MSc

An investigation was undertaken to evaluate the lactation performance of the crossbred cattle (Zebu x Taurus) and to compare the performance of Brown Swiss and Jersey crosses under field conditions so that a breeding policy could be recommended. First lactation milk yield in 305 days, age at first calving and first lactation length were the characters studied. For this, data on the Brown Swiss crossbred maintained by the farmers at Mavelikkara and Kattappana and on Jersey crossbreds at Kanjirappally and Chalakudy under the milk recording – cum – progeny testing scheme of the Kerala Livestock Development and Milk Marketing Board were utilized. The observations spread over a period of four years from 1978 to 1981.
The uncorrected average first lactation yields were 1508.8 + 14.3 kg in Brown Swiss half – breds, 1562.6 + 28.7 kg in unclassified Brown Swiss crosses, 1380.3 + 47.0 kg in Jersey half – breds and 1558.0 + 31.5 kg in unclassified Jersey crosses.
The least squares means of first lactation yields in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half – breds and unclassified Jersey crosses were 1482.0 + 19.7 kg, 1544.7 + 32.4 kg, 1359.2 + 57.4 kg and 1559.8 + 37.3 kg respectively. The Duncan’s multiple range test showed that the Jersey half – breds had significantly lower production compared to all other genetic groups. The production of unclassified Jersey crosses had been significantly higher than the Brown Swiss half – breds as well as Jersey half – breds.
Least squares analysis on pooled data and Brown Swiss half – breds showed the significant influence of age at first calving, year of calving and sex of the calf on first lactation milk yield. But, season of calving did not significantly influence the milk yield.
The uncorrected average age at first calving in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half _ breds and unclassified Jersey crosses were 46.0 + 0.4 months, 38.4 + 0.6 months, 41.7 + 1.4 months and 39.5 + 1.2 months respectively. The least squares means of age at first calving in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half – breds and unclassified Jersey crosses were 46.0 + 0.5, 38.0 + 0.8, 41.1 + 2.1 and 38.9 + 1.5 months respectively. Brown Swiss half – breds had significantly higher age at first calving compared to the other three groups which were homogenous.
The effect of year on age at first calving was not significant in Brown Swiss half – breds while pooled data analysis showed a significant effect of year on age at first calving.
The uncorrected average lactation lengths in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half – breds and unclassified Jersey crosses were 300.5 + 0.5 days, 299.6 + 1.0 days, 295.6 + 2.4 days and 295.3 + 1.7 days, respectively. This shows that all the crossbreds had fairly good lactation length.
Lactation milk yield and age at first calving are economically important to the farmer and in this context these two characters are to be considered together. The results obtained do not indicate the superiority of either Brown Swiss or Jersey crossbreds, over the other. The introduction of both Brown Swiss and Jersey improved the milk production of the cattle of Kerala. While aiming at a further improvement, emphasis should be given to the merit of the sires rather than the specificity of the exotic breed or the percentage of exotic inheritance.