Parity Of Dam Research Articles

Does Exposure to Summer Season at Different Stages of Intrauterine Development and Maternal Parity Affect Health and First-Lactation Milk Production of Female Offspring of Holstein Cows?

A suboptimal intrauterine environment during gestation may result in the programming of long-lasting structural and physiological alterations in the developing fetus, leading to health and production complications in adulthood. This observational study aimed to identify the impact of exposure to the summer season at different trimesters of gestation, dam parity, and their interaction on the postpartum disease incidence, first-lactation milk production, and herd lifespan of the offspring (F1 generation). Using a dataset collected from two commercial herds, the female offspring were categorized into three groups based on the trimester their dams experienced summer season during pregnancy: (1) first trimester (n = 2345), (2) second trimester (n = 3513), and (3) final trimester (n = 4988). The estimated 305-day milk production was lower in daughters (as a first-lactation cow) born to dams exposed to summer season during the first vs. third trimester. Summer season exposure during the first vs. third trimester resulted in the offspring that were less likely to remain in the herd (hazard ratio = 0.90; 95% CI = 0.84-0.95). Daughters of parous vs. nulliparous dams were more likely to experience dystocia and metritis but less likely to experience retained placenta. The risk of culling was higher in daughters of parous vs. nulliparous dams. Our preliminary findings suggest that the first trimester is a critical determinant of the female progeny's future productive performance and survivability. Dam parity was also identified as an influential factor affecting offspring health, as dystocia and metritis were more prevalent, and the culling risk was greater in daughters born to parous dams.

PSVII-14 Influence of dam parity and weaning strategy in previous lactation on feedlot performance of Nellore steers

Abstract In tropical beef cattle production systems, the impact of seasonality may be particularly challenging for young cows (primiparous or secondiparous) due to their increased nutritional requirements, encompassing maintenance, growth, gestation, and, in the case of secondiparous cows, lactation. Literature indicates that extending the duration of lactation during gestation is associated with decreased performance of progeny in their postnatal life. Therefore, implementing an early weaning approach can be an effective strategy to alleviate the nutritional demands of lactation in dams, thereby allocating more nutrients for fetal growth. This study aimed to evaluate the effect of early weaning on the feedlot performance of progeny that were in utero at the time of weaning intervention. To create experimental units, secondiparous and multiparous Nellore cows were assigned to one of two weaning strategies, where suckling calves were either; 1) early weaned 150 d (EW); or 2) conventional weaned at 240 d (CW). All calves were weaned at 150 d of lactation in 2022. Three bulls were used: Bull 1: had 13 calves with multiparous cows, had 7 calves with secondiparous cows, comprising 11 EW and 9 CW; Bull 2: had 10 calves with multiparous cows, had 6 calves with secondiparous cows, comprising 6 EW and 10 CW; and Bull 3: had 7 calves with multiparous cows, had 15 calves with secondiparous cows, comprising 11 EW and 11 CW. All cows were managed similarly after weaning, and through parturition, and weaning of subsequent calf, with resulting calves used for the current experiment. Nellore bulls (n = 57) with an initial body weight (BW) of 417.23 ± 9.12 kg and 18 mo of age were allocated to feedlot pens (equipped with Intergado equipment) and fed a common total mixed ration (80:20; concentrate:corn silage) for 97 ± 1.60 d. Bulls were distributed in a randomized complete block in a 2 × 2 factorial arrangement, considering dam weaning strategy in the previous lactation (EW and CW) and dam parity at subsequent calving (multiparous or secondiparous cows, MC and SC, respectively). Data were analyzed using PROC MIXED of SAS 9.4, with a model including the effects of dam weaning strategy, dam parity, and their interaction. Data were considered significant when P values were less than 0.05 and indicated a trend when 0.05 < P ≤ 0.10. There was an interaction between weaning strategy and cow parity, with calves born to SC-CW having reduced initial (P = 0.04) and final BW (P = 0.01) compared with all other groups (Figure 1 and 2). Steers from MC had greater dry matter intake (P = 0.003), and greater biological efficiency (P = 0.03; Table 1). Early weaning improved the final BW of steers born to secondiparous cows, suggesting it could be a strategy to enhance the performance of offspring and the reproductive performance of both secondiparous and multiparous cows.

