Journal of Animal Research: v.5 n.2, p. 223-226. June 2015
DOI Number: 10.5958/2277-940X.2015.00038.8
Identifying the Factors Affecting Birth Weight and Conception Rate
in Sahiwal Bulls
Binoy Chandra Naha 1 , Atish Kumar Chakravarty 2 , Mohsin Ayoub Mir 2* , C. S. Patil 3 ,
Arun Pratap Singh 2 and Dinesh Maher 2
1 Department of Animal Genetics, ICAR-Indian Veterinary Research Institute, Izatnagar, Barielly, Uttar Pradesh, INDIA.
2 Dairy Cattle Breeding Division, ICAR-National Dairy Research Institute, Karnal, Haryana, INDIA.
3 Department of Animal Genetics and Breeding , LUVAS, Hisar, Haryana, INDIA
* Corresponding author: MA Mir; Email: mohsinvet546@gmail.com
Received: 17 January, 2015
Accepted: 10 April, 2015
ABSTRACT
The data on growth and fertility traits of 43 Sahiwal bulls during 27 years (1987-2013) belonging to 8 sets of Sahiwal Breeding
Project at ICAR-National Dairy Research Institute, Karnal (Haryana), India were analysed using fixed linear model to assess the
effect of non-genetic factors on birth weight and fertility traits in Sahiwal bulls. The average birth weight (BW), conception rate
based on first AI (CRFAI) and overall conception rate (OCR) in Sahiwal bulls was estimated as 22.19 ± 0.05 kg, 45.95 ± 1.37%
and 46.38 ± 1.55%, with coefficient of variation of 13.42%, 21.84 % and 22.32%, respectively. The overall least-squares means
for birth weight, conception rate based on first AI and overall conception rate was estimated as 22.04 ± 1.08 kg, 46.24 ± 0.35%
and 46.86 ± 0.27%, respectively in Sahiwal breeding bulls. Period of birth had not influenced the birth weight of Sahiwal bulls,
though period of conception had significant (P < 0.01) effect on fertility traits. Season of birth/AI, parity and age of female did
not influenced the birth weight and fertility traits of Sahiwal bulls.
Keywords: Birth weight, conception rate, fertility, non-genetic factor, Sahiwal bull
The birth weight is an important economic trait affecting
date, most fertility related studies in dairy animals have
subsequent growth rate and other performance traits. The
done on female fertility but male fertility has not been
reproduction parameters in animals are more influenced
investigated substantially in India. The differences in
by environment (Mukhopadhyay et al., 2010). Under
bull management studies have shown differences among
breed improvement programme sires are considered to be
conception rate in different bulls (Gerard and Humblot,
“more than half of the herd” because; the contribution of
1991). In contrast to genetic evaluations for performance
bull in genetic improvement of herd is more than cow. The
and conformation traits, only a bull’s own records
term fertility denotes the ability of an animal to produce
contribute to his male fertility evaluation. Effect of non-
young ones. Male fertility is regulated by animal’s genetic
genetic factors can be assessed in terms of factors that
disposition and environmental factors. More conception
affect an entire herd. The non-genetic factors such as
rate of the bull is useful to improve the productive and
period, season, parity, stage of lactation and age of female
reproductive performance in the herd. Bull fertility helps
can influence the birth weight and conception rate of
in improving the herd reproductive performance. Fertility
the bull. Therefore, the present study was undertaken to
of the bull is often measured by the percentage of cycling
investigate the influence of various non-genetic factors on
cows exposed to the bull and impregnated during a specific
birth weight and fertility traits to suggest suitable selection
time period, usually 60 – 90 days (Hamilton, 2006). Till
strategies for improvement of Sahiwal bulls.