Journal of Animal Research: v.5 n.2, p. 227-230. June 2015
DOI Number: 10.5958/2277-940X.2015.00039.X
Non-Genetic Factors Affecting Growth and Production Traits in
Dorper Crossbred Sheep
Vikas bin Zaffer, Raman K. Taggar and Dibyendu Chakraborty *
Division of Animal Genetics and Breeding
FVSc & AH, SKUAST-Jammu, R. S. Pura, Jammu, J & K, INDIA
* Corresponding author: D Chakraborty;
Received: 04 September, 2014
Accepted: 30 May, 2015
Data on growth traits of 401 animals used in the present study were collected from history sheet of crossbred sheep maintained
at Government Sheep Breeding Farm Panthal, Reasi, J&K, India. Traits included in the study were birth weight (BWT), weaning
weight (WWT), 6-month body weight (6-BW), 12-month body weight (12-BW), mature body weight (MBW) and annual wool
production (AWP). The statistical analysis was carried out using LSMLMW computer programme. The overall least-squares
means were 2.857 ± 0.058 kg, 15.269 ± 0.296 kg, 17.034 ± 0.258 kg, 22.315 ± 0.298 kg, 29.375 ± 0.237 kg and 0.651 ± 0.012
kg, respectively for BWT, WWT, 6-BW, 12-BW, MBW and AWP. The co-efficient of variations for different traits were low to
moderate. Period of lambing had significant effect on all the traits except for BWT. Moreover, there was no definite trend for
different traits over different periods except for 12-BW, where increasing trend was obtained. Season of lambing had significant
effect only on WWT and MBW. Genetic group had non-significant effect on all the traits under study although, 50% genetic
groups were superior for most of the traits. Sex had significant effect on all the traits except for 6-BW and 12-BW. It can be
concluded from the study that growth traits and production traits are influenced by different non-genetic factors like period,
season and sex.
Keywords: Growth traits, Non-genetic factors, Dorper crossbred sheep, Annual wool production.
Improved production from our native sheep breeds is,
crossbreeding the desirable goal can be achieved in short
therefore, need of the day and to achieve broad avenues
span of time.
appear to be open. Either the sheep at hand must be
Birth weight, weaning weight, 6-month weight and
induced to yield more by selective breeding or to secure
12-month weight are the indicators of individual
concentrated doses of good genes as replacement from
performance and they have direct effect on the productivity
improved exotic breed into our native sheep breeds, which
and health status of sheep. These are the important factors
as they influence lamb’s survival and growth. The animals
our animals. The genetic improvement can be done, either
weighing heavier at birth and weaning have a better
by selection or by cross-breeding the indigenous breeds
survivability and may grow faster and likely to increase
with exotic fine wool breeds. Selection of genetically
the overall productivity.
superior animals is influenced by non-genetic factors
such as year, season and sex etc. due to which there is
Early growth traits are important factors influencing
difficulty in estimating the differences in breeding values
profitability in any meat producing enterprise. The birth
of individuals being selected, therefore identification and
weight of an animal and its early growth rate are highly
their correction factors will help in estimation of genetic
influenced by genetic potential of sheep. Therefore,
parameters. The improvement on account of selection
genetic studies on growth and production traits will be
could be achieved only after several generations, but by
ideal model for future on the basis of which selection can