no differences (P > 0.10) were detected between heifers and cows within d. For Trial 2, backgrounding treatments included a bermudagrass hay diet (CTRL); bermudagrass hay plus soybean meal (SBM) fed at 0.175% of BW (as-fed); bermudagrass hay plus SBM at 0.35% of BW; or a 70% concentrate (CONC) diet. During the receiving phase, all steers were fed CONC and intranasally challenged with BHV-1. Treatment x d interactions (P < 0.01) were observed for serum NEFA, total protein, SUN, glucose, immunoglobulin G (IgG), insulin, and rectal temperature. Three d after the BHV-1 challenge, IgG was greater (P < 0.05) for forage-fed steers vs. CONC. Three and 4 d after the challenge, rectal temperature was greater (P < 0.01) for protein supplemented steers vs. CTRL. Therefore, EW can increase BW and BC of first-calf heifers and decrease SUN in first-calf heifers and mature cows, and a higher quality diet fed to EW steers during a backgrounding phase enhances ADG and G:F, and increases febrile response (measured by rectal temperature) to an infectious BHV-1 respiratory challenge.

Stuart Heisler est un réalisateur américain travaillant dans le contexte des grands studios reposant sur une division en genres et sur des acteurs constituant des modèles pour les spectateurs et servant à attirer les foules dans la période allant des années 1930 aux années 1960. L’esthétique propre des films de Stuart Heisler sera étudiée dans ses détails à travers l’analyse filmique, dans une approche stylistique de la carrière du cinéaste, mais aussi en rapport avec la signification globale des films en rapport avec leur narration, le jeu de leurs acteurs et leur utilisation des décors. Les rapports entre cette esthétique et le mode de production des films peuvent être considérés comme la conséquence directe des modes de fabrication de la production hollywoodienne. Alors, comment caractériser ces évolutions conjointes ? Elles concernent à la fois le cinéaste et son contexte de production à travers le temps dans une perspective historiographique. L’étude combinera ainsi une approche stylistique et une approche historiographique de la carrière de Stuart Heisler. Caractériser ces évolutions permettra de comprendre les différentes facettes de la pratique du réalisateur, sa manière de création cinématographique pour chaque film, et enfin de faire le portrait artistique du réalisateur à travers sa pratique à l’intérieur du système de production dans lequel il s’inscrit. L’étude permettra de brosser le portrait artistique de Stuart Heisler à partir de son insertion dans plusieurs contextes de production correspondant à l’évolution conjointe de la carrière du cinéaste et des structures de production. Il s’agira de définir les formes et les modalités de la coalescence esthétique particulière du style du réalisateur, partant de sa situation de monteur durant les années 1920 et 1930 lors de ses débuts de carrière avant la réalisation à proprement dit. L’influence de ses collaborateurs sur Stuart Heisler sera étudiée avant le passage du réalisateur à la réalisation en 1936. Ce dernier va vers plus d’indépendance en 1944 et 1945 alors que sa volonté personnelle reste encadrée par la production. Stuart Heisler va vers la situation d’un réalisateur développant un style particulier durant les années 1940 et 1950 autour de la figure filmique. La figure centrale de l’incendie repose sur le pro-filmique détruit. La figure de l’incendie est également en rapport avec l’éclatement, puis se retrouve lors la réalisation de télévision durant les années 1950 et 1960. Le réalisateur se tourne vers la réalisation de télévision dans les années 1950-1960. La familiarité du cinéaste avec son travail se retrouve dans la série télévisée. Le travail étudiera finalement les influences suscitées par le style de Stuart Heisler
Stuart Heisler is an American director working in the context of major studios based on a division into genres and on actors constituting models for spectators and used to attract crowds in the period from the 1930s to the 1960s. Films by Stuart Heisler will be studied in detail through film analysis, in a stylistic approach of the filmmaker’s career, but also in relation to the global meaning of the films in relation to their narrative, the acting and their use of sets. The relationship between this aesthetic and the films’ modes of production of the can be considered as a direct consequence of Hollywood’s modes of production. So, how to characterize these joint evolutions? They concern both the filmmaker and his production context through time in a historiographical perspective. The study will combine a stylistic and a historiographic approach of Stuart Heisler’s career. Characterizing these evolutions will make it possible to understand the different facets of the director's practice, his manner of cinematographic creation for each film, and finally to make the artistic portrait of the director through his practice within the production system in which he is working. The study will paint the artistic portrait of Stuart Heisler through his insertion in several contexts of production corresponding to the joint evolution of the filmmaker’s career and his production structures. It will define the forms and the modalities of the particular aesthetic coalescence of the director's style, starting from his position as editor during the 1920’s and 1930’s during his career beginnings before the actual directing. The influence of the different collaborators have on Stuart Heisler will be studied before the passage from editing to directing in 1936. Heisler goes towards more independence in 1944 and 1945 whereas his personal will remains framed by the production. Stuart Heisler goes to the situation of a director developing a particular style during the 1940s and 1950s centered around the filmic figure. The central figure of the fire is founded on the destruction of the pro-filmic. The figure of the fire is also related to the figure of bursting and is visible for television production during the 1950s and 1960s. The director is turning towards television in the 1950’s and 1960’s. The filmmaker's familiarity with his work is reflected in the television series. The work will finally study the works inspired by Stuart Heisler's style

