| The experiment investigated the effect of corn particle size on growth performance, nutrient digestibilities,α-amylase activity and digestive tract development. The purpose of the present study was to probe into the best corn particle size.Experiment 1 Effects of corn particle size on growth performance and nutrient digestibility in young dairy goatsTwenty-four dairy goats (seven mo. old, mean BW 17.53 kg) were used in a randomized complete design experiment of three treatments to determine the effects of corn particle size on growth performance and nutrient digestibility. The three groups had the same diets (28.35% corn) with finely cracked corn (mean particle size 0.76 mm), coarsely cracked corn (mean particle size 2.57 mm), and whole grain. Experimental periods lasted 60 d.The results showed that corn particle size did not affect DMI, growth performance and the total tract apparent digestibility of DM, GE, CP, NDF and ADF (P>0.05). Compared with finely and coarsely cracked corn, ADG had the tendency of improvement (P=0.1396), and starch digestibility in the total tract was reduced (P<0.05) in young dairy goats fed whole corn.Experiment 2 Effects of corn particle size on starch digestibility andα-amylase activity in young dairy goatsThe objective of this experiment was to determine the effects of corn particle size on pH, starch digestion on different site and extent, andα-amylase activity in the pancreas and the digesta of the small intestines in young dairy goats. After trial 1, twelve young dairy goats, used to carry on digestion experiment, were slaughtered. In the slaughter experiment, the digesta were collected from the rumen and the small intestine to measure pH, starch digestibility, andα-amylase activity in the digesta of the small intestine; the pancreases were collected to measure the weight andα-amylase activity.The results showed that corn particle size did not affect pH in the rumen and the small...
|
PDF Full Text Request