This study investigated lipid metabolism differences between low and high residual feed intake(LRFI and HRFI)bulls.Fifty-five Simmental bulls(449.84±8.49 kg)were fed the same diet for 161 d to determine RFI value...This study investigated lipid metabolism differences between low and high residual feed intake(LRFI and HRFI)bulls.Fifty-five Simmental bulls(449.84±8.49 kg)were fed the same diet for 161 d to determine RFI values.At the end of experiment,back fat thickness(BFT)and rib eye area(REA)were measured via ultrasound,and serum samples were collected for lipid metabolismindicators.Post-slaughter,subcutaneous adipose tissue was analyzed for lipid metabolism indicators,histology,transcriptomics,and lipid metabolomics.Results:1)Ultrasound showed LRFI bulls had lower BFT(P=0.031)but higher REA(P0.021).2)Serum total cholesterol(P=0.028)and low-density lipoprotein cholesterol(P=0.015)were lower in LRFI bulls.Leptin levels were lower in both serum(P=0.007)and adipose tissue(P=0.001)in LRFI bulls,as were acetyl-CoA carboxylase levels in serum(P=0.032)and adipose tissue(P=0.043).Conversely,adipose triglyceride lipase levels were higher in both serum(P=0.045)and adipose tissue(P=0.043),while adipose tissue fatty acid synthase levels were lower(P=0.035)inLRFIbulls.3)Transcriptomics identified two pathways,adenosine monophosphate-activated protein kinase(AMPK)and cyclic adenosine monophosphate(cAMP),involving five lipid metabolismrelated genes.Among these,adenylate cyclase activating polypeptide 1 receptor type 1(ADCYAP1R1),adenylate cyclase 10(ADCY10),and adenylate cyclase activating polypeptide 1(ADCYAP1)were significantly upregulated(P<0.05),while leptin receptor(LEPR)was downregulated(P0.047)in LRFI bulls.Additionally,leptin(LEP)showed a downward trend(P=0.098)in LRFI bulls.4)Lipid metabolomics revealed that the LRFI group had significantly higher levels of wax ester(WE)(P=0.040)and significantly lower levels of monogalacto-syldiacylglycerol(MGDG)(P0.040)compared to the HRFI group.Additionally,sphingomyelin(SPH)showed a trend towards lower abundance(P=0.054),and C12:0 levels tended to be higher(P=0.089)in the LRFI group.In conclusion,differences in theAMPK and cAMP signaling in adipose tissue are associated with reduced lipid synthesis and enhanced lipid degradation inLRFI bulls,which may contribute to reduced lipid deposition.展开更多
This study investigated whether vitamin A(VA)administration during the neonatal stage could increase the number of intramuscular adipocytes in Hu sheep by promoting vascularity.A total of 56 newborn male Hu sheep were...This study investigated whether vitamin A(VA)administration during the neonatal stage could increase the number of intramuscular adipocytes in Hu sheep by promoting vascularity.A total of 56 newborn male Hu sheep were divided into four groups and received intramuscular injections of either 0,7500 IU retinoic acid(RA),7500 IU VA,or a combination of 7500 IU VA and 5 mg SU5416(an angiogenic inhibitor),at 1,7,14,and 21 days of age.At 15 days of age,6 sheep from each group were randomly selected and sacrificed for intramuscular adipogenic capacity analysis.The remaining 8 sheep in each group were raised until they were 8 months old.VA-treated sheep exhibited an increase in preadipocytes,elevated expression of adipogenic genes(CCAAT enhancer binding protein alpha[CEBPA]and CCAAT enhancer binding protein beta[CEBPB])and angiogenic genes(vascular endothelial growth factor A[VEGFA]),and stromal vascular fraction cells in the longissimus dorsi(LD)muscle with enhanced adipogenic capacity(P<0.05).These effects were entirely negated by SU5416.Upon slaughter,VA increased final weight,carcass weight,and average daily gain(P<0.05)but did not affect feed intake at 21 to 32 weeks(P=0.824).VA increased the number of intramuscular adipocytes in the LD and semitendinosus(ST)muscle(P<0.05)without changing the adipocyte number of the omentum,perirenal and subcutaneous fats(P>0.05).VA injections also increased intramuscular triglyceride(TG)content(P=0.016)without changing the omentum fat weight or subcutaneous fat thickness(P>0.05),but it did increase the perirenal fat weight(P=0.011).Consistently,SU5416 mitigated the effects of VA on intramuscular TG content and adipocyte count,correlating with a decrease in vascularity.In contrast,RA injections didn't affect the intramuscular fat(P=0.744)but reduced the TG content of the omentum and perirenal fat(P<0.05).In conclusion,intramuscular injections of VA but not RA at the neonatal stage improved the growth performance of Hu sheep,increasing the number of intramuscular adipocytes and marbling by promoting angiogenesis.展开更多
