0
Two different experiments were conducted for the present study. In Exp 1 a total of 48 pigs were distributed into 4 dietary treatments according to initial body weight (6 pens/ treatment and 2 animals/pen). The four dietary treatments were: 1) a basal diet + sulphate minerals, 2) basal diet + amino acid chelated minerals, 3) soybean hulls diet (5%) + sulphate minerals and 4) soybean hulls (5%) + metal amino acids chelated minerals. Animals were individually weighed at the start of the trial and after 5 weeks and feed consumption was also measured. Chromium oxide was used as indigestible marker. Average daily gain (ADG), average daily feed intake (ADFI) and feed to gain ratio (FGR) were also calculated. The coefficients of total tract apparent digestibility for DM and N were determined at the end of 5 weeks. In Exp 2, four barrows were used in a 4 x 4 Latin square arrangement of 4 experimental periods in which the 4 experimental diets were fed in order to assess the effects of soybean hulls and MAC on noxious gas emissions from faeces and slurry. In each period there was 7 days of adaptation and 1 day of sample collection (faeces and urine).
In Exp 1, no effects were observed throughout the experimental period on growth performance due to the different dietary treatments. The coefficients of the total tract apparent digestibility of dry matter (DM) and nitrogen (N) remained unaffected by soybean hulls or MAC dietary supplementation. In Exp 2, it was observed that pig fed with soybean hulls tended to have lower NH3 emissions from faeces (P=0.09) than those fed control diet. No effects were observed in the NH3 emission by the MAC supplementation, however an interaction was observed between soybean hulls and MAC in faeces and slurry (P=0.05, P=0.01). Animals fed the soybean hulls supplemented diets tended to show lower H2S emission from the slurry (P=0.07), but lower H2S emission was observed in both faeces and slurry (P<0.05) in pigs fed the soybean hulls and MAC supplemented diets.
It is concluded that the interaction between soybean hulls and metal amino acid chelated minerals have a positive effect on noxious gas emission. The emission of NH3 from pig faeces could be substantially reduced by soybean hulls supplementation and the emission of H2S it is reduced in both from faeces and slurry due to the inclusion of metal amino acid chelated minerals.
Y Wang, JH Cho, JS Yoo, HJ Kim, Y. Huang, SO Shin, TX Zhou and IH Kim. 2008. Journal of animal and feed Sciences. 17: 171-181.
