Lysolecithin-derived feed additive improves feedlot performance, carcass characteristics, and muscle fatty acid profile of Bos indicus-influenced cattle fed in a tropical environment.

Lysolecithin might increase ruminal and intestinal emulsification, leading to increased digestibility, but there is minimum information about which is the most appropriate phase to start supplementation and its impacts on feedlot performance and muscle fatty acid profile. Two experiments were conducted to evaluate the effects of phase-feeding of Lysoforte™ eXtend (LYSO). In the first experiment, 1,760 predominantly Bos indicus bullocks (initial body weight of 400 ± 0.561 kg) were allocated in a complete randomized block design. LYSO was supplemented at 1 g/1% of ether extract from the diet. Treatments were no LYSO supplementation (NON); LYSO starting during the growing period and continuing during the finishing period; LYSO starting during the finishing period (FIN); and LYSO during adaptation, growing, and finishing periods (ALL). In the second experiment, the same treatments were evaluated with 96 bullocks (64 Nellore and 32½ Nellore × ½ Angus) in a 4 × 2 factorial arrangement (treatments × genotype). For both studies, intake and average daily gain were accessed; carcass characteristics were evaluated in the first experiment, while digestibility of nutrients and profile of muscle fatty acids were measured in the second experiment. In the first experiment, LYSO increased final body weight (P < 0.022) and average daily gain (GRO and FIN; P < 0.05). In the second study, a treatment × breed × feeding phase interaction was observed with Nellore having a greater average daily gain (P < 0.05) than crossbreds in every feeding phase that LYSO was introduced to the diet. A treatment × feeding phase interaction was observed for digestibility, such that LYSO increased total dry matter (P = 0.004), crude protein (P = 0.043), and NDF (P = 0.001) digestibility during the finishing period. A treatment × breed × day classification was observed (P < 0.05). During the finishing phase, crossbreds treated with LYSO had greater DMI (P < 0.05) on very hot days than NON. Also, animals treated with LYSO presented a greater C18:3 n3 concentration (P = 0.047) in the longissimus. Overall, feeding LYSO during GRO and FIN enhanced feedlot performance and should lead to higher intakes during very hot days of the finishing feeding period.

Temporary reduction of digestible lysine in nursery pig diets: performance and economic analysis / Redução temporária de lisina digestível em dietas de leitões em fase de creche: desempenho e viabilidade econômica

To evaluate the effects of temporary dietary lysine restriction on nursery pigs' growth performance and its economic viability compared to control diets, 144 piglets (21-d-old) were assigned to randomized blocks, with two treatments and twelve replicates. The treatments were control-lys: lysine level as recommended from 21-32 and 32-42 days and low-lys: 90% of the lysine level of the control-lys diets. From 42 to 62 days, all animals received a control diet. From 21 to 32 days, pigs fed low-lys had worse average daily gain (ADG), feed conversion, and 32-d body weight (BW; P ≤ 0.05). From 32 to 42 days, pigs fed low-lys had lower average daily feed intake, ADG, and 42-d BW (P ≤ 0.05). From 42 to 62 days, pigs had similar performance (P > 0.05). Overall (21 to 62 days), pigs fed the low-lys had lower (P <0.05) ADG and final BW. At 27 and 29 days, pigs fed the low-lys diet had a higher (P≤0.05) incidence of diarrhea. The lowest feed cost and the highest economic efficiency index were recorded for the low-lys treatment. However, pigs fed the control-lys presented a 3.9% higher profitability. In conclusion, a temporary reduction of lysine in the diets of nursery pigs followed by an unrestricted diet in the subsequent period led to worse growth performance and lower economic viability.(AU)

Objetivou-se com este estudo avaliar os efeitos da restrição temporária de lisina na dieta sobre o desempenho e viabilidade econômica de leitões em fase de creche. Foram utilizados 144 leitões, distribuídos em blocos ao acaso, com dois tratamentos e 12 repetições. Os tratamentos foram controle-lis, nível de lisina recomendado dos 21 aos 32 e 32 aos 42 dias de idade e baixa-lis, 90% do nível de lisina das dietas controle-lis. Dos 42 aos 62 dias, todos os animais receberam dieta controle. De 21 a 32 dias, leitões alimentados com baixa-lis tiveram pior ganho médio diário (GMD), conversão alimentar e peso corporal aos 32 dias (P≤0,05). Dos 32 aos 42 dias, leitões alimentados com baixa-lis apresentaram menor consumo médio de ração diário, GMD e peso aos 42 dias (P≤0,05). Dos 21 aos 62 dias, leitões alimentados com baixa-lis apresentaram GMD e peso corporal final menores (P≤0,05) quando comparados aos alimentados com controle-lis. At 27 and 29 days of age, pigs fed the low-lys diet had a higher (P≤0.05) incidence of diarrhea Aos 27 e 29 dias, leitões alimentados com baixa-lis apresentaram maior (P≤0.05) indicência de diarreia. O menor custo de alimentação e o maior índice de eficiência econômica foram registrados para baixa-lis. No entanto, os suínos alimentados com controle-lis apresentaram rentabilidade 3,9% maior. Como conclusão, a restrição temporária de lisina nas dietas de leitões piora o desempenho e diminui a viabilidade econômica.(AU)

Metabolic Impact of Light Phase-Restricted Fructose Consumption Is Linked to Changes in Hypothalamic AMPK Phosphorylation and Melatonin Production in Rats.

