Pre-weaning Average Daily Gain Research Articles

Estimation of genetic parameters as well as trends for growth traits in Harnali sheep

The current study focussed on the growth traits pertaining to Harnali sheep maintained at Sheep Farm, LUVAS, Hisar and data were recorded from pedigree sheets of 1278 animals. Growth traits considered were birth weight (BW), weaning weight (WW), six-month weight (6MW), yearling weight (YW), and pre-weaning average daily gain (PRWDG) and least-squares means for corresponding traits found to be 3.28±0.02 kg, 12.89±0.07 kg, 17.06±0.06 kg, 24.36±0.06 kg, and 106.74±0.61 g, respectively. Effect of different factors like period of birth, sex of animal and dams’ weight at lambing was studied on growth traits. Except YW, significant effect of period of birth was observed on all the growth traits. Sex had significant influence on BW only however, dams’ weight at lambing affected significantly all the considered growth traits except YW. By leveraging the sire component of variance and covariance from mixed model analysis, the paternal half-sib correlation method was used to estimate genetic as well as phenotypic parameters. Estimates of heritability for BW, WW, 6MW, YW and PRWDG were 0.28±0.07, 0.33±0.07, 0.31±0.07, 0.12±0.04 and 0.27±0.06, respectively. Genetic as well as phenotypic trends for WW and PRWDG were found to be positive. Moderate range of genetic variability at weaning weight and its positive genetic and phenotypic correlations with growth traits specially six month’s weight indicated that genetic improvement could be possible through early selection at weaning weight in Harnali sheep.

Weight Changes in Bali Cattle During Lactation at Different Seasons in the Cattle-Oil Palm Production System

The season impacts livestock productivity and cattle kept in grazing production systems in tropical conditions. This research aims to determine the effect of season on the weight changes of Bali cows and calves on oil palm plantations. This research used 20 Bali cattle kept semi-intensively in oil palm plantation areas without feed supplementation in 2016–2018. Cows and calves were weighed at calving and every month until weaning (150 days). Season grouping was based on calving time: dry season (DS) May–October and rainy season (RS) November–April. Data were analyzed by independent T-test statistics using the SPSS 20.0 application. The results of observations showed that cows' body weight decreased gradually until the fourth month of lactation in both seasons. Cows' weight changes were only significantly different in the second month, in which cows at DS were better than RS (P<0.05). The pre-weaning average daily gain (ADG) of calves each month was not significantly different between the two seasons, and they could reach a body weight of 60.60 kg (RS) and 61.47 kg (DS) at weaning. Season differences do not impact weight changes in the Bali cows and calves in the cattle-oil palm plantation production system.

Behavioral and Morphological Traits of Nellore Cattle That Can Influence Calf Survival and Performance from Birth to Weaning

This study aimed to identify behavioral and morphological traits of Nellore cattle that can influence calves’ survival and pre-weaning performance. It was performed in two units of a large-scale cow–calf operation farm located in the Central-West region of Brazil, with 975 cow–calf dyads, by scoring cows’ maternal protective behavior, body condition, horns, udder suspension (US), teat size (TS) and calves’ vigor. TS was used to determine teat symmetry (TSm). The production unit where calves were born, their birth date, sex, and birth (BW) and weaning weights were also recorded. Cow ages at calving and production units were used to categorize the cows into twelve classes (Cage). The Shapiro–Wilk test alongside tables of frequencies were used to determine if continuous and categorical variables followed a normal distribution, respectively. Two datasets were considered in statistical analyses: (i) 975 dyad records were used to identify potential factors influencing calf survivability and (ii) 936 records of weaned calves were used to assess pre-weaning performance. Generalized linear models were used to assess the effect of target traits on the calves’ weight adjusted for 210 days of age (W210, kg) and pre-weaning average daily gain (preADG, kg/day). Tukey’s test was used to compare W210 and preADG means. Pearson’s correlation coefficients were estimated between BW, W210 and preADG. Cage, US and the TSm significantly affected pre-weaning calf performance (p < 0.01). Older cows (independently of the production unit) and those with intermediate US and symmetrical teats weaned heavier calves. As expected, positive and significant correlation was observed between BW and preADG (r = 0.35), which, in turn, was highly correlated with W210 (r = 0.99). We concluded that none of the behavioral and morphological traits influenced calf survivability, but cow age, US and TSm impacted pre-weaning performance, with 8- to 11-year-old cows and those with intermediate US and symmetric teats leading to better calf performance at weaning.

