Liveweight gain and efficiency of feed utilization by Bunaji cows during early lactation
A feeding trial was carried out to study the effect of feeding increasing levels of total digestible nutrients (TDN) on the live weight of Bunaji cows during early lactation. The feeding trial ran for 56 days, starting on the 6th day after parturition. The experimental cows, in a completely randomized design, were randomly allocated to four diets at 3.5, 4.5, 5.5 and 6.5 kg TDN levels. These diets were compounded using cottonseed cake, dried brewer's grains and Lablab purpureus hay. The daily feed intake; daily milk yield and two weekly live weight changes in the cows were recorded. The mean daily dry matter and crude protein consumed per metabolic size increased significantly (P< 0.05) as the dietary TDN increased from 3.5 to 6.5 kg. The values were 82.4, 106.6, 118.2 and 131.2 g kg-1W0.75 day-1 for dry matter intake and 22.5, 29.0, 33.1 and 38.0 gkg-1 W0.75 day-1 for crude protein intake for the diets at the 3.5, 4.5, 5.5 and 6.5 kg TDN levels respectively. The daily milk yield ranged from 1.83 to 3.83 kg, while the live weight gain ranged from 598.2 to 946.4 g day -1. The experimental diets were better utilized for live weight gain at the 3.5, 4.5 and 6.5 kg TDN levels, with the mean efficiency of feed utilization ratios of 7.1:1, 9.3:1 and 9.9: 1 respectively. The least efficiency of feed utilization ratio of 13.5:1 was obtained at the 5.5 kg TDN level.
Keywords: TDN, Bunaji cows, live weight gain.