Nutritive Value of Leaf Protein Concentrate and Condensed Green Juice Prepared From a Oats-Annual Meadow Grass Mixture for Growing Pigs

Abstract

The nutritive value of a leaf protein concentrate (LPC) and a green juice prepared from a mixture of 33 parts of oats (Avena sativa L.) and 67 parts of annual meadow grass (Poa annua L.) for growing pigs were studied. The green juice was concentrated to 40% of the initial volume by reverse osmosis and referred to as RO. Two experiments were made. In each experiment, a litter of 8 Landrace pigs weighing about 10kg were divided into two groups of 4. Four-week experimental period was preceded by 1-week preliminary period. Each pig was fed 5% as dry matter of diet per body weight per day. One half of the daily ration was given at 9:00 and the other half at 16:00. In Experiment 1, the nutritive value of a LPC-bran diet (LPC diet) was compared with that of a fish meal-bran diet (fish meal diet) and in Experiment 2, a RO-fish meal-bran diet was compared with a fish meal-bran diet. LPC and RO constituted 28 and 20% of dry matter of corresponding diets. Each diet contained 18% crude protein. There were no statistically significant differences in pig growth, apparent digestibility of crude protein, feed conversion ratio and plasma urea nitrogen among the three feed treatments. But the plasma amino acid concentrations were different each other. The postprandial (4 hours after the morning meal) total essential amino acid level was highest in pigs on LPC diet and lowest in those on fish meal diet. In every pig, the concentration of each essential amino acid in the postprandial plasma was higher than that in the fasting plasma which was taken immediately before the morning meal. This is a result of the fact that each diet contained enough amino acids to meet the requirement of pig weighing 10-20kg recommended by National Research Council -of Agriculture, Forestry and Fishery of Japan. From the above, it was concluded that about 30% and 20% of dry matter of growing pig diet could be substituted by the LPC and the green juice, respectively, without any ill-effects in the experiments of 4 week duration.