Background： Upon binding luteinizing hormone in the ovary, the luteinizing hormone/choriogonadotropin receptor （LHCGR） is necessary for follicular maturation and ovulation, as well as luteal function. We detected m...Background： Upon binding luteinizing hormone in the ovary, the luteinizing hormone/choriogonadotropin receptor （LHCGR） is necessary for follicular maturation and ovulation, as well as luteal function. We detected mutations in the LHCGR gene and evaluated their association with superovulation. Methods： Using polymerase chain reaction-single strand sequencing, we examined polymorphisms in LHCGR and Chinese Holstein heifers. conformation polymorphism （PCR-SSCP） and DNA the genotypes associated with superovulation traits in 127 Results： A G/T polymorphism （ss52050737） in exon 11 was significantly associated with the total number of ova and the number of transferable embryos. Conclusions： LHCGR may be a new predictor for superovulation in Chinese Holstein heifers.展开更多
Background: High-altitude pulmonary hypertension(HAPH) is a life-threating condition for animals in high altitude,and disturbance of endothelial nitric oxide(NO) synthesis contributes to its pathogenesis. N-carbamylgl...Background: High-altitude pulmonary hypertension(HAPH) is a life-threating condition for animals in high altitude,and disturbance of endothelial nitric oxide(NO) synthesis contributes to its pathogenesis. N-carbamylglutamate(NCG), which enhances arginine synthesis, promotes endogenous synthesis of NO. In this study, we determined the effects of NCG on alleviating HAPH in Holstein heifers that ascended to Tibet(Lhasa, 3,658 m).Methods: Exp. 1, 2,000 Holstein heifers were transported from low elevation(1,027 m) to Lhasa. After being exposed to hypoxia for 1 yr, Holstein heifers were assigned to a healthy group(Control, n = 6) with mean pulmonary hypertension(mPAP) < 41 mmHg, and an HAPH affected group(HAPH, n = 6) with mPAP > 49 mmHg.Lung tissues were collected to evaluate histopathological changes and the expression of endothelial nitric oxide synthase(eNOS). Exp. 2, ten healthy heifers and 10 HAPH affected heifers were supplemented with NCG(20 g/d per heifer) for 4 wk. Physiological parameters were determined and blood samples were collected on d-1 and d 28 of the feeding trial.Results: Expression of e NOS in small pulmonary arteriole intima was higher in the healthy than HAPH group(P = 0.006), whereas HAPH group had significantly thicker media and adventitia than healthy group(all P < 0.05). The mRNA of eNOS and protein level of eNOS were higher in the lungs of heifers in the healthy group than in the HAPH group(both P < 0.001), whereas endothelin-1 protein levels were higher in HAPH group than in the healthy group(P = 0.025). NCG supplementation decreased mPAP and ammonia(both P = 0.001), whereas it increased the expression of eNOS, arginine, and plasma NO(all P < 0.05).Conclusions: The expression of eNOS was decreased in Holstein heifers with HAPH. NCG supplementation decreased m PAP through the restoration of eNOS and endogenous NO synthesis.展开更多
旨在研究母牛初次配种妊娠月龄(age at first pregnancy,AFP)对其泌乳性能和主要繁殖性能的影响。本研究以我国北方地区2个规模化奶牛场13927头荷斯坦母牛(A牧场8091头,B牧场5836头)的生产数据为基础,统计了母牛AFP、头胎和二胎的产奶...旨在研究母牛初次配种妊娠月龄(age at first pregnancy,AFP)对其泌乳性能和主要繁殖性能的影响。本研究以我国北方地区2个规模化奶牛场13927头荷斯坦母牛(A牧场8091头,B牧场5836头)的生产数据为基础,统计了母牛AFP、头胎和二胎的产奶量、产后首次发情时间、首次配种时间和首次受孕时间,然后将母牛根据AFP的早晚(12~19月龄)分为8组,对各试验组母牛的头胎和二胎产奶量和主要繁殖性能的数据进行比较分析。结果表明:1)2个规模化奶牛场荷斯坦青年牛AFP以13和14月龄为主(总占比70.1%);2)AFP可显著影响荷斯坦青年牛头胎和二胎的305 d产奶量(P<0.05),其中AFP为14月龄时A牧场头胎和二胎305 d产奶量均最高,分别为15102和15534 kg;3)AFP可显著影响荷斯坦青年牛头胎和二胎产后首次发情时间和受孕时间(P<0.05),AFP为14月龄时头胎产后首次发情和受孕情况最优;4)对于产后首配时间,除A牧场头胎AFP为16月龄时产后首次配种时间显著高于AFP为17月龄时(P<0.05)外,其余各组间均无显著性差异(P≥0.05),并且各组间配种时间相差≤5 d;5)通过对A牧场在场牛(2703头)与淘汰牛(660头)的AFP记录数据分析发现,在场牛的AFP为14.52月龄,显著高于淘汰牛的AFP(P<0.05)。因此,在北方地区现有的生产管理水平下,14月龄可能是荷斯坦青年牛最适宜的初次配种妊娠月龄,这对我国规模化奶牛场选择荷斯坦青年牛适宜的初次配种月龄具有一定参考价值。展开更多
