Milk yield and rectal temperature in West African Dwarf goats as affected by wattle and litter size
This study was conducted to investigate milk yield and rectal temperature in West African Dwarf (WAD) goats as affected by wattle and litter size. A total of 28 lactating does were used for the experiment. 13 does had wattle (bilateral) while 15 had no wattle. 14 does had twin birth while the other 14 had single birth. The goats were fed at 5% body weight with combination of concentrate and grass (Panicum maximum and Pennisetum purpureum) in ratio 50:50 twice per day in the morning and evening (zero grazing). The lactating does were hand milked once per day (08.00) and thrice per week for the period of 12 weeks. The goats were housed in cross ventilated pens with slatted floor. Rectal temperature was taken after milking of each animals using digital thermometer. Data collected were analysed using SAS (2010) in a randomized complete block design. The results showed that wattle and litter size had significant effect on milk yield and rectal temperature in WAD goats. Wattled animals produce significantly (P<0.05) higher milk yield of 297.72 g/day compared to their nonwattled counterparts (255.11 g/day). Animals with wattle however had higher rectal temperature of 39.35ºC compared to animals without wattle (39.23ºC). Also twin littered does produced daily milk milk yield of 292.74 g/day significantly (P<0.05) higher than single littered counterparts (257.04 g/day). The interaction between wattle and litter size showed that there was no significant difference in daily milk yield in wattled animals regardless of the litter size. However, in non-wattle animals, does with twin birth produced daily milk yield of 283 g/day significantly (P<0.05) higher than 235 g/day for does with single birth. Also, wattled does with single birth had significantly (P<0.05) higher rectal temperature of 39.43ºC when compared with wattled does with twin birth. However, in nonwattle animals, does with single birth had significantly lower rectal temperature of 39.18ºC as compared with does with twin birth (39.29ºC). It was concluded that WAD goats with wattle and twin birth produces more milk than those without wattle and single birth. Therefore, WAD goats with wattle should be selected for lactation purpose especially those with twin birth.
Keywords: wattle, litter size, WAD goats, milk yield, rectal temperature