Intake and digestion of lucerne hay and wheat straw by cattle 14 to 56 weeks of age

Abstract

Eight Friesian calves, 8 weeks of age, were prepared with rumen and abomasal cannulae. Four calves were given lucerne and four calves were given wheat straw sprayed with urea and minerals. The diets were changed over between the calves every 6 weeks until the calves were 56 weeks of age. The particles in the rumen that passed through a 1 mm screen during wet sieving were 66 to 73% of the total particles in the rumen of calves given lucerne and 77 to 84% of the particles in the rumen of the calves given wheat straw. The digestion of organic matter in the stomach was 71 to 79% of the total organic matter digested in the calves given lucerne. In the calves given wheat straw, between 82 and 95% of the total organic matter digestion occurred in the stomach. The apparent digestion of dry matter in the calves given lucerne was 61-6856 and did not change with age of the calves. The apparent digestion of dry matter when the calves were given wheat straw was 42% at 14 weeks of age, and it increased to 53% at 56 weeks of age. The digestion of nitrogen in the intestine in the heifers given wheat straw increased to 26 weeks of age while that of heifers given lucerne hay decreased.