Digestible lysine levels for barrows with high genetic potencial from 95 to 125 kg

Avaliou-se o efeito de níveis de lisina digestível sobre o desempenho e a composição de carcaça de suínos machos castrados de alto potencial genético para deposição de carne. Foram utilizados 80 animais com peso inicial de 95,55 ± 1,04 distribuídos em delineamento experimental de blocos ao acaso, com cinco dietas (0,540; 0,642; 0,744; 0,846 e 0,948% de lisina digestível), oito repetições e dois animais por unidade experimental. As dietas experimentais e água foram fornecidas à vontade durante todo o período experimental. Os níveis de lisina digestível não influenciaram o consumo de ração diário e o peso de carcaça dos animais. O ganho de peso diário e a conversão alimentar melhoraram de forma quadrática até os níveis de lisina digestível estimados de 0,803 e 0,817%, respectivamente. Foi observado efeito linear crescente dos tratamentos sobre o consumo diário de lisina e sobre a quantidade de carne. Embora, a deposição diária de carne tenha aumentado de forma linear, o modelo LRP foi o que melhor se ajustou aos dados que permaneceram em um platô a partir do nível de lisina digestível de 0,803%. Os níveis de lisina digestível influenciaram a espessura de toucinho P2 dos animais que reduziu de forma linear. O nível de lisina digestível de 0,803%, que corresponde a consumo de 24,60 g/dia de lisina digestível, proporciona os melhores resultados de ganho de peso e deposição de carne, enquanto o nível de 0,817%, correspondente a consumo de 25,03 g/dia de lisina, proporciona melhor conversão alimentar e o de 0,948%, correspondente a consumo de 29,09 g/dia de lisina digestível, promove maior deposição de carne e espessura de toucinho em suínos machos castrados na fase dos 95 aos 125 kg.This work evaluated levels of digestible lysine on performance and carcass composition of barrows with high genetic potential for meat deposition. It was used 80 animals with initial body weight of 95.55 ± 1.04 kg, distributed in a completely randomized block design, with 5 diets (0.540; 0.642; 0.744; 0.846 and 0.948% of digestible lysine), eight replicates and two animals per experimental unit. The experimental diets and water were provided ad libitum throughout the experimental period. Digestible lysine levels did not change daily feed intake and carcass weight of the animals. Daily weight gain and feed conversion improved in a quadratic way up to the estimated levels of 0.803 and 0.871% of digestible lysine, respectively. It was observed an increasing linear effect of the treatments on daily lysine intake and amount of meat. Although daily meat deposition had increased in a linear way, the LRP was the model that best adjusted to the data which remained on a plateau from 0.803% of digestible lysine level. The levels of digestible lysine influenced the P2 backfat thickness of the animals which decreased in a linear way. The digestible lysine level of 0.803%, corresponding to an intake of 24.60 g/day of digestible lysine provides the best results of weight gain and meat deposition whereas the level of 0.817% corresponding to an intake of 25.30 g/day of lysine provides the best result of feed conversion, and the digestible lysine level of 0.948% corresponding to an intake of 29.09 g/day of digestible lysine provides the best results of meat deposition and backfat thickness of barrows from 95 to 125 kg

L-glutamine and L-glutamate in diets with different lactose levels for piglets weaned at 21 days of age

This study was developed to evaluate the effects of adding L-glutamine and L-glutamate in diets with no lactose or with 4.0 or 8.0% lactose inclusion for piglets weaned at 21 days old. One hundred and eight piglets with initial weight of 6.12±0.70 kg were allotted in a complete randomized block design, in a 3 × 2 factorial arrangement, with six treatments, six replicates, and three piglets per experimental unit. The experimental diets were supplied from 21 to 35 days. From 36 to 49 days, animals received the same diet with no lactose inclusion, but the animals in the treatments with L-glutamine + L-glutamate in the previous phase continued to receive diets containing these ingredients. There was no interaction between the level of lactose and the inclusion of L-glutamine + L-glutamate on the parameters evaluated. The levels of lactose did not affect the performance of piglets in either of the two periods. Adding L-glutamine and L-glutamate in the diet positively influenced the weight gain of pigs from 21 to 49 days of age and increased the villous height in the duodenum, jejunum and ileum. Inclusion of L-glutamine + L-glutamate in diets for piglets weaned at 21 days of age improves the performance and the intestinal mucosa morphology, regardless of lactose addition