The research is conducted to, ¡nvestigate the difference between cross bred
dairy cows (Kenana x Friesian) with local breed (kenana) in sorne reproductive traits.
The research also seek for the best cross that can be kept in the research
area.
200 dairy cows including local breed ( kenana.) 50%62.5% and 75% cross
bred dairy cows were studied ¡n five suecessive years (1997-200 1) The average birth
weight was 21.5, 25.4,25,9 and 25,6 kgs for local, breed 50%, 62.5% and 75%
respectively. Furthermore number of services per conception was 138, 1.36, 1.36, and
1.47, for the local 50% 62.5% and 25% respectively On the other hand the average of
first calving age weight was 262.6, 358.9, 376.2 for local 50%, 62 and 75%
respectively, the average gestation penod per cow was 281.1 282.4 and 282.9 days
for ¡ocal 50 62.5 and 74% respectively. The statistícal analysis showed that 62.5%
crossbred cows had better performance than the others.
The research concluded that extension should encourage the famiers to adopt
62% hybrid to carry out further studies on milk production for the different breeds.
Keywords: Dairy cows, reproductive
INTRODUCTION
Tropical dairy cows suffer from many factors the low quality forage, hot
stress, disease and low production. Genetic improvement is one of the main
tools that can increase the production In addition to environmental
¡rrprovement. cross breeding is one of the effective means that can upgrade
the production of kenana and Butaria cows which are the best milk producing
cows in the sudan.
Researchs were carried out to raise the yield of local breed Saeed et
a!. (1988).
50% cross herd cows were the best in the environment of Sudan and
to sub extence 62.5% Dairy farm was attached to kenana Sugar company in
1981 and fewer kenana cows had been adapted there . professionals in
kenana scheme began to improve their herd by crossing loca' breeds with
pure Fresiari.
The study is seeking for the best rate that may show better r productive
performance ¡n the (SSR) Analysis.
MATERIALS AND METHODS
The research area
The research is going carried out in kenana Sugaz' company dairy farm.