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1.
OBJECTIVE: To assess effects on functions of peripheral blood mononuclear cells (PBMC) obtained from ewes for each of several fatty acids represented in ovine plasma at concentrations mimicking those of ketotic or healthy ewes. SAMPLE POPULATION: Blood samples obtained from 6 Sardinian ewes. PROCEDURE: The PBMC were cultured in media that contained oleic (OA), palmitic (PA), stearic (SA), linoleic (LA), or palmitoleic (POA) acid at concentrations similar to those of ketotic or healthy ewes. Synthesis of DNA was stimulated by use of concanavalin A or pokeweed mitogen (PWM). Secretion of IgM was stimulated by use of PWM. RESULTS: High concentrations (900, 450, and 225 micromol/L) of OA significantly inhibited DNA synthesis and IgM secretion of PBMC. Conversely, low concentrations (56 or 28 micromol/L) of OA significantly enhanced DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, or 75 micromol/L) significantly inhibited DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, 75, or 38 micromol/L) also significantly inhibited IgM secretion of PBMC. None of the concentrations of LA and POA affected PBMC functions. CONCLUSION AND CLINICAL RELEVANCE: Impaired immunoresponsiveness of ketotic ewes is likely associated with an increase of plasma concentrations of OA, PA, or SA and not with that of LA or POA. At physiologic concentrations, single fatty acids are likely to participate in modulation of immunoresponsiveness by exerting suppressive or stimulatory effects on immune cells.  相似文献   

2.
OBJECTIVE: To determine the effects of moderate feed restriction, single or twin pregnancy, and subclinical pregnancy toxemia (PT) on immune responses of ewes. ANIMALS: 16 Sardinian ewes. PROCEDURE: Six weeks before lambing, ewes were assigned to 1 of 2 groups (n = 8/group) matched for number of fetuses, body condition score, and plasma glucose, non-esterified fatty acids (NEFA), and beta hydroxybutyrate (BHBA) concentrations, and feed intake was restricted for 1 of the groups. Cell-mediated immunity was evaluated in vivo and in vitro. Humoral immunity was evaluated in vivo by determining production of IgG antibodies against keyhole limpet hemocyanin (KLH). RESULTS: Four ewes developed subclinical PT (plasma BHBA concentration > 0.86 mmol/L without any clinical signs of disease). Whether feed was restricted and type of pregnancy (single vs twin) did not have any significant effects on cell-mediated and humoral immune responses. Ewes with subclinical PT had significantly lower in vitro proliferation of phytohemagglutinin-stimulated peripheral blood mononuclear cells and significantly lower values for KLH-specific IgG than did healthy ewes. Plasma BHBA and NEFA concentrations were negatively correlated with in vitro proliferation of peripheral blood mononuclear cells; plasma NEFA concentration was negatively correlated with values for KLH-specific IgG. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that subclinical PT may be associated with impairments in cell-mediated and humoral immune responses in sheep.  相似文献   

