Analysis of association between various fertility indicators and production traits in Mehsana buffaloes.

Female fertility in domestic animals in India has exhaustively suffered owing to indiscriminate breeding with single objective of increasing milk production. First lactation data on 7782 Mehsana buffaloes sired by 184 bulls maintained under field progeny testing programme at Dudhsagar Research and Development Association, Dudhsagar Dairy, Mehsana, over a period of 24 years were used for study of fertility traits viz. days open, first to successful service period (FTSS) and daughter pregnancy rate (DPR) and production traits viz. first lactation milk yield (FLMY), first lactation fat yield (FLFY) and average fat percentage (AFP). The voluntary waiting period (VWP) was standardised based on the higher estimates for FLMY and FLMY per unit first calving interval. VWP for Mehsana buffaloes was standardised as 63 days after first calving and consequently DPR of Mehsana buffalo was also estimated as 31%. Fertility traits were further evaluated in terms of production traits. Regression analysis revealed that the increase in 1 kg FLFY and 100 kg FLMY led to the increase of First Service Period by 0.013 days and decrease in the DPR by 1.89%, respectively. Increase in milk yield led to increase in FTSS. However, for each 100 kg increase in fat yield and 1% increase in AFP, there is increase in DPR by 0.08% and 0.051%, respectively. Based on the present findings, it may be recommended to have a breeding programme which give due weightage to both production and fertility traits.

Elucidation of genotype-environment interactions and genetic stability parameters for yield, quality and agromorphological traits in ashwagandha (Withania somnifera (L.) Dunal).

The present study was undertaken to delineate genotype-environment interactions and stability status of 16 genotypes of ashwagandha (Withania somnifera (L.) Dunal) in context to the 12 characters, namely plant height, number of primary branches, number of secondary branches, days to flowering, days to maturity, number of berries, number of seeds/berry, root length, root diameter, root branches, dry root yield and total alkaloid content (%). Experiment was carried out in a randomized complete block design with three replicationsover three different locations (S. K. Nagar, Jagudan and Bhiloda) in north Gujarat for three years (2016-17, 2017-18 and 2018-19). Pooled analysis of variance revealed that the mean squares due to genotypes and genotype 9 environment interaction along with linear and nonlinear components were highly significant (P<0.01) for most of the traits under study. Stability parameters for component traits through Eberhart and Russell model showed that genotypes that can be used directly in breeding programme are SKA-4 for early flowering, SKA-21 for early maturity and SKA-1, SKA-4, SKA-6 and SKA-17 for shorter plant height. Further, SKA-21 could be used for improving number of primary branches per plant, SKA-11 and SKA-17 for number of secondary branches per plant, SKA-19 for number of berries per plant, SKA-6, SKA-21, SKA-27 and AWS-1 for root branches and SKA-17 for root length as these genotypes were found to be moststable across the environments for mentioned traits. The result revealed that some reliable predictions about genotype 9 environment interaction and its unpredictable components were involved significantly in determining the stability of genotypes. Hence, the present investigation can be exploited for the identification of more productive genotypes in specific environments, leading to significant increase in root productivity of ashwagandha.