Influence of additive and maternal effects on production and reproduction traits in Murrah buffaloes: Insights from Bayesian analysis.

The aim of this research was to assess genetic parameters for first lactation production and reproduction traits in Murrah buffaloes by employing additive and maternal effects. Data on pedigree and specific traits of 640 Murrah buffaloes were gathered from 1997 to 2020. These traits encompassed first lactation milk yield (FLMY), 305-day first lactation milk yield (305FLMY), first lactation length (FLL), first lactation peak yield (FPY), first service period (FSP), first calving interval (FCI) and first dry period (FDP). Genetic evaluations employed six univariate animal models, accounting for both direct and maternal effects, facilitated by THRGIBBS1F90 and POSTGIBBSF90 programs. Fixed factors included in the analysis were period of calving, season of calving and age at first calving. The Bayesian estimates for direct heritability, derived from the most suitable model, were as follows: FLMY: 0.28 ± 0.01, 305FLMY: 0.30 ± 0.01, FLL: 0.19 ± 0.01, FPY: 0.18 ± 0.01, FSP: 0.12 ± 0.01, FCI: 0.14 ± 0.01 and FDP: 0.12 ± 0.01. Maternal effects were found significant, ranging from 5% to 10%, in first lactation traits under Model 2 and Model 5. Additionally, positive and significant genetic and phenotypic correlations were observed among the studied traits. In conclusion, selection based on 305-day first lactation milk yield suggests potential for genetic enhancement in Murrah buffaloes, advocating its inclusion in breeding programmes to bolster early performance. Also, consideration of maternal influences is necessary for genetic progress of animals.

Estimation of the seminal parameters of rooster and its association with fertility traits in synthetic dam line.

The objective of the present study was to assess the seminal parameters of rooster and its association with fertility traits (%), viz., hatchability of the fertile egg set (HFES), hatchability of the total egg set (HTES), and fertility (FERT). The data records pertained to traits of interest were obtained from various registers maintained at Poultry farm, of the Department of Animal Genetics and Breeding, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar (India). The relationship between seminal and fertility characteristics was investigated using regression analysis and correlation. Moreover, the efficacy of seminal characteristics to distinguish between roosters with low and high fertility traits was evaluated using linear discriminant analysis (LDA). The findings showed that reproductive traits and seminal characteristics were significantly (P < 0.05) correlated. The LDA showed that the seminal parameters can effectively separate the roosters into those with high and poor reproductive features. It was revealed from LDA that seminal features showed higher classification accuracy for FERT (80.77%). Hatchability is dependent on eggs that have been artificially incubated; hence, these crucial traits are comparatively weaker for HTES (65.38%) and HFES (67.31%). Cross-validation of the seminal parameter LDA corroborated the aforementioned and related conclusions. It is suggested that the studied LDA function may be utilised to choose genotypes with improved reproductive traits based on seminal variables.

Prevalence of babesiosis in bovines of India: a meta-analytical approach for 30 years (1990-2019).

BACKGROUND: India has a massive population of bovines, which makes the framework of the economy mainly relying on milk and meat production. Parasitic diseases such as babesiosis are detrimental to bovines by decreasing animal welfare and production efficiency. AIM: Performing a meta-analysis of the prevalence of babesiosis over 30 years viz 1990 to 2019 within India to pool out individual studies from different country regions. MATERIAL AND METHODS: The studies were reviewed thoroughly to assess the quality, and it was done by following the preferred reporting items for systematic review and meta-analysis (PRISMA) and MOOSE protocols. The prevalence of babesiosis in cattle and buffaloes was calculated using meta-analysis tools using R-software and Q Statistics. RESULTS: The systematic review and meta-analysis performed on 47 studies among bovine, 48 studies among cattle, and 13 studies among buffaloes revealed the (pooled) prevalence of babesiosis in India as 10.9% (6.3%-18.2%; Q = 5132.03, d.f. = 46, P < 0.001), 11.9% (6.9%-19.8%; Q = 5060.2, d.f.=47, P < 0.001), and 6.0% (2.6%-13.2%; Q = 500.55, d.f.=12, P < 0.001), respectively, which provides a rather exact scenario of the prevalence of this haemoparasitic disease across the country. In addition, cattle were having higher risk of babesiosis than buffalo. CONCLUSION: The findings from the meta-analysis showed that the disease is prevalent across the country, and that bovines are highly affected by it. CLINICAL RELEVANCE: Appropriate prevention and control measures should be taken to mitigate this disease and enhance welfare and production performances of bovines.

