Data on 2,365 Mecheri sheep (1,201 males and 1,164 females), maintained at the Mecheri Sheep Research Station, Pottaneri, India, and recorded between 1979 and 2006, were analysed to study the growth related traits and their genetic control. The body weights at different ages (i.e. at birth, weaning (3 months), 6, 9 and 12 months) were recorded and collected from the birth and growth registers maintained in the farm. The average weights of Mecheri sheep at birth, and at 12 months of age were 2.24±0 .

The present study was conducted to calculate the genetic parameters for direct and maternal in uences on Mecheri sheep growth features by Bayesian analysis using multi-trait animal model for designing suitable breeding application and genetic assessment methodologies. The genetic determinants for varying body weights at different ages were calculated using data from 2825 Mecheri lambs born between 2010 and 2020 that were kept in a warm and semiarid climate. Mecheri sheep body weight (mean ± SE) at various stages viz., BW, WW and BW12 were 2.6 ± 0.01, 11.1 ± 0.05 and 20.7 ± 0.13 kg respectively. The direct estimates of heritability (± SD) for BW, WW, BW6 and BW12 were 0.21 ± 0.041, 0.21 ± 0.041, 0.12 ± 0.052 and 0.13 ± 0.053 respectively and the maternal heritability for BW, WW, BW6 and BW12 was 0.18 ± 0.021, 0.08 ± 0.023, 0.11 ± 0.022 and 0.13 ± 0.033, respectively. Estimates of maternal heritability suggests that even at later stages, there were considerable maternal effects. For several growth traits, positive estimates of additive genetic connections were observed, with values ranging from low to high. The additive genetic correlation between WW and BW6, BW9 and BW12 was 0.70 ± 0.145, 0.57 ± 0.171 and 0.50 ± 0.194. The maternal genetic correlations ranged from 0.06 ± 0.152 (BW-BW12) to 0.86 ± 0.046 (BW6-BW9) and the residual correlation increased progressively from 0.18 ± 0.034 (BW-WW) to 0.85 ± 0.013 (BW9-BW12). The medium to high estimates of heritability and genetic correlation of body weight parameters at various ages in Mecheri sheep indicated the genetic potential for all traits. In general, the features WW and BW6 both refer to the same genetic growth process, hence, it is recommended to undertake single trait selection based on weight at weaning age rather than using the present selection procedure of weight at six-month of age. By choosing the top performers from the Mecheri sheep ocks, it is possible to take advantage of the strong genetic potential for improvement in these parameters.

Cotton gin trash (CGT) is composed of fibreresidues, leaves, dust particles, soil, and other materials derived during the ginning and yarn-spinning process inprocessing industries. In the cotton-spinning industrial clusters, farmers are using CGT as one of the alternative roughage feeds for their sheep, mainly during forage shortages in the summer months. Baseline information on farmers using gin and the factors driving them to choose CGT as a roughage source needs to be identified for future planning regarding the usage of CGT in sheep feeding. Considering the above facts, the present study was undertaken to assess the socio-personal characteristics and managemental practices associated with farmers using cotton gin in the feeding of sheep; also, it was conducted to identify the factors driving the choice of the CGT as the primary source of roughage in the cotton-spinning industry cluster of Tamil Nadu, India. For this, a survey among 80 sheep farmers was carried out using a pre-tested interview schedule. The collected data were analysed using descriptive statistics and logit regression. The results indicated that the majority of male, aged, and large-land farmers were involved in practicing CGT feeding during the summer and also indicated the non-availability of green fodder during the same period of time. The coarse type of CGT is preferred over the fine type of CGT trash in that area due to quality perception and price. The replacement level of CGT as roughage ranged from 33 to 75% of the total roughage requirement per day. About 88% of farmers were highly satisfied with the results of using CGT and they also expressed that the presence of foreign particles and dust was the major problem with using CGT. The choice of CGT as primary roughage among sheep farmers was primarily influenced by selective farming contexts, namely, landholding, access to labour, and the feeding practices of other livestock with cotton gin. Furthermore, research needs to be focused on improving the quality of CGT in the future as it is being utilised largely by sheep farmers.

The progression of genetic selection techniques to enhance farm animal performance traits is guided by the present level of genetic variation and maternal impact in each trait, as well as the genetic association between traits. This study was conducted on a population of Mecheri sheep maintained from 1980 to 2018 at Mecheri Sheep Research Station, Pottaneri, India, to determine variance and covariance components, as well as genetic parameters for various production performance traits. The production traits of Mecheri sheep assessed include: birth weight (BW), weaning weight (WW), six-month weight (SMW), nine-month weight (NMW) and yearling weight (YW). The Bayesian approach using the Gibbs sampler analyzed six animal models with different combinations of additive direct and maternal additive effects was used. Direct genetics, maternal genetics and residual effects models were the major significantly contributors to total phenotypic variation for all the production traits studied. Direct heritability estimates of birth weight, WW, SMW, NMW and YW were 0.25, 0.20, 0.12, 0.14 and 0.13, respectively. The maternal heritability estimated for BW, WW, SMW, NMW and YW were 0.17, 0.10, 0.12, 0.14 and 0.14, respectively. The maternal effects had a major impact on the pre-weaning production traits. The genetic correlations estimated between different pairs of production traits studied ranged from 0.19 to 0.93. The body weight at birth exhibited higher genetic relationship with weaning weight than post-weaning growth characteristics, and the genetic correlation between weaning weight and post-weaning attributes was moderate to high (0.52 to 0.72). Based on the additive genetic variance in weaning weight and the correlation estimates of weaning weight with post-weaning traits, the weaning weight was proposed as a selection criterion for improving growth traits in Mecheri sheep.