Department of Animal and Food Sciences, University of Kentucky, Lexington, Kentucky 40546, USA.
J Anim Sci. 2012 Nov;90(11):3833-41. doi: 10.2527/jas.2011-4535. Epub 2012 Jun 4.
Weanling crossbred pigs (Sus scrofa; 72 barrows and 72 gilts; BW = 7.4 ± 1.1 kg) were used to evaluate dietary supplemental trace mineral (Cu, Fe, Mn, and Zn) source (inorganic vs. organic) and deletion (0, 2, 4, and 6 wk preharvest) on growth performance, carcass characteristics, and pork quality. Pigs were blocked by BW, ancestry, and sex, and randomly allotted to 24 pens, and fed a diet containing either inorganic or organic trace minerals supplemented at the 1998 NRC requirement estimates for each of 5 BW phases from 7 to 120 kg (equivalent to 14, 14, 42, 28, and 42-d periods, respectively). Two pigs were removed from each pen at the end of Phase IV (BW = 82.6 ± 6.0 kg), and 2 other pigs were removed at the end of Phase V (BW = 128.0 ± 8.3 kg) for collection of various tissues and for determination of carcass characteristics and pork quality. On d 1, 15, and 29 of Phase V, 3 pens within each source of minerals were switched to a common diet without supplemental trace minerals, whereas the remaining 3 pens within each source of minerals were fed diets containing trace minerals throughout the Phase V period. This resulted in 4 groups within each mineral treatment, in which trace mineral supplementation was deleted for 6, 4, 2, or 0 wk of Phase V. Trace mineral source (inorganic vs. organic) did not affect ADG, ADFI, and G:F (773 vs. 778 g/d, 1,680 vs. 1,708 g/d, and 461 vs. 456 g/kg, respectively) during the first 4 phases. During the mineral deletion period, ADG and G:F were not affected by the duration of trace mineral deletion, but ADFI increased when trace minerals were removed from the diet for 6 wk (6 vs. 0 wk, 3,393 vs. 3,163 g/d; P = 0.05). Hot carcass weight, cold carcass weight, carcass shrink, dressing percentage, LM area, 10th rib and midline average backfat, and carcass fat-free lean weight and percentage were not affected (P > 0.10) by the source of mineral or length of mineral deletion, but carcass length tended to decrease (P = 0.09) when time of trace mineral deletion increased. Increasing mineral deletion from 0 to 6 wk tended to reduce linearly (P = 0.08) Hunter a* scores on the day of carcass processing (24 h after slaughter), as well as 2 d after processing, and Hunter b* scores on d 2 and d 6 after processing. Results of this experiment indicate that use of organic trace minerals, rather than inorganic trace minerals, did not influence pig growth performance or carcass characteristics and quality; however, deletion of minerals during the last 6 wk before harvest increased ADFI and affected drip loss, some color scores of the LM, and carcass length.
我们使用断奶杂交猪（Sus scrofa；72 头公猪和 72 头母猪；BW=7.4±1.1kg）来评估日粮中补充微量元素（铜、铁、锰和锌）来源（无机与有机）和（0、2、4 和 6 周预收获前）对生长性能、胴体特性和猪肉质量的影响。猪按 BW、祖先和性别分组，并随机分配到 24 个围栏中，饲喂含有无机或有机微量元素的日粮，补充量为每个 5 BW 阶段（7-120kg）1998 年 NRC 估计的需求量（分别相当于 14、14、42、28 和 42 天期）。在第四阶段（BW=82.6±6.0kg）结束时，每个围栏中取出 2 头猪，在第五阶段（BW=128.0±8.3kg）结束时再取出 2 头猪，用于收集各种组织，并确定胴体特性和猪肉质量。在第五阶段的第 1、15 和 29 天，每个矿物质源的 3 个围栏转换为不含补充微量元素的普通日粮，而每个矿物质源的其余 3 个围栏则在整个第五阶段都饲喂含有微量元素的日粮。这导致每个矿物质处理组内有 4 个组，其中在第五阶段的 6、4、2 或 0 周内删除了微量元素补充。微量元素源（无机与有机）在第一 4 个阶段内对 ADG、ADFI 和 G:F（分别为 773、778g/d、461、456g/kg）没有影响。在矿物质删除期间，ADG 和 G:F 不受矿物质删除持续时间的影响，但当从日粮中删除矿物质 6 周时 ADFI 增加（6 与 0 周，3393 与 3163g/d；P=0.05）。热胴体重、冷胴体重、胴体收缩、屠宰率、LM 面积、第 10 肋骨和中线平均背膘、胴体无脂瘦肉重量和百分比（P＞0.10）不受矿物质源或矿物质删除长度的影响，但胴体长趋势下降（P=0.09）当矿物质删除时间增加时。从 0 到 6 周的矿物质删除量线性减少（P=0.08），影响屠宰后当天（屠宰后 24 小时）的 Hunter a评分以及屠宰后第 2 和第 6 天的 Hunter b评分。该实验结果表明，使用有机微量元素而不是无机微量元素不会影响猪的生长性能或胴体特性和质量；然而，在收获前最后 6 周内删除矿物质会增加 ADFI，并影响滴水损失、LM 的一些颜色评分和胴体长。