Genetic Analysis of Calf Survivability in Gir Crossbreds

Data of Gir crossbred calves, maintained at Research cum Development Project on Cattle, Mahatma Phule Krishi Vidyapeeth, Rahuri, for a period from 2005 to 2019 was collected to study effect of genetic and non-genetic factors on survivability traits of calf. The traits studied were cumulative survivability within 0 to 15 days, 0 to 30 days, 0 to 90 days, 0 to 180 days and 0 to 365 days. The least square means of cumulative survivability per cent of Gir crossbred calves at 0 to 15, 0 to 30, 0 to 90, 0 to 180 and 0 to 365 days were 83.27±2.16, 75.40±2.57, 62.29±2.99, 53.96±3.16 and 52.16±3.17, respectively. The period of birth had significant (P<0.05) effect on cumulative survivability trait at ages viz., D 0-30, D 0-90, D 0- 180 and D 0-365. Parity of dam and season of birth had non-significant effect on cumulative calf survivability traits. Significant (P<0.05) effect of calves’ sex on survivability traits was recorded at 0- 15, 0-30, 0-90, 0-180 and 0-365 days. Birth weight of calf had significant (P<0.01) effect on cumulative calf survivability at 0-15 and 0-30 days after birth. The paternal half sib method was use to estimate heritability for cumulative survivability traits the values were low in magnitude, ranged from 0.06 to 0.113. The genetic correlation between cumulative survivability traits ranges between 0.38 to 0.95. Survivability patterns of calves with different genetic groups in Gir crossbred calves showed non significant effect.

Small for Gestational Age Calves: Part I-Concept and Definition, Contributing Prenatal Factors and Neonatal Body Morphometrics in Holstein Friesian Calves.

Low birth weight (BW) calves exhibit higher mortality rates, reduced body weights at parturition, lower first-lactation milk yields, and longer parturition to first insemination intervals. In human medicine, small for gestational age (SGA) births are associated with increased perinatal morbidity and long-term metabolic risks. This study aimed to define SGA in Holstein Friesian (HF) calves, evaluate their body measurements and proportions, and identify its prenatal risk factors. Four linear regression models were built with weight as a function for gestation length for bull and heifer calves born from nulli- or multiparous dams. Calves with a BW below the 10th percentile were classified as SGA. Differences in body measurements were analyzed using ANOVA, and logistic regression models identified prenatal risk factors to be born SGA. Gestation length, calf sex, and dam parity were crucial variables in defining SGA. SGA calves had significantly smaller body measurements (p < 0.001) and larger body proportions (p < 0.001) compared to average and large calves. For nulliparous dams, a higher 2nd trimester temperature-humidity index (p = 0.032) and older age at parturition (>26 months, p = 0.026) significantly increased the birth of SGA calves. For multiparous dams, both low (<5800 kg, p = 0.049) and high (6700-8600 kg, p = 0.027) milk yields during gestation lead to more SGA births, although very high-yielding dams (>8600 kg) did not birth more SGA calves. This study establishes SGA in HF calves, suggests SGA calves are asymmetrical with evidence of "brain sparing", and highlights the impact of prenatal factors on calf size at birth. Further research is needed to determine the long-term effects of being born SGA on growth, reproductive performance, and productivity.

Changes in the metabolomic profiles of mammary secretion in relation to dam litter size and parity number in Black Bengal goats.

The colostrum is essential for a kid's survival and development. The metabolomic profiles of mammary secretion in goats are limited. This study investigated the metabolomic profiles of mammary secretion in purebred Black Bengal goats and their relationships with litter size and parity number. 500 MHz nuclear magnetic resonance was used to analyze the metabolomic profiles of 43 colostrum and milk samples collected on delivery day and day 7 after parturition, respectively. Fifty-one metabolites were distinguished between colostrum and milk based on heatmap visualization and hierarchical cluster analysis. In colostrum, most compounds were present in significantly greater amounts than in milk. Milk of goats with multiple litter sizes had higher levels of lactose while fat, protein, total solids, solid not fat, and most of the metabolites were lower. The parity number of dams shows no difference in the composition of all components between primiparous and multiparous goats. The components in colostrum were significantly more concentrated than those in milk. The multiple litter sizes in dams led to a significant impact on the composition of lactose and other milk metabolites.

229 Effects of sire line on survivability traits of commercial pigs sired by PIC 800 or a North American competitor Duroc Line from birth to market