Relationship between FAMACHA© scores and zootechnical indicators of a sheep production system

In Brazil, lamb producers face challenges raising their animals because of high anthelmintic resistance and loss of productivity due to parasites. It is well known that parasitic infections can reduce the performance of sheep. However, until the publication of this work, no research was found that quantified the effects that anemia reflected by FAMACHA© scores can exert on other zootechnical indicators in a lamb production system. The objective of this study was to use the FAMACHA© scores to quantify the impacts of anemia in ewes at breeding and lambing on the productive and reproductive performance of a meat sheep flock. The variables evaluated were i) FAMACHA© score of ewes at breeding and lambing, ii) body condition score of ewes at breeding and at lambing, iii) average daily gain of lambs until weaning, iv) ewe’s age, v) birth weights per individual lamb and litter, vi) weaning weight, vii) ewe’s weight, viii) litter size and ix) pre-weaning survival. The treatments evaluated corresponded to the FAMACHA© score of the ewes during breeding and lambing. Quantitative responses were submitted to analyses of variance and compared by Duncan’s test. In contrast, qualitative or discrete responses were evaluated by the Kruskal & Wallis test and compared to Dunn’s test. The Wilcoxon test was performed to compare the FAMACHA© scores of ewes at breeding and lambing. All statistical analyzes were performed using the R-Studio software version 4.2.0 at a 5% significance level. The FAMACHA© score of breeding ewes was related to the body condition score at breeding, ewe weight, pre-weaning survival, ewe age, litter size, and birth weight. Furthermore, the FAMACHA© score of ewes at lambing was related to the body condition score at lambing, ewe weight, pre-weaning survival, birth weight per lamb and litter, pre-weaning average daily gain, weaning weight, and age of the ewe. There was no significant difference between the test times of the FAMACHA© scores of the ewes, indicating that an ewe will present a similar score at both stages. It was concluded that ewes with FAMACHA© scores of 4 and 5 and their offspring showed the worst productive and reproductive performances. Conversely, the ewes with FAMACHA© 1 obtained the opposite result, demonstrating better technical performance.

Effects of corn processing index and forage source on performance, blood parameters, and ruminal fermentation of dairy calves

The objective of this study was to investigate the effects of corn processing index (CPI)—particularly at 70% and 85%—in starter feed in combination with the provision of forage, either alfalfa hay (AH) or wheat straw (WS), on feed intake, growth performance, rumen pH, and blood metabolites of dairy calves. Forty-eight male Holstein calves (43.0 ± 1.5 kg body weight) were randomly assigned (n = 12 calves per treatment) to one of four dietary treatments: (1) a textured starter diet containing 70% CPI and AH (70CPIAH), (2) a textured starter feed containing 70% CPI combined with WS (70CPIWS), (3) a textured starter feed containing 85% CPI and AH (85CPIAH), (4) a textured starter feed containing 85% CPI combined with WS (85CPIWS). Intake of starter feed (TMR) and milk was individually monitored and recorded daily, while body weight was measured weekly. On days 30 and 65, blood samples were collected from all calves 3 h after morning feeding. No interaction was detected between the CPI of starter feed diets and forage provision for starter intake, dry matter intake (DMI), metabolizable energy intake (MEI), feed efficiency (FE), average daily gain (ADG), and body weight (BW). The preweaning and overall DMI, preweaning, postweaning and overall FE and ADG, preweaning and overall starter intake, preweaning and overall ME intake, and postweaning and overall BW were greater for calves fed 85CPI than those fed 70CPI starter diets. Postweaning and overall ADG and postweaning FE were greater in calves fed WS than those fed AH. Body length and hip width were greater for calves offered 85CPI than in fed 70CPI. Wheat straw supplementation increased rumen pH at day 65 in calves fed 70CPI, but not in those fed 85CPI. No interaction was found between the CPI in the starter feed diet and the forage source for starter intake and DMI, MEI, FE, and BW. The results showed that including corn with 85% processing index in dairy calf starters improved their growth performance.

Effects of the breeding season, birth type and sex on growth and reproductive performances of sheep breeds.

The study aimed at determining the effects of breed type, breeding season, sex and type of birth on the growth and reproductive traits of lambs. Two ewe breed types (Gellaper and Swakara) and four ram breed types (Damara, Dorper, GeDo and Swakara) were used. Two lambing seasons, spring (March-May) and autumn (September-November), were considered. Gellaper-based lambs born in autumn had higher (P < 0.05) mean birth weight (4.58 kg) compared to spring-born lambs (3.43 kg). Ram lambs were heavier (P < 0.05) than ewe lambs at weaning and post-weaning age. Singletons were heavier than twins (P < 0.05) at birth, weaning and breeding. Single and autumn-born lambs had a higher average daily gain (ADG) than spring-born lambs (P < 0.05). Ram lambs had a higher pre-weaning and overall ADG (P < 0.05) compared with ewe lambs. Swakara-based lambs gained more from weaning to mating compared to Gellaper-based lambs (P < 0.05). The conception, lambing and annual reproductive rate were all influenced by breed type and season (P < 0.05). Swakara-based lambs had higher reproductive capabilities, while Gellaper-based lambs grew faster but take longer to breed type; autumn lambing gave rise to low birth weights but heavier lambs at weaning and post-weaning, hence suitable for mutton production.

