Abstract
Lysine tends to be the first limiting amino acid in the feeds for pigs. A type of high-lysine naked barley (HLNB, Shikoku 79) has been recently developed by Shikoku National Agricultural Experiment Station. Chemical and amino acid analyses, an in-vitro digestion trial with intestinal fluid of pigs and an energy and nitrogen balance trial with growing pigs were conducted using corn as the control so as to determine the nutritive value of the HLNB. Six piglets each weighing approx. 30kg were used for the balance trial, which were individually housed in the metabolism cages and were fed daily 1200g of one of the three experimental diets. The three different types of feed were the HLNB alone, the corn alone and the mixture of corn with soybean meal. The experiment was conducted for two test cycles each comprising 4 preparatory days and 4 experiment days to collect feces and urine. 1) The HLNB contained 13.4% crude protein (CP), and 0.68% lysine. Its CP content was higher than that of naked barley of 11.2% demonstrated in the Japanese Standard Tables for feed components. The lysine content in the CP was 5.1%, which was substantially higher than that of corn of 2.8%. 2) In the in-vitro test, the digestible crude protein (DCP) and the digestible energy (DE) of the HLNB were 11.7% and 3.14kcal/g, respectively, which were higher than the counterparts of corn of 6.1% and 2.90kcal/g, respectively. 3) In the test on metabolism, the apparent digestibilities for CP of the HLNB diet and corn diet were 83.7% and 75.2%, respectively, the former being higher. The digestibilities of gross energy with the HLNB diet and corn diet were 86.4% and 84.6%, respectively, while the DE and metabolizable energy were 3.28kcal/g and 3.17kcal/g, respectively and 3.19kcal/g and 3.11kcal/g, respectively. The figures of the HLNB tended to be slightly higher than those of corn. The daily nitrogen retention of 10.1g for both the HLNB diet and corn-soybean meal diet were significantly higher than that of corn diet of 3.5g (p<0.05). 4) The results suggested that the HLNB is an excellent grain because of its higher lysine content and its higher utility as an energy source.
