Use of Heating Methods and Xylose to Increase Rumen Undegradable Protein of Alternative Protein Sources: 1) Peanut Meal

SIMPLE SUMMARY: Protein is a nutrient with a high cost in beef production. Thus, it is crucial to study techniques that improve animal protein utilization. Furthermore, the more productive the animal, the higher its rumen undegradable protein (RUP) requirements. This protein escapes ruminal fermentation to be digested in the intestine. Peanut meal is a feasible byproduct with excellent protein content but low RUP. This problem is commonly solved by submitting the feed to heat processing methods (such as autoclaves or conventional and microwave ovens) with or without treatment with sugars (such as xylose). Thus, here, we submit peanut meal to these different heat techniques, with and without xylose treatment, aiming to increase its RUP content. Overall, our results suggest that the tested methods effectively increased the RUP content of the peanut meal. The best treatments were as follows: for an autoclave, xylose-treated peanut meal with 24 min of heating; for a conventional oven, 60 min of heating for both xylose-treated and -untreated peanut meals; and for a microwave oven, xylose-treated peanut meals with 4 and 6 min of heating. Nevertheless, further research is recommended to evaluate the effects of these ingredients on the parameters of ruminal fermentation and animal performance. ABSTRACT: Peanut meal has an excellent total protein content but also has low rumen undegradable protein (RUP). High-performance ruminants have high RUP requirements. We aimed to evaluate the effects of processing peanut meal with an autoclave and conventional and microwave ovens, with and without using xylose on its ruminal kinetics degradation parameters and intestinal digestibility (ID). In situ studies were conducted to determine dry matter (DM) and crude protein (CP) rumen degradation kinetics. In vitro studies were conducted to evaluate intestinal digestibility (ID). The control treatment had a greater fraction A for DM and CP than peanut meals processed with an autoclave or conventional oven. The control had greater kd for CP compared with the microwave. The addition of xylose decreased fraction A, the degradation rate of fraction B (kd) and RUP, and increased the protein B fraction of autoclaved peanut meal. We observed a decrease in effective degradability (ED) and increased RUP for processed treatments in all experiments compared with the control. Processing methods did not affect the protein ID of autoclaved peanut meal compared to the control. An interaction between xylose and heating time was observed, where increasing heating time linearly reduced the ID of xylose-untreated treatments. Overall, these results suggest that the tested methods effectively increased the RUP content of peanut meal.