Abstract This study aimed to evaluate differences in survivability traits on pigs originating from two sire lines from birth to market. A total of 28,426 commercial pigs sired by either PIC 800 boars (n = 13,960 pigs) or a North American competitor Duroc line (Sire A; n = 14,466 pigs) were used in this study. PIC Camborough sows from 2 sister-sow farms were bred using semen from both genetic lines was mated equally and randomly across sows to ensure sire lines and parity of dams were balanced across farms. Pigs were individually identified at birth by genetic line and cross-fostering was done following standard farm practices. At weaning (average wean age 22 d of age, average body weight 6.8kg), pigs from both lines were sent to nurseries or Wean-to-finish sites (n = 11,541 PIC 800 and n = 11,922 Sire A), comingling in the same barns and pens. Starting inventories for each genetic line were recorded at weaning for all sites, end of nursery (4 wk post weaning), and 1 to 2 wk before start of marketing (target market weight 127kg at 160 d of age). For each production period, information on mortality and morbidity traits (n = 10,600 PIC 800 and n = 10,974 Sire A) was collected. Data were analyzed using R separately for each production period (i.e., Pre-weaning, Grow-to-finish, and Wean-to-finish) and not pooled from birth to market due to some groups not being kept intact. Morbidity and mortality data were analyzed using binomial models with a fixed effect of sire line and a random effect of sow farm or nursery/wean-to-finish site for pre-wean traits or post-weaning traits, respectively. Pigs from farms without removal reason record were excluded from analysis of removal reasons (Table 1). Overall pre-wean mortality was less (P ≤ 0.05) for PIC 800 pigs than Sire A pigs (8.5 vs. 9.6%, for PIC 800 and Sire A, respectively), mostly due to having fewer (P ≤ 0.05) pigs laid-on (4.8 vs 5.9%, respectively). At 4 wk post weaning, PIC 800 pigs had less (P ≤ 0.05) fallout rate than Sire A pigs (2.5 vs 3.5%, for PIC 800 and Sire A, respectively), with no differences (P &amp;gt; 0.05) in mortality rate (1.2 vs 1.3%, respectively). Grow-to-finish morbidity and mortality rates were less (P ≤ 0.05) for PIC 800 (2.1 and 1.3%, for morbidity and mortality rates, respectively) compared with Sire A (2.5 and 1.8%, respectively). Likewise, wean-to-finish morbidity and mortality rates were less (P ≤ 0.05) for PIC 800 (2.5 and 3.7%, for morbidity and mortality rates, respectively) compared with Sire A (3.0 and 4.7%, respectively). Results suggest PIC 800 sired pigs consistently had lower incidence of morbidity and mortality than Sire A pigs across all stages of production included in this study.

Tumor necrosis factor-α is transferred to equine neonates via colostrum but is not associated with their health status

We followed the hypothesis that equine neonates with reduced transfer of tumor necrosis factor-α (TNFα) are at increased risk of neonatal infection. We investigated TNFα concentrations in colostrum of healthy mares and blood of their neonates in a non-hospitalized population of Warmblood mares where delivery, neonatal adaptation and health was closely monitored by veterinarians. Concentration of TNFα and IgG was determined in colostrum respective milk and in neonatal blood collected immediately after delivery and 18 h thereafter in 97 foals that were assigned to groups failure of passive transfer (FPT; n = 31) and control (CON; n = 66) based on serum IgG concentration at 18 h of age. Foal health was assessed repeatedly during the first 24 h of life. Statistical analysis was done with p < 0.05 indicating significance. There were no significant differences between foal groups FPT and CON regarding age and parity of dams, gestation length (FPT 343 ± 10, CON 340 ± 8 days) and foal sex. Concentrations of TNFα in colostrum at birth and in foals at 18 h varied but did not differ between groups (colostrum FPT 6.1 ± 9.1, CON 9.9 ± 31.5 ng/ml; foal FPT 2.3 ± 5.9, CON 2.4 ± 5.3 ng/ml; n.s.). There was an increase in the mean serum TNFα concentration until 18 h in foals (n.s. between groups). Results of the present study confirm previous findings of TNFα transfer from the mare to the neonate via colostrum but do not suggest that transfer of TNFα via colostrum is important for protection of the neonate against infectious diseases.

A large population study to assess the magnitude of prenatal programming in dairy cattle