Identification and assessment of stress and associated stressors among veterinary students in India using a cross-sectional questionnaire survey.

Background: Veterinary education, is a rigorous professional training program, which exposes students to significant academic and non-academic pressures. The identification of stressors and stress levels among veterinary students mighty help the designing and implementation of coping strategies to protect the students' mental health. Methods: A 44-item based cross-sectional questionnaire survey was prepared and disseminated among veterinary students in India to identify the stressors responsible, measure the amount of stress, and relate stress to characteristics like gender, degree year, and family income. A total of n = 611 veterinary students across 14 states including 27 colleges/universities participated in the study. The collected data was evaluated for sampling adequacy, construct validity, and reliability using a set of statistical tests. Results: The analysis revealed high sampling adequacy with a KMO value of 0.957 and a highly significant anti-image correlation (p < 0.001). The principal component analysis generated six factors or subscales which effectively explained 51.98% of the variance in the data, depicting high construct validity. The Cronbach's alpha value of 0.957 revealed high internal consistency for the questionnaire. Analysis revealed more than 94% of pupils under stress, with levels ranging from moderate to severe. Academic-related stressor (95.58%) was the leading cause of overall stress in the present study followed by inter- and intrapersonal and career related-stressors (93.12%) and exams and evaluation-related stressor (90.99%). In comparison to male students, female students reported significantly higher levels of overall stress, academic stress, and intrapersonal and interpersonal stress (p < 0.001) using Chi-square. The students from lower-income families experienced significantly higher overall stress as well as stress due to family responsibilities (p < 0.001). The first-year undergraduate students reported significantly higher (p < 0.001) stress due to family responsibilities-related stressors whereas second-year students due to social activities-related stressors. The hierarchal regression model predicted that gender, family income, academic-related stressors, inter- and intrapersonal and career-related stressors, and social activities-related stressors can be employed to evaluate overall stress among students, as they ensured the maximum variance in the data (p < 0.001). Conclusions: To the best of our knowledge, this is the first Indian study to identify stressors, quantify associated stress and predict major attributes to be targeted in future studies for veterinary students.

5d CIDR-Heatsynch improves the circulatory estradiol levels, estrus expression and conception rate in anestrus buffalo (Bubalus bubalis).

The present study aimed to investigate whether increasing estradiol (E2) during preovulatory period would increase estrous expression, luteal profiles and conception rate in 5d CIDR based timed AI protocol. A total 156 anestrus buffalo allocated (78 per group) to either 5d CIDR-Cosynch (d-5: CIDR + GnRH; d0: PGF2α+CIDR removal; 72 h post-CIDR removal: GnRH) or 5d CIDR-Heatsynch (d-5: CIDR + GnRH; d0: PGF2α+CIDR removal; 24 h post-CIDR removal: estradiol benzoate) group. All the buffaloes inseminated at 72 and 84 h post-CIDR removal. A subset of buffalo (n = 58) were subjected to examination of the follicle diameter and luteal profile during protocol, post-AI on days 5 and 12. The buffalo in 5d CIDR-Heatsynch had greater (p < .05) E2 concentrations, estrus induction and increasing trend (p < .08) for conception rate (57.7% vs. 43.6%) than 5d CIDR-Cosynch. The percentage of pregnant buffalo that exhibited estrus signs was greater (p < .01) in 5d CIDR-Heatsynch than 5d CIDR-Cosynch. Positive correlation (p < .01) was observed between POF and E2 concentrations; POF and CL diameter, CL diameter and P4 concentrations. Estrus response and P4 concentrations were indicators of probability of pregnancy. In conclusion, 5d CIDR-Heatsynch tended to improve conception rate. The estrus expression and P4 concentrations (d5 and 12 post-first-AI) is the indicator of probability of pregnancy in buffalo.