On-farm performance evaluation of Maale goats under agro-pastoral management in Southwest Ethiopia

This study was conducted in Maale district Southwest Ethiopia with the objective of evaluating the productive and reproductive performance of Maale goats under agro-pastoral management conditions. Thirty households that have flocks numbers of more than ten were purposely selected and monitored from July 2018 to July 2019. Growth data of birth weight, three month, six month, nine month and yearly weight; birth type and parity were collected. The data were analyzed using the General Linear Model (GLM) procedure of SPSS (21). The overall mean birth weight of the kids was 2.57±0.05 kg (males 2.68±0.07 and females 2.47±0.07 kg). The weaning and six months weight of kids was significantly different (p&lt;0.05) between sexes of kids with 7.66±0.25 and 6.90±0.23 kg for male and female kids, respectively. The average body weight of males and females for six months; nine months and yearly were 11.57±0.30, 10.42±0.28; 15.42±0.27, 14.69±0.25 and 19.03±0.28, 18.43±0.25 kg, respectively. The birth type showed a significant (p&lt;0.05) difference in birth weight. The result further indicated that the weaning weight of single and twin kids was highly significant (p&lt; 0.001) and recorded as 7.66±0.25 and 6.90±0.23 kg, respectively. The overall pre-weaning average daily gain was 51.64±1.89 g day-1 (54.47±2.81 male and 48.93±2.53 g day-1 female). The birth type was significantly (p=0.01) different in pre-weaning growth rate and recorded 57.24±1.63 and 45.24±3.59 g day-1 for single and twin kids, respectively. Twins had higher post-weaning average daily gain than single and recorded as 43.61±1.48 and 40.76 ±0.70 g day-1, respectively. It was concluded that, along with other management interventions, the reproduction and growth performance of Maale goats is reasonably good and suited for community-based breeding strategies and higher performance could be expected. Int. J. Agril. Res. Innov. Tech. 12(2): 7-13, December 2022

Effect of varying levels of fibre and starch in calf starters containing finely groundmaize grain on the performance of pre-ruminant calves

The nutrient composition and particle size of calf starter play a major role in shaping appropriate rumen development and starter intake and average daily gain in pre-ruminant dairy calves. Hence, a feeding trial was conducted to assess the effect of feeding calf starters containing finely ground maize grain with varying levels of fibre and starch on the performance of pre-ruminant dairy calves fed no roughage. Three iso-nitrogenous calf starters containing different levels of finely ground maize grain and soybean hulls (maize:soybean hulls 40:10;30:20; 20:30) were evaluated through a feeding trial using 18Holstein Friesian crossbred female calves (average body weight34.19 ± 0.94 kg). The calves were divided into three groups of 6calves each in a completely randomized design. Milk was offered to calves twice daily from the fourth day of age up to 63 day of age as per the step up/step down milk feeding schedule. In addition, calves in each group were offered respective calf starters individually ad libitum from 3 to 63 day of age. Daily starter intake and fortnightly body weight of calves were recorded during the trial. The calves were monitored for rumination from the third day of age until rumination was noticed. Blood samples were collected from calves on 63day of age for estimation of various biochemical constituents. The level of starch and fibre in calf starters containing finely ground maize grain (57.72% of particles with a size of 1.18 mm above) had no influence on overall calf starter dry matter intake (401.89 to 424.68 g/d), average daily gain(0.660 to 0.700 kg/d), feed conversion efficiency, feed cost/kggain, initiation of rumination and blood biochemical constituentsin pre-ruminant dairy calves. Maximum pre-weaning average daily gain (700 g/d) can be achieved in Holstein Friesian crossbred female calves through feeding milk by step up/step down method and calf starter containing finely ground maize grain and soybeanhulls in the ratio of 20:30 without offering any roughage.

Stochastic, individual animal systems simulation model of beef cow-calf production: development and validation.

