Influence of udder stimulation, stage of lactation and parity on milk yield in West African Dwarf goats
Influence of udder stimulation, stage of lactation and parity on milk yield in West African Dwarf (WAD) goats was investigated in this experiment using 28 lactating does weighing between 15-24 kg. The animals were raised in an intensive system of management. For udder stimulation, the animals were divided into 2 groups; 13 animals were stimulated by washing, drying, massaging and butting the udder before milking while the other 15 were not stimulated, the udders were just milked. 12 weeks of lactation was divided into 3 stages of lactation; early (first 4 weeks), mid (second 4 weeks) and late (last 4 weeks). The animals were on parities 1, 2 and 3. The goats were fed on 5% body weight with combination of grass and concentrate in ratio 50:50 twice per day in the morning and evening. The lactating does were hand milked once per day on the milking days and thrice per week for the period of 12 weeks. Kids were separated from their dams at 5pm in the evening and milking commenced at 8:00 am the following day to give 15hrs milk yield which was converted to daily milk yield. Data collected was analysed using SAS analytical package in a complete randomized block design. The results showed that udder stimulation, stage of lactation and parity had significant effect on milk yield (P<0.05). Does whose udders were stimulated produced 303.96 g/goat/day compared to non-stimulated does (249.70 g/goat/day). Animals in early stage of lactation produced significantly (P<0.05) higher daily milk yield (355.73g/goat/day) compared with animals in mid (273.68 g/goat/day) and late (195.26 g/goat/day) stages of lactation. Similarly daily milk yield increased with increase in parity. Animals in parity 3 had higher (P<0.05) daily milk yield of 332.46 g/goat/day compared to animals in parity 2 (283.72g/day) and 1 (215.14 g/goat/day). Left teat of the does produced significantly (P<0.05) more milk than the right teat. Therefore, it is recommended that goats udder in higher parity be stimulated prior to milking at early stage of lactation for higher milk production.
Keywords: udder stimulation, stage of lactation, parity, milk yield, WAD goats