By-product from biscuit manufacture as corn replacements in sheep diets: nutritional and metabolic traits

The objective was to evaluate the effect of by-product from biscuit manufacture (BBM) as an alternative to corn with different replacement levels on the nutritional and metabolic parameters of sheep. The diets were formulated to meet the requirements of finishing lambs aiming at a weight gain of 200 g/day, based on Tifton 85 grass hay, soybean meal, and BBM replacing corn at 0, 15, 30, and 45%. A digestion system (TE-150, TECNAL®) was used for the in vitro digestibility analysis. The experiment was conducted in two parts: incubation of the feed and incubation of the diets. For the in vivo studies, twenty 4-month-old non-castrated male Morada Nova lambs, weighing on average 17.1 kg were used. A trial of nutrient intake and apparent digestibility was conducted over a period of 21 days, with a 15-day adaptation period a 7-day sample collection period. For the assessment of ingestive behavior, the time spent on different activities was recorded through visual observation of the animals every five minutes, for three full 24-h periods. Data were subjected to regression analysis. For the metabolic parameter trial, rumen fluid and blood were collected at pre-established times: 0 h (pre-prandial) and 2, 5, 8 h post-prandial, and the data recorded were subjected to split-plot analysis. The different substitution levels showed similarities in nutrient intake and apparent digestibility (P < 0.05). There was a positive linear effect of diets containing BBM on the efficiency of dry matter intake and neutral detergent fiber rumination. Substituting corn with BBM up to 45% in sheep diets maintained similar nutritional and metabolic parameters as well as ingestive behavior compared to a diet containing only corn as the energy source.