dc.description.abstract | To assess the growth performance of the different cattle genotypes from birth to 18 month of age
at Songa Research Station in Rwanda, this study was designed. Records of animals born between
1998 and 2008 were evaluated using nested statistical model. Four cattle genetic groups:
crossbreds of Ankole dams with Brown Swiss, Friesian, Jersey and Sahiwal were used in the
study. Birth weight was not significantly affected by genotype, sex of the calf year and season of
birth. However the calves sired by Brown Swiss and Friesians were heavier than those sired by
Jerseys, while calves sired by Sahiwal were intermediate. Effects of genotype, year of birth and
season of birth on weaning weight were all highly significant (P<0.001) Weaned Friesian x
Ankole calves (FA) were significantly heavier than those of all other genotypes except Brown
Swiss X Ankole (BA) and Sahiwal X Ankole (SA) crossbreds. The heaviest calves were born
during season 4 of the year, though weaning weights across seasons did not differ significantly
(P>O.05). Male weaned calves (179.3 ± 6.0 kg) were heavier than female weaners (164.6 ± 9.9
kg). A wide range of weaning weight for BA and FA genotypes were observed, compared with
the range of mean weights for JA, SJA, SA, and SJA suggesting that genotypes containing Jersey
and Sahiwal genomes are more resilient to environment pressure. Mature weights of animals was
significantly affected by genotype (P<0.01), sex (P<0.0001), and year of birth (P<0.0001) while
season and its interaction with genotype (P>0.05) did not influence it. Overall, genotype BA
grew faster??? than all other genotypes though its growth rate was not significantly higher than
. genotype FA, while the lowest growth rate was registered in genotype SA. However, the speed
of growth was similar to those in genotypes JA, SJA, SA and SJA. From results, it was
concluded that AS, AJS and ASJ were suitable genotype for Rwanda. The major factors to
consider during the breeding of the various genotypes include season of birth and year of birth. | en |