Levels of true digestible lisiane and metabolizable energy for growing pigs: effect on nitrogen and energy balance

Abstract

An experiment was conducted at the Department of Animal Husbandry of Universidade Federal de Lavras aiming to study the nitrogen and energy balance in diets with reduced crude protein rates (CP) and different levels of energy and lysine for growing pigs. 52 castrated pigs (initial weight = 36.13 ± 2.8 kg) of high genetic potential were used, housed individually in metabolism cages (experimental unit). The treatments consisted of 12 diets with three levels of metabolizable energy (ME) (3060, 3230 and 3400 kcal / kg) and four of true digestible lysine (TDL) (0.7, 0.9, 1.1 and 1, 3%) with 14% CP plus a control diet with 3230 kcal ME / kg, 1.03% TDL and 18% CP. We used a DBC in time 3x4 +1 factorial design with four replications to verify the absorbed nitrogen (AN), N retained (NR), the NR / NA (%),absorbed energy (AE), retained energy (RE) and the ratio RE /AE (%). In relation retained nitrogen / absorbed nitrogen was declining linear regression (P <0.05) when 3400 kcal / kg was used, where the lowest levels (0.7 and 0.9%) of TDL showed the best results. In the study of energy balance, for the variables retained energy and the relationship between energy there was no difference (P> 0.05) between the control treatment and other experimental diets. It is concluded that the levels 3230 kcal / kg and 1.03% of TDL can be used without affecting the utilization of nitrogen by growing pigs in diets with reduced crude protein content.Index terms: Synthetic amino acids, nutrition, metabolism, ideal protein. RESUMOFoi conduzido um experimento no Departamento de Zootecnia da Universidade Federal de Lavras com o objetivo de estudar o balanço de nitrogênio e energético em rações contendo reduzido teor de proteína bruta (PB) e diferentes níveis de energia e lisina para suínos em crescimento. Foram utilizados 52 suínos machos castrados (peso inicial = 36,13 ± 2,8 kg) de alto potencial genético, alojados individualmente em gaiolas de metabolismo (unidade experimental). Os tratamentos consistiram em 12 dietas formuladas com três níveis de energia metabolizável (EM) (3060, 3230 e 3400 kcal/kg) e quatro de lisina digestível verdadeira (LISD) (0,7; 0,9; 1,1 e 1,3%) com 14% PB mais um tratamento controle, com 3230 kcal EM/kg, 1,03% LISD e 18% PB. Utilizouse um DBC no tempo em fatorial 3x4+1, com quatro repetições, para verificar o N absorvido (NA), N retido (NR), a relação NR/ NA (%), energia absorvida (EA), energia retida (ER) e a relação ER/EA (%). Na relação nitrogênio retido /nitrogênio absorvido houve regressão linear decrescente (P<0,05) quando 3400 kcal/kg foi utilizado, onde os menores níveis (0,7 e 0,9%) de LISD apresentaram os melhores resultados. No estudo do balanço energético, para a variáveis energia retida e a relação entre energia não houve diferença (P>0,05) entre o tratamento controle e as demais dietas experimentais. Conclui-se que os níveis 3230 kcal EM/kg e 1,03% de LISD podem ser utilizados sem afetar o aproveitamento do nitrogênio pelos suínos em crescimento, em rações com reduzido teor de proteína bruta.T...

Leptin gene transfer regulates fibromuscular development and lipid deposition in muscles via SIRT1, FOXO3a and PGC-1α in mice in vivo

“…Regulation of energy metabolism has thus become a topic of great interest and extensive research in animal science. Nutrition and genetic factors are the major determinants of energy metabolism in pigs (1). In a previous study, we used microarray analysis to compare longissimus dorsi muscle gene expression profiles between Landrace and Jinhua swine, which is a Chinese breed known for good meat quality that is bright red, tender, juicy and rich in muscle fat (2).…”