The performance of an adult dairy cow may be influenced by events that occur before her birth. The present study investigated potential effects of 2 prenatal groups of factors, Assisted Reproductive Techniques (ART) and maternal characteristics (e.g., dam parity), on offspring performance during their first lactation, in populations of 2 dairy cow breeds: French Holstein and Montbéliarde. The different ART studied included the type of semen (conventional or X-sorted) used for Artificial Insemination (AI) and the technology of conception used (AI, embryo transfer, or in vitro fertilization). Three maternal characteristics were considered: (1) the dam age at first calving, (2) dam parity number, and (3) indicators of dam udder health during gestation (somatic cell score and events of clinical mastitis). First, we investigated whether heifer survival from 3d to 18 mo old was associated with any of the prenatal factors considered. We then estimated the associations of these prenatal factors with 8 traits of commercial interest: (1) stature, (2-4) milk, fat, and protein yields, (5) somatic cell score, (6) clinical mastitis, and (7-8) heifer and cow conception rate, all measured on genotyped cows. Linear models were used for this study with the prenatal factors as covariates in the model, and for the 8 traits, phenotypes were adjusted for their corresponding genomic estimated breeding value. The results indicated that the survival rate of heifers born from embryo transfer was significantly higher than that of heifers born from AI (probably due to preferential management practices), while the other prenatal factors did not explain differences in heifer survival. Among the Montbéliarde cows born from AI, those born from X-sorted semen showed a lightly but significantly lower milk yield than those born without X-sorting of the semen (-52 kg of milk in the first lactation). Among the Holstein cows, those born from embryo transfer presented significantly lower milk performance than cows born from AI. Regarding the maternal characteristics, none or very weak associations were found between the dam age at first calving and the offspring performance in both breeds. Dam parity, on the other hand, was associated with offspring performance for milk, fat, and protein yield in both breeds, however not in the same direction. In the Holstein breed, an increase in dam parity was favorable for offspring performance for milk, fat, and protein yield, whereas in the Montbéliarde breed, an increase in dam parity was associated with lower milk and protein yield and no association was found for fat yield. The udder health of the dam during gestation was not or only weakly associated with the traits studied in the offspring. Although some significant associations were identified due to the large sample size, the effects were modest, typically less than 1% of the phenotypic mean, and were not consistently observed across the 2 breeds.

Evaluation of models for estimation of genetic parameters for post-weaning body measurements and their association with yearling weight in Nellore sheep.

The objective of this study was to obtain (co) variance components and genetic parameter estimates for post-weaning body measurements such as body length (BL), height at withers (HW), and chest girth (HG) recorded at six (SBL, SHW, and SHG), nine (NBL, NHW, and NHG) and twelve (YBL, YHW, and YHG) months of age along with yearling weight (YW) in Nellore sheep maintained at livestock research station, Palamaner, Andhra Pradesh, India and also the association among body measurements with YW was studied. Data on 2,076 Nellore sheep (descended from 75 sires and 522 dams) recorded between 2007 and 2016 (10 years) were utilized in the study. Lambing year, sex of lamb, season of lambing and parity of dam were included in the model as fixed effects and ewe weight was kept as a covariate. Analyses were conducted with six animal models with different combinations of direct and maternal genetic effects using restricted maximum likelihood procedure. Best model for each trait was determined based on Akaike's information criterion. Moderate estimates of direct heritability were obtained for the studied traits viz., BL (0.02 to 0.24), HW (0.31 to 0.49), and CG (0.08 to 0.35) and their corresponding maternal heritability estimates were in the range of 0.00 to 0.07 (BL), 0.13 to 0.17 (HW), and 0.07 to 0.13 (CG), respectively. Positive direct genetic and phenotypic correlations among the traits and they ranged from 0.07 (YBL-YW) to 0.99 (SBL-SHG, SHG-YW, and NBL-YBL) and 0.01 (SBL-YBL) to 0.99 (NBL-NHG), respectively. Further, the genetic correlations among all the body measurements and YW were positive and ranged from 0.07 (YW and YBL) to 0.99 (YW and SHG). There was a strong association of chest girth at six months with YW. Further, it is indicated that moderate improvement of post-weaning body measurements in Nellore sheep would be possible through selection.

Genetic analysis of body weight and growth curve parameters in Muzaffarnagari sheep of India.

The objective of this study was to estimate genetic effects on parameters of the Brody and Richards growth curves using body weight records from birth to 12 months of age on 2287 Muzaffarnagari lamb for a period of 29 years (1976-2004). Estimated growth curve parameters were analysed using six univariate animal models, and genetic correlations among and between the parameters of each function and between parameters of the functions and observed birth and yearling weights were estimated using bivariate analyses. Significant environmental factors including birth year, sex, season, birth status and dam parity were included as fixed effects in all models. Likelihood ratio tests indicated that maternal genetic effects were significant only for birth weight (BW) and degree of maturity at birth (u0 ) for the Brody and Richards functions. For these traits, direct heritabilities were similar (0.21, 0.19 and 0.17, respectively), but the estimated maternal heritability for BW (0.18) was twice that of u0 for both functions. Heritabilites for yearling weight and asymptotic final body weights for the Brody and Richards functions were 0.28, 0.17 and 0.21, respectively. The remaining growth curve parameters were lowly heritable, ranging from zero for the predicted degree of maturity at the age of maximum growth rate for the Richards function to 0.08 for the maturing rate parameter of the Brody function. Genetic correlations between corresponding parameters for different growth functions exceeded 0.88. Our results showed that the Brody and Richards functions had similar genetic architecture, but the Richards function had no apparent advantages over the more easily interpreted Brody function. Failure to identify maternal genetic effects on maturing rate parameters suggested that both functions failed to identify potentially important maternal genetic effects. Therefore, there is no usefulness of estimated growth curve parameters in selection compared to the simple multi-trait genetic evaluations of individual body weights.

