Reproductive and lactation performances of Ayrshire and Boran crossbred cattle kept in smallholder farms in Mufindi district, Tanzania
Livestock Research for Rural Development
Department of Animal Science and Production, Sokoine University of Agriculture, P.O.Box 3004, Morogoro, Tanzania
This study was carried out to determine the reproduction and lactation parameters of Ayrshire x Boran F1 crosses kept by small-scale farmers in Mufindi district, Tanzania. The study involved 48 small-scale dairy farmers located in six villages. The mean (± s.e.) herd size of the selected farmers was 3.7 ± 0.3. Data on breeding dates, calving dates, drying off dates, daily milk yield and deaths of calves were obtained from records kept by the selected farmers from 1997 to 2007. The data were used to compute age at first calving, calving interval, days open, number of services per conception, calf mortality, lactation milk yield, lactation length and dry period. The overall mean for age at first calving (AFC) was 38.4 ± 0.5 months and for calving interval was 402.6 ± 3.0 days. The AFC was significantly (P ≤ 0.001) influenced by the season of birth while calving interval was significantly (P ≤ 0.001) affected by the year of calving and parity. The overall mean length of the days open period was 100.7 ± 3.6 days. Year of calving, season of calving and parity significantly (P≤ 0.05) affected the length of the days-open period. The number of services per conception was between 2 and 3. The overall calf mortality rate was 18.2% and was significantly (P ≤ 0.05) influenced by year of birth and sex of the animal. The overall mean lactation length was 287.7 ± 2.5 days. Lactation milk yield increased with parity from 1260.6 to 1760.5 litres in the first and fourth parity, respectively. Lactation length and lactation milk yield were significantly (P≤ 0.05) affected by year of calving and parity. The overall mean dry period was 107.5 ± 4.5 days. The dry period was significantly (P ≤ 0.05) affected by year of calving, season of calving and parity. It is concluded that the performance of the Boran x Ayrshire crossbred cows in the study area is unsatisfactory due to advanced age at first calving, prolonged calving intervals, shorter lactation length, lower lactation milk yield and high calf mortality rate.