Association of DRB 3 EXON 2 Alleles with Productive and Reproductive Performance of Crossbred Cattle

Bovine leukocyte antigen (BoLA) is essentially responsible for disease resistance in cattle; however there is possibility of its association with other economically important traits. BoLA has been studied extensively for DRB3 gene polymorphism in zebu as well as exotic cattle and their association with several disease resistance traits. In this report we tried to study the association of DRB3 polymorphism in crossbred cattle with milk characteristics and reproduction status. A total of 11 alleles were found in the population that had more than 3% frequency. Least squares mean for 305 days milk yield in crossbred cows was 2412.79±68 kg and average daily milk protein yield was 2.98±0.02 g. In the study we could not see statistically significant association of DRB3 polymorphism with the milk yield or milk protein content of the crossbred cattle, indicating they are independent of each other. For reproductive status of cattle, we could clearly see the biased distribution of alleles for the repeat or normal breeders. Alleles DRB3*0801, *0701, *2801 and *1505 were exclusive to normal breeder category. Similarly alleles *1101, *0801, *1801 and *1601 had higher frequency in normal breeder category. There was no allele exclusive to repeat breeder category, however, alleles *3201, *0201 and *1103 had tendency to fall in repeat breeder category

Bayesian Statistics: Concepts and Applications in Animal Breeding – A Review

Statistics uses two major approaches- conventional (or frequentist) and Bayesian approach. Bayesian approach provides a complete paradigm for both statistical inference and decision making under uncertainty. Bayesian methods solve many of the difficulties faced by conventional statistical methods, and extend the applicability of statistical methods. It exploits the use of probabilistic models to formulate scientific problems. To use Bayesian statistics, there is computational difficulty and secondly, Bayesian methods require specifying prior probability distributions. Markov Chain Monte-Carlo (MCMC) methods were applied to overcome the computational difficulty, and interest in Bayesian methods was renewed. In Bayesian statistics, Bayesian structural equation model (SEM) is used. It provides a powerful and flexible approach for studying quantitative traits for wide spectrum problems and thus it has no operational difficulties, with the exception of some complex cases. In this method, the problems are solved at ease, and the statisticians feel it comfortable with the particular way of expressing the results and employing the software available to analyze a large variety of problems

Evaluating animal models comprising additive genetic and maternal effects on growth traits in German Angora rabbit

[EN] This investigation was carried out to estimate the genetic parameters for German Angora rabbits using most appropriate animal model comprising additive and maternal effects. The pedigree information and data on growth traits were collected from 5221 rabbits, which descended from 699 does and 294 bucks over a period of 21 yr (2001 2021) kept at Northern Temperate Regional Station, Garsa, Kullu (Himachal Pradesh), India. The average daily gain (ADG) and Kleiber ratio (KR) were calculated at different age intervals. Analyses were carried out by restricted maximum likelihood procedure fitting six animal models with various combinations of direct and maternal effects. The best model was evaluated on the basis of a likelihood ratio test. Analysis revealed that the model including both direct and maternal genetic effects along with permanent effect of the dam was most suitable for all traits except for body weight (BW) at 6th wk of age, ADG from 6th to 12th wk of age and KR associated to ADG from 12th to 18th wk of age. The direct heritability estimates from the best model were ranged from, 0.34±0.05 to 0.49±0.05 for BW; 0.19±0.04, to 0.46±0.06 for ADG and 0.21±0.04 to 0.41±0.05 for KR, respectively. Direct heritability estimates were overestimated when maternal effects were ignored. Maternal effects on BW declined from 0.49±0.04 at weaning to 0.06±0.03 at 12th wk of age and 0.09±0.04 at 18th wk of age. Correlations between direct and maternal effects ranged from ?0.44±0.15 to?0.52±0.14 for body weights, indicating biological antagonism between these effects. Genetic correlations among various growth traits were positive and high, indicating scope for correlated response in later expressed traits. Analysis revealed that maternal additive influences were only important until weaning, whereas permanent environmental maternal influences were present in all growth traits considered in this study. The moderate estimates of heritability for growth traits and Kleiber ratio of rabbit in this study indicate that rates of genetic progress may be possible for these traits by selection under the standard management system.Authors are thankful to acknowledge the contribution of the all former in-charges, associated with the German Angora Rabbit projects and technical staffs for management and recording of data. The support provided by Director, ICAR-CSWRI, Avikanagar, in providing the necessary facilities and funds for execution of the project is also gratefully acknowledgedRahim, AR.; Rajaravindra, KS.; Chaudhary, R.; Chaturvedi, OH.; Gowane, GR. (2024). Evaluating animal models comprising additive genetic and maternal effects on growth traits in German Angora rabbit. World Rabbit Science. 32(3):161-174. https://doi.org/10.4995/wrs.2024.1856216117432