3.
The hindlimb arteriovenous difference (AVD) model was used to determine whether 30 mg/ kg of the nitric oxide synthase (NOS) inhibitor L-NGnitroarginine methyl ester (hydrochloride; L-NAME) inhibited ovine NO synthesis and influenced muscle metabolism. Eight Border Leicester x Merino cross lambs (50 to 55 kg BW) were infused with saline (control) or saline containing L-NAME via an indwelling jugular vein catheter in a balanced randomized crossover design with 3 d between treatments. The abdominal aorta and deep femoral vein were catheterized for assessment of AVD of hind limb metabolism. Arterial hematocrit and insulin concentration and both arterial and venous concentrations of nitrate/nitrite (NOx), glucose, lactate, NEFA, and urea were determined. Infusion of L-NAME decreased arterial NOx concentrations (P = 0.049), indicating inhibition of systemic NO synthesis. Treatment had no effect on arterial (3.5 vs. 3.6 +/- 0.19 mmol/L for control and L-NAME lambs, respectively; P = 0.39) or venous (3.3 vs. 3.4 +/- 0.16 mmol/L, P = 0.55) plasma glucose concentrations or on glucose AVD (0.19 vs. 0.27 +/- 0.065 mmol/L, P = 0.20). There was an interaction (P = 0.038) between time and treatment, such that L-NAME initially increased the AVD of glucose (up to 180 m) divergent from control lambs. The response was then decreased before a possible inflection beyond 240 min. Infusion of L-NAME increased hindlimb venous NEFA (222 vs. 272 +/- 13.2 micromol/L, P = 0.007) and NEFA AVD (79.4 vs. -13.3 +/- 31.5 micromol/L, P = 0.018). These metabolic changes were independent of plasma insulin concentrations, which were not affected by L-NAME infusion (25.3 vs. 27.8 +/- 3.62 mU/L, P = 0.85). The increase in hindlimb lipolysis after L-NAME infusion does not seem to be due to increased lipolysis of plasma triacylglycerol because circulating arterial (155 vs. 142 +/- 20.8 micromol/L, P = 0.58), venous (154 vs. 140 +/- 20.5 micromol/L, P = 0.50), and AVD (1.0 vs. 2.9 +/- 3.17 micromol/L, P = 0.38) triacylglycerol concentrations were unaffected by L-NAME infusion. In conclusion, these data indicate that infusion of 30 mg of L-NAME/kg inhibits NO synthesis, which in turn influences fat and carbohydrate metabolism in the ovine hindlimb independently of plasma insulin concentrations.  相似文献   

4.
本研究对上海地区9个牧场奶牛产后低钙血症和酮病的发病率进行了调查,结果表明:奶牛产后12 h内的低钙血症发病率平均为86.1%,血钙平均浓度为(1.82±0.02)mmol/L,产后3~7 d低钙血症发病率平均为35.2%,血钙平均浓度为(2.05±0.01)mmol/L,表明随着泌乳天数的增加,低钙血症有缓解趋势。奶牛产后12 h内酮病发病率平均为5.5%,血液β-羟丁酸(BHBA)平均浓度为(0.68±0.04)mmol/L,产后3~7 d酮病发病率平均为16.3%,血液BHBA平均浓度为(0.98±0.07)mmol/L,表明随着泌乳天数增加能量负平衡有加重趋势。奶牛产后12 h内高游离脂肪酸(NEFA)发生率平均为49.4%,血液NEFA平均浓度为(0.76±0.03)Meq/L,产后3~7 d高NEFA发生率平均为41.3%,血液NEFA平均浓度为(0.71±0.03)Meq/L,表明泌乳初期高NEFA发生率远高于酮病发病率,随着泌乳天数增加血液NEFA浓度有下降趋势。奶牛产后血液中钙的浓度与NEFA浓度呈极显著负相关(P0.01),血液中NEFA浓度与BHBA浓度呈极显著正相关(P0.01)。  相似文献   

5.
The objective of this study was to determine the effect of a monensin controlled-release capsule on the proportion of cows with subclinical ketosis (SK). During July to August 2001, 300 cows dried-off 50-70 days before expected parturition were randomly assigned to either a treatment (n = 150, oral capsule, 335 mg/d of monesin for 95 d) or control group (no capsule, n = 150). At 14 days postpartum, a milk sample was obtained and evaluated for beta-hydroxybutyrate (BHBA) using a semi-quantitative ketone test strip. In a sub-sample of 50 cows per group a blood sample was taken and analyzed for BHBA using an ELISA kit. Milk BHBA > or = 200 micromol/L was used as the cut-off value for diagnosis of SK. The incidence of SK based on the milk test was statistically different between groups (P < or = 0.05) with a value of 26.6% for control and 14.5% for cows treated with monensin, respectively. Cows treated with monensin were 0.68 times less likely to give a positive result for milk BHBA than non-treated cows (0.53-0.80; 95% CI). Serum BHBA concentrations did not differ between groups (0.81 +/- 0.09 mmol/L versus 0.70 +/- 0.07 mmol/L for controls and treated, respectively; P > 0.05). However, for each incremental increase in serum BHBA of 0.1 mmol/L occurrence of SK increased 52% (OR = 1.52; 1.21-1.91; 95% CI).  相似文献   