A stochastic, individual animal systems simulation model describing U.S. beef cow-calf production was developed and parameterized to match typical U.S. Angus genetics under cow-calf production conditions in the Kansas Flint Hills. Model simulation results were compared to available actual, multivariate U.S. cow-calf production data reported according to beef cow-calf standardized performance analysis (SPA) methodology through North Dakota State University's CHAPS program to assess model validity. Individual animal nutrition, reproduction, growth, and health characteristics, as well as production state are determined on a daily time step. Any number of days can be simulated. These capabilities allow for decision analysis and assessment of long-run outcomes of various genetic, management, and economic scenarios regarding multiple metrics simultaneously. Parameterizing the model to match Kansas Flint Hills production conditions for the years 1995 through 2018, 32 different genetic combinations for mature cow weight and peak lactation potential were simulated with 100 iterations each. Sire mature cow weight genetics ranged from 454 to 771 kg in 45 to 46 kg increments. Sire peak lactation genetics were considered at 6.8, 9, 11.3, and 13.6 kg/d for all eight mature cow weights. Utilizing model results for the years 2000 to 2018, raw model results were assessed against actual historical cow-calf production data. Exploratory factor analysis was applied to interpret the underlying factor scores of model output relative to actual cow-calf production data. Comparing modeled herd output with CHAPS herd data, median average calf weaning age, average cow age, percent pregnant per cow exposed, and percent calf mortality per calf born of model output was 3.4 d greater, 0.2 yr greater, 1 percentage point less, and 1.7 percentage points greater, respectively. Subtracting the median CHAPS pre-weaning average daily gain from the median modeled pre-weaning average daily gain for each of the eight respective mature cow weight genetics categories, and then calculating the median of the eight values, the median difference was -0.21 kg/d. Performing the same calculation for birth weight and adjusted 205 d weaning weight, the modeled data was 4.9 and 48.6 kg lighter than the CHAPS data, respectively. Management and genetic details underlying the CHAPS data were unknown.

English

The objectives of this study were to identify the environmental factors that influenced growth traits and to evaluate phenotypic response of growth traits to selection at weaning (S1) and 18 months of age (S2) in Tswana cattle. Phenotypic analysis for average daily gains (ADGs) and growth traits were conducted using 7226 records of animals, which were born between 1995 and 2013 from 1662 dams and 188 sires in 54 contemporary groups, using mixed models. Growth traits analysed were birth weight (BWT), weaning weight (WWT), yearling weight (YWT) and 18-month weight (EWT). The analysed ADGs were pre-weaning average daily gain (ADG1) and post-weaning average daily gain (ADG2). The identified significant environmental effects for growth traits and ADGs were sex of the animal, dam age, selection line and contemporary group. S1 resulted in increased BWT, WWT, YWT, EWT and ADGs compared with S2. Animals from both S1 and S2 exhibited higher weights and ADGs than those in the unselected control line (S3). The significant environmental factors should be accounted for whenever genetic evaluation for growth performance of Tswana cattle breed is carried out. Mass selection for weaning weight can yield optimal improvement on growth performance of Tswana cattle when properly carried out. Key words: Environmental factors, growth performance, growth traits, cattle, selection.

Least Square Analysis of Variance for the Assessment of Natural Consequences for Birth Weight, Weaning Weight, Yearling Weight, Pre-weaning Daily Weight Acquire, and Greasy Fleece Weight of Kajli Sheep in Pakistan

The current study was completed to analyze the effect of natural components on various improvement affecting traits of Kajli sheep in Pakistan. For this reason, we apply two huge contemporary datasets in sheep to explore factors that influence the traits. Therefore, the generation information record of 13715 Kajli sheep lambing accumulated from 1994 to 2010 at Livestock Experimental Stations Khushab and Khizarabad, Punjab. Information records were genuinely analyzed through utilizing PC modified Mixed Model Harvey’s Least Squares and Maximum Likelihood. The two farms information data was analyzed by utilizing an animal model program. The factual model was incorporated to evaluate the Birth Weight (BW), 120 days at Weaning Weight (WW), Pre-Weaning Average Daily Gain (PRADG), Yearling Weight (YW) and Greasy Fleece Weight (GFW). Year of Birth (YOB), Birth Season (BS), Birth Types (BT) and sex was the fix effect in the model. Results indicated that, the overall general values for birth weight, weaning weight, yearling weight, pre-weaning weight and fleece weight were noted. Year of birth, type of birth, sex, and herd was influenced altogether significantly while, birth weight and greasy fleece weight, the period of birth showed no essential difference. In weaning weight and pre-weaning increment normally, year of birth, sort of birth and herd showed a critical contact except for sex. Male sheep were heavier than female sheep and single conceived sheep were also basically heavier than twins were during offspring birth. Results emulate that the Kajli sheep breed can be improved on through selection and further developed management. The cascade type of influence of the current investigation has levelheaded ramification not just for sheep farming by and by just as for intensified associate of boundaries which definitely convince deviation of weight, weight has become itself essential forecaster of in a matter of seconds wellness results. These outcomes displayed there are complex associations among hereditary qualities and ecological elements of parental, placental and fetal beginning. These are profoundly affected traits by maternal sustenance, genes, be concerned, the executive, environment, occasional diversity of seasons.

Growth performance and mammary gland development of Holstein calves fed milk with 15% solids and treated with growth promoters.