Mathematical modeling for egg production and egg weight curves in a synthetic white leghorn.

This study was conducted to evaluate 8 mathematical models, namely, Logistic (LM), Morgqan Mercer Flodin (MMF), Polynomial Fit (PF), Rational Function (RF), Sinusoidal Fit (SF), Quadratic fit (QF), Gompertz function (GF), and Modification Compartmental Model (MCM) fitted to weekly egg production and egg weight of synthetic White Leghorn (SWL) population 21 to 40 wk of age of 5 generations (2015-16 to 2019-20). The relevant data for the present investigation were collected from SWL population, maintained in the department of Animal Genetics and Breeding, LUVAS, Hisar (India). The efficiency or reliability of the models were obtained by various criteria of goodness of fit such as coefficients of determination (R2), Root Mean Square Error (RMSE), Akaike's Information Criterion (AIC), Bayesian Information Criterion (BIC), graphical analysis, and Chi-square test. The results indicated that RF, MCM, SF, and PF were best models for fitting weekly egg production curve due to higher values of R2 and low values of RMSE, AIC, and BIC as compare to remaining models. In case of weekly egg weight, the best values of goodness of fit criteria were showed by MMF model followed by MCM and LM model. The results indicated that these models could be conveniently used for fitting for weekly egg production and egg weight in synthetic white leghorn, respectively.

Genetic Parameters for First Lactation and Lifetime Traits of Nili-Ravi Buffaloes.

The data on first lactation and lifetime performance records of 501 Nili-Ravi were collected for a period from 1983 to 2017 (35 years) maintained at ICAR-Central Institute for Research on Buffaloes, Sub-Campus, Nabha, Punjab. The data were analyzed to calculate heritability, genetic and phenotypic correlation for first lactation traits, viz., Age at First Calving (AFC), First Lactation Total Milk Yield (FLTMY), First Lactation Standard (305 days or less) Milk Yield (FLSMY), First Peak Milk Yield (FPY), First Lactation Length (FLL), First Dry Period (FDP), First Service Period (FSP) and First Calving Interval (FCI), Herd Life (HL), Productive Life (PL), Productive Days (PD), Unproductive Days (UD), Breeding Efficiency (BE), Total Lifetime Milk Yield (Total LTMY), Standard Lifetime Milk Yield (Standard LTMY), Milk Yield Per Day of Productive Life (MY/PL), Milk Yield Per Day of Productive Days (MY/PD), and Milk Yield Per Day of Herd Life (MY/HL). For estimation of variance component and heritability separately for each trait, the uni-trait animal model was equipped, whereas to estimate genetic and phenotypic correlations between traits, bi-trait animal models were fitted. The estimates of heritability for production and reproduction traits of Nili-Ravi were medium, i.e., 0.365 ± 0.087, 0.353 ± 0.071, 0.318 ± 0.082, 0.354 ± 0.076, and 0.362 ± 0.086 for FLSMY, FDP, FSP, FCI, and AFC, respectively. The estimates of heritability were low, i.e., 0.062 ± 0.088, 0.123 ± 0.090, 0.158 ± 0.090, 0.155 ± 0.091, and 0.129 ± 0.091 for HL, PL, PD, Total LTMY, and Standard LTMY and high, i.e., 0.669 ± 0.096 for BE. Genetic correlation for FLTMY was high with FLL (0.710 ± 0.103), and genetic correlation of FLTMY was high and positive with HL, Total LTMY, MY/PL, and MY/PD while low and positive with PL. Genetic correlation of AFC was low and negative with PL, PD, UD, BE, Total LTMY, Standard LTMY, MY/PL, and MY/PD and negative with MY/HL. Significant positive phenotypic association of FPY was seen with FLTMY, FLSMY, FLL, AFC, HL, Total LTMY, and Standard LTMY. Higher heritability of first lactation traits especially FPY suggests sufficient additive genetic variability, which can be exploited under selection and breeding policy in order to improve overall performance of Nili-Ravi buffaloes.