Calf morbidity, mortality, and management practices in dairy farms in Jimma City, Southwestern Ethiopia

BackgroundThis research aims to determine the incidence of calf morbidity, mortality and its potential predisposing factors in the first six months of life. Morbidity and mortality of dairy calves are persistent problems for dairy farmers worldwide. For effective control and prevention programs on calf health, it is imperative to estimate the extent of calf morbidity and mortality, and associated risk factors. Although few studies have investigated the epidemiology of calf morbidity and mortality in Ethiopia, comprehensive information is scarce in this area.MethodsData were collected through a cross-sectional survey and longitudinal follow-up on purposively selected dairy farms. A longitudinal study was conducted on 235 calves from birth to 6 months of age. Survival analysis methods using the Kaplan–Meier (K-M) method, and mixed effect Cox proportional hazard regression were employed to compute the life-to-event data on morbidity and mortality.ResultsFrom the 235 calves studied, 53 morbidity and 15 mortality events were recorded. This gives an overall morbidity and mortality incidence rate of 55 per 100-calf 6-months at risk (risk rate of 42.07%) and 14 per 100-calf 6-months at risk (risk rate of 12.97%), respectively. Diarrhea (13.84%) followed by pneumonia (8.97%) were the most common diseases that occurred in calves, respectively. Similarly, diarrhea (33.3%) and pneumonia (26.7%) were the leading causes of death. Dam parity (p < 0.001) and pen cleaning (p < 0.001) were significant predictors of calf morbidity. Dam parity (p = 0.007), calving status (p = 0.005), pen cleaning (p = 0.04), and floor type (p = 0.001) of houses were significantly associated with mortality. The hazard of diarrhea was significantly associated with sex (p = 0.003), first colostrum feeding time (p = 0.028), pen cleaning (p = 0.010), and breeding method (p = 0.013).ConclusionThe rates of morbidity and mortality reported in the study were higher than the economically acceptable, also affecting the welfare of the animals. The risk factors found need due attention in the management practices of dairy calves in Ethiopia.

Death-and-culling rates of calves and associated economic losses in the first month of life on dairy farms in eastern Hokkaido, Japan

The objective of this study was to analyze death and culling (DC) of calves during the first month of life and associated economic losses on dairy farms in eastern Hokkaido, Japan. The DC in the first month of life of 4411 Holstein and Wagyu crossbred calves born in the year 2019–2020 on 39 dairy farms milking Holsteins was investigated. Based on a target DC rate of 6.75%, farms were classified into two groups, those with high DC rates (HDC, 11.68%, n = 18) and those with low DC rates (LDC, 2.67%, n = 21), and analyzed for DC factors (breed, sex, parity of dams, and housing type of dams) and diseases causing DC, their loss estimates, and replenishment of DC calves (birth rate, purchase of heifers, and housing type of dams). Comparisons between groups were made using the Kaplan-Meier method, the Mann-Whitney U test, and chi-square test. The DC rate of Holsteins was significantly higher (P < 0.001) for HDC farms than for LDC ones. But, the DC rate of Wagyu crossbreds was not different between the groups, which suggested hybrid vigor. The DC rates for digestive diseases were significantly higher (P < 0.01) in the HDC farms, except for congenital diseases and deaths of unknown cause. The overall loss estimates of DC per calf-month for all farms was 8892, JPY/calf-months, 14,726 for HDC farms, and 4065 for LDC farms. The loss estimates of items with significant differences in DC rates were significantly higher (P < 0.05) in the HDC farms, with higher loss estimates for Holsteins and digestive diseases being the most common characteristics of HDC farms. In binomial logistic regression analysis with ”HDC farms or not” as the response variable and replenishment of DC calves as the explanatory variable, HDC was significantly more likely (OR: 1.10, P < 0.05) on farms with a higher birth proportion of Holsteins, and HDC farms supplemented the DC calves by increasing the birth proportion of Holsteins.

