Genetic evaluation of reproductive traits in Jersey crossbred heifersat an organized farm of eastern India

Abstract

The present study was conducted on data of reproductive traits (viz., age at first service and age at first calving) in Jersey crossbred heifers, maintained at the Eastern Regional Station of ICAR-National Dairy Research Institute, Kalyani, West Bengal over a period of 38 years to determine the effects of genetic and non-genetic factors. The data were classified according to season of birth, period of birth of animals and distributed in eight genetic groups having different level of Jersey inheritance. The least square mean of age at first service (AFS) and age at first calving (AFC) were 750.61±12.35 and 1089.36±13.99 days respectively. Sire had highly significant (P<0.01) influence on both AFS and AFC in the present study whereas, the genetic group had only significant effect on age at first calving. The half-bred of Jersey and Tharparkar crosses (1/2 Jersey-1/2 Tharparkar) had significantly lower AFC (987.47±43.21 days) than half-bred of Jersey and Red Sindhi and other crosses in this study. Moreover, the animals having less than 50 % and more than 62.5 % Jersey inheritance had highest AFC than other crosses. On the other hand, period of birth had significant effect on both AFS and AFC; however, season of birth only influenced AFC. Heritability estimates of AFS and AFC were observed 0.46±0.19 and 0.30±0.19 respectively. Strong genetic correlation (0.81±0.19) was estimated between these traits. Since, these traits have moderate to high heritability, it indicates faster improvement of these traits through selection.

Genetic Parameters for First Lactation and Lifetime Traits of Nili-Ravi Buffaloes

“…In accordance with our findings, Chaudhari ( 8 ) recorded medium heritability for FSP and FCI in Nili-Ravi. Medium heritability for AFC was reported by Kumar et al ( 13 ) in Murrah, Singh and Yadav ( 14 ) in Nili-Ravi, and Kumar et al ( 15 ) in cattle. In contrast, high heritability was observed for the FLTMY and FLSMY in Nili-Ravi ( 3 ).…”

“…in Murrah,Singh and Yadav (14) in Nili-Ravi, and Kumar et al(15) in cattle. In contrast, high heritability was observed for the FLTMY and FLSMY in Nili-Ravi (3).…”

Estimation of direct and maternal covariance along with genetic and phenotypic trends of reproduction traits in Murrah buffalo

“…In contrast, Kumar et al. (2016) illustrated a wider range of heritability (0.04 to 0.10) and maternal effects (0.06 to 0.09), highlighting the diverse genetic nature of SP across different cattle populations. Radwan et al.…”

“…Comparing our findings with the breadth of existing research, Kumar and Mandal's (2021) study on Jersey crossbred cows reported a higher heritability ranging from 0.14 to 0.20 and a similar maternal effect (m 2 = 0.00 to 0.02), emphasizing the shared genetic influences but with higher heritability in their study. In contrast, Kumar et al (2016) illustrated a wider range of heritability (0.04 to 0.10) and maternal effects (0.06 to 0.09), highlighting the diverse genetic nature of SP across different cattle populations. Radwan et al (2017) explored SP in Holstein cattle, revealing a higher heritability (0.49 to 0.233) and substantial additive genetic variance (2226.61 to 3275.48), signifying breed-specific complexities.…”

​An Evaluation of the Reproductive Performance of Sahiwal Heifers in the High Humid Climatic Condition of Assam

“…Lower than the present finding has been reported by Narwaria et al (2015) and Wakchaure and Meena (2010) in Sahiwal cows being 1136.14 ± 10.48 days and 1078.09 ± 21.12 days, respectively. Kumar et al (2017) studied in Jersey crossbred heifers and found 1089.36 ± 13.99 days of age at first calving with the coefficient of variation 14.27%. A relatively higher value for age at first calving was reported by Rehman et al (2008) in Sahiwal cows (1390 ± 3.9 days) and Moulick et al (1972) in Deshi cows (44.5 ± 6.8 months).…”