The effect of feeding level on protein and energy utilization in young and mature Kacang goats

Abstract

Abstract A study was conducted to evaluate the amount of feeding on nutrient utilization of Kacang goats. This study used 16 heads, consisting of 8 young Kacang goats (5-6 months old), weighing 12.75 kg (CV = 2.4%), and 8 mature Kacang goats (12-15 months old), weighing 17.34 kg (CV = 2.7%). The diet was in the form of pellets, consisting of 25% wheat straw, 32% soybean meal, 39% rice bran, 3% sugarcane molasses, and 1% minerals. This study used a completely randomized design (CRD) in a nested structure. The main factor (the nest) was the age of the goat, i.e. young and mature, while the second factor (the nested factor) was feeding level, i.e. low (maintenance level) and high (twice maintenance level). The parameters were dry matter intake (DMI), dry matter digestibility (DMD), protein and energy intake, protein and energy digestibility, protein and energy retention, body weight gain (BWG), and feed conversion. The results showed the goat of high feeding level had higher DMI (P<0.05) than that of low feeding level, both in the young goat (243 g/d vs 466 g/d) and the mature goat (303g/d vs 657). There was no significant difference (P>0.05) in DMD between feeding levels and between age of goats (averaged 73.67%). The goats of high level had higher (P<0.01) nutrients retention in goats and the mature goats. The goats of high feeding level had significantly higher (P<0.05) BWG than that of low feeding level (14.64 g/d vs 41.95 g/d in the young goat and 18.35 g/d vs 58.77 g/d in the mature goat). The high feeding level resulted in lower FCR (P<0.01) than the lower feeding level, both in the young goats (16.40 vs 11.44) and in the mature goats (16.47 vs 11.47). It can be concluded that young and mature Kacang goats had similar abilities in feed digestion. The higher feeding level resulted in the better utilization of dietary protein and energy, and productivity of the goat.