Soybean meal from damaged grains replacing standard soybean meal in diets of feedlot lambs

Abstract

Two studies were carried out to evaluate the effects of levels of soybean meal produced from damaged soybean grains replacing normal soybean meal on in vitro and in situ digestibility of ruminant diets as well as on intake, digestibility, and animal performance of growing/finishing lambs. In trial 1, we evaluated the in vitro digestibility of each soybean meals (normal and damaged), as well as diets containing levels of the damaged replacing the normal (0, 333, 667 and 1,000 g.kg −1 ) soybean meal on kinetic parameters of in vitro cumulative gas production, in vitro dry matter and crude protein digestibility, in situ rumen-degradable protein, rumen-undegradable protein, and in vitro intestinal digestibility of rumen-undegradable protein. In trial 2, we used 48 growing/finishing lambs to evaluate the effects of damaged soybean meal levels (0, 333, 667, and 1,000 g.kg −1 ) replacing normal soybean meal in feedlot diets (20:80 roughage:concentrate ratio) on intake and digestibility of nutrients and on animal performance. The damaged soybean meal presented lower values for total gas production and in vitro dry matter digestibility than normal soybean meal. Higher rumen-undegradable protein was estimated for damaged soybean meal than for the normal and consequently lower rumen-degradable protein for damaged compared to normal. Because of the lower rumen-degradable protein, damaged soybean meal promoted lower in vitro ammonium nitrogen (NH 3 -N) concentrations than the normal in feedlot diets. In the in vivo trial, there were no effects of damaged soybean meal levels in the diets on intake and digestibility of nutrients (dry matter, organic matter, crude protein, and fiber) as well as on total weight gain, average daily gain, carcass yield, or feeding efficiency. Thus, damaged soybean meal can fully replace the normal one in lamb feedlot diets (in up to of 1,000 g.kg −1 of the normal soybean meal) without causing adverse effects on intake and digestibility of nutrients and on animal performance.

Nutritive value of defective soybean grains for ruminants

“…As consequence of the absence of effect on nutrient intake and digestibility, replacing Standard by Fermented SBG also did not affect animal performance or feed e ciency. The average values of animal performance variables can be considered as normal for crossbreed ewes used in Brazil in terms of ADG (177 g.animal -1 ), CY (49.55%), and EF (0.218 kg of body weight gain.kg -1 of feed) [24,5].…”

“…The occurrence of defective grain is negatively associated with its nutritive value, since is assumed that damages cause changes in chemical composition of the grains as well as defective grains are not useful to animal nutrition due to presence of mycotoxins. However, until recently there were no data regarding nutritive value of defective grains, since Carvalho et al [5] were the rst ones to evaluate the use of SBM from defective grains (80% of defective grains) replacing standard SBM in lamb diets, who did not observe negative effects on the intake and digestion of nutrients as well as on animal performance. It needs to be emphasized that the forementioned authors did not nd mycotoxins in SBM from defective grains in their study.…”