Effects of elevated concentrations of soybean molasses on feedlot performance and meat quality of lambs

Soybean molasses increases subcutaneous fat deposition while reducing lipid oxidation in the meat of castrated lambs

This study aimed to evaluate the effect of including soybean molasses (SM) on performance, blood parameters, carcass traits, meat quality, fatty acid, and muscle (longissimus thoracis) transcriptomic profiles of castrated lambs. Twenty Dorper × Santa Inês lambs (20.06 ± 0.76 kg body weight [BW]) were assigned to a randomized block design, stratified by BW, with the following treatments: CON: 0 g/kg of SM and SM20: 200 g/kg of SM on dry matter basis, allocated in individual pens. The diet consisted of 840 g/kg concentrate and 160 g/kg corn silage for 76 d, with the first 12 d as an adaptation period and the remaining 64 d on the finishing diet. The SM20 diet increased blood urea concentration (P = 0.03) while reduced glucose concentration (P = 0.04). Lambs fed SM showed higher subcutaneous fat deposition (P = 0.04) and higher subcutaneous adipocyte diameter (P < 0.01), in addition to reduced meat lipid oxidation (P < 0.01). SM reduced the quantity of branched-chain fatty acids in longissimus thoracis (P = 0.05) and increased the quantity of saturated fatty acids (P = 0.01). In the transcriptomic analysis, 294 genes were identified as differentially expressed, which belong to pathways such as oxidative phosphorylation, citric acid cycle, and monosaccharide metabolic process. In conclusion, diet with SM increased carcass fat deposition, reduced lipid oxidation, and changed the energy metabolism, supporting its use in ruminant nutrition.

Soybean Molasses in Animal Nutrition

Simple Summary

Soybean molasses is a by-product of the soybean processing industry that is accumulated in large quantities and usually disposed of like liquid manure or in landfills, thus causing severe ecological problems. At the same time, soybean molasses has a promising potential to be included regularly in animal diets because of its high nutritive value and functional properties. It is rich in sugars and is a cheap energy source for animals compared to other energy-rich feed ingredients. This paper reviews current knowledge on the valorization of soybean molasses as an alternative feed ingredient focusing on its composition and application in animal nutrition in general.

Abstract

Concerning the increasing global demand for food and accumulation of huge amounts of biomass waste from the agro-food industry whose manipulation is usually inadequate, the potential of livestock to convert by-products as alternative feed ingredients into valuable proteins has been proposed as an outstanding option. Soybean molasses present a by-product of soybean protein concentrate production with low commercial cost but high nutritive and functional value. It is a rich source of soluble carbohydrates in the form of sugars and soybean phytochemicals. Therefore, this paper provides a review of published works about the production of soybean molasses, chemical composition, and nutritive value. In addition, the possibility of the application of soybean molasses in animal nutrition as a pelleting aid and functional feed ingredient is also discussed. Special attention is devoted to the influence of the inclusion of soybean molasses in the diets for ruminants, non-ruminants, and aquaculture on animal performance and health.