Effect of breed on the voluntary intake of grazing ewes during lactation

Abstract

TWO EXPERIMENTS WERE CONDUCTED USING OATS, HIGH TANNIN SORGHUM (HTS), CORN, AND LOW TANNIN SORGHUM (LTS) IN STARTER DIETS DURING THE FI RST 14 DAYS AFTER WEANING. IN THE FIRST EXPERIMENT, 20 PIGLETS WEANED AT 20.4 DAYS WERE USED TO EVALUATE THE EFFECT OF THESE CEREALS ON TOTAL APPARENT DIGESTIBILITY OF NUTRIENTS. THE PIGLETS WERE ASSIGNED TO ONE OF FIVE DIETS: ONE CORN-STARCHBASED CONTROL DIET CONTAINING CASEIN AND SKIMMED MILK, AND FOUR EXPERIMENTAL DIETS WHERE ONE CEREAL SUBSTITUTED THE CORN STARCH. FECES WERE COLLECTED FROM EACH PIG EVERY DAY OF THE SECOND WEEK AFTER WEANING TO MEASURE THE COEFFICIENT OF APPARENT TOTAL DIGESTIBILITY (CATD) OF DRY MATTER (DM), CRUDE PROTEIN (CP), ENERGY (E) AND NEUTRAL DETERGENT FIBER (NDF). THE EXPERIMENTAL DIETS HAD A LOWER (P < 0.001) CATDDM AND CATDCP THAN THE CONTROL DIET, EXCEPT FOR OATS CATDCP. CORN AND SORGHUM DIETS HAD SIMILAR CATDDM, CATDCP AND CATDE. CATDNDF WAS LOWER (P < 0.01) IN PIGLETS FED OATS AND HIGH TANNIN SORGHUM. CEREAL INCLUSION IN PIGLET'S DIETS DECREASED ENERGY DIGESTIBILITY (P < 0.01). THE SECOND EXPERIMENT WAS A DIETARY PREFERENCE TEST USING THE FOUR CEREAL DIETS. SEVENTY-TWO PIGLETS WEANED AT 21 DAYS WERE USED. THE PIGLETS EXPRESSED THEIR DIETARY PREFERENCE IN DESCENDING ORDER, AS FOLLOWS: OATS, CORN, LOW TANNIN SORGHUM AND HIGH TANNIN SORGHUM. IT IS CONCLUDED THAT OATS STIMULATED EARLY FEED INTAKE BUT THAT PIGLETS HAD A BETTER CAPACITY TO DIGEST DIETS WITH HIGH STARCH CONTENT AND LOW LEVELS OF FIBER AND TANNIN, SUCH AS CORN AND SORGHUM DIETS, WHICH ARE THUS RECOMMENDED FOR THE POSTWEANING PHASE.