【摘要】 试验旨在研究营养限制期不同能氮水平和补偿期对羔羊肉品质的影响。选用80只蒙古羔羊,随机分为4组,分别为对照组(CG)、中等限制Ⅰ组(RG1)、中等限制Ⅱ组(RG2)和严重限制组(RG3)。营养限制期(60 d)4组羔羊日粮能量(ME)和蛋白质(CP)水平分别为10.88、10.88、9.41、8.62 MJ/kg和15.0%、10.0%、10.0%、5.7%。营养补偿期(90 d)4组羔羊日粮能量水平一致(ME 9.75 MJ/kg、CP 12%)。营养限制期结束和补偿期结束时,每组分别屠宰4只羔羊,测定背最长肌pH、失水率和剪切力值及胴体营养水平。结果表明,限制期结束时,RG3组羔羊背最长肌pH1和胴体粗蛋白质、粗灰分含量显著高于CG组(P<0.05),背最长肌剪切力值显著低于CG组(P<0.05),胴体干物质含量极显著低于CG组(P<0.01);补偿期结束时,RG2组羔羊背最长肌pH1显著高于CG组(P<0.05);RG1和RG2组羔羊背最长肌剪切力值和胴体粗蛋白质含量显著高于CG组(P<0.05);RG3组羔羊胴体粗灰分含量显著高于CG组(P<0.05)。因此,背最长肌pH、嫩度及胴体化学组成均受到营养限制的影响,经补偿后除嫩度外均能恢复到对照组水平,且随着受限程度的加剧,恢复速度越慢。更多还原

【Abstract】 This experiment was conducted to investigate the effects of the nutrition restriction period( 0 to 60 d) with different energy( ME) and protein( CP) levels and compensation period( 61 to 150 d) on meat quality of lambs. Eighty Mongolian lambs were randomly divided into four treatment groups,the control group( CG),the moderate restriction groups( RG1 and RG2),and the severe restriction group( RG3). Dietary nutrition level were ME 10. 88 MJ / kg and CP 15. 0%,ME 10. 88 MJ / kg and CP 10. 0%,ME 9. 41 MJ /kg and CP 10. 0%,ME 8. 62 MJ / kg and CP 5. 7% during the nutrition restriction period for CG,RG1,RG2 and RG3,respectively. In nutritional compensation period all groups were offered the same levels diet( ME 9. 75 MJ / kg,CP 12%). Four lambs of each group were slaughtered at the end of the restriction period and compensation period. The pH 1 value,pH 24 h value,the rate of water loss and shear force values of lamb the longissimus dorsi( LD) muscle were measured,and the chemical compositions of carcass were also detected after the nutrition restriction period and compensation. The results showed that at the end of the restriction period,the pH 1 value of LD and the content of carcass crude protein,crude ash of RG3 group were significantly higher than the CG group( P<0. 05),the shear force value of LD was significantly lower than the CG group( P<0. 05),and the content of carcass dry matter was extremely significantly lower than the CG group( P<0. 01). At the end of the compensation,the pH 1 value of LD of RG2 group was significantly higher than the CG group( P<0. 05),the shear force value of LD and the content of carcass crude protein of RG1 and RG2 groups were significantly higher than the CG group( P<0. 05). The content of carcass crude ash of RG3 group was significantly higher than the CG group( P<0. 05). The results suggested that the pH value,tenderness and the carcass composition were all affected by the nutrition restriction. However,there were no differences between the control group and treatment groups except tenderness. The compensatory rates decreased with the increasing of nutrition restriction.更多还原