The objective of this study was to evaluate growth performance, and mammary gland parenchyma (PAR) development in Holstein female calves fed whole milk combined with milk replacer for 15% total solids (15TS) or only milk (11% TS; 11TS). The effects of zilpaterol hydrochloride (ZH) and an estrogenic implant (EI) on growth performance, serum metabolites, and PAR development in post-weaning calves (63-90days of age) fed 15TS or 11TS were also investigated. In the first phase, 78 calves were randomly divided into two groups (n = 39/group), 15TS, or 11TS (5 to 8 L/day; starter ad libitum). After weaning, calves were randomly assigned to four treatments, no EI, EI, ZH, and ZH-EI. In phase 1, 15TS calves had greater (P < 0.01) average body weight at weaning than 11TS calves (82.0 ± 5.8 vs. 74.1 ± 5.7kg). Pre-weaning average daily gain (718 ± 67 vs. 576 ± 64g/day)was higher (P < 0.01)for 15TS calves than 11TS calves. Feed/gain (1.5 ± 0.3 vs. 1.8 ± 0.3kg of DMI/kg of gain) was lower (P < 0.01) for 15TS calves than 11TS calves. PAR area (8.8 ± 3.3 vs. 5.0 ± 1.6 cm2) was greater (P < 0.01) for 15TS calves than 11TS calves. No differences (P > 0.10) in average daily gain (986 ± 79g/day across treatments) were observed in calves receiving ZH, EI, or ZH-EI fed 15TS or 11TS diets previously. However, the PAR area of 15TS calves administered ZH-EI was 2.2 times greater (P < 0.01) than 11TS calves with no ZH and CI. This study demonstrated the benefits of supplying milk with 15% TS for enhancing overall animal growth and PAR development. Further use of ZH and EI during the post-weaning period did improve mammary PAR growth.

Phenotypic and genetic parameter estimates for early growth, growth rate and growth efficiency-related traits of Fogera cattle in Ethiopia.

BackgroundUnderstanding the phenotypic and genetic parameter estimates of growth traits is important for an effective livestock genetic improvement programme.ObjectivesIn this study, we evaluated the phenotypic performances and estimated genetic parameters for birthweight (BWT), weaning weight (WWT), pre‐weaning average daily gain (PADG), pre‐weaning Kleiber ratio (PKR), pre‐weaning growth efficiency (PGE) and pre‐weaning relative growth rate (PRGR) of Fogera cattle in Ethiopia.MethodsGrowth data collected from 2000 to 2018 in Andassa Livestock Research Center were used for the study. General linear model of SAS 9.1 was used to estimate the least squares mean (LSM) ± standard error (SE) for phenotypic performances, and AI‐REML of Wombat software combined with a series of five single‐trait animal models to estimate phenotypic variance and its direct, maternal and residual components. Calf sex, calf birth season and calf birth year were the fixed effects considered.ResultsThe overall LSM ± SE BWT, WWT, PADG, PKR, PGE and PRGR were 21.28 ± 0.05 kg, 97.99 ± 0.67 kg, 320.29 ± 2.79 g, 10.10 ± 0.04, 3.51 ± 0.35 and 1.95 ± 0.00, respectively. All the fixed effects considered significantly (p < 0.001) affected all the traits. The direct heritability estimates for BWT, WWT, PADG, PKR, PGE and PRGR were 0.21 ± 0.07, 0.26 ± 0.01, 0.55 ± 0.19, 0.53 ± 0.18, 0.33 ± 0.00 and 0.50 ± 0.00, respectively. The genetic correlations among the traits ranged from negative (−0.20 ± 0.04; BWT‐PKR) to positive (0.99 ± 0.00; BW‐PGE, BW‐GR, WWT‐PGE, WWT‐PGR, ADG‐PGR, PKR‐PGR, PKR‐PGE and PGE‐PGR). Similarly, the phenotypic correlations ranged from −0.03 ± 0.20 to 0.99 ± 0.01; BWT‐PGE, BWT‐PRGR, WWT‐PGE, WWT‐PRGR, PKR‐PGE, PKR‐PRGR and PGE‐PRGR).ConclusionThe positive and larger phenotypic and genetic correlations between most of the traits implied that selection based on one trait could improve the other traits. However, the negative phenotypic and genetic correlation between BWT‐PKRA implies that selection of Fogera calves based on either of the traits has an adverse effect on the other. Therefore, caution should be taken when designing the selection criteria for growth improvement.

On-farm evaluation of growth and reproductive performances of Washera and Gumuz sheep in northwestern Ethiopia: Basics for setting up breeding objectives/goals.

