ABSTRACT

A study was conducted to evaluate the milk yield and milk composition at different stages of lactation (early, mid and late) of crossbred (RS X WAD) does. Five lactating crossbred (RS X WAD) does in their 2nd and 3rd parities were used to carry out this research in a complete randomized design (CRD) experiment. Data collected were milk yield and milk composition. Week 3 and week 6 of early lactation had the highest and the lowest daily milk yields of 135.80g and 108.49g respectively, while weeks 8 and 9 had the highest and the lowest daily milk yields were of 120.13g and 76.51g respectively in the mid lactation stage. For the late lactation, the highest and the lowest daily milk yield were recorded in week 15 (66.85g) and week 18 (52.06g) respectively. Generally, milk yield of the goats decreased significantly (P<0.05) as the lactation stages advanced from early to late with daily milk yield of 100.64g, 86.91g and 52.21g, respectively for early, mid and late lactation stages. Most of the milk components: total solids, ash, butter fat, crude protein, solids-not-fat showed significantly (P><0.005) higher values in the late lactation stage of crossbred (RS X WAD) does except for milk energy that took a reverse order to the other milk components. Simple regression analysis indicated that milk yield was negative and non significantly (P><0.05) corrected with TS (r= -0.12; P>0.05), and negatively corrected with crude protein (r= -0.490;P<0.05), Milk yield was positively correlated with lactose (r=0.38: P><0.05) and butter fat (r=0.378; P><0.05). Total solids was positively but not significantly correlated with BF (r= 0.074; P>0.05), CP (r =0.144; P>0.05), and energy (r= 0.051; P>0.05). Energy and butter fat were positively and significantly correlated (r= 0.852: P<0.001). Also solid not fat was positively and non- significantly correlated with lactose (r= 0.119: P>0.05) and crude protein (r= 0.072: P>0.05). the results of this study therefore showed that lactation stage influenced the milk yield and composition in RS X WAD crossbred goats