The objective of this experiment was to evaluate the effect of supplementing rumen-protected Lys based on a Lys-deficient diet on liver metabolism in growing Holstein heifers.The experiment was conducted for 3 months ...The objective of this experiment was to evaluate the effect of supplementing rumen-protected Lys based on a Lys-deficient diet on liver metabolism in growing Holstein heifers.The experiment was conducted for 3 months with 36 Holstein heifers(initial body weight:200±9.0 kg;7-month-old).Heifers were randomly assigned to 2 diets based on corn,soybean meal,alfalfa hay,and wheat bran:control,Lysdeficient diet(LD;0.66%Lys in diet),and Lys-adequate diet(LA;1.00%Lys in diet).The results showed no difference in growth performance between the 2 groups(P>0.05).However,there was a clear trend of increasing feed conversion rate with Lys supplementation(0.05<P<0.01).The serum urea nitrogen concentration was significantly decreased,and the aspartate aminotransferase-to-alanine aminotransferase ratio was significantly decreased by Lys supplementation(P<0.05).Moreover,growing heifers fed a Lys-adequate diet had lower levels of urine nitrogen excretion and higher levels of the biological value of nitrogen(P<0.05).Metabolomic analysis revealed that 5 types of phosphatidylcholine and 3 types of ceramide were significantly increased and enriched in sphingolipid metabolism and glycero phospholipid metabolism(P<0.05).His,Leu,and Asp levels were significantly decreased in the liver following Lys supplementation(P<0.05).In conclusion,Lys supplementation may promote the synthesis of body tissue proteins,as evidenced by significantly decreased amino acids in the liver and urine N excretion,it also improves hepatic lipid metabolism by providing lipoprotein precursors.展开更多
基金supported by grant #2011BAD19B01,#2011BAD19B03 and #2011BAD19B04 from the National Key Technology R&D program#2011AA100303 from National High-Tech R&D Program
文摘Background： Upon binding luteinizing hormone in the ovary, the luteinizing hormone/choriogonadotropin receptor （LHCGR） is necessary for follicular maturation and ovulation, as well as luteal function. We detected mutations in the LHCGR gene and evaluated their association with superovulation. Methods： Using polymerase chain reaction-single strand sequencing, we examined polymorphisms in LHCGR and Chinese Holstein heifers. conformation polymorphism （PCR-SSCP） and DNA the genotypes associated with superovulation traits in 127 Results： A G/T polymorphism （ss52050737） in exon 11 was significantly associated with the total number of ova and the number of transferable embryos. Conclusions： LHCGR may be a new predictor for superovulation in Chinese Holstein heifers.
基金provided by the National Dairy Industry and Technology System(Beijing,P.R.China)
文摘Background: High-altitude pulmonary hypertension(HAPH) is a life-threating condition for animals in high altitude,and disturbance of endothelial nitric oxide(NO) synthesis contributes to its pathogenesis. N-carbamylglutamate(NCG), which enhances arginine synthesis, promotes endogenous synthesis of NO. In this study, we determined the effects of NCG on alleviating HAPH in Holstein heifers that ascended to Tibet(Lhasa, 3,658 m).Methods: Exp. 1, 2,000 Holstein heifers were transported from low elevation(1,027 m) to Lhasa. After being exposed to hypoxia for 1 yr, Holstein heifers were assigned to a healthy group(Control, n = 6) with mean pulmonary hypertension(mPAP) < 41 mmHg, and an HAPH affected group(HAPH, n = 6) with mPAP > 49 mmHg.Lung tissues were collected to evaluate histopathological changes and the expression of endothelial nitric oxide synthase(eNOS). Exp. 2, ten healthy heifers and 10 HAPH affected heifers were supplemented with NCG(20 g/d per heifer) for 4 wk. Physiological parameters were determined and blood samples were collected on d-1 and d 28 of the feeding trial.Results: Expression of e NOS in small pulmonary arteriole intima was higher in the healthy than HAPH group(P = 0.006), whereas HAPH group had significantly thicker media and adventitia than healthy group(all P < 0.05). The mRNA of eNOS and protein level of eNOS were higher in the lungs of heifers in the healthy group than in the HAPH group(both P < 0.001), whereas endothelin-1 protein levels were higher in HAPH group than in the healthy group(P = 0.025). NCG supplementation decreased mPAP and ammonia(both P = 0.001), whereas it increased the expression of eNOS, arginine, and plasma NO(all P < 0.05).Conclusions: The expression of eNOS was decreased in Holstein heifers with HAPH. NCG supplementation decreased m PAP through the restoration of eNOS and endogenous NO synthesis.
