Studies on age at first semen freezing and age at first semen use of Sahiwal bulls

Abstract

The objective of this study was to investigate the studies on the reproduction traits i.e. Age at first semen freezing and Age at first semen use in Sahiwal bulls. Informations on Sahiwal bulls during last 27 years (1987-2013) were collected from reproductive records, bull AI register maintained at different sections of institute viz. record room of DCB Division, Cattle Yard, Artificial Breeding Research Centre (ABRC), National Dairy Research Institute (NDRI), Karnal. The present study revealed that the average Age at first freezing and Age at first use in Sahiwal breeding bulls were estimated as (3.17 ± 0.01) years and (5.35 ± 0.01) years, respectively and the coefficient of variation were 18.93% and 20%, respectively. It was found that highest rank was in Set VIII^th and lowest rank was in Set IV^th for early Age at first semen freezing of Sahiwal bull. For early Age at first semen use of bull, highest rank was in Set IX^th and lowest rank was in Set III^{th .} Since, temporary environmental factors are major role in inheritance of traits so better breeding management should be implemented. Multi-trait evaluation with reproductive traits may be carried out for simultaneous improvement of reproductive performances of Sahiwal bulls in the herd.