Effect of level of dietary calcium and phosphorus on the site of absorption and utilization of phosphorus in gestating and lactating ruminants /
Two digestion trials were conducted to determine the effect of level of Ca and P on the site and extent of absorption of P in gestating and lactating ruminants. Gestating Nubian dairy nannies (n=8; 41-55 kg) with abomasal cannulas were used in the gestation feeding trial, which consisted of three 2...
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| Format: | Thesis eBook |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2002.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Summary: | Two digestion trials were conducted to determine the effect of level of Ca and P on the site and extent of absorption of P in gestating and lactating ruminants. Gestating Nubian dairy nannies (n=8; 41-55 kg) with abomasal cannulas were used in the gestation feeding trial, which consisted of three 20 d dietary treatment periods. Nannies were randomly assigned to the following dietary treatments of Ca and P: 1) Ca 0.4%, P 0.3% (LCLP), 2) Ca 0.8%, P 0.3% (HCLP) and 3) Ca 0.8% and P 0.6% (HCHP) in a replicated 3x3 Latin Square designed experiment. Reassignment of diets during subsequent periods assured that animals would not consume a diet they were previously exposed to. All diets contained 0.25% chromium oxide as a digestive tract marker. Limestone and monocalcium phosphate were utilized to supply the necessary Ca and P. Six d sample periods were used to collect diets beginning on d 13 of each period, refusals beginning on d 14 and abomasal digesta and feces beginning on d 15. Blood was collected 3 h post-feeding on d 20. Nannies fed HCLP had more (P<.05) Ca passing the abomasal cannula than LCLP. Animals fed HCLP excreted more (P<.05) Ca in the feces than those fed LCLP, while increasing dietary P intake had no effect (P>.05) on fecal excretion. Increasing dietary P in the presence of elevated Ca decreased (P<.05) serum Ca. Feeding high Ca in the presence of low dietary P increased (P<.05) serum inorganic P. The lactation feeding trial consisted of two 20 d feeding periods. At parturition, nannies (n=3) from the gestation feeding trial were assigned to one of two dietary treatments of Ca and P: 1) HCLP and 2) HCHP. In addition to samples previously described, milk was collected to determine 24 h milk production and Ca and P concentrations. No differences (P>.05) were detected between dietary treatment groups because the desired P intake was not achieved. These data suggest that dietary Ca levels may be increased with increasing Ca requirements for gestation and lactation without increasing P to maintain a 1.5:1 to 2:1 ratio. |
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| Item Description: | "Major subject: Nutrition". Vita. |
| Physical Description: | vii, 54 leaves : illustrations ; 28 cm. Also available online. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references (leaves 44-51). |