Estimates of covariance components and genetic parameters for growth, average daily gain and Kleiber ratio in Harnali sheep.

The aim of the present study was to estimate the (co)variance components and genetic parameters for various growth traits (weight at birth (BWT) and 3 (WT3), 6 (WT6), 9 (WT9), and 12 (WT12) months of age), average daily gain (ADG1, 0-3; ADG2, 3-6; and ADG3, 6-12 months of age), and Kleiber's ratio (KR1:ADG1/WT30.75 and KR2:ADG2/WT60.75) by using records of 526 lambs of 41 sires and 186 dams in Harnali Sheep maintained at Department of Animal Genetics and Breeding, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar (Haryana), India for the period of year 2014-2019. Restricted maximum likelihood procedure (REML) was employed for estimation of covariance components and genetic parameters by considering direct effects with or without maternal effects. The estimates of direct heritability for BWT, WT3, WT6, WT9, WT12, ADG1, ADG2, ADG3, KR1, and KR2 were 0.10, 0.45, 0.32, 0.36, 0.23, 0.43, 0.02, 0.001, 0.38, and 0.02, respectively. It was observed that maternal effects had significant influence on BWT trait only, and corresponding estimate of maternal heritability was 0.16. This indicated the importance of maternal ability in Harnali sheep for initial growth performance. Moderate estimate of direct additive heritability of weaning weight (WT3) and moderate genetic correlations of it with other traits indicated that the current practice of selection at 6 months may be replaced by early selection at WT3 in order to improve the growth performance in Harnali sheep.

Genetic divergence studies on reproduction and production traits among Gir crosses.

The study was undertaken to estimate the genetic divergence among FG, IFG, FJG, IFJG, and R crosses of Gir cow on the basis of age at first conception, age at first calving, and lactation milk yield per day of lactation length using Mahalanobis D2 statistics. The genetic groups' influence was significant (P < 0.01) for all traits separately and simultaneously (V test) based on three traits. The differences in the D2 values among all the genetic groups' combinations were significant except IFG with R genetic group combination. The total D2 values for age at first conception (AFCon), age at first calving (AFC), and lactation milk yield per day of lactation length (LMY/LL) were 18.85, 0.06, and 9.01 respectively. The percent contribution of AFCon to the total D2 value was maximum as 67.51 followed by LMY/LL as 32.27 and lowest of AFC as 0.22. Among the clusters formed on the basis of D2 values, IFG, IFJG, and R formed one cluster, whereas, FG and FJG formed second cluster. The magnitude of inter-cluster distance was greater than intra-cluster distance.

A systematic review and meta-analysis of prevalence of subclinical mastitis in dairy cows in India.

The purpose of the study was to provide the pooled estimate of the prevalence of subclinical mastitis among dairy cows in India and to examine the consistency of those estimates between published studies. We have conducted a systematic review of prevalence of subclinical mastitis in dairy cows for the period 1995-2014 using electronic and non-electronic databases. Meta-analysis of 28 studies was done under random effects model using Metaprop package in R software. The pooled estimate of prevalence of subclinical mastitis on cow-basis was obtained using 6344 cows from 25 studies and was found to be 46.35 % (95 % CI 39.38; 53.46). Meta-analysis for quarter-wise prevalence of subclinical mastitis was carried out using 18,721 udder quarters of dairy cows from 23 studies, and the pooled estimate of prevalence of subclinical mastitis on quarter-basis was found to be 23.25 % (95 % CI 18.15; 29.27). Meta-analysis showed that there is statistically high heterogeneity for the prevalence estimates between published studies. The present study reported that there is high prevalence of subclinical mastitis in dairy cows in India, which might be responsible for low productivity in lactating cows in India over the years and needs to be controlled by adopting scientific, managemental, and therapeutic measures. Dairy farmers can reduce incidence and economic losses due to subclinical mastitis under the guidance of field veterinarians.