Recent studies show that the metabolic effects of fructose may vary depending on the phase of its consumption along with the light/dark cycle. Here, we investigated the metabolic outcomes of fructose consumption by rats during either the light (LPF) or the dark (DPF) phases of the light/dark cycle. This experimental approach was combined with other interventions, including restriction of chow availability to the dark phase, melatonin administration or intracerebroventricular inhibition of adenosine monophosphate-activated protein kinase (AMPK) with Compound C. LPF, but not DPF rats, exhibited increased hypothalamic AMPK phosphorylation, glucose intolerance, reduced urinary 6-sulfatoxymelatonin (6-S-Mel) (a metabolite of melatonin) and increased corticosterone levels. LPF, but not DPF rats, also exhibited increased chow ingestion during the light phase. The mentioned changes were blunted by Compound C. LPF rats subjected to dark phase-restricted feeding still exhibited increased hypothalamic AMPK phosphorylation but failed to develop the endocrine and metabolic changes. Moreover, melatonin administration to LPF rats reduced corticosterone and prevented glucose intolerance. Altogether, the present data suggests that consumption of fructose during the light phase results in out-of-phase feeding due to increased hypothalamic AMPK phosphorylation. This shift in spontaneous chow ingestion is responsible for the reduction of 6-S-Mel and glucose intolerance.

Day-restricted feeding during pregnancy and lactation programs glucose intolerance and impaired insulin secretion in male rat offspring.

AIM: The maternal environment during pregnancy and lactation plays a determining role in programming energy metabolism in offspring. Among a myriad of maternal factors, disruptions in the light/dark cycle during pregnancy can program glucose intolerance in offspring. Out-of-phase feeding has recently been reported to influence metabolism in adult humans and rodents; however, it is not known whether this environmental factor impacts offspring metabolism when applied during pregnancy and lactation. This study aims to determine whether maternal day-restricted feeding (DF) influences energy metabolism in offspring. METHODS: Pregnant and lactating Wistar rats were subjected to ad libitum (AL) or DF during pregnancy and lactation. The offspring born to the AL and DF dams were intra- and interfostered, which resulted in 4 group types. RESULTS: The male offspring born to and breastfed by the DF dams (DF/DF off) were glucose intolerant, but without parallel insulin resistance as adults. Experiments with isolated pancreatic islets demonstrated that the male DF/DF off rats had reduced insulin secretion with no parallel disruption in calcium handling. However, this reduction in insulin secretion was accompanied by increased miRNA-29a and miRNA34a expression and decreased syntaxin 1a protein levels. CONCLUSION: We conclude that out-of-phase feeding during pregnancy and lactation can lead to glucose intolerance in male offspring, which is caused by a disruption in insulin secretion capacity. This metabolic programming is possibly caused by mechanisms dependent on miRNA modulation of syntaxin 1a.

Exigência de lisina, planos nutricionais e modelos matemáticos na determinação de exigências de frangos de corte / Requirements of lysine, nutritional plans and mathematical models for determination of the requirements of broilers

Dentre os diversos nutrientes que podem interferir no desempenho e na qualidade da carcaça, a lisina parece exercer os efeitos mais pronunciados, pois a suplementação adicional desta melhora o ganho de peso, a conversão alimentar e reduz a gordura abdominal. Tratando-se especificamente de aminoácidos, a deficiência na fase inicial impede a máxima deposição protéica enquanto o excesso no final da fase, além de representar desperdício, gera gasto calórico adicional relativo à excreção destes na forma de ácido úrico. A solução apresentada para este impasse nutricional tem sido a recomendação da adoção de um maior número de dietas durante o ciclo de vida das aves, conhecido como programa de alimentação múltiplo, onde as diferenças entre o exigido e o fornecido são menores. Na formulação das dietas para os programas de alimentação múltiplos, os pesquisadores têm adotado modelos matemáticos desenvolvidos a partir das exigências estabelecidas via experimentos de desempenho ou da curva de crescimento e deposição de proteína das aves. Dentre os modelos matemáticos disponíveis, a equação de Gompertz, é a que melhor descreve o crescimento dos frangos, bem como dos diversos tecidos. O uso de modelos matemáticos para descrever o crescimento das aves permite informação adequada do peso versus idade e minimiza qualquer efeito aleatório causado, por exemplo, pelo ambiente. Predizer a performance das aves submetidas a diferentes condições alimentares e de manejo ou mesmo de diferentes linhagens é uma informação que o uso da equação de Gompertz pode fornecer aos profissionais da área.

Among the different nutrients that can interfere with performance and carcass quality, lysine appears to exert the most pronounced effect, since this additional supplementation improves weight gain, feed conversion and reduces abdominal fat. Specifically about amino acids, the deficiency in the initial phase prevents the maximum proteic deposition while the excess at the end of the phase, beyond it represents waste, it spends additional energy with excretion in the form of uric acid. The solution proposed for this nutritional impasse has been the recommendation of the adoption of a larger number of diets during the life of birds, known as phase-feeding program, where the differences between required and supplied are lower. In formulating the diets for the phase-feeding, researchers have used mathematical models developed from the requirements set by performance experiments or growth curve and deposition of protein in birds. Among the models available, the Gompertz equation is that best describes the growth of chickens and various tissues. The use of mathematical models to describe the growth of birds allows adequate information of weight versus age and minimizes any random effect caused, for example, by the environment. Predict the performance of birds under different feeding conditions and management or even of different strains is information that the use of the Gompertz equation can provide the professionals of the area.