Growth and reproductive performance traits are traits of economic importance for sheep selection and productivity improvement interventions. This study aimed at comparative evaluation of growth and reproductive performance traits of sheep in the highland and lowland agro-ecologies of northwestern Ethiopia. Data on growth performance traits were collected from 144 Washera (78 males and 66 females) lambs and 72 Gumuz (37 males and 35 females) lambs. Data on reproductive performance traits were collected from 260 Washera (130 rams and 130 ewes) sheep and 150 Gumuz (75 rams and 75 ewes) sheep. General linear model univariate procedure was employed to analyze the collected data. Breed, the interaction effect between breed and season of birth as well as the interaction effect between breed and type of birth all exerted very high significant effect (P<0.001) on live weight at all age groups. Breed type affected pre-weaning average daily weight gain significantly (P<0.01). Pre-weaning average daily weight gain of Washera (70 g/day) was found much better performance than 60 g/day of Gumuz. Breed type exerts significant (P<0.05) effect on age at first lambing, lambing interval, annual reproductive rate and number of lambs born per ewe life time. Average age at first lambing and lambing interval of Washera sheep were 11.69 months and 9.27 months, respectively. The corresponding values for Gumuz sheep were 12.51 months and 10.43 months, respectively. Production and reproduction performance values of traits varied across the two breeds and sexes as well. These values can be used to set up breeding objectives or goals for selective breeding of sheep giving special emphasis to growth traits believed to have medium heritability values.

Effects of supplements differing in fatty acid profile to late gestational beef cows on cow performance, calf growth performance, and mRNA expression of genes associated with myogenesis and adipogenesis

BackgroundMaternal nutrition during gestation affects fetal development, which has long-term programming effects on offspring postnatal growth performance. With a critical role in protein and lipid metabolism, essential fatty acids can influence the development of muscle and adipose tissue. The experiment investigated the effects of late gestation supplements (77 d prepartum), either rich in saturated and monounsaturated fatty acids (CON; 155 g/cow/d EnerGII) or polyunsaturated fatty acids (PUFA; 80 g/cow/d Strata and 80 g/cow/d Prequel), on cow performance and subsequent calf growth performance as well as mRNA expression in longissimus muscle (LM) and subcutaneous adipose tissue at birth and weaning.ResultsThere was no difference (P ≥ 0.34) in cow body weight (BW) or body condition score from pre-supplementation through weaning. Relative concentrations of C18:3n-3 and C20:4n-6 decreased (P ≤ 0.05) to a greater extent from mid-supplementation to calving for PUFA compared with CON cows. Cow plasma C20:0, C20:5n-3, and C22:6n-3 were increased (P ≤ 0.01) in PUFA during supplementation period. At birth, PUFA steers had greater (P = 0.01) plasma C20:5n-3. No differences (P ≥ 0.33) were detected in steer birth BW or dam milk production, however, CON steers tended (P = 0.06) to have greater pre-weaning average daily gain and had greater (P = 0.05) weaning BW compared with PUFA. For mRNA expression in steers: MYH7 and C/EBPβ in LM increased (P ≤ 0.04) to a greater extent from birth to weaning for PUFA compared with CON; MYF5 in LM and C/EBPβ in adipose tissue tended (P ≤ 0.08) to decrease more from birth to weaning for CON compared with PUFA; SCD in PUFA adipose tissue tended (P = 0.08) to decrease to a greater extent from birth to weaning than CON. In addition, maternal PUFA supplementation tended (P = 0.08) to decrease MYOG mRNA expression in LM and decreased (P = 0.02) ZFP423 in adipose tissue during the pre-weaning stage.ConclusionsLate gestation PUFA supplementation decreased pre-weaning growth performance of the subsequent steer progeny compared with CON supplementation, which could have been a result of downregulated mRNA expression of myogenic genes during pre-weaning period.

Impact of 2 Versus 1 Colostrum Meals on Failure of Transfer of Passive Immunity, Pre-Weaning Morbidity and Mortality, and Performance of Dairy Calves in a Large Dairy Herd.

Simple SummaryThis retrospective study of records from a dairy farm explored the impact of receiving a second feeding of colostrum 5–6 h after an initial meal of 3 L of quality-tested colostrum on calf health and productivity until the first lactation. Calves that received a second feeding were less likely to develop failure of transfer of passive immunity or morbidity pre-weaning than calves only receiving one feeding. Similarly, calves receiving a second feeding showed a greater growth rate until weaning and tended to produce more milk in the first lactation. However, receiving a second feeding was not associated with differences in pre-weaning mortality or reproductive efficiency. Our results show that feeding calves a second meal of colostrum within the first few hours of life has a positive impact on calf health and might have positive effects into the first lactation.Failure of transfer of passive immunity (FTPI) due to inadequate ingestion of colostral immunoglobulins by calves is associated with increased mortality and morbidity risks. Feeding calves a sufficient amount of quality-tested colostrum within the first hours of life is essential for successfully transferring passive immunity. Many farms have implemented a second meal of colostrum to maximize the opportunities for passive immunity transfer. However, excellent passive immunity can be achieved with a single feeding of sufficient quality-tested colostrum. Moreover, there is currently no evidence demonstrating the impact of a second colostrum feeding within 24 h of life in calves receiving adequate volumes of quality-tested colostrum in an initial feeding. Hence, the objective of this retrospective cohort study was to compare the risks of FPTI, pre-weaning morbidity and mortality, and growth and performance between dairy calves that received one or two feedings of colostrum. For this, the health and production records of a large dairy herd were analyzed. At this farm, newborn calves receive 3 L of quality-tested colostrum soon after birth, followed by another 2 L 5–6 h later. However, at times of shortages of colostrum, calves only receive the initial 3 L meal. The records of 2064 male and 2272 female calves were analyzed, where 4156 and 180 calves received 2 and 1 colostrum meals, respectively. Data from both sexes were included in the analysis of the risks of FTPI, morbidity, and mortality; however, only data from heifer calves were utilized for growth and performance analysis. Survival analysis, and logistic and linear regression models were used to investigate the impact of receiving two feedings of colostrum on calf FTPI status, morbidity, mortality, reproductive indices, pre-weaning average daily gain (ADG), and first lactation 305-d Mature Equivalent milk production (305ME). Calves that received two feedings of colostrum had lower odds of FTPI, a lower probability of being treated for respiratory disease, diarrhea, or any disease, and a greater pre-weaning ADG. However, there was no association between the number of colostrum feedings and pre-weaning mortality, and the probabilities of first insemination and first calving, although heifers receiving two colostrum feedings tended to receive fewer inseminations and to have a greater first lactation 305ME. Collectively, our results suggest that feeding calves a second feeding of colostrum 5–6 h after the initial feeding soon after birth could be an effective strategy to decrease FTPI and morbidity and optimize ADG in dairy calves pre-weaning.