6.
Ewes bearing more than 1 fetus are more susceptible to pregnancy toxemia than those with a single fetus. Crossbreeding programs in Israel increased the occurrences of ewes bearing more than 2 fetuses; therefore, the aim was to assess the exacerbation in the metabolic status of ewes pregnant with several fetuses. Fifty ewes, genetically developed to achieve multiple-fetus pregnancies, were monitored, on average, from d 115 of pregnancy until lambing for plasma concentrations of several key metabolites and insulin. The numbers of fetuses were examined by ultrasonography at 35 d of pregnancy. Blood samples were collected weekly, and concentrations of glucose, β-hydroxybutyrate (BHBA), NEFA, triglycerides, cholesterol, total calcium, and insulin were determined. The average litter size was 2.75 (±1.1), and 1 (1F), 2 (2F), 3 (3F), and 4 or more (4F) fetuses were conceived, respectively, by 6 (12%), 17 (34%), 14 (28%), and 13 (26%) ewes. Total birth weights of lambs were 6.1, 9.5, 12.7, and 15.0 kg for 1F, 2F, 3F, and 4F, respectively (P < 0.001). Plasma glucose concentrations in 1F were greater than those in 3F and 4F (P < 0.05) and were similar among 2F, 3F, and 4F. Trends toward increasing plasma concentrations of BHBA and NEFA were observed as the number of fetuses increased and also as lambing approached. Plasma concentrations of BHBA and NEFA were, respectively, 3.7 (P < 0.002) and 2.1 (P < 0.001) times as great in 4F ewes as in 1F ewes. Trends toward decreased concentrations of triglycerides and cholesterol were observed as litter size increased. Insulin concentrations in blood decreased considerably as the numbers of fetuses increased and, on average, they were less by a factor of 5 in the 4F ewes than in the 1F ewes (P < 0.001). Moreover, insulin concentrations during the week before lambing were extremely low (e.g., 0.54 μIU/mL in the 4F ewes). Insulin concentrations were reduced in ewes bearing >3 fetuses, even 5 wk before lambing; this decline apparently began earlier than the last month of gestation. Therefore, it seems that insulin has a pivotal role in the etiology of pregnancy ketonemia in ewes carrying multiple fetuses. The present findings may suggest that the decline in insulin concentrations that apparently occurs in the earlier stages of pregnancy represents a homeorhetic control to spare glucose for the brains and fetoplacental units of the dams. The results clearly demonstrate the increased susceptibility to pregnancy toxemia of ewes carrying multiple fetuses. Appropriate nutritional strategies should be developed for ewes that conceive >3 fetuses, to meet the increased nutritional requirements of the fetoplacental unit.  相似文献   

7.
AIM: To determine concurrent changes in serum methylmalonic acid (MMA) and vitamin B12 concentrations of ewes and their lambs on cobalt-deficient properties, subsequent to cobalt supplementation. METHODS: Three experiments were carried out on two farms. Groups of ewes (n=25-50) were either supplemented with cobalt bullets during late pregnancy, 23-47 days before the mean lambing date, or left unsupplemented. In two experiments, lambs from within each group were supplemented directly by vitamin B12 injection at 3-weekly intervals from birth, and in the third experiment by injection with micro-encapsulated vitamin B12 at tailing and 3 months later. Pasture samples were obtained for analysis of cobalt content at each sampling time. Blood samples were obtained and liveweight recorded from ewes and lambs at approximately monthly intervals. On one farm (two experiments), liver and milk samples were obtained from ewes and liver samples from lambs. RESULTS: Serum vitamin B12 concentrations in unsupplemented ewes fell below 250 pmol/L during early lactation in all experiments and mean concentrations as low as 100 pmol/L were recorded. MMA concentration was maintained below 2 micromol/L in serum from supplemented ewes but increased to mean concentrations ranging from 7 to 14 micromol/L at the nadir of serum vitamin B12 concentration during peak lactation. A significant liveweight response to supplementation was recorded in ewes on one property, and the vitamin B12 concentration in the ewes' milk and in the livers of their lambs more than doubled. No liveweight-gain response to supplementation was observed in lambs on this property. Mean serum MMA concentrations in lambs ranged from <2 in supplemented, to 19.2 micromol/L in unsupplemented lambs, and the latter had concurrent serum vitamin B12 concentrations of >300 pmol/L. Pasture cobalt concentration was lowest at 0.04-0.09 microg/kg dry matter (DM) on the property on which responses in lambs occurred but considerably higher (>0.09 microg/kg DM) on the property on which responses in ewes occurred. On the second property, serum vitamin B12 concentrations in lambs at tailing were extremely low (100 pmol/L), irrespective of supplementation of dams with cobalt. Mean serum MMA concentration was increased to 20 and 42 micromol/L in lambs from supplemented and non-supplemented ewes, respectively. Weight-gain response to direct supplementation of lambs with vitamin B12 occurred during suckling in the latter, but not the former. Lambs from ewes supplemented with vitamin B12 showed a much bigger increase in serum vitamin B12 concentrations a month after supplementation than did lambs from unsupplemented ewes (+1,400 pmol/L vs + 650 pmol/L). CONCLUSIONS: Serum MMA concentration gave a more precise indication of responsiveness to vitamin B12 or cobalt supplementation than serum vitamin B12 concentrations in ewes and lambs. Neither very low serum vitamin B12 nor elevated MMA concentrations were necessarily indicative of responsiveness to supplementation in suckling lambs, but the latter gave an early indication of impending responsiveness. Supplementation of the ewe with a cobalt bullet appeared to protect the growth performance of the lamb for 90 days and influence the subsequent serum vitamin B12 response in the lamb to vitamin B12 supplementation. CLINICAL SIGNIFICANCE: Supplementing ewes with cobalt bullets in late pregnancy can improve the vitamin B12 status of their lambs, and modify their response to vitamin B12 supplementation.  相似文献   

