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 maternal and additive effect on reproduction and productive traits in Hardhenu cattle.

The study aimed to assess performance traits in Hardhenu cattle by analysing data from 445 animals born to 59 sires and 227 dams. The investigation focused on estimating (co)variance components and genetic parameters for reproduction and production traits in dairy cattle. Results from least-squares analysis indicated a significant effect (p < .01) of the period of calving (POC) on key production traits, including first lactation milk yield (FLMY), 300-day milk yield (FLMY300), first peak yield (FPY) and total lactation milk yield (TLMY) in studied population. The least squares means for these traits were reported as follows: FLMY (2665.68 ± 45.66 kg), FLMY300 (2425.52 ± 34.41 kg), FLL (312.95 ± 3.83 days), FPY (11.52 ± 0.15 kg) and TLMY (9282.44 ± 167.03 kg) in Hardhenu cattle. In the studied population, only additive genetic variability was found to be present and there was absence of any significant maternal effect with respect to targeted traits in the resource population. Direct heritability estimates (h2) for FLMY, FLMY300, FLL, FPY, TLMY and other traits ranged from 0.03 to 0.41 in Hardhenu cattle. These findings offer valuable insights into the genetic factors influencing performance traits, contributing to the enhancement of breeding and management practices in Hardhenu cattle.

Comparative analysis of tuberculin and defined antigen skin tests for detection of bovine tuberculosis in buffaloes (Bubalus bubalis) in Haryana state, India.

BACKGROUND: Bovine tuberculosis (bTB) is a chronic disease that results from infection with any member of the Mycobacterium tuberculosis complex. Infected animals are typically diagnosed with tuberculin-based intradermal skin tests according to World Organization of Animal Health which are presently in use. However, tuberculin is not suitable for use in BCG-vaccinated animals due to a high rate of false-positive reactions. Peptide-based defined skin test (DST) antigens have been identified using antigens (ESAT-6, CFP-10 and Rv3615c) which are absent from BCG, but their performance in buffaloes remains unknown. To assess the comparative performance of DST with the tuberculin-based single intradermal test (SIT) and the single intradermal comparative cervical test (SICCT), we screened 543 female buffaloes from 49 organized dairy farms in two districts of Haryana state in India. RESULTS: We found that 37 (7%), 4 (1%) and 18 (3%) buffaloes were reactors with the SIT, SICCT and DST tests, respectively. Of the 37 SIT reactors, four were positive with SICCT and 12 were positive with the DST. The results show that none of the animals tested positive with all three tests, and 6 DST positive animals were SIT negative. Together, a total of 43 animals were reactors with SIT, DST, or both, and the two assays showed moderate agreement (Cohen's Kappa 0.41; 95% Confidence Interval (CI): 0.23, 0.59). In contrast, only slight agreement (Cohen's Kappa 0.18; 95% CI: 0.02, 0.34) was observed between SIT and SICCT. Using a Bayesian latent class model, we estimated test specificities of 96.5% (95% CI, 92-99%), 99.7% (95% CI: 98-100%) and 99.0% (95% CI: 97-100%) for SIT, SICCT and DST, respectively, but considerably lower sensitivities of 58% (95% CI: 35-87%), 9% (95% CI: 3-21%), and 34% (95% CI: 18-55%) albeit with broad and overlapping credible intervals. CONCLUSION: Taken together, our investigation suggests that DST has a test specificity comparable with SICCT, and sensitivity intermediate between SIT and SICCT for the identification of buffaloes suspected of tuberculosis. Our study highlights an urgent need for future well-powered trials with detailed necropsy, with immunological and microbiological profiling of reactor and non-reactor animals to better define the underlying factors for the large observed discrepancies in assay performance, particularly between SIT and SICCT.

Seroprevalence and risk factors associated with Toxoplasma gondii in pigs in Haryana, India.

