Functional oils are known for their compounds with antioxidant, antimicrobial and anti-inflammatory properties, and are used in ruminant nutrition as alternatives to chemicals in order to improve performance. This study aimed to compare the influence of castor and cashew nut shell oils with pure organic selenium (hydroxy-selenomethionine) plus vitamin E, which are known and well-stablished antioxidants, on the performance traits, shelf life and microbial quality of the meat, physiological functions and oxidative stress control of lambs. Thirty-two Dorper x Santa Ines lambs (initial bodyweight of 22.42 ± 3.9 kg and 60 days of age) were submitted to a diet consisting of Cynodon dactylon hay (6%) and concentrate (94%). The animals were divided into four treatments: control, without additives; functional oils (FO), 0.50 g/kg DM of castor and cashew nut shell oils; hydroxy-selenomethionine and vitamin E (SeE), 0.50 mg/kg of organic selenium and 100 IU/kg DM of vitamin E; FO plus SeE, at the same doses as the other groups. Blood samples were collected after 1, 30 and 53 days on feed. After 54 days, the lambs were slaughtered and rumen health, carcass and meat traits, shelf life, and microbiological quality were evaluated. There were no differences in performance or carcass traits. A higher muscle and serum Se concentration (p < 0.0001), lower lipid peroxidation in meat during display (p < 0.0001), and a lower count of psychrotrophic microorganisms on day 5 were observed in the SeE and FO plus SeE groups. The treatments reduced the counts of Enterobacteriaceae, and Staphylococcus spp. FO animals showed higher GSH-Px activity on day 30, while the peroxidase activity was higher in FO plus SeE animals (p = 0.035). SeE and FO plus SeE animals had lower serum ALT and AST levels. Functional oils improved the microbiological quality of meat. Hydroxy-selenomethionine and vitamin E prevented oxidative stress, lipid peroxidation, and microbial spoilage.

This study aimed to assess the influence of lamb finishing systems on zootechnical performance, as well as on carcass and meat quality. The experiment was conducted at the APTA’s experimental farm. Thirty-three lambs were used – both sexes, initial age of 90 ± 3 days, Texel with Santa Inês, each animal being one experimental unit, with 6 males and 5 females per treatment. Treatments consisted of: lambs finished on pasture, in semi-feedlot or in feedlot. The lambs were slaughtered with average live weight of 35 kg. Weight gain and carcass measures were taken by ultrasound. After slaughter, carcass conformation and yield, pH, temperature, color, water retention capacity and tenderness were measured. Animals finished on pasture had lower weight gain, were slaughtered at an older age, with lighter carcass weight, smaller loin area, lower shank compactness index, besides lighter shoulder and shank weights, compared to the other production systems (p < 0.05). There was no difference between the semi-feedlot and the feedlot systems for the assessed characteristics. In conclusion, production systems affect animal performance, as well as carcass and meat quality, especially when it comes to important production aspects, such as slaughter age and yield of premium cuts.

Objective: The objective of this experiment was to compare conventional antioxidants and plant extracts for oxidative stress control in lambs fed a high-concentrate diet.Methods: Forty-eight male Dorper×Santa Ines lambs with an initial weight of 20±1.49 kg and 60 days of age, were used to evaluate the effects of feeding a combination of <i>Macleaya cordata</i> and <i>Magnolia officinalis</i> plant extracts (0 vs 320 mg/kg dry matter [DM]) in combination with selenium+vitamin E (0 vs 100 IU/kg DM of vitamin E and 0.1 mg/kg DM of selenium) in a completely randomized block design in a 2×2 factorial arrangement. The animals were housed in individual pens and received a high-concentrate diet consisting of 80% whole corn and 20% protein pellet for 60 days. The animals were weighed at the beginning of the experiment and every 14 days for performance monitoring. Three blood samplings were performed during the experimental period for the evaluation of oxidative and protein parameters.Results: The treatments with vitamin E and selenium as additives had a positive influence on final weight, daily weight gain, carcass weight, and selenium content in longissimus muscle (p = 0.01). Plant extracts tended to improve final weight (p = 0.064) and daily weight gain (p = 0.059), showing similar effect as selenium and vitamin E. There was no effect of treatment on blood proteins, indicating that the animals were healthy throughout the experiment.Conclusion: The use of plant extracts had a similar effect as the addition of selenium and vitamin E, with dietary inclusion of additives resulting in better performance of lambs but both supplements did not have strong influence on oxidative stress.

