No abstract

No abstract

Este trabalho foi conduzido com o objetivo de verificar o efeito da adição de antibiótico, probiótico, prebiótico e gluconato de sódio para suínos no período de 28 a 142 dias de idade, correspondente às fases de creche, crescimento e terminação. Foram utilizados 168 leitões desmamados aos 21 dias de idade, distribuídos em delineamento inteiramente casualizado em 42 baias com quatro suínos machos castrados em cada unidade experimental, com seis repetições e sete dietas: ração basal (controle negativo); ração basal + antibiótico; ração basal + probiótico; ração basal + prebiótico; ração basal + probiótico + prebiótico (simbiótico); ração basal + gluconato de sódio; ração basal + gluconato de sódio + probiótico. O desempenho dos animais diferiu entre as dietas e foi melhor nos animais que receberam ração com aditivos no período de 28 a 142 dias de idade. Entre os aditivos, o simbiótico foi mais eficiente, pois promoveu os melhores resultados de ganho de peso e conversão alimentar. Do mesmo modo, a adição de gluconato de sódio + probiótico, prebiótico e probiótico nas rações foi mais eficiente que a adição de antibiótico. A utilização dos aditivos avaliados em substituição ao antibiótico não compromete as características de carcaça e a morfometria intestinal. A associação do probiótico e prebiótico (simbiótico) estudados melhora o desempenho dos suínos nas fases de creche, crescimento e terminação.

To clarify the relationship between beef genetic selection for growth and precocity with muscle metabolism and metabolites, we performed metabolomic analysis using Longissimus lumborum (LL) muscle from Nellore cattle with divergent selection for these traits (high growth, HG; low growth, LG; high precocity, HP; low precocity, LP). Genetic potential for growth affected muscle protein and energetic metabolism. HG animals had a high concentration of arginine, carnosine, and leucine compared to LG animals. HP animals presented a high concentration of glutamine, betaine, creatinine, isoleucine, carnitine, acetyl carnitine, and lower levels of glucose compared to LP animals, affecting protein and fatty acid metabolism. Intensity of selection (high or low) was correlated with changes in protein metabolism, and the type of selection (growth or precocity) affected fat metabolism. In conclusion, both HG and HP appear to be correlated with a high concentration of protein metabolites and changes in protein metabolic pathways, while selection for precocity is more correlated with changes in fat metabolism compared to animals selected for growth.

Chitosan (CHI) is a natural biopolymer with antimicrobial, anti-inflammatory, antioxidant and digestive modulatory effects, which can be used in the ruminant diet to replace antibiotics. The aim of this study was to evaluate the effects of CHI on lamb growth traits, nutrients digestibility, muscle and fatty deposition, meat fatty acid (FA) profile, meat quality traits and serum metabolome. Thirty 30-month-old male lambs, half Suffolk and half Dorper, with an average BW of 21.65 ± 0.86 kg, were fed in a feedlot system for a total of 70 days. The lambs were separated into two groups according to the diet: the control (CON) group which received the basal diet and the CHI group which received the basal diet with the addition of CHI as 2 g/kg of DM in the diet. Lambs supplemented with CHI had a greater (P < 0.05) final BW, DM intake, final body metabolic weight (P < 0.05) and lower residual feed intake than the CON group. Animals fed CHI had a greater (P < 0.05) starch digestibility at 14 and 28 days, average daily gain at 14, 42 and 56 days, greater feed efficiency at 28 days and feed conversation at 14 and 42 days in feedlot. Most of the carcass traits were not affected (P > 0.05) by the treatment; however, the CHI supplementation improved (P < 0.05) dressing and longissimus muscle area. The treatments had no effect (P > 0.05) on the meat colour and other quality measurements. Meat from the CHI-fed lambs had a greater concentration (P < 0.05) of oleic-cis-9 acid, linoleic acid, linolenic-trans-6 acid, arachidonic acid and eicosapentaenoic acid. According to the variable importance in projection score, the most important metabolites to differentiate between the CON and the CHI group were hippurate, acetate, hypoxanthine, arginine, malonate, creatine, choline, myo-inositol, 2-oxoglutarate, alanine, glycerol, carnosine, histidine, glutamate and 3-hydroxyisobutyrate. Similarly, fold change (FC) analysis highlighted succinate (FC = 1.53), arginine (FC = 1.51), hippurate (FC = 0.68), myo-inositol (FC = 1.48), hypoxanthine (FC = 1.45), acetate (FC = 0.73) and malonate (FC = 1.35) as metabolites significantly different between groups. In conclusion, the present data showed that CHI changes the muscle metabolism improving muscle mass deposition, the lamb’s performance and carcass dressing. In addition, CHI led to an alteration in the FA metabolism, changes in the meat FA profile and improvements in meat quality.