AIMS: Toxoplasmosis is one of the most common food-borne parasitic zoonosis, caused by Toxoplasma gondii, an obligate intracellular protozoan parasite. A cross-sectional study was carried out to determine the seroprevalence of T. gondii and associated risk factors in pigs in Haryana, India. METHODS AND RESULTS: Serum samples were collected from 429 pigs from three agroclimatic zones (I-III) of Haryana and analysed for the presence of antibodies against T. gondii using a commercial indirect enzyme-linked immunosorbent assay (ELISA). Anti-T. gondii antibodies were detected in 106 animals (24.7%), with the highest seropositivity in zone II (31.3%) followed by zone III (24.4%) and zone I (18.3%). Risk factors associated with higher seropositivity in pigs were farm size (higher in large-sized farms), age (higher in pigs >1 year of age), sex (higher in males), type of feeding (higher in combination of homemade and hotel waste) and housing (higher in free-ranging pigs). CONCLUSIONS: The findings of the study testify to the exposure of pigs (of all agro-climatic zones) to T. gondii. Hence, the observations are of significant medical and veterinary importance for devising and implementing control measures to check the dissemination of toxoplasmosis to pigs and eventually to humans.

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.

Modelling the growth curve and estimation of associated genetic parameters in Munjal sheep.

The study of growth curves in sheep is an effective approach to monitor the animal development for predicting the growth rate and improving overall flock performance. The purpose of the present work was to study the growth curve traits of Munjal sheep using different non-linear models and to estimate the genetic parameters of those traits for the possibility of inclusion of them under selection strategy. Total 2285 weight records at birth, 3, 6 and 12 months of age of 706 lambs born to 48 sires and 149 dams were collected from the registers maintained from 2004 to 2019. Various non-linear growth models viz., Brody, Gompertz, logistic, Bertalanffy and negative exponential were fitted to targeted growth curve traits and then evaluated using goodness of fit criteria such as adjusted R2, root means square error (RMSE), Akaike's information criterion (AIC) and Bayesian information criterion (BIC). The genetic parameters of growth curve traits were estimated using animal model. The results suggested that Brody model was best fitted to the data than other models. The growth curve estimates for mature weight (A), inflexion point (B) and rate of maturation (k) under Brody model were 25.82 ± 1.72, 0.84 ± 0.04, and 0.21 ± 0.04, respectively for female lambs, and 29.55 ± 2.04, 0.86 ± 0.03 and 0.19 ± 0.04, respectively for male lambs. The males showed superiority for mature weights whereas female lambs had higher maturation rates. The estimates of direct heritability for A, B and k were 0.33, 0.41 and 0.10, respectively. The moderate estimate of direct heritability of A and its negative genetic correlation with k indicated the scope of genetic improvement through selection based on mature weights. Therefore, it was concluded from the present findings that Brody model was the one that best describes the growth curve in the Munjal sheep and the selection based on mature weights can be employed for genetic improvement of Munjal flock.

Evaluation of physiological and morphological parameters for early prediction of prenatal litter size in goats.

The aim of the present study was to evaluate the physiological and morphological parameters of pregnant does for early prediction of prenatal litter size. In total, 33 does were screened using ultrasonography and further categorized into three groups based on does bearing twins (n = 12), a single fetus (n = 12), or non-pregnant does (n = 9). The rectal temperature °F (RT) and respiration rate (RR) as physiological parameters, while abdominal girth in cm (AG) and udder circumference in cm (UC) as morphological parameters were recorded at different gestation times, i.e. 118, 125, 132 and 140 days. In addition to this, age (years) and weight at service (kg) were also used. The statistical analyses included analysis of variance (ANOVA) and linear discriminant analysis (LDA). The results indicated that groups had significant (P < 0.05) differences among morphological parameters at each gestation time, with higher AG and UC in does bearing twins followed by a single fetus and non-pregnant does. However, both physiological parameters were non-significantly (P > 0.05) associated with litter size groups. It was also revealed that the studied parameters showed increasing trends over gestation time in single and twin fetus categories, but they were on par among non-pregnant does. The results of the LDA revealed that estimated function based on age, weight at service, RR, RT, AG and UC had greater (ranging from 75.00 to 91.70%) accuracy, sensitivity and specificity at different gestation times. It was concluded that using an estimated function, future pregnant does may be identified in advance for single or twin litter size, with greater accuracy.

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.

Effect of BsaA I genotyped intronic SNP of leptin gene on production and reproduction traits in Indian dairy cattle.