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Este estudo foi conduzido com o objetivo de avaliar a influência da lignina purificada como aditivo em dietas com elevada proporção de concentrado sobre desempenho, morfometria ruminal, características da carne e estresse oxidativo em cordeiros. Foram utilizados trinta e dois cordeiros cruzados da raça Dorper X Santa Inês com peso vivo inicial e idade de 23±6,3 kg e 60 dias, respectivamente. Os animais foram mantidos em baias individuais, alimentados com dieta composta por 10% de volumoso (feno de capim-coastcross‖) e 90% de concentrado, e distribuídos em delineamento de blocos casualizados em um dos quatro tratamentos: controle (CTL), sem aditivos, monensina (MON), onde receberam a ração CTL e MON (15 mg/kg MS), lignina kraft (LKR), recebendo ração CTL contendo LKR(12,5 g/kg MS); e selênio e vitamina E (SeE), que consistiu na ração CTL com Selênio (Se) e vitamina E (0,33 mg/kg e 100 UI/kg, respectivamente). Os cordeiros tiveram o peso mensurado a cada 14 dias. Amostras de sangue foram coletadas antes do início dos tratamentos, aos 29 e 54 dias de estudo, para avaliar a atividade de enzimas antioxidantes. Após 55 dias de confinamento, os animais foram abatidos e a incidência de rumenites e morfometria de papilas foram avaliadas, bem como características de carcaça, da carne e vida de prateleira. Os dados foram analisados pelo modelo MIXED procedure do SAS 9.3, com nível de significância de 5%. Nenhum efeito dos tratamentos foi observado sobre o desempenho ou características de carcaça. Os cordeiros que consumiram LKR tiveram maior incidência de rumenites (P=0,03). Não houve interação entre tempo e tratamentos, nem efeito dos tratamentos sobre a atividade da maioria das enzimas avaliadas, no entanto, aos 29 dias de estudo, observou-se maior atividade de peroxidases no LKR em comparação ao MON (P = 0,005) e SeE (P = 0,015). Aos 29 dias de estudo, níveis mais baixos de catalase foram observados no MON em comparação com o CTL (P = 0,030). Aos 54 dias, o MON apresentou menor atividade comparado ao SeE (P = 0,042). Para vida de prateleira, o SeE foi efetivo em manter a baixa oxidação lipídica, uma vez que apresentou os menores valores em todos os tempos de avaliação (P = 0,005). Não houve ação protetiva da lignina Kraft sobre a mucosa da parede ruminal e nenhum efeito positivo no desempenho, porém apresentou aumento da atividade das peroxidases.

This study aimed to evaluate the effects of molybdenum (Mo) and organic and inorganic sources of copper (Cu) and sulfur (S) on performance and blood concentration of these minerals in lambs. Forty male non-castrated crossbred Dorper x Santa Inês lambs (20 ± 1.2 kg of body weight and 90 ± 2 d of age) were randomly allocated into one of the 10 following treatments: T0) control, basal diet; T1) Mo; T2) inorganic Cu and inorganic S; T3) inorganic Cu and organic S; T4) organic Cu and inorganic S; T5) organic Cu and organic S; T6) Mo plus inorganic Cu and inorganic S; T7) Mo plus inorganic Cu and organic S; T8) Mo plus organic Cu and inorganic S; T9) Mo plus organic Cu and organic S. The animals were kept in individual pens and received a total mixed ration during 84 days. Body weight and blood sampling was performed every 28 days. All animals were slaughtered after 84 days and carcass traits were evaluated. No effects of treatments were observed on body weight and carcass traits. Dietary molybdenum and sulfur-supplemented animals had reduced serum concentrations of copper and ceruloplasmin. Also, an interaction among Mo x Cu sources x S sources was detected for both copper and ceruloplasmin serum concentrations. Organic sources of Cu and S led to increased serum concentration of S. Further, Mo supplementation influenced positively its blood concentration.