Nugent R A, Jenkins T G
Roman L. Hruska U.S. Meat Anim. Res. Center, U.S. Department of Agriculture, Clay Center, NE 68933-0166.
J Anim Sci. 1991 Dec;69(12):4777-92. doi: 10.2527/1991.69124777x.
The 4 yr productivity of 25% (QF; n = 533) and 50% (HF; n = 531) Finnsheep ewes exposed to either Suffolk or Columbia rams in one of three production systems was monitored to test the effects of system, terminal sire breed, maternal line, and their interactions on annual market lamb production. Ewe lambs and yearlings were randomly assigned to either a high-input accelerated lambing system (HIGH), a high-input annual system (MED), or a low-input annual system (LOW). Nursery facilities were available for weak lambs or those born in triplet or more births for the HIGH and MED but not for the LOW systems. Accelerated lambing protocol required early weaning. Sex-adjusted lamb weaning weights were corrected to within-system mean ages of 42 d for HIGH and 70 d for MED and LOW. The HIGH ewes weaned 1.55 lambs per year compared with 1.46 for MED and 1.18 for LOW (P less than .01). However, because of early weaning, HIGH yielded the lowest weight of weaned lamb per year. The MED ewes weaned 5.9 and 11.1 more kilograms of lamb per year than the LOW and HIGH ewes, respectively (P less than .01). The HIGH system may be economically feasible if young lambs could be inexpensively grown to feeder or market lamb weight. The HIGH ewes did not, however, increase lamb numbers in proportion to increased exposures compared with the annual systems. Breed-group effects for ewe productivity (kilogram of lamb weaned per ewe per year) were consistent across management systems, although some interactions among breed group and system were present for components of productivity. Suffolk rams yielded an advantage of 1.6 kg of weaned lamb per exposure over Columbia rams (P less than .05) due to a 3% better lamb survival (P less than .01) and heavier weaning weight, especially in the LOW system. The HF ewes weaned .1 more lambs per exposure than QF ewes (P less than .01); .06 of the lambs were nursery-reared. However, lambs from HF ewes had a 2% lower survival rate (P less than .05) and were 1.4 kg lighter at weaning (P less than .01), so overall productivity among HF and QF ewes was similar.
在三种生产系统之一中，将25%（QF；n = 533）和50%（HF；n = 531）的芬兰母羊与萨福克或哥伦比亚公羊杂交，监测其4年的生产性能，以测试生产系统、终端父本品种、母系及其相互作用对年度上市羔羊生产的影响。母羊羔和周岁母羊被随机分配到高投入加速产羔系统（HIGH）、高投入年度系统（MED）或低投入年度系统（LOW）。HIGH和MED系统有育幼设施，可供弱羔或多胞胎出生的羔羊使用，但LOW系统没有。加速产羔方案需要早期断奶。对性别调整后的羔羊断奶体重进行校正，使其达到HIGH系统42天、MED和LOW系统70天的系统内平均年龄。HIGH系统的母羊每年断奶1.55只羔羊，MED系统为1.46只，LOW系统为1.18只（P < 0.01）。然而，由于早期断奶，HIGH系统每年断奶羔羊的体重最低。MED系统的母羊每年比LOW和HIGH系统的母羊分别多断奶5.9千克和11.1千克羔羊（P < 0.01）。如果能以低成本将幼羔饲养到育肥或上市羔羊体重，HIGH系统在经济上可能是可行的。然而，与年度系统相比，HIGH系统的母羊产羔数量并未随配种次数增加而成比例增加。母羊生产性能（每只母羊每年断奶羔羊的千克数）的品种组效应在各管理系统中是一致的，尽管品种组和系统之间在生产性能组成部分上存在一些相互作用。由于羔羊存活率高3%（P < 0.01）且断奶体重更重，尤其是在LOW系统中，萨福克公羊每次配种比哥伦比亚公羊多产出1.6千克断奶羔羊（P < 0.05）。HF母羊每次配种比QF母羊多断奶0.1只羔羊（P < 0.01）；其中0.06只羔羊是在育幼室饲养的。然而，HF母羊所产羔羊的存活率低2%（P < 0.05），断奶时轻1.4千克（P < 0.01），因此HF和QF母羊的总体生产性能相似。
