植物甾醇酯对产蛋末期蛋鸡产蛋性能、蛋品质、肝脏抗氧化能力及卵黄前体物质合成的影响

Effects of Phytosterol Ester on Laying Performance,Egg Quality,Liver Antioxidant Capacity and Yolk Precursor Synthesis of Laying Hens during Late Laying Period

本试验旨在研究植物甾醇酯(PSE)对产蛋末期蛋鸡产蛋性能、蛋品质、肝脏抗氧化能力及卵黄前体物质合成的影响,为延长产蛋高峰期、挖掘蛋鸡的最大产蛋潜力提供技术方案。选用180只113周龄产蛋率[(77.22±2.50)%]相近的健康京粉六号蛋鸡,随机分为3个组,即CON组(饲喂基础饲粮,对照组)、100 PSE组(饲喂基础饲粮+100 mg/kg PSE)和200 PSE组(饲喂基础饲粮+200 mg/kg PSE),每组6个重复,每个重复10只鸡。预试期为7 d,正试期为56 d。以4周为一个阶段考察产蛋性能和蛋品质,试验结束后每个重复取2只鸡屠宰,测定血清生殖激素指标、抗氧化指标与肝脏抗氧化指标、卵黄前体物质含量及抗氧化和卵黄前体物质合成相关基因表达情况。结果显示:1)CON组全期(1~8周)产蛋率为75.33%,100 PSE组和200PSE组全期产蛋率较CON组分别提高6.37%(P<0.05)和8.62%(P<0.05);100 PSE组的前期(1~4周)和全期平均蛋重均显著高于CON组(P<0.05),其后期(5~8周)料蛋比显著低于CON组和200 PSE组(P<0.05)。2)与CON组相比,200 PSE组第28和56天的蛋黄颜色分别提高16.48%(P<0.01)和17.26%(P<0.01),蛋壳重量分别提高6.57%(P<0.01)和10.85%(P<0.05)。100 PSE组和200 PSE组第56天的蛋重和蛋壳表面积均显著高于CON组(P<0.05)。3)与CON组相比,100 PSE组和200 PSE组血清中雌二醇(E2)水平分别提高10.29%(P<0.05)和14.77%(P<0.05),孕酮(Prog)水平分别提高10.15%(P<0.05)和23.91%(P<0.05);200 PSE组血清中促卵泡素(FSH)和促黄体素(LH)水平较CON组分别提高38.46%(P<0.01)和42.06%(P<0.01)。4)与CON组相比,100 PSE组和200 PSE组血清中总超氧化物歧化酶(T-SOD)活性分别提高13.67%(P>0.05)和50.11%(P<0.05)。100 PSE组和200 PSE组肝脏中丙二醛(MDA)含量较CON组均呈下降趋势(P=0.078);200 PSE组肝脏中过氧化氢酶(CAT)活性较CON组呈上升趋势(P=0.067)。5)与CON组相比,200 PSE组肝脏中Kelch样环氧氯丙烷相关蛋白1(Keap1)mRNA相对表达量显著下调(P<0.05)。6)与CON组相比,200PSE组血清中卵黄蛋白原(VTG)含量提高25.03%(P<0.05)。100 PSE组和200 PSE组肝脏中极低密度脂蛋白(VLDL)含量较CON组分别提高28.42%(P<0.01)和37.66%(P<0.01),肝脏中VTG含量分别提高21.64%(P<0.05)和32.43%(P<0.05)。7)与CON组相比,100 PSE组和200 PSE组肝脏中卵黄蛋白原Ⅱ(VTGⅡ)mRNA相对表达量显著上调(P<0.05)。200 PSE组肝脏中雌激素受体-α(ER-α)mRNA相对表达量极显著高于CON组和100 PSE组(P<0.01),同时,极低密度载脂蛋白Ⅱ(ApoVLDLⅡ)mRNA相对表达量显著高于CON组(P<0.05)。综上所述,PSE可提高蛋鸡血清生殖激素水平和肝脏抗氧化能力,促进肝脏合成卵黄前体物质,从而提高产蛋末期蛋鸡的产蛋性能和蛋品质,以添加量为200 mg/kg时效果较好。

