Effect of Substitution of Corn Grain and Soybean Meal with Corn Gluten Feed or Corn Distiller Dried Grains and Soluble in Ruminants

Four Barbarine breed sheep (initial average BW and age 58 kg and 18 month, respectively), receiving a basal diet composed of oat hay, were used in a Latin square design (4 4) to study the effect of the total substitution of soybean meal (D1: Sb: 23.5% of concentrate) by corn distillers dried grains with soluble (D2: DDGS: 45%) or corn gluten feed (D3: CGF: 65%) or a mixture of the 2 ingredients (D4: CGF+DDGS, respectively 23 and 26%) on intake, digestibility and nitrogen balance. The proportion of concentrate in diet was adjusted at a level of 25% of the total dry matter intake. Each experimental period lasted 28 days (21 and 7 days, respectively for adaptation and measurements). The compound feeds were approximatively iso-nitrogenous and iso-energetic. The obtained results showed that the studied corn co-products were characterized by a high quality of crude protein. The voluntary intake of hay and total diet DM were not affected by the applied substitution (average value 53.2 g DMkg-0.75 day-1). No effect of substitution was noted on DM, OM and CP digestibility or N balance. In contrast, an improvement of the digestibility of crude fiber was observed (p<0.05), mainly in diet containing DDGS. The biological quality of N expressed as the ratio: Retained N/Absorbed N, seamed to be higher in SBM, DDGS and GDDS diets (averaged 30.5%) than in CGF one (26.6%). It was concluded that substituting soybean with corn co-products in concentrate supplied at a rate of 25% of DM total intake did not affect nutritive value of oat hay based ration and the studied diets were nutritionally similar.