Polymorphisms in hormone-sensitive lipase and leptin receptor genes and their association with growth traits in Barki lambs.

Background and Aim:Marker-assisted selection has many advantages over conventional selection in animal breeding. The candidate gene approach has been applied to identify genetic markers associated with economically important traits in livestock. This study was established to investigate variation in the hormone-sensitive lipase (HSL) and leptin receptor (LEPR) genes, and their association with growth traits in Barki lambs.Materials and Methods:Records for birth weight (BW), pre-weaning average daily gain (ADG1), weaning weight (WW), post-weaning average daily gain (ADG2), and marketing weight (MW) were obtained from 247 Barki lambs. Polymerase chain reaction–single-stranded conformational polymorphism analyses were used to detect variation in exon 9 of HSL and exon 19 of LEPR. General linear models were used to test for associations between the variation in ovine HSL and LEPR, and growth traits.Results:The SSCP banding patterns for HSL showed three variants (H1, H2, and H3), which contained two nucleotide-sequence differences (c.1865C>T and c.2038T>C). Two SSCP banding patterns (L1 and L2) were observed for LEPR and these contained two nucleotide-sequence differences (c.2800G>A and c.2978C>G). The HSL genotype showed no effect on the studied traits. The LEPR genotype was proven to have significant effects (p<0.05) on ADG2 and MW. The presence of the L1 variant was associated (p<0.01) with decreased ADG2 and MW.Conclusion:The finding of an association between LEPR gene variation and growth rate after weaning in Barki lambs warrants efforts to improve this trait.

Nucleotide Supplementation to Whole Milk Has Beneficial Effects on Post-Weaning Holstein Calf Performance.

Simple SummaryThe positive effects of nucleotide (NU) supplementation in milk replacer have been elucidated in infants and partly in dairy calves; however, NU addition to whole milk has not been evaluated yet. In this study, a NU-containing supplement was added to whole milk at rate of 0.5 and 1 g/d. Without any effects on pre-weaning performance, post-weaning intake was improved as NU increased and final body weight was greater in NU supplemented calves. Nucleotide supplementation to whole milk linearly decreased days with loose feces in the first month of life. These results show that NU has beneficial effect on calf health status and intake even if it is supplemented to whole milk.The positive effects of nucleotide (NU) supplementation in milk replacer have been elucidated in infants and in dairy calves; however, NU addition to whole milk has not been evaluated previously. This study aimed to assess NU supplementation in the whole milk on calf growth and health. Thirty Holstein calves (body weight: 39.1 ± 1.0 kg; 3 d after birth) were randomly assigned to the following treatments: whole milk without any supplementation (NU0), whole milk + 0.5 g/d added a NU-containing supplement to whole milk (NUCS0.5), and whole milk + 1 g/d added a NU-containing supplement to whole milk (NUCS1). Calves were weaned at d 55 and stayed on study until d 75. Calves had free access to feed and water throughout the study. Dry matter intakes (DMI) were similar among treatments (p > 0.05) during the pre-weaning period; however, increasing NU resulted in a linear (p < 0.05) increase in DMI during the post weaning period (2158, 2432, and 2518 g/d for NU0, NUCS0.5, and NUCS1, respectively). Treatments did not affect body weight (BW) at the first and second month of study, but final BW linearly increased as NU was added (87.1, 90.6, and 95.4 kg for NU0, NUCS0.5, and NUCS1, respectively). Neither pre-weaning average daily gain nor post-weaning average daily gain was affected by treatments; accordingly, feed efficiency was similar among treatment groups. Days with loose fecal score were linearly decreased as NU was added to whole milk during the first month of life, while the fecal score did not differ among treatments until the end of the study. No difference was observed in the skeletal growth of calves in the current study. Therefore, it can be concluded that NU supplementation in the whole milk has some beneficial effects on calf performance in terms of final BW, post-weaning DMI, and less days with loose feces.