基金supported by grants from the National Key Research and Development Program of China (2024YFD1301100)
文摘This study investigated lipid metabolism differences between low and high residual feed intake(LRFI and HRFI)bulls.Fifty-five Simmental bulls(449.84±8.49 kg)were fed the same diet for 161 d to determine RFI values.At the end of experiment,back fat thickness(BFT)and rib eye area(REA)were measured via ultrasound,and serum samples were collected for lipid metabolismindicators.Post-slaughter,subcutaneous adipose tissue was analyzed for lipid metabolism indicators,histology,transcriptomics,and lipid metabolomics.Results:1)Ultrasound showed LRFI bulls had lower BFT(P=0.031)but higher REA(P0.021).2)Serum total cholesterol(P=0.028)and low-density lipoprotein cholesterol(P=0.015)were lower in LRFI bulls.Leptin levels were lower in both serum(P=0.007)and adipose tissue(P=0.001)in LRFI bulls,as were acetyl-CoA carboxylase levels in serum(P=0.032)and adipose tissue(P=0.043).Conversely,adipose triglyceride lipase levels were higher in both serum(P=0.045)and adipose tissue(P=0.043),while adipose tissue fatty acid synthase levels were lower(P=0.035)inLRFIbulls.3)Transcriptomics identified two pathways,adenosine monophosphate-activated protein kinase(AMPK)and cyclic adenosine monophosphate(cAMP),involving five lipid metabolismrelated genes.Among these,adenylate cyclase activating polypeptide 1 receptor type 1(ADCYAP1R1),adenylate cyclase 10(ADCY10),and adenylate cyclase activating polypeptide 1(ADCYAP1)were significantly upregulated(P<0.05),while leptin receptor(LEPR)was downregulated(P0.047)in LRFI bulls.Additionally,leptin(LEP)showed a downward trend(P=0.098)in LRFI bulls.4)Lipid metabolomics revealed that the LRFI group had significantly higher levels of wax ester(WE)(P=0.040)and significantly lower levels of monogalacto-syldiacylglycerol(MGDG)(P0.040)compared to the HRFI group.Additionally,sphingomyelin(SPH)showed a trend towards lower abundance(P=0.054),and C12:0 levels tended to be higher(P=0.089)in the LRFI group.In conclusion,differences in theAMPK and cAMP signaling in adipose tissue are associated with reduced lipid synthesis and enhanced lipid degradation inLRFI bulls,which may contribute to reduced lipid deposition.
基金supported by grants from the National Natural Science Foundation of China (32272892,31972559)the Key Research and Development Program-Key Projects (2021YFD1200900 and 2023YFD1301302)the Young Talent Supporting Program Funding of the College of Animal Science and Technology,and China Agricultural University Education Foundation Grant(1041-2221002)
文摘This study investigated whether vitamin A(VA)administration during the neonatal stage could increase the number of intramuscular adipocytes in Hu sheep by promoting vascularity.A total of 56 newborn male Hu sheep were divided into four groups and received intramuscular injections of either 0,7500 IU retinoic acid(RA),7500 IU VA,or a combination of 7500 IU VA and 5 mg SU5416(an angiogenic inhibitor),at 1,7,14,and 21 days of age.At 15 days of age,6 sheep from each group were randomly selected and sacrificed for intramuscular adipogenic capacity analysis.The remaining 8 sheep in each group were raised until they were 8 months old.VA-treated sheep exhibited an increase in preadipocytes,elevated expression of adipogenic genes(CCAAT enhancer binding protein alpha[CEBPA]and CCAAT enhancer binding protein beta[CEBPB])and angiogenic genes(vascular endothelial growth factor A[VEGFA]),and stromal vascular fraction cells in the longissimus dorsi(LD)muscle with enhanced adipogenic capacity(P<0.05).These effects were entirely negated by SU5416.Upon slaughter,VA increased final weight,carcass weight,and average daily gain(P<0.05)but did not affect feed intake at 21 to 32 weeks(P=0.824).VA increased the number of intramuscular adipocytes in the LD and semitendinosus(ST)muscle(P<0.05)without changing the adipocyte number of the omentum,perirenal and subcutaneous fats(P>0.05).VA injections also increased intramuscular triglyceride(TG)content(P=0.016)without changing the omentum fat weight or subcutaneous fat thickness(P>0.05),but it did increase the perirenal fat weight(P=0.011).Consistently,SU5416 mitigated the effects of VA on intramuscular TG content and adipocyte count,correlating with a decrease in vascularity.In contrast,RA injections didn't affect the intramuscular fat(P=0.744)but reduced the TG content of the omentum and perirenal fat(P<0.05).In conclusion,intramuscular injections of VA but not RA at the neonatal stage improved the growth performance of Hu sheep,increasing the number of intramuscular adipocytes and marbling by promoting angiogenesis.
