• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.83-89
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• 1994

The effects of inorganic selenium (Se), selenate and selenite on Se balance levels in the different ruminal fluid fractions were studied using Japanese Corriedale wethers with an average body weight of 47 kg. A $3{\times}3$ Latin square design was used with three animal, three periods and three treatments. In each period, there was 7 d dietary adjustment followed by 5 d total collection of urine and feces. Ruminal fluid samples were obtained at 0, 1, 3, 5 and 7 h postprandially on the final day of the collection period. The three dietary treatments were: (1) without Se supplementation (control); (2) with Se supplement as sodium selenate; and (3) sodium selenite at a rate of 0.2 mg Se/kg dietary DM. The basal diet was timothy hay (Phleum pratense L.) fed 2% of body weight/d. Results indicated that Se balance were higher (p < 0.05) for those animals under supplementation than those animals under control. Overall data gathered showed a similar digestion balance of selenate and selenite in sheep. Inorganic Se, both selenate and selenite produced positive Se contents of the ruminal feed particles and protozoa. Bacterial Se increased (p < 0.05) on the first three hours post-prandially in Se supplemented diets. Gross ruminal fluid fraction, although there was improvement on their Se content under the supplemented diets, the changes were insignificant over the control. free inorganic Se and Se in soluble protein of the ruminal fluid were not significantly different for selenate and selenite. Most of the Se in the ruminal fluids of the animals under supplementation were insoluble, indicating the influence of rumen environments on Se bioavaliability.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.5
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• pp.557-562
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• 1996

The effects of diets differing in protein content through soybean meal supplementation on ruminal fractionation of selenium (Se) were studied. A $3{\times}3$ Latin square design was used with three Japanese Corriedale wethers (45 kg average body weight), three periods, and three dietary treatment. The three dietary treatments were : Diet 1, without soybean meal supplementation (14% crude protein, CP); Diet 2, with 10% soybean meal supplementation (16.5% CP); and Diet 3, with 20% soybean meal supplementation (19% CP). All the diets had a Se supplementation in the form of sodium selenite at 0.2 mg Se/kg dietary DM. The Se supplement and the concentrate mixture were fed only in the morning before the hay was given. Daily feeding schedule for gay was set at 09:00 and 17:00 h. On the final day of collection period, ruminal fluid samples were obtained at 0.5, 2, 6, 12 and 24 h post-feeding starting at 09:00 h. Total ruminal fluid Se was markedly higher (p<0.05) in Diet 3 than those in Diets 1 and 2 at almost all sampling time except at 24 h. The proportion of Se in soluble protein to the total ruminal Se was higher (p< 0.05) in Diet 3 (40%) followed by Diet 2 (28%) and Diet 1 (21%). The proportion of free inorganic Se to the total ruminal Se was the reverse, especially after two hours where Diet 1 (p<0.05) was higher than the other diets. Bacterial Se was lower (p < 0.05) in Diet 1 than those in Diets 2 and 3 at any sampling time. The highest was observed at 2 h postprandially in all diets with a value of 421, 556, $655{\mu}g/kg$ bacterial DM for Diet 1, 2 and 3, respectively. No differences (p>0.05) were observed on ruminal pH, ammonia and total nolatile fatty acids although increasing protein supplementation tended to decline the ruminal pH and increase ruminal ammonia. This study concludes that increasing dietary protein content by soybean meal supplementation can affect the ruminal Se metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.91-96
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• 1994

This study was conducted to determine the effect of inorganic selenium (Se) sources on rumen bacterial yield, ruminal volatile fatty acid (VFA) production and total tract digestion of timothy hay (Phlewm pratense L.) in Japanese Corriedale wethers. A $3{\times}3$ Latin square design was used with three wethers, three periods and three treatments. In each period, there was 7 d dietary adjustment followed by 5 d total collection of urine and feces. Ruminal fluid samples were obtained at 0, 1, 3, 5 and 7 h postprandially on the final day of the collection period. The three dietary treatments were: (1) without Se supplementation (control); (2) with Se supplementation as sodium selenate; and (3) sodium selenite at a rate 0.2 mg Se/kg dietary DM. The basal diet was timothy hay fed at 2% of body weight/d. Results indicated that there was slight decrease in rumen bacterial yield of animal supplement with inorganic Se, however, differences over the control were insignificant. It was found that Se content of ruminal fluid was negatively correlated (p < 0.05) to rumen bacterial yield. The various VFA contents and acetate and propionate ratio of the different ruminal fluid samples were insignificant across treatment means and the same manner was observed to the different digestibilities (DM, OM, CP, NDF, ADF and NDS). This study concludes that Se supplementation at 0.2 mg Se/kg dietary DM either from sodium selenate or sodium selenite could not significantly influence rumen bacterial functions.