8.
本试验旨在探讨β-羟丁酸（BHBA）对体外原代培养犊牛肝细胞凋亡的影响以及p38MAPK在其中的调控作用。选择培养72h的肝细胞,添加不同浓度的BHBA（0、0．6、1．2、2．4mmol／L）,培养9h,每个浓度3个重复。另外选取细胞,p38MAPK抑制剂SB203580（10pmol／L）预处理1h后,添加BHBA,使其终浓度为2．4retool／L;PI／An—nexinV—FITC双染,运用荧光显微镜观察肝细胞凋亡情况;ELISA法检测p38的活性;实时荧光定量PCR方法检测p38、Caspase-3、Caspase9、bcl2基因的mRNA表达水平。结果表明,与对照组相比,1．2和2．4mmol／I—BHBA组的肝细胞凋亡明显增加;p38酶活性明显升高;p38、caspase-3和caspase-9基因mRNA表达水平均显著增加（P〈0．01）。bcl2基因mRNA表达水平显著降低（P〈0．05）;添加p38抑制剂后,caspase-3和caspase-9基因mRNA表达水平显著降低（P〈0．01）,bcl-2基因mRNA表达水平显著增加（P〈O．05）。高浓度的BHBA可以诱导体外原代培养犊牛肝细胞凋亡,p38在BHBA诱导的细胞凋亡中发挥重要作用。  相似文献   