Construction of new selection criteria for Malpura sheep

Malpura sheep is one of the heavy mutton type sheep breeds found in semi-arid region of Rajasthan. Objective of the study was to revise the earlier selection criteria and set up a new one for Malpura sheep. The data on 2,995 Malpura sheep descended from 188 sires and 1,021 dams for 11 years (2004–2014) was used to construct the indices using various combination of traits. Genetic parameters were estimated for the traits to be included in the analysis for the data. Estimate of additive genetic variance for 6 month live weight (6WT) was low (h2 = 0.19±0.04). It was recommended to incorporate external germplasm for enhancing the additive genetic variability of the flock. The selection indices were constructed and highest accuracy (51.9%) was observed for the index that involves weaning weight (WWT) and first greasy fleece weight (GFW). Estimated genetic gain after 1 generation post selection was measured to be 221 g in WWT and 81.753 g in GFW. Possibility of direct selection for single trait (6WT) was explored. Results revealed higher response for 6WT (897 g) and high correlated response for other traits such as WWT (0.566 kg), ADG1 (5.601 g), ADG2 (3.132g) and GFW (26.52 g) as compared to index selection. As milk yield of dam has strong influence on pre-weaning gain, preliminary selection at weaning followed by direct selection at 6 month age based on single trait selection (6WT) was recommended as selection criteria

Estimation of (co)variance components for body weight traits in intercross synthetic sheep

This study was carried out on the recently developed intercross sheep developed from Bharat merino and Gaddi sSynthetic in the temperate region in the state of Himachal Pradesh of India. Study aimed to estimate the genetic parameters and (co)variance components for body weights at birth (BW) and 3-month (3BW), 6-month (6BW), 9-month (9BW) and 12-month (12BW) month age in a closed flock of intercross sheep maintained at North Temperate Regional Station of ICAR-CSWRI, Garsa, India. Data records on 1505 sheep descended from 565 dams and 154 sires over the period of 10 years were utilized. Data were corrected for possible fixed environmental effects such as lambing year, parity, sex of lamb, ewe weight at lambing for further genetic analysis. The restricted maximum likelihood procedure fitting animal models with different combinations of direct and maternal effects were used for genetic analysis. Analysis revealed significant influences of lambing year, parity, sex of lamb and ewe weight at lambing on studied traits. Direct heritability estimates for BW, 3BW, 6BW, 9BW and 12BW were 0.14±0.04, 0.18±0.05, 0.00±0.04, 0.05±0.05 and 0.05±0.05, respectively. Maternal effects significantly influenced the BW and estimated maternal heritability for the trait was 0.17±0.03. The correlation among body weights were medium to high except between BW and 12BW and it ranged from 0.16±0.51 to 0.99±0.19. Results suggest that maternal effects were important for initial growth performance. The heritability estimates for weaning weight was moderate and its positive association with other growth traits indicated that the present selection practice at six months may be shifted to early selection at weaning weight for further genetic improvement

Sequence based typing for BoLA-DQA1 alleles in Indian zebu and its crossbred populations

Polymorphism in the major histocompatibility complex of the bovine, which is referred to as bovine leukocyte antigens (BoLAs), was intensively investigated for identifying marker(s) for bovine diseases and immunological traits. This approach requires identifying and documenting the allelic diversity of BoLA among different breeds of cattle using PCR-SBT technique. In this study, we could standardise the most useful approach of unravelling polymorphism in DQA1 exon 2 of cattle using PCR-sequence based typing (SBT). We could identify 16 different DQA1 alleles in 43 zebu and crossbred cattle, out of which 26 were homozygous and 17 were heterozygous. PCR- SBT has proved to be the most useful method for exploring the allelic polymorphism in DQA1 gene in zebu and its crossbred cattle in our study. Further use of this technique is equally appropriate for all kinds of traits i.e. production, reproduction and growth type of traits and beneficial for establishing new breeding objectives

