Partial replacement of soybean meal with different protein sources in piglet feed during the nursery phase.

OBJECTIVE: Evaluate the partial replacement of soybean meal with different protein sources in piglet feed during the nursery phase in terms of digestibility of feed, nitrogen balance, growth performance and blood parameters. METHODS: Experiment I involved 24 crossbred entire male pigs with an initial body weight of 18.28 ± 0.7 kg, and used a randomized complete block design consisting of three treatments (Fish Meal - FM, Soybean Protein Concentrate - SPC, and Soybean Meal - SM) and eight replicates, with one pig per experimental unit. Experiment II involved 1843 crossbred male and female pigs with an initial body weight of 6.79 ± 0.90 kg, and was based on a completely randomized design with a 2 × 3 factorial arrangement (two sexes and three protein sources) and 13 replicates. RESULTS: The results of Experiment I indicate a significant effect (p <0.05) of the treatment on digestible protein (FM: 17.84%; SPC: 16.72% and SM: 18.13%) and on total nitrogen excretion (TNE, g/kg BW0.75/day) in which pigs fed with SM-based feed had TNE values that were 5.36% and 3.72% higher than SPC and FM, respectively. In the Experiment II, there was difference (p <0.01) between sexes in the starter phase and total period in daily feed intake (DFI) values, which were higher in females, and between the protein sources in DFI, final weight and daily weight gain, which were higher in piglets fed with SPC. For urea in both phases and glucose in the pre-starter II phase, there was a difference (p <0.05) between protein sources and between sexes, in starter phase in urea levels (females: 57.11 mg/dL and males: 50.60 mg/dL). CONCLUSION: The use of feed only at basis of SM influences larger TNE (g/kg BW0.75/day), promotes a reduction in the growth performance of piglets and increases plasma urea levels in pre-starter II.

Ingestive behavior of lambs fed diets containing castor seed meal.

The objective of this study was to evaluate the substitution of soybean meal for castor seed meal (CSM) in diets for feedlot lambs and the effects of these diets on their ingestive behavior. Fifty male Santa Inês lambs were used. The diets were composed of Tifton 85 hay and a concentrate containing detoxified CSM substituting 0, 25, 50, 75, or 100 % of the soybean meal. There was no effect (P > 0.05) of the CSM levels on the feeding, rumination, idle times, chews and time spent chewing per bolus, total chewing time, number of boli chewed, and number of chews per day. The dry matter (DM) intake decreased linearly (P < 0.05), but did not affect the neutral detergent fiber (NDF) intake. The feeding and rumination efficiencies had a quadratic response (P < 0.05). The experimental diets did not affect (P > 0.05) the numbers of feeding, rumination, and idle periods, but had a quadratic effect (P < 0.05) on the time per feeding activity and on the chewing periods. Substitution of soybean meal for detoxified CSM reduces the DM intake but does not change the ingestive behavior.