Chandrashekhar S. Patil

Estimates of genetic parameters for fat yield in Murrah buffaloes.

Aim: The present study was performed to investigate the effect of genetic and non-genetic factors affecting milk fat yield and to estimate genetic parameters of monthly test day fat yields (MTDFY) and lactation 305-day fat yield (L305FY) in Murrah buffaloes. Materials and Methods: The data on total of 10381 MTDFY records comprising the first four lactations of 470 Murrah buffaloes calved from 1993 to 2014 were assessed. These buffaloes were sired by 75 bulls maintained in an organized farm at ICAR-National Dairy Research Institute, Karnal. Least squares maximum likelihood program was used to estimate genetic and non-genetic parameters. Heritability estimates were obtained using paternal half-sib correlation method. Genetic and phenotypic correlations among MTDFY, and 305-day fat yield were calculated from the analysis of variance and covariance matrix among sire groups. Results: The overall least squares mean of L305FY was found to be 175.74±4.12 kg. The least squares mean of overall MTDFY ranged from 3.33±0.14 kg (TD-11) to 7.06±0.17 kg (TD-3). The h2 estimate of L305FY was found to be 0.33±0.16 in this study. The estimates of phenotypic and genetic correlations between 305-day fat yield and different MTDFY ranged from 0.32 to 0.48 and 0.51 to 0.99, respectively. Conclusions: In this study, all the genetic and non-genetic factors except age at the first calving group, significantly affected the traits under study. The estimates of phenotypic and genetic correlations of MTDFY with 305-day fat yield was generally higher in the MTDFY-5 of lactation suggesting that this TD yields could be used as the selection criteria for early evaluation and selection of Murrah buffaloes.

Short Note: Seed Source Variation in Seedling and Nodulation Characters in Dalbergia sissoo Roxb

Abstract Study was conducted involving 20 seed sources of Dalbergia sissoo Roxb., collected from the greater part of its distributional range to understand the variation, particularly in nodulation pattern associated with seed sources. Seedling height, number of nodules per seedling and seedling biomass exhibited strong seed source dependent variation. While collar diameter and nodule diameter showed statistically non-significant differences among seed sources. Significant positive correlations were observed between growth characters (seedling height, collar diameter and root length). Highly significant positive correlation was observed between total number of nodules/seedling with root length and seedling dry matter indicating the influence of root length on nodulation and in turn the effect of nodulation on seedling biomass production. The selection therefore, should be aimed at seed source with highest level of susceptibility to root nodulation with rhizobia which could perform well in the initial stages of plantation establishment on poor sites.

Influence of non-genetic factors on performance traits in Murrah buffaloes

The study on 522 Murrah buffaloes scattered over 19 years (1993 to 2011) in NDRI Livestock Farm was conducted to reveal the effect of non-genetic factors on performance traits. The fixed linear models were used to estimate the effect of nongenetic factors. The overall least-squares means of Age at First Calving (AFC), Service Period (SP), Days to First Service (DFS), Lactation Length (LL), Test Day 5 Milk Yield (TD 5 MY) and 305 days or less Milk Yield (305 DMY) were obtained as 44.03 ± 0.38 months, 146.28 ± 5.58 days, 89.28 ± 2.23 days, 286.08 ± 2.23 days, 8.13 ± 0.12 kg and 2078.20 ± 31.21 kg, respectively. Season of birth had significant effect (P<0.01) on AFC, autumn was the favourable season of birth for Murrah buffaloes. Season of calving significantly influenced (P<0.01) SP and DFS, where rainy and autumn were observed as favourable for fertility in Murrah buffaloes. Period of calving and parity had significant effect on reproduction traits (P<0.05) and production traits (P<0.01), except lactation length. Age group at first calving significantly influenced SP (P<0.01) and LL (P<0.05). Since, temporary environmental factors play a major role on performance traits, better breeding management should be implemented.

Genetic parameters of fertility and production traits in Murrah buffaloes

Data of 522 Murrah buffaloes sired by 72 bulls scattered over a period of 19 years (1993 to 2011) maintained at National Dairy Research Institute, Karnal were edited to records of 404 buffaloes upto fourth lactation for estimating the genetic parameters of fertility and production traits. Fertility was defined in terms of pregnancy rate (PR), while production traits included Test Day Five Milk Yield (TD 5MY), 305 Days or less Milk Yield (MY) and 305 days or less Wet Average (WA). The heritability of PR, TD 5 MY, MY and WA were estimated as 0.02 ± 0.005, 0.12 ± 0.04, 0.17± 0.04 and 0.15 ± 0.03. The repeatability of PR, TD 5 MY, MY and WA were estimated as 0.09 ± 0.04, 0.18 ± 0.05, 0.27 ± 0.04 and 0.26 ± 0.04. The pregnancy rate had low negative phenotypic correlations with TD 5 MY (-0.09 ± 0.03), MY (-0.08 ± 0.04) and WA (-0.12 ± 0.02). The magnitudes of phenotypic correlation indicated that Murrah buffaloes have good fertility and is not declining sharply with the increasing of milk production in the herd. Better breeding management should be maintained for sustaining reproduction and production efficiency.