Chemical composition and rumen degradability of protein of browse and shrubs fed to sheep in Ghana

Abstract

The chemical composition and protein degradability of Antiaris africana, Delonix regia, Milletia thonningii, Khaya senegalensis, Griffonia simplicifolia, Ritchea reflexa and Securinega virosa as well as treated or untreated rice straw were studied. The rice straw was treated with either sodium hydroxide (4.42 per cent w/w) or urea (7.55 per cent w/w) was used in the treatment of the straw. Wethers averaging 23.2 1 0.60 kg liveweight and fitted with rumen canulae were fed with the straw and browse and 5 g sample placed in a nylon bag and incubated in the rumen. Data were fitted to the equation P = a + b(1-e-et) where P is extent of degradation at time t, a is percentage loss of water soluble component, b is percentage loss of water insoluble component, c is rate of degradation of component b, and (a + b) is the maximum percentage loss of protein. Significant differences (P<0.05) were observed in the chemical composition of browse, with protein values ranging between 13 and 22 per cent. For the straw, the crude protein ranged between 5 and 10 per cent. Similarly, significant differences (P< 0.05) were observed in the values of a, b, (a + b) and c among browse and straw. For the browse, the values for a ranged between 11 and 25 per cent, b varied between 40 and 60 per cent, (a + b) varied between 51 and 84 per cent, while c ranged between 0.011 and 0.043 h-1. The corresponding range of values for the straw were 6.1- 10.5, 38-50, 44-61 per cent and 0.020-0.011 h-1 for a, b, (a + b) and c, respectively. The browse and shrubs are very good sources of protein supplements, especially when used with straws.


Ghana Jnl agric. Sci. Vol.31(1) 1998: 93-97