This experiment was conducted to investigate the effects of phytosterol ester(PSE)on laying performance,egg quality,liver antioxidant capacity and yolk precursor synthesis of laying hens during late laying period,and to provide technical solutions for prolonging the laying peak period and tapping the maximum laying potential of laying hens.A total of 180 healthy Jingfen No.6 laying hens at 113 weeks of age with similar laying rate[(77.22±2.50)%]were randomly divided into 3 groups,they were CON group(fed a basal diet,as control group),100 PSE group(fed the basal diet+100 mg/kg PSE)and 200 PSE group(fed the basal diet+200 mg/kg PSE),with 6 replicates per group and 10 chickens per replicate.The pre-feeding period was 7 days and the experimental period was 56 days.The laying performance and egg quality were investigated in four weeks.After the experiment,two chickens were slaughtered in each replicate to investigate the reproductive hormone indices and antioxidant indices in serum,and the liver antioxidant indices,yolk precursor content and the expression of genes related to antioxidant and yolk precursor synthesis liver.The results showed as follows:1)during the whole period(1 to 8 weeks),the laying rate of the CON group was 75.33%,and the laying rate of the 100 PSE group and the 200 PSE group was increased by 6.37%(P<0.05)and 8.62%(P<0.05),respectively.The average egg weight in the earlier period(1 to 4 weeks)and the whole period of 100 PSE group was significantly higher than that of the CON group(P<0.05),and the feed/egg ratio in the later period(5 to 8 weeks)was significantly lower than that of the CON group and the 200 PSE group(P<0.05).2)Compared with the CON group,the yolk color of 200 PSE group on the 28th day and the 56th day was improved by 16.48%(P<0.01)and 17.26%(P<0.01),and the eggshell weight was increased by 6.57%(P<0.01)and 10.85%(P<0.05),respectively.The egg weight and eggshell surface area of the 100 PSE group and the 200 PSE group on the 56th day were significantly higher than those of the CON group(P<0.05).3)Compared with the CON group,the serum estradiol(E 2)level of the 100 PSE group and the 200 PSE group was increased by 10.29%(P<0.05)and 14.77%(P<0.05),and the serum progesterone(Prog)level increased by 10.15%(P<0.05)and 23.91%(P<0.05),respectively.The levels of follicular stimulating hormone(FSH)and luteinizing hormone(LH)in serum of the 200 PSE group were 38.46%(P<0.01)and 42.06%(P<0.01)higher than those of the CON group,respectively.4)Compared with the CON group,the activity of total superoxide dismutase(T-SOD)in serum of the 100 PSE group and the 200 PSE group was increased by 13.67%(P>0.05)and 50.11%(P<0.05),respectively.There was a downward trend in the content of malondialdehyde(MDA)in liver of the 100 PSE group and the 200 PSE group compared with the CON group(P=0.078).In the meantime,the activity of catalase(CAT)in liver of the 200 PSE group showed an upward trend compared with the CON group(P=0.067).5)Compared with the CON group,the mRNA relative expression level of Kelch-like epichlorohydrin-associated protein 1(Keap1)in liver of the 200 PSE group was significantly down-regulated(P<0.05).6)Compared with the CON group,the serum vitellogenin(VTG)content of the 200 PSE group was increased by 25.03%(P<0.05).In the liver,the content of very low density lipoprotein(VLDL)of the 100 PSE group and the 200 PSE group was increased by 28.42%(P<0.01)and 37.66%(P<0.01),and the content of VTG was increased by 21.64%(P<0.05)and 32.43%(P<0.05)compared with the CON group,respectively.7)Compared with the CON group,the mRNA relative expression level of vitellogenin Ⅱ(VTGⅡ)in liver of the 100 PSE group and the 200 PSE group was significantly up-regulated(P<0.05).The mRNA relative expression level of estrogen receptor-α(ER-α)was extremely significantly higher than that of the CON group and the 100 PSE group(P<0.01),and the mRNA relative expression level of very low-density apoli-poprotein Ⅱ(ApoVLDLⅡ)was significantly higher than that of the CON group(P<0.05).In conclusion,PSE can improve the serum reproductive hormone levels and liver antioxidant capacity of laying hens,and promote the synthesis of yolk precursors in the liver,thus improving the laying performance and egg quality of laying hens during late laying period.The addition amount of 200 mg/kg has a better effect.