Priolo A, Waghorn G C, Lanza M, Biondi L, Pennisi P
Istituto di Scienze e Tecnologie delle Produzioni Animali, University of Catania, Italy.
J Anim Sci. 2000 Apr;78(4):810-6. doi: 10.2527/2000.784810x.
We conducted an experiment to evaluate the effects that a diet containing condensed tannins with and without polyethylene glycol (PEG) has on lamb growth and meat quality. Twenty-three male Comisana lambs were introduced to the three experimental diets between 45 and 50 d of age. Eight were given a diet containing 56% of Ceratonia siliqua (carob) pulp (tannin group), another eight received the same diet with a supplement of 40 g of PEG for each kilogram of diet (PEG group), and the remaining seven lambs were given a conventional maize-based diet (maize group). Voluntary feed intake and live weights were measured until slaughter at 105 d of age, and digestibility measurements were undertaken toward the end of the feeding trial. Carcass yield, meat quality characteristics, and a taste panel evaluation were conducted. The tannin-based diet contained 2.5% condensed tannins (DM basis), and lambs given this diet had lower growth rates and poorer feed efficiencies (P < .01) compared with the other treatment groups. Daily gain was similar between the maize and PEG lambs, although the efficiency of feed conversion was highest in the maize group. The digestibility of DM, N, and fiber was reduced (P < .05) by the condensed tannins. Lambs fed the tannin diet had a lower carcass yield (P < .05) and had less fat (P < .05), and the meat had a higher ultimate pH (P < .01) than those given the PEG or maize diets. Condensed tannins affected meat color, which was lighter (L*) than meat from lambs given the PEG-containing diet (P < .01). Sensory evaluation showed that panelists preferred meat from lambs receiving PEG and maize treatments compared with those receiving the tannin diet, and this could be related to differences in meat ultimate pH and carcass fatness. These results show that condensed tannins from carob pulp are very detrimental to feed digestibility and lamb performance. Inclusion of 40 g of PEG/kg diet eliminated the effects of condensed tannins so that lamb performance and meat quality were similar to lambs given a maize-based diet.
我们进行了一项实验，以评估含缩合单宁且添加或不添加聚乙二醇（PEG）的日粮对羔羊生长性能和肉质的影响。23只雄性科米萨纳羔羊在45至50日龄时开始采食三种实验日粮。其中8只采食含56%长角豆（角豆）果肉的日粮（单宁组），另外8只采食相同日粮并每千克日粮添加40克PEG（PEG组），其余7只羔羊采食传统的玉米型日粮（玉米组）。记录自愿采食量和体重直至105日龄屠宰，并在饲养试验末期进行消化率测定。测定了胴体产率、肉质特性，并进行了感官评价。含单宁的日粮含有2.5%的缩合单宁（干物质基础），与其他处理组相比，采食该日粮的羔羊生长速度较慢且饲料效率较低（P < 0.01）。玉米组和PEG组羔羊的日增重相似，不过玉米组的饲料转化率最高。缩合单宁降低了干物质、氮和纤维的消化率（P < 0.05）。采食单宁日粮的羔羊胴体产率较低（P < 0.05）且脂肪较少（P < 0.05），其肉的最终pH值高于采食PEG或玉米日粮的羔羊（P < 0.01）。缩合单宁影响肉色，使其比采食含PEG日粮的羔羊的肉颜色更浅（L*）（P < 0.01）。感官评价表明，与采食单宁日粮的羔羊相比，评价员更喜欢采食PEG和玉米处理的羔羊的肉，这可能与肉的最终pH值和胴体脂肪含量的差异有关。这些结果表明，角豆果肉中的缩合单宁对饲料消化率和羔羊生产性能非常不利。每千克日粮添加40克PEG可消除缩合单宁的影响，使羔羊生产性能和肉质与采食玉米型日粮的羔羊相似。
