Effect of graded levels of concentrate mixture containing 4% palm oil on digestion and nitrogen retention by red Sokoto goats fed basal diet of Digitaria smutsii hay
Sixteen male Red Sokoto goats (RSG) of average weight of 21.50 ± 1.04 kg were used to determine the effects of feeding levels of concentrate mixture containing 4% palm oil on nutrient digestion by Red Sokoto goats fed basal diet of wooly finger grass (Digitaria smutsii, Stent) hay. The goats were randomly assigned to four feeding levels of concentrate mixture at 1.0, 1.5, 2.0 and 2.5% of body weight designated as treatments 1%C, 1.5%C, 2%C and 2.5%C, respectively. The animals were individually fed Digitaria smutsii hay ad libitum and supplemented with concentrate mixture at their assigned feeding level. Voluntary feed and water intakes, total urine and faecal outputs were measured for seven consecutive days after an adjustment period of fourteen days. The results showed that the levels of the concentrate fed significantly (P<0.05) improved the intakes of total DM, OM, CP, EE, and non-structural carbohydrates (NSC) with a linear (P<0.01) trend. The consumption of concentrate did not substitute that of hay until at 2.5%C when hay intake was comparatively lower. Generally, digestibility of nutrients linearly (P<0.05) increased with the level of concentrate supplementation, except that of NSC which had a quadratic trend (P<0.05). Feeding levels of concentrate mixture significantly (P<0.05) increased percent nitrogen retention (range, 13.66 – 41.38) by 83% with a significant (P<0.01) linear response. It is concluded that supplementation of Red Sokoto goats on basal diet of Digitaria smutsii hay at 2% of body weight with concentrate mixture containing 4% palm oil enhanced consumption of hay, total dry matter intake and marked increase in digestibility of nutrients and nitrogen retention.
Keywords: Red Sokoto goats, concentrate levels, Digitaria smutsii, digestion, nitrogen retention