Isoleucine and valine supplementation of a low-protein corn-wheat-soybean meal-based diet for piglets: Growth performance and nitrogen balance1

Abstract

The effects of Ile and Val supplementation of a low-CP, corn-wheat-soybean meal-based piglet diet on growth performance, incidence of diarrhea, and N balance were studied using 60 Landrace x Duroc male piglets in a 4-wk experiment. The 60 individually caged piglets were divided into 5 dietary treatments, each consisting of 12 piglets. Diet 1 was a positive control diet (20% CP); diet 2 was a low-CP negative control diet (17% CP); diets 3, 4, and 5 were low-CP diets to which Ile, Val, or the combination of Ile and Val were added, respectively. All diets were supplemented with Lys, Met, Thr, and Trp to provide the required concentrations of these AA according to the 1998 NRC. Average daily gain and ADFI were similar among pigs fed the positive control, Val-added, and the Val plus Ile-added diets. On wk-2 and wk-4, fecal score was greater (softer feces) in piglets fed the 20% CP level compared with the remaining treatments (P < 0.01). Nitrogen intake was decreased (P < 0.0001) in pigs fed diets containing low levels of CP compared with pigs fed the 20% CP diet. Fecal N excretion (g/d) was decreased (P < 0.05) in piglets fed low-CP diets at wk 1 and wk 4 of feeding, and in urine at wk 4 of feeding. Crude protein levels or AA supplementation had no effect on N retention efficiencies. These results indicate that the supplementation of Val alone, or in combination with Ile, to a low-CP piglet diet with adequate levels of Lys, Met, Thr, and Trp is necessary to achieve maximum performance in pigs consuming corn-wheat-soybean meal-based diets.

Response of piglets to the standardized ileal digestible isoleucine, histidine and leucine supply in cereal–soybean meal-based diets

“…Valine is the fifth limiting AA in a cereal-soybean meal-based diet (Figueroa et al, 2003;Lordelo et al, 2008;Barea et al, 2009b). On the basis of the current AA requirement estimates (National Research Council (NRC), 1998; British Society of Animal Science (BSAS), 2003), Ile, His or Leu may be the sixth limiting -E-mail: jaap.vanmilgen@rennes.inra.fr AA in cereal-soybean meal-based diets.…”

Leucine levels in low protein diets for pigs in the initial phase

“…The optimal SID leucine level (1.24%) obtained for plasma urea concentration, determined by the association of the quadratic model and LRP model, are close to that recommended by the NRC (2012) for 10 to 25 kg pigs (1.23% SID leucine).The use of industrial AA allows a formulation of diets with low CP content (LORDELO et al, 2008), as in the present study (15.16% CP), taking into account the nutritional requirements of the essential AA and allowing an increase in the efficiency of nitrogen use in the diet. However, according to Mansilla et al (2015), the CP affects the concentration of endogenous nitrogen, which is an important for non-essential AA synthesis.…”

Redução da proteína bruta em rações sobre os balanços metabólicos de suínos mantidos em diferentes condições térmicas

“…A redução na excreção total de N também foi relatada por Lordelo et al (2008) que utilizaram rações com baixa proteína bruta suplementadas com isoleucina e valina, sendo que na primeira semana os leitões apresentaram redução de 26% e, após a quarta semana, a redução na excreção total foi de 29% em relação aos animais que receberam rações com níveis de PB altos.…”

“…A ULP não foi influenciada pelos níveis de proteína bruta PB da ração, fato que pode ser atribuído ao N retido e N excretado nas fezes também não terem sido influenciados. Os valores médios observados para ULP foi de 40,2% em estresse térmico e 44,4% em condição de conforto térmico, sendo que Paiano et al (2009) Lordelo et al (2008), como uma ineficiência metabólica do animal em reter o nitrogênio absorvido que está além das suas necessidades de consumo, excretando-o por meio da urina.…”