In the present study, candidate single nucleotide polymorphism (SNP) g.92450765 G > A of leptin gene was explored for Bos indicus cattle with an aim to explore its possible effect on production and reproduction traits. The genotypic and allelic frequencies of BsaA 1 genotyped SNP g.92450765 G > A indicated the predominance of AG (0.65) genotyped Sahiwal cows in our studied population. The least-squares analysis showed a significant association (p < 0.05) of identified genetic variants with total milk yield (TMY) and 305 days milk yield (MY) (p < 0.05). The GG genotyped cows were found to be associated with higher milk yields. However, for reproduction traits under study AA genotype was found to be more favorable with respect to service period and calving interval (p < 0.05). Computational analysis was also performed to predict changes if any in the transcription factor binding sites (TFBS) caused due to the identified SNP in the intronic region of the leptin gene. TFBS analysis predicted that the targeted SNP at g.92450765G > A may lead to the disappearance of TFBS such as Hypermethylated in cancer 2 protein (HIC2), Max-binding protein MNT (MNT), Cyclic AMP-dependent transcription factor -3 (ATF3), Myc-associated factor X (MAX) and Microphthalmia-associated transcription factor (MITF). It may lead to changes in transcriptional regulation.

Influence of single nucleotide polymorphism in the IGF-1 gene on performance and conformation traits in Munjal sheep.

Genetic polymorphism research in livestock species aims to assess genetic differences within and among breeds, primarily for conservation and development objectives. The aim of the present study was to determine the point mutation in the IGF-1 gene (g.855G>C and g.857G>A) and its association with performance traits in Munjal sheep. In total, 50 Munjal sheep were selected and the genomic DNA was isolated using the Automated Maxell RSC DNA/RNA purification system and the Maxwell RSC whole blood DNA kit. A reported set of primers was used to amplify the 294-bp fragment encompassing the targeted region, i.e. the 5' flanking region of the IGF-1 gene. The polymerase chain reaction product of 294-bp size harbouring the g.857G>A mutation in the 5' flanking region of the IGF-1 gene was digested with HaeII enzyme. Three possible genotypes were defined by distinct banding patterns, i.e. GG (194, 100 bp), GA (294, 194, 100 bp) and AA (294 bp) in the studied population of Munjal sheep. The genotypic and allelic frequencies of g.857G>A single nucleotide polymorphism of the IGF-1 gene indicated that the frequency of the A allele was higher in the studied population, i.e. 0.59 and the GA genotype was found to be the predominant genotype (0.66). Allele A of the IGF-1 gene was found to be associated with higher body weights and can be used in selection criteria for improving the performance of Munjal sheep. The positive effect of the IGF-1 gene on several conformational traits as observed in this study suggests that this area of the ovine IGF-I gene is particularly important and warrants further investigation on a larger population size.

Candidate K232A mutation of DGAT1 gene associated with production and reproduction traits in Indian Dairy cattle.

The present study was conducted on Hardhenu and Sahiwal cows to evaluate the genetic diversity and the effect of candidate K232A mutation of diacylglycerol O-acyltransferase (DGAT1) gene on performance traits. PCR product of 413 bp size targeting K232A mutation of DGAT 1 gene was genotyped by Eae1 restriction enzyme and further confirmed by sequencing. The PCR-RFLP analysis for K232A showed that the frequencies of alleles K and A were 0.80 and 0.20 in Hardhenu and 0.98 and 0.02 in Sahiwal cattle, respectively. The frequencies of genotypes for KK and KA genotype were estimated as 0.60 and 0.40 in Hardhenu and 0.96 and 0.04 in Sahiwal cattle, respectively. Chi-square test showed that K232A SNP did not meet with the Hardy-Weinberg equilibrium (p < .01) in Hardhenu cattle. Association analysis revealed that KA genotype was significantly associated with total milk yield (p < .01) and 305 days milk yield (p < .01)in Hardhenu cattle. Hardhenu cows having KA genotype comparatively revealed favorable mean values for AFS (880.31 ± 26.65), AFC (1166.36 ± 19.94), SP (157.46 ± 22.80), CI (441.41 ± 44.28) and AI/Conception (1.80 ± 0.17), indicating that KA genotype can be used as a candidate marker for simultaneous improvement of both production and reproduction traits.

