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Effect of diet and space on barrow performance: Experiments and model development
Abstract
Three experiments were conducted using feather meal as a source of dietary excess protein and space allocation to manipulate feed intake of barrows to improve carcass leanness. The results of the three experiments indicated that feed intake of barrows was reduced for the first two to three weeks after feather meal diets were began and then feed intakes gradually increased to a level similar to control barrows. Carcass leanness of barrows was not consistently improved by feather meal diets. Results suggested that feeding feather meal diets to barrows after their maximum rate of protein deposition was reached resulted in leaner carcasses. However, the daily lean gain of barrows was reduced by feather meal diets when fed before the maximum protein deposition rate was reached. Use of feather meal also improved the apparent digestibilities of calcium and phosphorus, resulting in reduction of calcium and phosphorus. Reducing space allocation of barrows decreased their feed intake. Results also suggested that body weight was affected by space allocation earlier in the trial than feed intake of barrows. This indicated that the reduction of feed intake was the consequence of the reduction of body weight affected by crowding. The evaluations of a swine growth model using two newly suggested growth parameters from literature (Whittemore, 1998; Emmans and Kyriazakis, 1999) resulted in very high growth rates and feed efficiencies. Therefore, a new set of growth parameters was suggested to lower the growth rate predictions of the model to improve its prediction precision. The evaluation of the swine growth model using the research data indicated that the model was unable to predict the responses of barrows fed feather meal diets. However, the model was capable of predicting the responses of barrows fed common corn-soybean meal diets in both crowded and uncrowded pens. Further research is needed to reveal the feed intake reduction mechanism for pigs fed feather meal diets before it can be implemented into the model.
Subject Area
Livestock
Recommended Citation
Ssu, Kuo-Wei, "Effect of diet and space on barrow performance: Experiments and model development" (2001). ETD collection for University of Nebraska-Lincoln. AAI3016327.
https://digitalcommons.unl.edu/dissertations/AAI3016327