Temperature humidity index: influence on milk yield and milk composition of multiparous west african dwarf does

This study examined the influence of ambient temperature (AT), relative humidity (RH) and temperature-humidity index (THI) on milk yield (MY) and milk compositions (MC) of West African Dwarf (WAD) goats using a total of thirty-six (36) lactating does. The goats were milked twice daily for twelve (12) weeks during which, AT and RH were monitored. The AT and RH data were used to generate THI. The milk collected at every milking was quantified and also analysed for MC, The AT, RH and THI during each milking period were categorized into low, medium and high ranges, under which the corresponding MY and MC were fixed. The data generated were subjected to Analysis of Variance of a Completely Randomized Design. The result revealed that the highest MY (350.28 mL), recorded during low AT range, was not significantly different from 329.43 mL obtained during medium AT, while high RH range (70-99%) facilitates higher MY (364.30 mL) compare to low and medium ranges. AT exerted no significant difference on all the MCs except protein. Milk fat was highest (7.34%) at low THI, while the lactose (11.30%) at high THI range was significantly higher compared to other ranges. A relatively higher MY (324.35 mL) and milk density (1034.94 kg/m3) was obtained within medium THI range (75.6-85.6). It is concluded that, AT and RH exhibit a synergistic effect on MY and some of the MCs.It is recommended that thermo-comfort THI for dairy WAD goats is between 75.6 and 85.6