Milk secretion rate in tropical dual purpose cows (B. taurus x B. indicus).

摘要

The milk secretion rate at peak lactation and the udder secretory capacity of 8 crossbred dual purpose cows were determined. Cumulative milk volume (CMV) and secretion rate were estimated by milking each cow at 3-, 6-, 9-, 15- and 24-h intervals. Each measurement was on different days on the same week, and were performed four times for each interval for 4 weeks. Empty udder volume (EUV) was measured during the second week of the experiment. Oxytocin (10 IU intramuscularly) was administered to ensure complete udder emptiness. It was shown that CMV was 0.38, 0.74, 1.237, 1.69 and 2.40+or-0.041 litres/litre EUV, while milk secretion rate were 0.0125, 0.123, 0.137, 0.113 and 0.100+or-0.004 litres/h/litre EUV for 3-, 6-, 9-, 15- and 24-h milking intervals, respectively. A significant relationship was found between milk yield (MY) and EUV. During extended milking intervals, MY loss was higher in cows which produced more milk. In conclusion, CMV and milk secretion rate must be taken into consideration when designing milking and restricted suckling regimes for dual purpose crossbred cattle..