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.

Efficacy and Safety of Inosine Pranobex in COVID-19 Patients: A Multicenter Phase 3 Randomized Double-Blind, Placebo-Controlled Trial.

Inosine pranobex (IP), an immunomodulatory agent, is used in the treatment of various viral infections. The results of a phase 3 randomized controlled trial are reported, evaluating the efficacy and safety of IP in the treatment of mild to moderate COVID-19. It includes 416 symptomatic patients with confirmed SARS-CoV-2 infection. In addition to a defined standard of care, patients  randomly (1:1) receive either IP 500 mg tablet (IP group) or a matching placebo (placebo group) at 50 mg kg-1 body weight/day rounded to the nearest 500 mg dose (maximum 4 g day-1) administered in 3-4 divided doses for 10 days. Compared to the placebo group, IP group shows significantly higher rates of clinical response (CR) and clinical cure (CC) on Day-6 for both non-hospitalized patients and the total population. IP group shows significantly earlier CR and CC with fewer adverse events and no mortality. Based on these findings and the fact that IP increases natural killer cell-mediated cytotoxicity of virus-infected cells as an early immune response to viral infection and enhances NKG2D ligand expression, it is concluded that IP should be started early to maximize the benefit in mild to moderate COVID-19 patients. (Trial registration number: CTRI/2021/02/030892).

Neural network and Bayesian-based prediction of breeding values in Beetal goat.

The estimation of breeding values is prime concern for animal breeders in order to achieve desired genetic progress of farm animals. However, current methods for estimating BV involve simultaneous selection of animal model which are computationally intensive and time-consuming. The present attempt was made to predict breeding values of weaning trait under artificial neural networks (ANN), Bayesian technique (BT), and multiple regression (MR) methods. The data records comprising year of birth, sex, type of birth, dam's weight at kidding, birth weight, weaning weight, and estimated breeding values (BV) for weaning weight (under animal model) pertaining to 849 kids born to 37 sires and 237 dams between 2004 and 2019 were used in this study. All three methods, viz., ANN under multilayer perceptron (2 hidden layers), BT under Markov chain Monte Carlo (MCMC) approach, and MR under full model, were used for 75% training dataset initially and prediction model developed was applied on 25% test dataset. The initial analysis showed positive and significant (P < 0.01) relationship of BV with other variables which hinted that BV may be predicted with accuracy. Then, it was revealed from the results indicated that ANN, BT, and MR methods have similar accuracy (r = 0.86 to 0.87) for prediction of BV. However, ANN showed slightly higher but negligible model adequacy than BT and MR method. The prediction error under three methods was almost equal. The results indicated that these methods could be used as potential alternative for recurrent prediction of BV based on phenotypic data in order to optimize selection plans at young age in resourced population of Beetal goat.

Estimation of inbreeding and its effects on growth traits in Beetal goat.

The purpose of the present study was to estimate the inbreeding coefficient and its effects on various growth traits in Beetal goat using pedigree records of 963 kids born to 38 sires and 287 dams over the period of 2004 to 2019. The inbreeding coefficients for each individual were obtained under animal model. The effects of inbreeding along with other fixed effects such as year of birth, sex of kid, type of birth, and dam's weight at kidding on growth traits viz., weight at birth (BWT), 3 (WT3), 6 (WT6), 9 (WT9), and 12 (WT12) months of age were studied using least-squares analysis. Additionally, average daily gain and Kleiber ratio up to weaning age (90 days) were studied under the same model. The overall inbreeding coefficient was low in magnitude (1.42%) and ranged from 0 to 25% over the study period. The significant (P < 0.05) increase in average inbreeding coefficient (%) over the years was observed among the studied population. Although, the effects of various factors had significant (P < 0.05) influence on growth traits under least-squares model, the regression of targeted traits on inbreeding were non-significant (P > 0.05) and the same ranged from - 0.06 to 0.04. The present findings indicated that there was no inbreeding depression among the growth traits of Beetal goat. However, as inbreeding (%) raised in recent years only, the scientific efforts must be taken to avoid inbreeding at resourced population by introducing new germplasms at earliest.

