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The carotenoids and liposoluble vitamins in the plasma and tissues of the lambs under different maternal feedings and fattening concentrates was studied. During lactation, 21 lambs were housed with their dams, that received a total mixed ration (intensive); 21 ewe–lamb pairs grazed on alfalfa; and 21 pairs grazed on sainfoin. After weaning, half of the lambs in each maternal feeding group received a commercial concentrate (control) and the other half a concentrate with quebracho (Schinopsis balansae), as a source of condensed tannins, until they were slaughtered (23 kg). The analyte concentrations in the plasma of lambs at weaning reflected the content in the feedstuffs. Grazing during suckling more than doubled the contents of lutein in the liver and retinol in the tissues compared to the intensive feeding. The content of α-tocopherol in the tissues was greatest in sainfoin lambs, intermediate in alfalfa lambs, and lowest in the intensive lambs. The quebracho concentrate decreased α-tocopherol (by 41–81%) and γ-tocopherol (by 65–89%) contents in the lamb tissues. The use of the analytes in the plasma at weaning correctly classified 100% of the lambs into the maternal feeding (intensive vs. grazing (alfalfa + sainfoin)) but has to be improved in the carcass and tissues separately.

The inclusion of different proportions of field pea (0%, 10%, 20% and 30%) for partially replacing soybean in the fattening concentrate of lambs was studied for its impact on apparent digestibility and performance during fattening. In the in vivo digestibility trial, 12 lambs (33 kg body weight) were placed in metabolic crates for two periods and received restricted amounts of concentrate and straw. The performance trial involved 54 lambs (13.4 kg body weight) that received concentrate plus straw ad libitum from weaning to slaughter. The intake of crude protein was higher in the 0% pea group than in the other groups (p < 0.05). The inclusion of field pea did not affect the digestibility, N retained or blood metabolites. In the performance trial, most traits were not affected, although a cubic effect of field pea inclusion on hot carcass weight and dressing percentage was observed (p < 0.05). The inclusion of field pea did not affect total protein, urea or β-hydroxybutyrate concentrations but it affected creatinine and cholesterol concentrations (p < 0.05). In conclusion, field pea can constitute up to 30% of the fattening concentrate of lambs without deleterious effects on the digestibility and performance during fattening, and with minor effects on carcass characteristics.

Context Good transition from suckling to high-concentrate diets is essential to avoid nutritional disorders during the fattening period of beef calves. Aims Assessing the optimal feeding strategies during the preweaning period of beef calves for an adequate adaptation to high-concentrate diets. Methods A total of 30 female beef calves (15 Parda de Montaña and 15 Pirenaica), managed under restricted suckling, were assigned to three preweaning diets (milk only [MO], milk plus hay [MH], milk plus concentrate [MC]), fed from the third month until weaning at 5 months. During the subsequent transition period (1 month), all animals received a fattening concentrate plus wheat straw ad libitum. Key results Milk intake did not differ among diets; solids intake was similar for MH and MC calves. Preweaning supplementation improved performance at the end of the suckling period (MC &gt; MH &gt; MO). During transition, concentrate intake was lower for MO calves; MH calves showed the lowest feed efficiency. At the end of transition, MC calves showed the highest liveweight and average daily gain (MC &gt; MH = MO). Rumen pH at weaning did not differ from that at the end of transition in MC calves, whereas MH and MO animals showed lower values at the latter. Supplemented calves showed higher volatile fatty acids concentration than MO calves at weaning; MC calves showed the lowest values at the end of the transition period. Ammonia and lactic acid concentration at weaning was the highest for MO and MC calves respectively, with no differences between diets at the end of transition. Glucose and non-esterified fatty acids concentrations were only affected by age; urea and β-hydroxybutyrate were affected by the interaction between diet and age. Economic profitability at weaning was higher for supplemented calves (MH = MC &gt; MO), and ranked MC &gt; MO &gt; MH at the end of the transition. Gains during the suckling period, and hence the economic margin, were higher for Parda de Montaña than for Pirenaica calves; during transition the economic margin was similar. Conclusions Preweaning supplementation with concentrates is the most interesting option in terms of performance and profitability. Implications Preweaning solid supplementation increases calf performance and provides better rumen development, essential for a smooth transition to fattening diets.

The use of pea (Pisum sativum) has been recommended to replace soybean meal in the diet of ruminants, but it may affect meat quality. The aim of this study was to evaluate the effect of the proportion of pea (0%, 10%, 20% and 30%) in fattening concentrates fed to light lambs for 41 days on carcass colour and on the meat quality. Pea inclusion affected neither the colour of the lamb carcasses nor affected most of the parameters of the meat quality. However, the inclusion of pea affected the cholesterol content, and the 20%pea concentrate yielded meat with greater cholesterol contents than the 30%pea concentrate did (p < 0.05). The inclusion of pea had minor effects on individual FAs but affected the total saturated fatty acids (p < 0.01) and the thrombogenicity index (p < 0.05). A greater total saturated fatty acid content was recorded for the 20%pea concentrate than for the rest of the concentrates, and a greater thrombogenicity index was recorded for the 20% concentrate than for the 10%pea concentrate. The results indicated the viability of the inclusion of pea in the fattening concentrate of light lambs without impairing meat quality, with the 30%pea concentrate being the most suitable to reduce the soya-dependency.

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