Effect of housing improvement and other factors on the growth of heifer calves on Kenyan smallholder dairy farms.

This trial evaluated average daily gain (ADG) effects of heifer calves (< 1year old) from affordable housing improvements to the roof and flooring on 150 randomly allocated smallholder dairy farms. During the 16-month data collection period, bimonthly farm visits were used to measure weight and other animal- and farm-level factors on the 187 study calves. Multivariable linear regression was used to model ln ADG and ADG during pre-weaning and post-weaning periods, respectively. Median pre-weaning and post-weaning ADGs were 0.307 (interquartile range (IQR): 0.227-0.398) and 0.487 (IQR: 0.354-0.675) kg/d, respectively. In the final pre-weaning model (p<0.050), factors positively associated with ln ADG were calf age at first acaricide application, and total number of calf pens, while factors negatively associated with ln ADG included calf mortality risk over the last 5years and calf age at first ad lib access to water. In an interaction term, for calves from parity 3+ dams, ADG was lower when milk was fed twice/day than thrice/day, with no difference in calves of lower parity dams. In the final post-weaning model, housing improvements increased ADG by 5.6%. Other factors positively associated with post-weaning ADG were feeding of calf pellets, wheat bran, maize bran, and hay. Calf age at first introduction of concentrate and calf mortality risk over the last 5years were negatively associated with ADG. In an interaction term, ADG was high when there were faecal coccidia oocysts and when calves had visual or physical contact with their dams, but low when faecal coccidia cysts were present, and these dam-calf connections were absent. In a second interaction term, ADG increased with more calf pens for female principal farmers, while remaining low for male principal farmers. In conclusion, while controlling for other factors of ADG, making affordable calf housing improvements enhanced ADG, particularly during the post-weaning period.

Short- and long-term effects of initial serum total protein, average starter feed intake during the last week of the preweaning period, and rearing body gain on primiparous dairy heifers' performance

The aim of this study was to evaluate the short- and long-term effects of initial serum total protein (STP) concentration, average starter feed intake (SI) during the last week of the preweaning period, and average daily gain (ADG) on the growth, fertility, and performance of Holstein heifers during their first lactation. Eighty-four female Holstein dairy calves were weaned at d 56 of age and then the study continued until the end of the first lactation. Growth performance, including body weight, ADG, withers height, and its change were analyzed monthly from 3 to 450 d of life, and reproduction data and performance in the first lactation of primiparous dairy heifers over a 4-yr period (2015 to 2019) were recorded. In the first 24 h of life, calves received 4 L of colostrum (<2 h and <12 h after birth); on d 2 and 3: 2 feedings/d of 2 L of transition milk; from d 4 to 49: 6 L/d of milk replacer (150 g of powder/L as-fed) in 3 feedings; and from d 50 to 56: 2 L/d of milk replacer in 1 feeding. The calves were fed pelleted starter feed from d 4 to 56, and after that from 8 wk until 3 mo of age, a dry total mixed ration with an 85:15 ratio of weaning pelleted starter to straw. From 3 to 7 mo and from 8 mo of age to calving, the total mixed ration contained 16.9% and ~14.0% crude protein, respectively, on a dry matter basis and ~2.40 Mcal of metabolizable energy/kg on a dry matter basis. The results of the current study showed that the initial STP concentration of primiparous dairy heifers was associated with improved growth performance, especially greater body weight and withers height. In addition, with increasing levels of initial STP concentration, age at first estrus, artificial insemination (AI) service, pregnancy, and calving was decreased by 16, 18, 25, and 25 d, respectively. Initial STP concentration was positively correlated with milk production and increased total milk yield and yield of energy-corrected milk by about 1,558 kg and 1,149 kg during first lactation. Calves with higher average starter feed intake during the last week of the preweaning period had better growth performance, which in turn was positively associated with fertility parameters, accelerated first estrus (by 17 d), and reduced age at AI service (by 13 d). Preweaning ADG was favorably associated with fertility performance of heifers, with faster occurrence of first estrus and a reduction in age at AI service, pregnancy, and calving. Also, increasing preweaning ADG increased milk yield, energy-corrected milk, and 4% fat-corrected milk at 305 DIM by about 829, 754, and 763 kg at first lactation of primiparous heifers. These results indicate that in the rearing period, particular attention should be paid to the initial STP concentration, average SI during the last week of this period, and rearing ADG to increase growth, fertility, and performance in the first lactation of primiparous dairy heifers.