9.
The relationships between placental lactogen (PL), insulin-like growth factor (IGF) -1 and -2, insulin, glucose and nonesterified fatty acids (NEFA) were studied in 10 triplet-bearing ewes in late gestation (120-129 days) which were on ad libitum feeding. To extend the range of plasma metabolite concentrations the ewes received a continuous abomasal infusion from 100 days of gestation until delivery. Three were infused with glucose (160 g/day), 2 received sodium caseinate and 3 were infused with control fluid alone. From 120 days the animals were fed 3 hourly intervals from a belt feeder to achieve steady state and at 125-130 days had intravenous plasma samples pooled for analysis. There was no effect of nutritional supplementation on birth weight. Casein supplementation was associated with reduced maternal PL concentrations but glucose supplementation had no effect on PL concentrations. Circulating PL concentrations showed a positive correlation to IGF-2 activity (r = 0.64, P less than 0.05) and a negative relation to IGF-1 concentrations (r = -0.73, P less than 0.05). IGF-1 levels were higher (P less than 0.05) and IGF-2 levels were lower (P less than 0.05) in nutritionally supplemented ewes. In the ewe, NEFA concentrations showed a negative relationship to IGF-1 (r = -0.75, P less than 0.05) and a positive relationship with IGF-2 (r = 0.87, P less than 0.1). Similar relationships were observed in the ewe at term. These observations suggest that nutritional factors and PL may be important determinants of IGF-2 secretion in the late-gestation ewe. They suggest the possibility that IGF-2 mediates the lipolytic effects of PL.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Insulin resistance during late gestation may act as a predisposing factor of ovine pregnancy toxaemia (OPT). To evaluate the insulin action on energy metabolism in ewes with different susceptibilities to OPT, intravenous glucose tolerance tests (1 mmol glucose/kg body weight) were performed in 5.6 ± 0.7 year old, slightly underfed German Blackheaded Mutton ewes [high‐risk (HR) ewes] and 2.5 year old, overnourished Finnish Landrace ewes [low‐risk (LR) ewes] during mid and late pregnancy, during early lactation and during the dry period. Plasma samples were analysed for glucose, insulin, non‐esterified fatty acids (NEFA) and β‐hydroxybutyrate (β‐HB). The glucose elimination rate and the glucose‐stimulated first‐phase insulin secretion were significantly (p < 0.05) lower in the HR, in relation to the LR group combining the data of all gestational stages. The basal rate of lipolysis was significantly increased in the HR ewes during late pregnancy, but the NEFA clearance after the glucose load was similar in both groups during all reproductive stages. Plasma β‐HB concentrations decreased only in the LR ewes after the glucose load during late pregnancy. Results indicate an insulin resistance in the HR ewes regarding the glucose utilization and the ketone body formation during late pregnancy. The insulin resistance in the HR ewes may represent one predisposing factor responsible for the susceptibility to OPT. Further scientific work is necessary to elucidate whether this insulin resistance was due to breed, age or nutritional state.  相似文献   

11.
为研究线粒体融合蛋白2(mitofusin 2,MFN2)对高β-羟丁酸(β-hydroxybutyrate,BHBA)活化NF-κB炎性通路的影响,体外培养奶牛肝细胞,添加不同浓度(0.0,1.2,2.4,4.8 mmol/L)的BHBA,并转染过表达MFN2的腺病毒,运用Western blot和qRT-PCR技术检测NF-κB炎性通路关键分子的基因和蛋白表达。结果显示,随着BHBA浓度的增加,IKBα和NF-κB p65的磷酸化水平以及IL-1β、IL-6和TNFα的mRNA表达均显著升高,MFN2的基因和蛋白表达水平则显著降低;过表达MFN2后,显著抑制了高BHBA诱导的IKBα和NF-κB p65磷酸化水平及IL-1β、IL-6、TNFαmRNA表达水平的升高。结果表明,在奶牛肝细胞中过表达MFN2可以显著抑制高BHBA活化的NF-κB炎性通路。  相似文献   

12.
OBJECTIVE: To determine the effect of feeding frequency and cow-specific factors on diurnal variations of blood metabolites concentrations. ANIMALS: 40 dairy cows from 2 herds. PROCEDURE: Each herd was fed concentrate at a specific feeding frequency (automatic vs twice daily). Blood samples were collected 4 times daily. Plasma concentrations of glucose, nonesterified fatty acids (NEFA), and beta-hydroxybutyrate (BHBA) were analyzed, and concentrations of urea, cholesterol, and total protein (TP) were determined in serum samples. A multivariate repeated-measures ANOVA was used to test the effect of time, feeding frequency, production group, parity, days after parturition, and daily milk yield on diurnal variations of metabolites. RESULTS: Concentrations of glucose, BHBA, and urea remained relatively constant in the herd that was fed by use of automatic distribution of concentrate; however, significant diurnal patterns were detected in the herd fed only twice daily. Only slight differences in glucose and urea concentrations were detected between high- and low-producing cows, but concentration of BHBA was significantly influenced by number of days in lactation. In contrast, diurnal variations in NEFA and cholesterol concentrations were similar between the 2 herds but differed with regard to production group. Concentrations of TP did not have relevant diurnal patterns and did not differ between production groups. CONCLUSIONS AND CLINICAL RELEVANCE: Diurnal variations and feeding frequency affect glucose, BHBA, and urea concentrations in cows. In contrast, concentrations of NEFA, cholesterol, and TP appear to be less sensitive to time of sample collection. Feeding frequency, composition of feed, or both, have a major impact on blood metabolites concentrations.  相似文献   

