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81.
Ninety culled dairy cows were used in this study and were paired by weight and conformation similarity. Forty-five cows were arterially infused immediately after bleeding with 10% volume by weight of a solution composed of dextrose (.23%), glycerin (.21%), a phosphate blend (.14%) and maltose (.1%). The remaining cows (45) served as controls. In infused carcasses, some quantity of solution retained was in the following order: supraspinatus, chuck greater than longissimus, loin greater than semitendinosus, round muscles. Accordingly, percentage of protein, ether-extractable fat, and protein fat-free amounts were lowered (P less than .05) and percentage of moisture and moisture protein ratio were raised (P less than .05) in the supraspinatus muscle. Tenderness (P less than .01) and protein extractability (P less than .15) were improved. No difference was observed in water-holding capacity between infused and control carcasses. Percentages of moisture fat-free (r = .85) and protein fat-free (r = -.97) were highly correlated to moisture-protein ratio. Moisture percentage of the fat-free tissue was shown to be a more consistent indicator of added moisture in infused whole carcasses compared with moisture:protein ratio and percentage of protein fat-free. Very low correlations were observed between tenderness, percentage of moisture, percentage of water-holding capacity, and ether-extractable fat. The economics of the infusion process to the beef industry is discussed. 相似文献
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The objective of this study was to determine the effect of postweaning exposure to females on the subsequent sexual performance of young rams. Twenty-five crossbred rams were reared in a group with ovariectomized females from 4.5 to 9 mo of age. Ewes were brought into estrus every 2 wk during this period. A companion group of 23 crossbred rams was not exposed to females following weaning. Four 30-min sexual performance tests were administered at 10 mo of age. Rams reared with males and females (RMF) exhibited more mounts (P less than .001) and more ejaculations (P less than .002) than rams reared only with males (RM). The frequency of successful matings by the latter group did not increase with experience. Nine rams were sexually inactive in the sexual performance tests. Follow-up tests revealed that two of the RMF rams and one RM ram developed and maintained a sexual preference for males. The six remaining rams eventually mated with females when tested in familiar pens and subsequently exhibited normal levels of sexual performance even when tested in an unfamiliar enclosure. Exposure to ewes during the postweaning prepubertal period enhanced sexual performance. However, early exposure to females did not ensure that all males developed sexual preferences for females. The environmental context in which sexual performance tests are administered may inhibit the expression of heterosexual behavior in a small percentage of animals. After heterosexual behavior was expressed, the rams continued to show normal levels of sexual performance.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Cattle on 18 of 21 farms in north-east Scotland were found to have low whole blood activities of the selenium-containing enzyme, glutathione peroxidase (less than 5 units per ml whole blood), and a low blood concentration of selenium (less than 0.05 mg per litre). These cattle had all been fed on locally produced feedstuffs without any mineral supplementation. The low selenium status in cattle occurred on farms with soils derived from a range of parent material, no one particular type predominating. 相似文献
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W F Price 《Journal of the American Veterinary Medical Association》1969,155(7):1267-1268
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