EFFECTS OF FESCUE ENDOPHYTE AND INTERSEEDED CLOVERS ON SUBSEQUENT FINISHING PERFORMANCE OF STEERS
EFFECTS OF FESCUE ENDOPHYTE AND INTERSEEDED CLOVERS ON SUBSEQUENT FINISHING PERFORMANCE OF STEERS
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DOI：
10.2134/jpa1990.0103
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发表时间：
1990-01-01
期刊：
影响因子：
--
通讯作者：
MUNTZ, SH
中科院分区：
文献类型：
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作者：
LUSBY, KS;MCMURPHY, WE;MUNTZ, SH
斯托克牛(Bos spp.)(L.)高羊茅(Festuca arundinacea Schreb.)感染内生真菌的牧场(丛生隐孢子菌、Morgan-Jones和Gams)。然而，在通过饲养场阶段评估对动物的残留影响到最终产品--屠体之前，不能完全评估放牧结果。在本研究中，安格斯(B.Taurus L.)，婆罗门(B.Indicus L.)--Angus，Angus.Times.Braham-Angus和Simtal(B Taurus L.).用1987年12~19个月龄的婆罗曼-安格斯公牛和1988年的54头公牛研究了放牧‘肯塔基31’高羊茅对后续饲养场生产性能的影响。从11月到5月，牛一直在羊茅牧场放牧。草地处理为：(1)高内生植物(HE)+76%感染羊茅；(2)HE+三叶草混播(HE+CLO)；(3)低内生植物(LE)+0.7%感染羊茅。5月21日，从俄克拉荷马州东部的这些牧场上移走了牛，在狗牙根上饲养了6d。Pers.]-黑麦草(Lolium MultiForum Lam.)并将450英里运往俄克拉荷马州西部的一个饲养场。然后分别饲喂117或113d(分别为1987年和1988年)并屠宰。不接受治疗。时代。记录了年份的交互作用，并跨年汇集了数据。放牧结束时，HE牛的体重比LE牛轻101磅，但在饲养场阶段，HE牛比LE牛多增重66磅。HE牛在6d保存期内增重较快，在运往饲养场的过程中体重下降较少，在饲养场的前48或49d(分别为1987年和1988年)增重较快。在饲养场中，一直在放牧HE+CLO牧场的放牧牛的增重与放牧放牧的放牧牛相似。HE+CLO牛的最终体重和屠体重量比LE牛重，这是因为在牧场和饲养场上略有增加，加上在6天保存期内获得了更大的增加。高羊茅放牧结束时和放牧6d后，高羊茅的直肠温度显著高于高羊茅。放牧HE+CLO的肉牛体温中等。到达饲养场后的第二天早上，没有发现直肠温度的差异。HE肉牛的屠体重量较轻，品质等级较低。这些结果表明，表现出羊茅中毒临床症状的牛可以补偿因放牧羊茅而减少的收益的67%。
Stocker cattle (Bos spp. L.) performance has been adversely affected on tall fescue (Festuca arundinacea Schreb.) pasture infected with the endophyte (Acremonium coenophialum Morgan-Jones and Gams). Grazing results, however, cannot be completely evaulated until the carryover effects on the animal are evaluated through the feedlot phase to the final product, the carcass. In this study 60 Angus (B. taurus L.), Brahman (B. indicus L.)-Angus, Angus .times. Braham-Angus, and Simmental (B taurus L.) .times. Brahman-Angus, 12- to 19-mo-old steers in 1987, and 54 in 1988, were used to study effects of grazing ''Kentucky 31'' tall fescue on subsequent feedlot performance. Steers had been grazing fescue pastures from November to May. The pasture treatments were: (i) high endophyte (HE) with 76% infected fescue; (ii) HE with 74% infected fescue interseeded with a mixture of clovers (HE + Clo); and (iii) low endophyte (LE) with 0.7% infected fescue. Steers were removed from these pastures in eastern Oklahoma on 21 May, held for 6 d on bermundagrass [Cynodon dactylon (L.) Pers.]-ryegrass (Lolium multiforum Lam.) pastures and shipped 450 mi to a feedlot in western Oklahoma. Steers were then fed for 117 or 113 d (years 1987 and 1988, respectively) and slaughtered. No treatment .times. year interaction was noted and data were pooled across years. The HE steers weighted 101 lb less than LE steers at the end of grazing, but HE steers gained 66 lb more during the feedlot phase than LE steers. The HE steers gained faster during the 6-d holding period, tended to lose less weight in transit to the feedlot, and gained faster during the first 48 or 49 d (years 1987 and 1988, respectively) in the feedlot. Steers which had been grazing HE + Clo pastures gained similarly to LE steers in the feedlot. The HE + Clo steers had heavier final body and carcass weights than LE steers because of slightly greater gains on pasture and in the feedlot, plus greater gains during the 6-d holding period. Rectal temperature was higher for HE than for LE at the end of fescue grazing and after the 6-d holding period. Temperatures of steers that grazed HE + Clo were intermediate. No differences in rectal temperatures were noted the morning following arrival at the feedlot. Carcass weights were lighter and quality grade tended to be lower for HE steers. These results suggest that steers showing clinical signs of fescue toxicosis can compensate for up to 67% of the reduced gains resulting from grazing fescue.