The use of iron sulfate and feed pelleting as detoxifying mechanisms for free gossypol in cottonseed diets for dairy cattle /
| Main Author: | |
|---|---|
| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
|
| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Thirty two lactating cows were fed diets with either a) 18.7% Soybean meal (SBM); b) 18.7% SBM plus 500 ppm supplemental iron from iron sulfate (FeS0₄.H₂0); c) 15% WCS; or d) 15% WCS plus 500 ppm supplemental iron from FeS0₄.H₂0. Dry matter intakes were similar except for cows fed the diet with SBM plus FeS0₄.H₂0 which was smaller P <.05. Cows fed WCS diets, ingested 23 g of free gossypol (FG). The FG excreted was substantially lower than FG intakes. The iron excreted was similar to the iron intakes in all cows. Blood metabolites did not differ among the groups, nor did productive performance (P < .05) and no signs of gossypol toxicity were seen. Twelve Holstein new b o m male calves were fed a commercial milk replacer for 4 weeks and then fed diets with either a) 27% SBM; b) 50% WCS; or c) 50% WCS plus 500 ppm of iron from FeS04 .H20. Dry matter intakes were similar for calves fed diets 1 and 2, but slightly lower for calves fed the diet with WCS plus FeS0₄.H₂0 (P < .05). Intakes of FG in WCS diets averaged 2 g of FG/calf/day, lower than the expected 4 g/calf, suggested a pelleting effect on FG. Excretion of FG was considerably smaller than intake and there were no apparent differences (P < .05) in the way the calves metabolized FG. Iron excretions reflected the differences in dietary iron. Blood components did not differ among the groups nor did their productive parameters (P < .05). Calves grew exceptionally well on these diets. Three batches of WCS and one of cottonseed meal (CSM) were analysed for FG and total gossypol (TG) prior and after being pelleted under 3 sets of conditions. Pelleting treatments were: 1) low temperature with no steam; 2) high temperature using high steam; and 3) medium temperature using medium steam. The pelleter was equipped with a centigrade multicoupler thermometer. In WCS, pelleting without steam decreased FG by 67%, medium steam by 56%, and high steam by 70%. In CSM, pelleting without steam decreased FG by 48%. Gossypol glands in the intact WCS appeared to be very sensitive to moisture and temperature. Presumably, the binding of FG occurred to proteins to which gossypol has high binding affinity as gossypin and congossypin. Pelleting could represent a mechanism to decrease toxicity when WCS is used in the diets of animals. |
|---|---|
| Item Description: | Typescript (photocopy). Vita. "Major subject: Nutrition." |
| Physical Description: | xi, 82 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |