Fabian J, Chiba L I, Kuhlers D L, Frobish L T, Nadarajah K, McElhenney W H
Department of Animal Sciences, Auburn University, AL 36849-5415, USA.
J Anim Sci. 2003 May;81(5):1142-9. doi: 10.2527/2003.8151142x.
We investigated the effect of distinct genotypes on growth performance, DM and N digestibilities, serum metabolite and hormonal profiles, and carcass and meat quality of pigs. Eight control-line and eight select-line pigs with an equal number of gilts and castrated males per genotype were chosen from the group of pigs subjected to selection for lean growth efficiency. Pigs were housed individually and allowed ad libitum access to common grower, finisher 1, and finisher 2 diets when they reached approximately 20, 50, and 80 kg, respectively, and water throughout the study. Although genotype had no effect on growth performance during the finisher 2 phase and overall, select-line pigs grew faster and more efficiently (P < 0.05) during the grower and finisher 1 phases than did control-line pigs. Dry matter and N digestibilities during the grower phase were lower (P < 0.05) in select-line pigs compared with control-line pigs. Select-line pigs had less ultrasound backfat (P < 0.05) at the end of the grower and finisher 2 phases. Serum urea N (P < 0.05) and leptin concentrations were lower in select-line pigs than in control-line pigs, but the effect of genotype on serum glucose, triglyceride, or insulin concentration was rather inconsistent. Select-line pigs had heavier heart (P < 0.05), liver (P = 0.08), and kidneys (P < 0.01), implying a higher metabolic activity. Less 10th-rib carcass backfat (P < 0.01) and a trend for larger carcass longissimus muscle area (P = 0.10) were reflected in the greater (P < 0.01) rate and efficiency of lean accretion in select-line pigs. Select-line pigs had lower subjective meat color (P < 0.01), marbling (P < 0.05), and firmness (P < 0.01) scores. Final serum leptin concentration was correlated positively with carcass backfat thickness (r = 0.73; P < 0.01) and negatively with overall feed intake (r = -0.77; P < 0.01). These results indicate that pigs with distinct genotypes exhibited differences in the growth rate, metabolite and hormonal profiles, and body composition. Further research is necessary to determine whether pigs with distinct genotypes respond differently to dietary manipulations, which would have an effect on developing optimal feeding strategies for efficient and sustainable pig production.
我们研究了不同基因型对猪的生长性能、干物质和氮消化率、血清代谢物和激素水平以及胴体和肉质的影响。从经过瘦肉生长效率选育的猪群中，选取了8头对照系猪和8头选择系猪，每个基因型的母猪和去势公猪数量相等。猪单独饲养，当体重分别达到约20、50和80 kg时，分别自由采食普通生长猪、育肥1期和育肥2期日粮，并在整个研究过程中自由饮水。尽管基因型在育肥2期及整个期间对生长性能没有影响，但选择系猪在生长猪和育肥1期比对照系猪生长得更快且更高效（P < 0.05）。与对照系猪相比，选择系猪在生长猪阶段的干物质和氮消化率较低（P < 0.05）。在生长猪和育肥2期结束时，选择系猪的超声背膘较薄（P < 0.05）。选择系猪的血清尿素氮（P < 0.05）和瘦素浓度低于对照系猪，但基因型对血清葡萄糖、甘油三酯或胰岛素浓度的影响相当不一致。选择系猪的心脏（P < 0.05）、肝脏（P = 0.08）和肾脏（P < 0.01）较重，这意味着其代谢活性较高。选择系猪的第10肋胴体背膘较薄（P < 0.01），并且有胴体最长肌面积较大的趋势（P = 0.10），这反映出选择系猪的瘦肉生长速度和效率更高（P < 0.01）。选择系猪的主观肉色（P < 0.01）、大理石花纹（P < 0.05）和硬度（P < 0.01）评分较低。最终血清瘦素浓度与胴体背膘厚度呈正相关（r = 0.73；P < 0.01），与总采食量呈负相关（r = -0.77；P < 0.01）。这些结果表明，不同基因型的猪在生长速度、代谢物和激素水平以及身体组成方面存在差异。有必要进一步研究不同基因型的猪对日粮调控的反应是否不同，这将有助于制定高效可持续养猪生产的最佳饲喂策略。