148 Does Increased Gametic Variance Translate to Increased Heterogeneity in progeny?

Abstract The expected genetic merit of a new-born calf is simply the average genetic merit estimates of its parents. Parents with a very heterogenous genotype could, however, potentially generate a more heterogenous group of progeny than parents with a more homogenous genotype. The objective of the present study was to test this hypothesis, and a secondary objective was to determine the expected progeny variability in their estimates of genetic merit for traits associated with dairy-beef production based on their expected genomic heterogeneity. Gametic variance for calving difficulty, calf mortality, gestation length, docility, feed intake, and carcass weight, fat, and conformation was estimated for 22,038 beef sires of multiple breeds. Sire gametic variance per trait was estimated for each chromosome from all heterozygous single nucleotide polymorphisms (SNP), their location within the genome, and the estimated effect of each SNP on each trait. Gametic variance was estimated for the whole genome as the sum of the estimated gametic variance of all chromosomes. Individual progeny phenotypic records for each trait were adjusted for animal sex, dam parity and dam genetic merit for the trait, heterosis, recombination loss, and contemporary group. The correlations between sire estimated gametic variance and the standard deviation of his (adjusted) progeny phenotypes were then estimated for all sires with at least 20 progeny records; the number of genotyped sires with at least 20 progeny ranged from 2,395 (heifer calving assistance) to 8,545 (calf mortality). The mean gametic variance, relative to the variance of sire genetic merit, for heifer calving difficulty, cow calving difficulty, calf mortality, gestation length, docility, feed intake, carcass weight, carcass conformation, carcass fat were 0.0002, 0.0005, 0.09, 0.07, 0.30, 0.02, 0.25, 0.05, and 0.12, respectively. With the exception of carcass fat and carcass weight, the correlations between the estimated gametic variance per sire and the standard deviation of his (adjusted) progeny phenotypes were non-existent (-0.06 to 0.04); the correlations between the standard deviation of the adjusted progeny phenotypes and the gametic variance for carcass fat and carcass weight were 0.29 and 0.16, respectively. The (weak) correlations between gametic variance and progeny phenotypes for carcass fat and carcass weight suggest that greater gametic variance is associated with increased progeny heterogeneity for both carcass traits. Nevertheless, accounting for gametic variance when selecting beef bulls for use on dairy females seems to provide little benefit.

Estimation the genetic parameters and evaluating the correlation between the maternal linear type traits and the birth weight of the progeny in Hanwoo cows

This study aimed to investigate the correlation between the linear type traits of mother cows (dams) and the birth weight(BW) of the progeny. The study used data collected between 2002 and 2018 by the Korea Animal Improvement Association (KAIA). This study evaluated the data specifically with respect to 19 traits. A statistical model was established to estimate the correlation between the maternal linear classification traits and the progeny BW. The significance of each statistical variable was analyzed using the generalized linear model (GLM) method in the SAS package 9.1.3 software, while the genetic parameters were estimated using the BLUPF90 Family program. The BW of Hanwoo cows increased by approximately 0.4 kg each year; however, the BW heritability was moderate (0.23). The linear classification traits showed values of 0.34, 0.37, 0.11, 0.45, 0.31, and 0.40, for ST (Vertical distance from the apex of the rump to the ground), BL (Horizontal distance between anterior shoulder point to the posterior extremity of the pin bone), RA (The slope from the rump to the pin bone), RL (Horizontal distance from the anterior rump to the tip of the pin bone), PBW (Lateral width of pin bone), and FS (Final score), respectively, with moderate heritability for all traits, except RA. The BW of the progeny showed phenotypic correlations of 0.06, -0.01, 0.03, and 0.04, and genetic correlations of 0.09, 0.03, 0.02, and -0.04 with ST, BL, RL, and PBW, respectively. The average parity in Hanwoo cows increased from 2.5 in 2016 to 2.8 in June 2020. There is a low genetic correlation between the maternal linear classification traits and the BW of the progeny. An increase in the parity of dams and a greater accumulation of progeny BW data and test records could lead to the accurate evaluation of the BW as a breeding objective trait.

Reproductive performance of Horro and Horro-crossbred dairy cows in Ethiopia's subhumid tropical environments.

Estrus detection, timing of insemination, feeding, and health care practices are all factors that can significantly affect cattle breeding efficiency and lifetime production. In Ethiopia's subhumid environment, the age at first calving, number of days open, duration from calving to first heat, and number of services per conception are economic traits that affect reproductive performance of Horro and Horro-crossbred dairy cows. Data collected at Ethiopia's Bako Agricultural Research Center between 1980-2019 was used to study the reproductive performance of Horro and Horro-crosses with Holstein Friesian and Jersey dairy cows. We identified overall mean ± standard error values of factors that affect reproductive performance, including age at first service (AFS) (29.2 ± 0.2 months), age at first calving (AFC) (39.8 ± 0.2 months), number of services per conception (NSC) (1.76 ± 0.4 months), calving interval (CI) (13.2 ± 0.3 months), days open (DO) (94.3 ± 4.3 days), conception rate (CR) (75.0 ± 1.3%), and replacement rate (RR) (28.4 ± 0.3%). The odds ratios of the 60-day and 90-day nonreturn rates (NRR) were 0.22 and 0.96, respectively. Sire and dam breed and birth period had significant (P < 0.001) effects on AFS and AFC, while season and dam parity had significant effects on CI and DO. Inconsistencies regarding feeding, heat detection, inseminator skills, insemination timing, animal health, and other husbandry practices may extend periods of AFS, AFC, CI, and DO. To optimize reproductive performance in Horro cows and Horro crossbreeds in Ethiopia's subhumid environments, improving management practices should be a priority.