13.
The aim of this study was to evaluate the oxidative status in ketotic cows. We observed changes in the oxidative status and correlations between the oxidative and metabolic status in non‐ketotic (n = 10), subclinical ketotic (n = 10) and ketotic cows (n = 10). Plasma samples were analysed by standard biochemical techniques and ELISA to determine traditional metabolic parameters: triglyceride (TG), phosphonium (P), calcium (Ca), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), immune globulin (Ig), total cholesterol (TC), high‐density lipoprotein (HDL), very low‐density lipoprotein (VLDL) and lactate dehydrogenase (LDH); energy metabolism indices: glucose, β‐hydroxybutyrate (BHBA) and non‐esterified fatty acids (NEFA); and indices of oxidative status: malondialdehyde (MDA), hydrogen peroxide (H2O2), vitamin C, vitamin E, superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), catalase (CAT), xanthine oxidase (XOD) and total antioxidant capacity (TAOC). The results of this study showed that plasma glucose levels were lower in ketotic and subclinical ketotic cows than in non‐ketotic cows; however, the plasma NEFA and BHBA concentrations were higher. In addition, significant decreases in TC, HDL and VLDL and significant increases in AST, ALT and LDH were observed in the plasma of the ketotic cows. The ketotic cows showed decreased plasma SOD, CAT, vitamin C and vitamin E, inhibited hydroxyl radical capacity and increased plasma H2O2 and MDA. There were positive correlations between the plasma NEFA and ALT, AST, LDH and MDA and negative correlations between the plasma NEFA and TC, HDL, VLDL, SOD, vitamin C, vitamin E, 1542280 uric acid and inhibited hydroxyl radical capacity. In addition, there were positive correlations between BHBA concentrations and ALT, AST and LDH and negative correlations between plasma BHBA concentrations and TC, HDL, VLDL, vitamin E and inhibited hydroxyl radical capacity. Overall, ketotic dairy cows experience oxidative stress, which is presumably associated with hyperketonemia and higher NEFA.  相似文献   

14.
AIM: To determine the effect of copper oxide (CuO) needles administered orally to ewes in early pregnancy on the copper (Cu) status of ewes throughout gestation and lactation, and of their lambs from birth to weaning. METHODS: In mid-April, after mating, 12 twin-bearing ewes were given an oral capsule containing 5 g CuO needles while 12 others served as untreated controls. Changes in Cu status were monitored by determining serum and liver Cu concentrations on Days 1, 62, 117, 153, 185 and 216 in the ewes, and at 1, 36, 68 and 99 days of age for lambs. Pasture herbage samples were collected at about 60-day intervals for Cu, molybdenum (Mo), iron (Fe) and sulphur (S) determinations. RESULTS: Copper status of the ewe flock was adequate, as initial mean serum and liver Cu concentrations were 15 micromol/L and 1,060 micromol/kg fresh tissue, respectively. The CuO needles did not affect serum Cu concentrations of the ewes or their lambs. Mean serum Cu concentration of all lambs at birth was about half that of ewes (8 vs 17 micromol/L), regardless of Cu supplementation, and not until at least 68 days of age was it similar to the dams'. Liver Cu concentrations of lambs at birth were also lower than that of the ewes (380 vs 640 micromol/kg fresh tissue among the controls), but changed little over time. CuO treatment increased liver Cu concentration in ewes for at least 185 days and in lambs for 36 days (p<0.05). Among untreated ewes, there was a seasonal decline in mean liver Cu concentrations, which were highest in autumn and lowest in early spring (1,060 vs 370 micromol/kg fresh tissue). The mean pasture mineral concentrations were Cu 5.7, Mo 0.48, Fe 194 and S 2,900 mg/kg dry matter (DM). CONCLUSIONS: CuO needles administered to ewes in early pregnancy increased their Cu status through gestation and early lactation, and the Cu status of their lambs for 36 days from birth. Serum Cu concentration was not affected by treatment but a marked rise was observed in all lambs between birth and 10 weeks of age. CLINICAL RELEVANCE: Copper deficiency in young lambs may be conveniently and effectively prevented by treating ewes with CuO needles during early pregnancy. The serum Cu concentration in lambs <8 weeks old may not reflect the Cu status of the flock.  相似文献   

