Record Details
Field | Value |
---|---|
Title | Energy-protein relationships in high-fat rations for growing-finishing swine |
Names |
Pate, Findlay Moye
(creator) Oldfield, J. E. (advisor) |
Date Issued | 1967-07-24 (iso8601) |
Note | Graduation date: 1968 |
Abstract | An experiment was conducted with 48 Yorkshire x Berkshire crossbred barrows to evaluate the influence of varying Calorie: protein ratios in high-fat rations on performance and carcass quality of growing-finishing swine. Pigs were individually fed rations containing three levels of fat (lard): 0, 15 and 30 percent. Each fat level was incorporated into rations differing by Calorie: protein ratio (Kcal. digestible energy per gram of crude protein). Two ratios were employed, based on (1) a ration containing 1500 Kcal. of digestible energy and 14 percent crude protein, approximately that commonly used in swine grower diets, and (2) a ration containing a similar energy level as (1) , with the crude protein level raised to 20 percent. Responses were obtained over two growth periods (60-130 and 130-200 pounds live weight). Animals were slaughtered after exceeding a weight of 200 pounds and carcass data were collected. Pigs consuming the higher protein diets exhibited a significantly poorer average daily gain (P < .01) and were less efficient in dry matter utilization (P < .05). Further evidences of the lower nutritive value of the higher protein diets were: an apparent reduction in daily intakes of digestible energy and dry-matter, and a significantly (P < .01) larger quantity of calculated digestible energy consumed per pound of gain. The poorer performance noted with the higher protein diets tended to become more pronounced with increasing levels of fat. Inclusion of increasing quantities of fat significantly (P < .01) improved both average daily gain and dry matter utilization. Considering the mean results from the two ratios used, average daily gain was increased by 7.5 and 18.4 percent and dry matter conversion by 21.3 and 45.0 percent with the addition of 15 and 30 percent fat, respectively. Further, additional fat resulted in significantly (P < .01) greater daily intakes of calculated digestible energy and crude protein. Calculated digestible energy consumption per pound of gain as an indication of energy utilization was not altered by varying fat levels. The effects of energy:protein ratio and fat supplementation on pig performance were comparable over the two growth periods studied. Statistically, the addition of fat to rations of older pigs was found to be more beneficial (P < .01) in relation to dry matter conversion than with younger animals. However, there was no indication that this interaction between growth stage and fat level existed with regard to calculated digestible energy consumed per pound of gain. This finding, along with the main effects of added fat on dry matter and calculated digestible energy consumption per pound of gain, showed that efficiency of gain would be more representative if reported in terms of energy utilization in studies concerned with varying caloric density. Additional fat brought about a definite trend toward increased carcass fatness. With increasing fat levels there was a significant, (P < .01) linear increase in backfat thickness and an apparent reduction in loin eye area. Increasing the quantity of dietary protein in relation to the energy content of the diet was ineffective in improving carcass desirability. Pigs fed the low-fat, high-protein ration had 0.28 inches more backfat (P < .05) and 0.49 square inches less loin eye area than comparable animals on the low-fat, low-protein ration. However, at the higher fat levels there was no indication of poorer carcass quality being associated with higher protein intake. |
Genre | Thesis/Dissertation |
Topic | Swine -- Feeding and feeds |
Identifier | http://hdl.handle.net/1957/46990 |