The digestible tryptophan requirements of starter, grower and finisher swine /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | One-thousand two-hundred sixty-six crossbred pigs were used in growth and digestion trials to determine the digestible tryptophan (TRP) requirement of starter (6 to 16 kg), grower (22 to 50 kg) and finisher (55 to 97 kg) pigs. Initial growth trials determined the correct composition of the TRP deficient basal diet. Subsequent growth trials evaluated a corn-fish meal--corn gluten meal basal diet, the basal diet with five incremental additions of L-TRP and a control corn-soybean meal diet. Tryptophan content of the six experimental diets ranged from .13 to .255% (starter pigs), .08 to .18% (grower pigs) and .063 to .163% (finisher pigs). In all trials average daily gain, average daily feed intake and gain/feed increased (P < .001) linearly and quadratically as dietary TRP increased. Broken-line regression analyses determined the total dietary TRP requirements to be .19, .13 and .09% (as fed basis) for starter, grower and finisher pigs. A digestion trial using grower pigs (29 kg initially) determined the apparent ileal digestibility of TRP in the basal starter and grower diets to be 72 and 70%, respectively; a similar trial with finisher pigs (55 kg initially) found 59% for the basal finisher diet. Mean digestibility of L-TRP was 97%. Based on these values and the total TRP requirements given above, the digestible TRP requirements are .15, .10 and .06 for starter, grower and finisher pigs, respectively. Two additional digestion trials determined that starter pigs digested the amino acids in the experimental diet less efficiently than grower pigs, and that confining growing pigs to digestion crates and limiting feed intake increased amino acid digestibilities as compared to open pens with ad libitum intake. These results suggest that amino acid digestibilities should be determined under conditions similar to the growth trials for maximum precision. The absolute differences in TRP digestibility caused by differences in a age, housing and feed intake were not large enough (7 percentage units) to have a practical impact on the digestible requirements given above. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Nutrition." |
| Physical Description: | xiii, 135 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |