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Livestock-Based Farming Systems, Renewable Resources
and the Environment |
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Four crossbred, castrated male pigs of average 10kg live weight were allocated according to a Latin Square Design to four diets arranged as a 2*2 factorial. The factors were fine or coarse grade of rice bran and Taro leaf-stem silage and rice distiller’s by-product as sources of supplementary protein. Measurements were made of intake, apparent digestibility of DM and crude protein and N balance.
The crude protein content (DM basis) of fine rice bran was higher than coarse bran (13.2% vs 9.05%), while the rice distillers' by-product was slightly higher than the Taro leaf-stem silage (25.2% and 18.3% in DM, respectively). The daily DM intake, the coefficients of apparent DM digestibility, and the N retention (Figures 1, 2 and 3), were higher for diets based on fine than on coarse bran, but with no differences between Taro leaf-stem silage and rice distillers' by-product except for N retention which was less on rice distillers' by-product than on Taro leaf-stem silage, especially on the coarse bran diet (Figure 4).. The high values for N retention as a percentage of N digested on all diets indicates a high and similar biological value of the protein in Taro leaf-stem silage and in rice distillers' by-product.
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| Figure 1. Mean values for DM intake of pigs fed coarse or fine rice bran and taro silage or rice distillers' by-product | Figure 2. Mean values for apparent DM digestibility in pigs fed coarse or fine rice bran and taro silage or rice distillers' by-product |
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| Figure 3 Effect of grade of rice bran on N retention in pigs fed Taro leaf-stem silage or rice distillers' by-product | Figure 4. Effect of Taro leaf-stem silage or rice distillers' by-product on N retention in pigs fed fine or coarse rice bran |