INGREDIENT AND PROCESSING INTERRELATIONSHIPS IN SWINE FEEDS: IV. EFFECTS OF VARIOUS LEVELS AND KINDS OF FIBROUS DILUENTS IN FINISHER RATIONS, FED AS MEAL OR PELLETS, ON PERFORMANCE AND CARCASS QUALITY OF SWINE

Abstract

A feeding experiment, of 2 × 2 × 3 × 5 factorial design (two sexes, pellets versus meal, three levels of fiber and five sources of fiber) involving 60 gilts and 60 barrows, weighing initially 100 ± 5 pounds, and individually fed to 200 ± 5 pounds, was carried out. The basal ration was composed of equal parts wheat and barley with soybean oil meal and meat meal as the protein supplement. This ration was diluted with three levels each of oat hulls, alfalfa meal, wheat bran, cellulose and ground corn cobs so as to obtain estimated T.D.N. levels in the ration of 62, 65 and 68 per cent. All rations were supplemented with vitamins and minerals. Each ration was fed as meal and as 3/16-inch pellets. Feed was allowed during two 1-hour periods daily and was, therefore, partially restricted.A Cr2O3-marker digestibility study was carried out in mid-test and the carcasses were assessed following slaughter.Daily feed intakes varied, depending on the diluent used, thus revealing that factors other than T.D.N. levels per se influence feed consumption by pigs self-fed rations balanced in other respects. The net effect on digestible energy intake was interpreted for each type of diluent in relation to the attainment of desirable rates of gain and carcass quality of Yorkshire pigs. Digestible energy intakes per day decreased by 43, 43, 36, 56 and 92 kcal. for each 1 per cent increase in the amount of oat hulls, alfalfa meal, wheat bran, cellulose or corn cobs, respectively.Pelleting was found to increase digestible energy intakes by 10 to 15 per cent, mainly as a result of improved digestibility of energy components.