Effects of excess dietary leucine and leucine catabolites on growth and immune responses in weanling pigs.

Two experiments with weanling pigs were conducted to study the effects on growth and immune responses of excess dietary L-leucine (LEU) and dietary supplementation with the LEU catabolites, alpha-ketoisocaproic acid (KIC) and beta-hydroxymethyl butyrate (HMB). In Exp. 1, 80 pigs were randomly allocated according to initial BW and ancestry to five replications of four dietary treatments (four pigs/pen). The control diet contained wheat, oat groats, menhaden fish meal, and dried whey and provided 1.12% LEU. Treatment diets were the control plus 1.12% LEU, 1.12% KIC, or .4% HMB. The experiment lasted 6 wk. In Exp. 2, 36 pigs were randomly allocated to nine replications of four dietary treatments in a 2 x 2 factorial arrangement. Treatments consisted of two concentrations of dietary LEU and a daily i.m. injection of dexamethasone (DEX) or saline. Pigs were fed a control corn-soybean meal and dried whey diet (1.56% LEU) or the control diet plus 1.56% of crystalline LEU. Pigs were individually penned and the experiment lasted 4 wk. Growth performance, plasma free amino acids, plasma urea nitrogen, and humoral and cellular immune responses were measured. Results indicated that LEU concentrations in practical diets and supplementation with KIC and HMB (Exp. 1) did not detrimentally affect growth and immune response. The high LEU concentration and DEX injection used in Exp. 2, however, were detrimental to both growth and immune response.

[Amino acid composition and biological value of pastries with protein-rich additives]. / Aminokislotnyi sostav i biologicheskaia tsennost' muchnykh konditerskikh izdelii, obogashchennykh belkovymi dobavkami.

The authors studied amino acid composition of confectionery (bisquits) enriched with dry fat-free milk, dried buttermilk, dry whey and soya bean flour. The biological value of the products was estimated by the sum of essential amino acids, by the ratio of essential amino acids and total nitrogen, by the chemical score and the variation coefficient of the amino acid score. It has been established that confectionery enriched with dry fat-free milk and dried buttermilk contain more lysine than those enriched with soya bean flour. The balance of amino acids is improved in the products enriched with dry fat-free milk and dried buttermilk. To improve the amino acid balance and increase protein content in food products it iz recommended that by-products of milk manufacturing be mildly used.