EFFECTS OF SULFATE SUPPLEMENTATION ON PERFORMANCE, ACID-BASE-BALANCE,AND NUTRIENT METABOLISM IN ANGORA KIDS

Twelve Angora goat kids (BW: mean +/- SE = 18.1 + 0.6 kg; castrated ma les) were individually fed isonitrogenous and isocaloric diets contain ing 0.11 (basal), 0.20, 0.28 or 0.38% S of dietary DM (added as CaSO4) . During the 8-wk growth phase, sulfate supplementation up to 0.20% S in the diet increased average daily gain (ADG) by 44%, dry matter inta ke (DMI) by 17%, and feed conversion efficiency (FE, ADG/DMI) by 23% c ompared with average Angora kids fed the other diets. Clean mohair pro duction was numerically highest for kids fed the 0.28% S diet, but moh air fiber diameter was not affected (P > 0.20) by added S. Mohair stap le length tended to increase quadratically (P < 0.20) with sulfate sup plementation. Average daily gain (P < 0.05) and DMI (P < 0.0001) were lower for Angora than for Alpine kids (70 vs. 95 g and 762 vs. 1125 g/ d, respectively), but FE was higher (P > 0.20) for Angora than Alpine kids. Plasma free cysteine was quadratically increased by S supplement ation in Angora kids. Blood pH did not differ between breeds. Blood HC O3-, total CO2 content, pCO2, base excess in extra-cellular fluids, an d standard bicarbonate were lower (P < 0.05) in Angora than in Alpine kids, but blood partial pressure of O2 and oxygen saturation were high er (P < 0.05) in Angora than in Alpine kids, perhaps due to increased heat dissipation via respiration by Angora kids. Plasma glucose, urina ry outputs of creatinine and uric acid were lower (P < 0.05), and plas ma free cysteine concentration higher (P < 0.01) for Angora than for A lpine kids. Ruminal L-lactate concentration (P < 0.001) and purine N c ontent in isolated bacteria (P < 0.01) were lower, but ruminal NH3-N c ontent (P < 0.10) was higher, and ruminal sulfide-S content (P < 0.20) tended to be higher for Angora than for Alpine kids. Angora kids were faunated, whereas Alpine kids were fauna-free. The N/S ratio in isola ted rumen bacteria was lower (P < 0.10) for Angora than for Alpine kid s. Calculated by regression, ADG was maximum with 0.22% S (N/S = 10.4: 1) for Angora kids vs. 0.21% S for Alpine kids.