Factor analysis for udder and teat type traits in Sahiwal and Karan Fries cows

Selecting female cows for productivity based on udder and teat traits is essential in field due to lack of available records. The objective of the present study was to reduce the dimensionality of the 17 udder and teat traits and to analyse their impact on milk productivity. The data on 256 cattle comprising 133 Sahiwal and 123 Karan Fries cows were used in this study over the years 2017-2019 from Livestock Research Centre (LRC) of ICAR-National Dairy Research Institute, Karnal. The 17 udder and teat traits were fore udder attachment (FUA), rear udder width (RUW), rear udder height (RUH), udder balance (UB), udder depth (UD), udder length (UL), udder width (UW), udder circumference (UC), central ligament/udder cleft (CL), teat circumference (TC), fore teat length (FTL), rear teat length (RTL), distance between fore and rear teat (DFR), distance between left and right teat (DLR), shortest distance from floor to fore teat (SDFT), shortest distance from floor to rear teat (SDRT) and teat diameter (TD). In the factor analysis, first five latent factors accounted for 62.22% of total variance in udder and teat measurements for Sahiwal cows and 65.67% in Karan Fries (KF) cows, respectively. In Sahiwal cows F1 represented better udder support and wideness (wide udders, udders were supported by strong suspensory ligament), whereas in KF cows, first factor reflected better udder dimension and distance between teats (longer length, width of udder and well placed teats). Factor analysis could reduce the multicollinearity of the data. It can be concluded that inclusion of udder and teat measurements in selection index can be a reliable criteria for selecting cows for higher milk yield

Farmer challenge-derived indicators for assessing sustainability of low-input ruminant production systems in sub-Saharan Africa

The process of consulting stakeholders, particularly farmers, in developing appropriate indicators for sustainability evaluation of low-input ruminant systems is often compromised by limited awareness and understanding of the sustainability concept by farmers in developing countries. Insights from farmers’ challenges present useful prospects for developing context-specific sustainability evaluation indicators for low-input ruminant systems. In the present review, a meta-analysis was used to develop farmer challenge-derived indicators for the sustainability evaluation of low-input ruminant farming system in sub-Saharan Africa. Key ecological challenges reported were low forage quality, poor soil quality, feed shortages and; economic challenges were low poor marketing structure, high cost of labour, and poor transport network, poor marketing infrastructure; and social challenges were rural to urban migration, lack of animal breeding management and inadequate access to information. The corresponding derived ecological indicators were biomass quality, soil quality, high winds; economic indicators were available marketing infrastructure, labour costs, transport networks; and social indicators were rural to urban migration, animal management training and access to information. The review shows that farmers’ challenges can be transformed to indicators for assessing the sustainability of the low-input ruminant farming system in sub-Saharan Africa.The Department of Science and Technology-National Research Foundation (DST-NRF) Centre of Excellence (CoE) in Food Security.http://www.journals.elsevier.com/environmental-and-sustainability-indicatorshj2020Gordon Institute of Business Science (GIBS

Genetic analysis of growth parameters and survival potential of Jamunapari goats in semiarid tropics

Goats are adaptable to varied farming environments and contribute significantly towards sustainable livestock production and food security. Selective breeding of goats for improved performance is an important component of sustainable production. The objectives of the present study were to determine the most appropriate models of analysis for growth traits, to estimate genetic parameters, survival potential of kids from birth to 12 months of age and to estimate genetic trends for growth traits of Jamunapari kids at different ages. Genetic parameter estimates were obtained from 6590 records generated between 1982 and 2012 from 5922 animals with a pedigree covering over 13 generations. The most parsimonious model for early growth traits included permanent environmental effects due to the dam (PE) and litter effects. Similarly, the most appropriate model for early average daily gain (ADG) between birth and 3 or 6 months also included PE and litter effects. The estimates of heritability for survival from birth to 12 months of age ranged from 0.10 to 0.43. The estimates of heritability for ADG varied from 0.04 to 0.41. In general, higher estimates of heritability were observed when a sire model was fitted in the random effect. There was no genetic variation observed for survival between birth and 3 months of age. However, heritability estimates of between 0.18 and 0.39 were observed for survivability during post-weaning period to 12 months of age. The genetic trend at 9 months of age and 12 months of age was 0.144 kg 0.189 kg per year respectively. The genetic trend at all the ages was positive during the study period.<br/