Intrinsic calf factors associated with the behavior of healthy pre-weaned group-housed dairy-bred calves.

Technology-derived behaviors are researched for disease detection in artificially-reared calves. Whilst existing studies demonstrate differences in behaviors between healthy and diseased calves, intrinsic calf factors (e.g., sex and birthweight) that may affect these behaviors have received little systematic study. This study aimed to understand the impact of a range of calf factors on milk feeding and activity variables of dairy-bred calves. Calves were group-housed from ~7 days to 39 days of age. Seven liters of milk replacer was available daily from an automatic milk feeder, which recorded feeding behaviors and live-weight. Calves were health scored daily and a tri-axial accelerometer used to record activity variables. Healthy calves were selected by excluding data collected 3 days either side of a poor health score or a treatment event. Thirty-one calves with 10 days each were analyzed. Mixed models were used to identify which of live-weight, age, sex, season of birth, age of inclusion into the group, dam parity, birthweight, and sire breed type (beef or dairy), had a significant influence on milk feeding and activity variables. Heavier calves visited the milk machine more frequently for shorter visits, drank faster and were more likely to drink their daily milk allowance than lighter calves. Older calves had a shorter mean standing bout length and were less active than younger calves. Calves born in summer had a longer daily lying time, performed more lying and standing bouts/day and had shorter mean standing bouts than those born in autumn or winter. Male calves had a longer mean lying bout length, drank more slowly and were less likely to consume their daily milk allowance than their female counterparts. Calves that were born heavier had fewer lying and standing bouts each day, a longer mean standing bout length and drank less milk per visit. Beef-sired calves had a longer mean lying bout length and drank more slowly than their dairy sired counterparts. Intrinsic calf factors influence different healthy calf behaviors in different ways. These factors must be considered in the design of research studies and the field application of behavior-based disease detection tools in artificially reared calves.

Associations between serum gamma-globulin concentration, enzyme activities, growth and survival in preweaning Alpine goat kids

Colostral immunity is crucial for young ruminants, but the individual factors that may affect passive transfer status and its effects on preweaning growth performance have not been widely investigated in goats. The methods to quantify immunoglobulins G can be expensive. Colostrum enzymes, though, pass the intestinal barrier and might be suitable as markers of passive transfer status, as demonstrated in other ruminant species. This study aimed to investigate the effect of sex, litter size, dam parity, and birth body weight on passive transfer status and the relationship between gamma-globulin concentration (GG) and pre-weaning growth performance in Alpine goat kids. The association between serum GG, serum total protein concentration and serum activity of colostrum enzymes including γ-glutamyltransferase (GGT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) was examined for their use as predictors of passive transfer status in neonatal goat kids. Sixty-six Alpine goat kids (39 males, 27 females), born to 28 does at one dairy goat farm during two delivery seasons, were enrolled. Kids nursed their dams in group housing until weaned at 50 days of age. Blood samples were collected 24 h after birth. Body weights (BW) were taken at birth and weaning. Serum enzyme activities and total protein concentration were measured using a clinical biochemical analyser. Serum GG was determined by gel electrophoresis. Statistical analysis was performed using GraphPad Prism (v. 8.2.1). No significant differences in serum GG between males and females, singlets and twins, multiparous’ and primiparous’ kids were found. No association was detected between birth BW and GG. Serum GG was strongly and significantly associated with TP (R2 =0.85; p 0.0001) and moderately associated with GGT (R2 =0.47; p 0.0001). No correlation was found with ALP, AST, and LDH. Although partial failure of passive transfer (FPT) was diagnosed in 23% of kids, no effects on morbidity (3%), mortality (0%) and pre-weaning growth performance were observed. Our results confirm that serum total proteins can be used to indirectly estimate immunoglobulin concentration. Contrarily, passive transfer status can be predicted with little success by measuring the activity of serum GGT. It is not advisable to use ALP, AST and LDH as indicators of passive transfer status. Finally, FTP is not necessarily associated with the health and preweaning growth performance of Alpine goat kids reared in non-intensive breeding systems that follow good farming practices.