文摘旨在研究母牛初次配种妊娠月龄(age at first pregnancy,AFP)对其泌乳性能和主要繁殖性能的影响。本研究以我国北方地区2个规模化奶牛场13927头荷斯坦母牛(A牧场8091头,B牧场5836头)的生产数据为基础,统计了母牛AFP、头胎和二胎的产奶量、产后首次发情时间、首次配种时间和首次受孕时间,然后将母牛根据AFP的早晚(12~19月龄)分为8组,对各试验组母牛的头胎和二胎产奶量和主要繁殖性能的数据进行比较分析。结果表明:1)2个规模化奶牛场荷斯坦青年牛AFP以13和14月龄为主(总占比70.1%);2)AFP可显著影响荷斯坦青年牛头胎和二胎的305 d产奶量(P<0.05),其中AFP为14月龄时A牧场头胎和二胎305 d产奶量均最高,分别为15102和15534 kg;3)AFP可显著影响荷斯坦青年牛头胎和二胎产后首次发情时间和受孕时间(P<0.05),AFP为14月龄时头胎产后首次发情和受孕情况最优;4)对于产后首配时间,除A牧场头胎AFP为16月龄时产后首次配种时间显著高于AFP为17月龄时(P<0.05)外,其余各组间均无显著性差异(P≥0.05),并且各组间配种时间相差≤5 d;5)通过对A牧场在场牛(2703头)与淘汰牛(660头)的AFP记录数据分析发现,在场牛的AFP为14.52月龄,显著高于淘汰牛的AFP(P<0.05)。因此,在北方地区现有的生产管理水平下,14月龄可能是荷斯坦青年牛最适宜的初次配种妊娠月龄,这对我国规模化奶牛场选择荷斯坦青年牛适宜的初次配种月龄具有一定参考价值。
基金supported,in part,by the Key Research and Development Program of Hebei Province(19226621D)Earmarked Fund for Beijing Dairy Industry Innovation Consortium of Agriculture Research System,Chinese Academy of Agricultural Science and Technology Innovation Project(CAAS-XTCX-2016011-01)+2 种基金Fundamental Research Funds for Central Non-profit Scientific Institution(Y2019CG08)Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2017-FRI-04)Science and Technology Open Cooperation Project of Henan Province(182106000035)Study on the Pattern of Diet Amino Acid for Different Physiological Stages of Heifers。
文摘The objective of this experiment was to evaluate the effect of supplementing rumen-protected Lys based on a Lys-deficient diet on liver metabolism in growing Holstein heifers.The experiment was conducted for 3 months with 36 Holstein heifers(initial body weight:200±9.0 kg;7-month-old).Heifers were randomly assigned to 2 diets based on corn,soybean meal,alfalfa hay,and wheat bran:control,Lysdeficient diet(LD;0.66%Lys in diet),and Lys-adequate diet(LA;1.00%Lys in diet).The results showed no difference in growth performance between the 2 groups(P>0.05).However,there was a clear trend of increasing feed conversion rate with Lys supplementation(0.05<P<0.01).The serum urea nitrogen concentration was significantly decreased,and the aspartate aminotransferase-to-alanine aminotransferase ratio was significantly decreased by Lys supplementation(P<0.05).Moreover,growing heifers fed a Lys-adequate diet had lower levels of urine nitrogen excretion and higher levels of the biological value of nitrogen(P<0.05).Metabolomic analysis revealed that 5 types of phosphatidylcholine and 3 types of ceramide were significantly increased and enriched in sphingolipid metabolism and glycero phospholipid metabolism(P<0.05).His,Leu,and Asp levels were significantly decreased in the liver following Lys supplementation(P<0.05).In conclusion,Lys supplementation may promote the synthesis of body tissue proteins,as evidenced by significantly decreased amino acids in the liver and urine N excretion,it also improves hepatic lipid metabolism by providing lipoprotein precursors.
