Impact Of Genotypes And Parity On Reproductive And Productive Attributes In Dairy Cattle Of Natore District, Bangladesh

Abstract

Impact of genotypes and parity on some vital reproductive and productive attributes in the local (L×L, n = 100) and four crossbred cows (L×F, L×SL, L×JR and L×S; n = 318) raised in randomly selected smallholder dairy farms scattered all over Natore District and adjacent areas have been assessed during a period from September 2007 to June 2010. With regard to reproductive attributes, significant differences existed among the cattle genotypes (P<0.05) except for gestation length (GL) and age at weaning (AW). The lowest age at puberty (AP) was found for L×F (21.42±0.37 months), while the highest for L×L (31.67±0.74 months). In terms of productivity, L×F cows produced the highest daily milk yield (DMY; 6.22±0.13 L), coupled with the highest total lactation yield (TLY; 2163.43±47.77 L), while L×L produced the lowest values (1.49±0.04 L and 416.40±12.3 L, respectively) for the traits. The effect of parity on both reproductive and productive attributes showed that the middle-aged dairy cows of the 3rd and 4th parities performed better than the younger (1st and 2nd parities) or the older (5th and beyond) ones. Considering the overall performance, the L×F cows could be ranked as the best genotype followed by their L×SL, L×JR, L×S and L×L counterparts in the study area. DOI: http://dx.doi.org/10.3329/jles.v6i0.9727 JLES 2011 6: 91-96