Comparison of different resuscitation methods for newborn calves after dystocia

This study aimed to compare the use of hand-powered vacuum pumps and the suspension by the hind legs within the scope of resuscitating newborn dystocial calves. For this study, data were collected from 60 dystocial calves of different breeds. Various reanimation methods were employed to these calves immediately after birth. In group I (n=20), the hand-powered vacuum pump from HK-Rheintechnik (Neuwied, Deutschland) was used to remove mucus and amniotic fluid from the respiratory tract. In group II (n=20), the McCulloch Medical (Elmwood, England) hand-powered vacuum pump was used to remove mucus and amniotic fluid from the respiratory tract. In group III (n=20) 10 to 12 liters of cold water were poured over the neck of 20 calves immediately after birth. In addition, the calves were suspended by the hind legs via a gate or a pole, so that the head hung downwards vertically. The calves' Time to Sternal Recumbency (T-SR) of the calves was measured following the different resuscitation procedures in order to assess their vitality. In addition, the calves were examined segmentally at one-hour post natum. Furthermore, the calves were examined clinically on the seventh day of life. In addition, we investigated whether confounding variables such as calf sex, dam parity, obstetric intervention, and the season affected T-SR. T-SR ranged from 1.5 to 10.5 minutes. There was no difference between the three initial treatment procedures (p=0.07). However, the T-SR of calves treated with a hand-powered vacuum pump tended to be shorter. No statistically significant difference between the pulse rates (p=0.73), respiratory rates (p=0.13), and rectal temperature (p=0.65) of the animals in the three groups on the first and seventh day of life was evident. There was no statistically significant difference in the incidence of the diseases up to the seventh day of life between the individual study groups. The present study was able to show that the use of hand-powered vacuum pumps is at least equivalent to suspending calves. When using hand-powered vacuum pumps, the girth of the muzzle must be taken into account, as this can limit their utility.

Environmental and biological factors that influence feeding behavior of Holstein calves in automated milk feeding systems

Automated milk feeders (AMF) used for dairy calves continuously provide individual feeding behavior measurements. The objective of this retrospective cohort study was to evaluate the association between temperature-humidity index (THI), birth weight, and dam parity characteristics on feeding behavior (i.e., milk consumption and drinking speed). Historical data sets generated from a single commercial dairy farm, where healthy (not treated for bovine respiratory disease, enteric disease, or injury) Holstein calves were fed up to 24 L/d of milk, were used for the analysis. A total of 5,312 female Holstein calves born between August 2015 and August 2021 (mean birth weight ± standard deviation: 40.7 ± 4.7 kg) on a commercial dairy farm were fed up to 24 L/d of nonsaleable milk for the first 32 d. For the analyses, feeding behavior data from the AMF system were combined with demographic data from the farm management software, and weather records from the closest public weather station (7 km away). Linear mixed models used to analyze daily milk consumption and drinking speed included THI, birth weight, dam parity, and feeding day as fixed effects, and feeder and calf within feeder as random effects. These models explained 57% of the total variation in milk consumption and 48% of the variation in drinking speed. Calves born from primiparous cows had the lowest milk consumption and the greatest drinking speed in comparison to calves born from multiparous cows. Calves with heavier birth weights had higher milk consumption and faster drinking speed than lighter calves. Drinking speed was negatively associated with THI. Including data derived from individual calves and their environmental conditions in data sets exploring feeding behavior from AMF would control for variation and improve the predictive models for performance assessment.

Proximate factors affecting mortality and maternal abandonment of young free-roaming feral horse foals

The burgeoning population of feral horses in the American west is due to high population growth, resulting from low adult mortality and high foal survival. In two populations of feral horses in western Utah, USA only 15 foals died (5%; mean age <1 month) over a 4-year period. Seven additional foals (age <70 days) were observed separated from their dam, with no return to suckling or associating with the dam (i.e., abandoned). Factors affecting fate of foals were examined by comparing dead and separated foals with siblings (n = 19 dams, n = 32 siblings). Foals becoming separated or dying were observed in all years of the study, were unrelated to horse density, environmental effects, or gather events. There was no effect of dam body condition, parity, or age on foal survival or separation, and no effect of length of time the dam was in a group, whether the foal was born into the same group as conceived, and number of group changes made by the dam while pregnant. Dams of foals that died or were separated were more likely to change groups within 2 months after the foal was first seen, mostly after foal death or separation. Separated foals were near their dam less often, but there was no difference in frequency of social interactions. Separation of foals and dams is a natural occurrence in feral horses and survival likelihood for these foals is high – all separated foals that remained on the range in this study survived.