ChileanJAR

A total of 70 cross-bred Large White X Landrace pigs were used in a feeding trial carried out in arder to study the effect on the replacement of barley by different levels of rye in the diets for growing finishing pigs. Futhermore the effect of supplementation with 50 ppm of oxytetracycline of the diet based on rye was also studied. Pigs of 22 Kg of initial liveweight and 3 month af age were allocated to 7 experimetnal groups of 10 pigs each, according to weight, sex and litter origin. Experimental groups were assigned at random to the following treatments: I. Barley based diet; II. rye replacing 12.5% of the barley in basal diet; III. Rye replacing 25.0%; IV. Rye replacing 37.5%; V. Rye replacing 50.0%; VI. Rye replacing 100.0%; VII. Rye replacing 100.0% plus 50 ppm of oxytetracycline. Replacement of barley by rye were made on weight by weight basis with no attemp to make diets isonitrogenus nor isocalorics.
The results indicate that during the growing period (up to 50 Kg) the total replacement of barley by rye (treatment VI) significantly reduced daily gains (P < 0.05). The differences found during the finishing period and troughout the experiment did not reach significance. However daily gains showed a clear tendency to be reduced as the level of rye increased, being this effect significantly linear (P < 0.01) to the regression analysis, an equivalent to 20g/day reduction on daily gains per each 25% level of replacement. Feed consumption showed thar rye reduced palatability of the meal since daily intake is decreased as the level of rye increased in the diet. There were no effect of level of rye on feed efficiency. Supplementation with 50 ppm of oxytetracucline, did not imporve the overall perfomance of pigs receiving rye based diets. Carcass quality insofar as back-fat measurement, dressing percent or carcass length were not affected by levels of rye. However the loin area for the pigs receiving the rye based diet without antibiotic su