The objectives of this thesis were to investigate 1) the use of behavior and activity monitoring for the identification of heifers at risk of disease, 2) the use of group level management practices to reduce the risk of disease, and 3) the identification of long-term impacts of bovine respiratory disease complex (BRD). For objective 1, lying posture, a decreased willingness to approach an observer and high lethargy scores were associated with diarrhea in calves under 2 weeks of age and a high lethargy score in 4-6 week old calves was associated with decreased average daily gain (ADG) in the first 8 weeks of life (n = 744). In weaned calves (n = 74) increased activity (increase in steps and decrease in lying), standing at the bunk not eating, and lying far from other calves in the first 3 days post-weaning were associated with decreased post-weaning weight gain. For objective 2, separating social mixing from movement to a novel environment, and administering prophylactic antibiotics to calves at high risk of disease, were investigated. Both mixing and movement to a novel environment increased activity levels in newly weaned dairy calves (n = 64). When calves were mixed prior to movement to a novel environment they had a smaller increase in activity compared to calves that were simultaneously mixed and moved. No differences in weight gain or calf starter intake were observed. Administration of a prophylactic antibiotic, tulathromycin, to 3 day old calves upon arrival at a heifer raising facility (n = 788) and 8 week old calves at first movement to group housing (n = 1,392 ) was found to reduce diarrhea and otitis media, and BRD, respectively. Objective 3 was addressed by monitoring calves that received tulathromycin at 8 weeks of age to determine the long-term impacts of BRD. Bovine Respiratory Disease complex was associated with decreased growth to 9 months of age, decreased survival to first calving, increased risk of dystocia and a greater age at first calving.
Natural Sciences and Engineering Research Council of Canada & Pfizer Animal Health

Management factors affecting dairy calves have broad impacts on behavioral development and implications for long-term welfare, and research in this area is increasingly focused on understanding the behavioral needs of the calf, to refine management and improve understanding of welfare. In this chapter, we summarize recent research addressing behavioral needs of pre-weaned calves and post-weaned heifers, encompassing aspects of social interactions and feeding, rest and comfort, and opportunities for other behavioral expression. In general, evidence suggests welfare and performance benefits of accommodating more natural behavioral expression, including social contact, higher milk intakes fed via a teat, dietary variety, and space and resources to accommodate preferred activities, such as grooming and play. Throughout these sections, consequences of restricting these behaviors includes development of abnormal oral behaviors. Emerging themes of this area of research include consideration of individual differences and implications and approaches to accommodate broader behavioral expression through increasing environmental complexity.

This chapter begins with a discussion of Kant, who led an almost abstract life of a confirmed bachelor. Heine links Kant's bachelorhood with his remote quarters, depicted as leading what we might call a “peaceful” (friedlich) life apart from the world, that is, one set within a “border fence”—an Umfriedigung or Einfriedigung, which are precisely the terms that the Grimms' Dictionary list as synonyms of Hag. The remainder of the chapter deals with Heinrich von Kleist's story “The Earthquake in Chile” (1807) and Johann Gottlieb Fichte, the erstwhile supporter of republican ideals and reputed Jacobin who felt compelled to instigate the latent power of the Prussian monarch.

This chapter details the first phase of Henry III's personal rule, between 1234 and 1241, which was the most successful period of his reign. He adopted Edward the Confessor as his patron saint and thereafter drew strength from the Confessor's support. He at last found a bride for himself in Eleanor of Provence, and soon had a son and heir named Edward, after the Confessor. He also gained loyal and clever councillors and an entirely new profile in international affairs. Henry made a statesmanlike settlement with the king of Scots, exploited the resources of Ireland without ever having to go there, gained the county of Chester for the crown and, after the death of Llywelyn, reasserted royal authority in Wales. He appears both as a legislator, concerned with the welfare of his realm, and as a reformer, reordering the finances of the crown. His accommodation with the political community was shown in the concession of a tax by parliament in return for his confirmation of Magna Carta. The relative calm of this period was helped by a long truce with France.

This chapter examines the closely fought elections of 2010 and 2015, the first of which produced the first British coalition government since 1945 in a period which saw the continued fragmentation of the party system and the rise of United Kingdom Independence Party (UKIP) and the Scottish National Party (SNP).Gordon Brown succeeded Tony Blair as Prime Minister in 2007, and initially impressions were favourable. However, almost as soon as Brown had decided against a ‘snap’ election to exploit his popularity, events turned against him and his party. The worldwide global financial crisis, which began in 2007, hit Britain particularly hard, and like Major’s Conservatives in the previous decade New Labour lost its reputation for economic competence. The Conservatives, under David Cameron who proclaimed himself ‘the heir to Blair’, won the largest number of seats in the 2010 election, which was particularly noteworthy for the introduction of televised leader debates. However, the 2010 contest resulted in a ‘hung parliament’ and a coalition between the Conservatives and the Liberal Democrats. The key events of the ensuing five years are examined, including the introduction of a Fixed-Term Parliaments Act which purportedly deprived Prime Ministers of the right to call elections at times of their own choosing. There were also referendums of Electoral Reform (2011) and Scottish independence (2014), in which the status quo was upheld without seeming to put an end to either question. In particular, the SNP continued to prosper despite the 2014 result, and in the 2015 general election it won almost all of the Scottish parliamentary seats. In England, UKIP had become a very serious threat both to Labour and the Conservatives, who had imposed unpopular cuts in public expenditure (‘austerity’) in response to the financial crisis. Meanwhile, the Liberal Democrats had lost much of their electoral appeal during their ill-fated alliance with Cameron’s Conservatives. The overall result of the 2015 election was an overall victory for the Conservatives, but by a margin which left Cameron vulnerable to Eurosceptics within his party.