Feeding Agroindustrial Byproducts to Light Lambs: Influence on Growth Performance, Diet Digestibility, Nitrogen Balance, Ruminal Fermentation, and Plasma Metabolites

Abstract

The objective of this study was to evaluate the effect of replacing cereals and protein concentrates in a high-cereal concentrate (control) for light lambs with corn distiller’s dried grains with solubles (DDGS; 18%), dried citrus pulp (DCP; 18%), and exhausted olive cake (EOC; 8%) in a byproduct (BYP) concentrate on growth performance, digestibility, ruminal fermentation, and plasma metabolites. Two homogeneous groups of Lacaune lambs (13.8 kg ± 0.25 kg) were fed one of each concentrates and barley straw ad libitum until reaching about 26 kg body weight. There were no differences between groups on feed intake, average daily gain, or feed conversion ratio, but the control diet had greater (p < 0.001) dry matter digestibility. Diet had no effect on post-mortem ruminal pH and total volatile fatty acid concentrations and profile, but NH3-N concentrations were lower (p = 0.003) for the BYP-fed group compared with the control one. However, plasma concentrations of amino acids, total proteins, urea, and hepatic enzymes were not affected by the diet. In conclusion, 44% of feed ingredients in the concentrate for light lambs can be replaced with a mixture of corn DDGS, DCP, and EOC without negatively affecting growing performance and animal health.

Feeding Agro-Industrial By-Products to Light Lambs: Influence on Meat Characteristics, Lipid Oxidation, and Fatty Acid Profile

“…The present study analyzes the quality of meat from lambs fed either a high-cereal concentrate or a concentrate containing corn DDGS, DCP, and EOC. Previously, de Evan et al [4] showed that there were no differences between concentrates in growing performance, digestibility of nutrients, and animal health of the lambs. There were also no differences in hot and cold carcass weights, which reached 14.4 and 13.6 kg for the CON and 14.2 and 13.6 kg for the BYP groups, respectively [4].…”

“…This is a companion paper to the study of de Evan et al [4], who reported the effects of by-product (BYP) concentrate on growth performance, diet digestibility, blood parameters, and ruminal fermentation of the lambs. The animals used in this experiment were cared for and handled in accordance with the Spanish guidelines for experimental animal protection.…”

“…The content in total soluble polyphenols in both concentrates was analyzed using the spectrophotometric Folin Ciocalteu assay as described by Singleton and Rossi [19], and results were reported as gallic acid equivalents (GAE). Other chemical analyses of the concentrates have been described by de Evan et al [4].…”

“…Diets and animals are described in detail by de Evan et al [4] and are only briefly summarized here. Two groups of 12 Lacaune male lambs each (13.8 ± 0.25 kg initial body weight) were penned individually in 1 m × 1 m pens with slatted floor and equipped with two feeders and an automatic drinker.…”

“…Recently, de Evan et al [4] reported that 44% of conventional feeds in a high-cereal concentrate for fattening lambs can be replaced by a mixture of corn dried distiller grains with solubles (DDGS), dried citrus pulp (DCP), and exhausted olive cake (EOC) without affecting lamb performance. Both DCP and EOC are rich in polyphenols and other bioactive compounds [5][6][7], and therefore, they might improve lamb meat composition and might increase meat shelf-life stability [8,9].…”