Survival analysis for estimating lamb survival up to weaning in Harnali sheep.

The present study was carried out to estimate lamb survival (in days) from birth to weaning under survival analysis using data records from 2057 Harnali lambs born to 134 sires and 623 dams between the period from 2001 to 2020. The weaning age in resourced population was 90 days from birth. The hazard ratio in terms of risk of death up to weaning was determined using Cox proportional hazards model by subjecting some fixed factors such as year of birth, sex of lamb, birth weight (kg), dam's weight at lambing (kg) and dam's age at lambing (years). The overall survivability up to weaning among lambs was 91.59% and Kaplan-Meier estimates of mean survival time up to weaning was 85.77 days. Cox proportional hazard modelling revealed that the hazards of death up to weaning was higher in male lambs [1.66, 95% confidence interval (CI): 1.22-2.26] compared with female lambs [hazard ratio (HR) = 1.00]. It was also observed that the hazards of death (HR = 0.91, 95% CI: 0.88-0.94) had decreasing trends over years. For birth weight (kg), hazard rate was 0.34 (95% CI: 0.25-0.46), which indicated that the risk of pre-weaning mortality was lower as birth weight increases. The weight and age of dams at lambing did not influence the survival time of studied population. The present findings indicated that survival time increased in studied lambs over the years and it could be increased more by giving more emphasis on better litter weight and general health aspects at farm level.

Investigation of cause-specific pre-weaning mortality in Harnali sheep.

Lamb mortality is an important aspect in sheep production system which affects farm profitability worldwide. The aim of the present study was to investigate the causes of pre-weaning mortality (PWM) in Harnali lambs with respect to various associated factors. The data records of 173 lambs which died before 90 days of age (weaning age) out of 2057 lambs born during 2001-2020 year were collected from various registers, and the respective causes of mortality were taken from the post-mortem reports. The association of various factors such as age, sex, period of birth, birth weight of lamb and causes of death with PWM was assessed using chi-square test and log-linear modelling. The results showed that respiratory and digestive diseases were major causes of PWM. The log-linear modelling showed significant (P < 0.05) association of age, sex and period of birth with PWM. In the first month of age, digestive disease was the predominant cause of death; however, with age of lamb advances, respiratory disease was more prevalent. It was also revealed that male lambs (odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.24, 0.97) had lesser deaths due to respiratory diseases as compared to digestive disease. The reverse scenario was observed in female lambs. The findings of the present study might be helpful for understanding the risks and common causes of PWM in lambs to implement appropriate management practices in order to reduce economic losses to sheep farmers.

Meta-analysis of MspI derived variants of growth hormone gene associated with milk yield in dairy cattle.

OBJECTIVE: The present work aimed to obtain common effect sizes for the gene frequency and association of MspI derived variants of growth hormone (GH) gene with milk yield in dairy cows. METHODS: We performed a systematic review and meta-analysis of 35 published studies identified in literature search from 2000 to 2020 (n = 4164). These studies were specific to fragment size (329) for genotypes viz., CC (224, 105 bp), CD (329, 224, 105 bp) and DD (329 bp). Pooled standard mean differences (SMDs) as effect sizes between allele pairs were derived using different genetic models. The heterogeneity between effects sizes across studies was estimated using I2 Index (%). RESULTS: The common effect size for gene frequency of allele C (224, 105 bp) was significantly (P < 0.05) higher in 2881 Bos taurus/cross cows (0.82; 95% CI: 0.74, 0.89; I2 = 97.81%) than 1283 Bos indicus cows (0.15; 95% CI: 0.12, 0.18; I2 = 71.90%), with overall gene frequency was 0.33 (95% CI: 0.21, 0.46; I2 = 99.29%). Additive (CC vs. DD) and dominant (CC + CD vs. DD) did not revealed significant (P > 0.05) association with milk yield. However, completely over dominant (CC + DD vs. CD) and recessive (CC vs. CD + DD) models showed significant (P < 0.05) and positive SMDs with milk yield specially at early lactations. There was no evidence of heterogeneity (I2 = 0.00%) between SMDs across studies. CONCLUSIONS: This meta-analysis suggested potential association of C allele for enhancing milk production of dairy cows.

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.