Bone mineral response to ammonium sulphate offered as a lick supplement in beef calves.
Sixteen Bonsmara calves (4 males, 12 females) between 10 and 18 months of age were blocked according to age and sex and randomly assigned to 2 groups. They were offered licks containing bone meal and salt (50:50 ratio) (control) and bone meal and ammonium sulphate (NH4SO4) at 1.25, 2.5, 5, 10, 15, and 18% (treatment) to evaluate the effects of dietary anions on bone phosphate (P) concentration. Bone P concentration was significantly (P < 0.05) higher in the NH4SO4 group compared with the control group, indicating that NH4SO4 was able to increase the P content of bone at each of the 6 concentrations used in the lick relative to the control animals, thereby improving the P status of the animals. Ammonium sulphate at 15% and 18 % in the lick also significantly (P < 0.05) increased bone P compared with the lower concentrations of NH4SO4. Bone calcium (Ca) fluctuated as a result of the acidogenic lick. There was absorption of Ca when P was being resorbed and resorption of Ca when P was being absorbed into and out of bone. Bone Ca:P ratio ranged from 3.2 to 6.4 among the control group and 1.6 to 4.3 among the treatment group. Animals receiving the acidogenic lick had a higher percentage ash compared to the control group for most of the experimental period. Bone magnesium (Mg) fluctuated in response to the acidogenic lick, and it was difficult to show a relationship between bone Mg and Ca or P. The overall mean cortical bone thickness was significantly (P < 0.05) greater in treatment (1.60 mm) compared with control (1.43 mm) calves and this was also true at sampling periods 2, 4, 5 and 6. Bone thickness followed bone P and not bone Ca. Results from this research indicate that the addition of ammonium sulphate to a lick had a beneficial effect in improving the P status by increasing bone P and improving the mineral status of bone by increasing the thickness of cortical bone and percentage ash.
Motsei
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Department of Animal Health, Faculty of Agriculture, Science and Technology, North-West University, Private Bag X2046 Mmabatho, 2735 South Africa. motseil@uniwest.ac.za
Beighle
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D000645:Ammonium Sulfate / Q000008:administration & dosage / Q000378:metabolism*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000737:chemistry* / Q000378:metabolism*; D002118:Calcium / Q000032:analysis / Q000378:metabolism; D002417:Cattle / Q000378:metabolism*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D008274:Magnesium / Q000032:analysis / Q000378:metabolism; D008297:Male; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D011897:Random Allocation
D010758:Phosphorus; D008274:Magnesium; D000645:Ammonium Sulfate; D002118:Calcium