15.
To determine the effects of maternal Se intake and plane of nutrition during mid or late gestation or both on AA concentrations and metabolite concentrations in the dam and fetus, pregnant ewe lambs (n = 64) were assigned to 1 of 8 treatments arranged in a 2 × 2 × 2 factorial array: Se level [initiated at breeding; adequate (ASe; 3.05 μg/kg of BW) or high (HSe; 70.4 μg/kg of BW)] and nutritional level [100% (control; CON) or 60% (restricted; RES) of NRC recommendations] fed at different times of gestation [d 50 to 90 (mid) or d 91 to 132 (late)]. A blood sample was obtained from each ewe and fetus on d 132 of gestation and used to measure circulating concentrations of glucose, NEFA, blood urea N, and AA. The late RES ewes and their fetuses had less (P ≤ 0.03) circulating glucose compared with late CON ewes and fetuses at d 132; however, no effect (P ≥ 0.14) of diet on the fetal:maternal glucose concentration ratio was observed. Late RES ewes had a smaller (P = 0.01) fetal:maternal NEFA ratio compared with late CON ewes. Ewes fed ASe had a greater (P = 0.01) fetal:maternal blood urea N ratio compared with HSe ewes. Fetal:maternal ratios of total circulating AA, total essential AA, and total nonessential AA were each affected (P ≤ 0.03) by the combination of Se treatment and late gestation nutritional level.  相似文献   

16.
The objectives were to determine the effects of short-term feeding of a toxic endophyte (Neotyphodium coenophialum)-infected tall fescue seed (Festuca arundinacea, cultivar 'Kentucky 31') on fecal shedding and intestinal concentrations of Escherichia coli O157:H7 and the concentrations of prolactin, cortisol, and NEFA in experimentally inoculated ewes. Twelve ewes (mean BW = 46 +/- 2 kg) were fed a diet containing either high endophyte-infected (HI-E) or low endophyte-infected (LO-E) tall fescue seed for 7 d. Each diet consisted of 50% (as-fed basis) tall fescue seed. Ewes were experimentally inoculated with antibiotic resistance-selected E. coli O157:H7 on d 1 of the feeding treatment, and fecal shedding of inoculated pathogens was monitored daily on d 2 to 6. On d 7, ewes were weighed and euthanized, and tissues and contents were sampled from the ileum, cecum, and rectum for quantitative enumeration of E. coli O157:H7. Urine was collected at euthanization to determine total ergot alkaloid concentrations. Ewes fed HI-E had lower (P < 0.001) DMI than did ewes fed LO-E (0.8 and 1.6 +/- 0.1 kg/d of DMI for HI-E and LO-E ewes, respectively); consequently, there was a tendency (P = 0.06) for HI-E ewes to lose 0.3 +/- 0.4 kg of BW/d and LO-E ewes to gain 0.2 +/- 0.4 kg of BW/d during the 7 d. Urinary ergot alkaloids were increased (P < 0.001) in ewes fed HI-E (47.8 +/- 9.4 ng/mg of creatinine) compared with those fed LO-E (6.2 +/- 9.4 ng/mg of creatinine). Prolactin tended (P = 0.06) to be decreased in ewes fed HI-E (7.2 +/- 7.0 ng/mL) compared with those fed LO-E (27.7 +/- 7.0 ng/mL). Fecal shedding of E. coli O157:H7 tended (P = 0.06) to be increased in HI-E ewes [5.4 cfu (log10)/g of feces] compared with LO-E ewes [4.5 cfu (log10)/g of feces]. The population of E. coli O157:H7 in luminal contents from the ileum, cecum, and rectum did not differ (P > 0.36) between treatments. Treatment did not influence (P = 0.30) the occurrence of E. coli O157:H7 in cecal or rectal tissues; however, ileal tissues from HI-E ewes tended (P = 0.12) to have an increased incidence of E. coli O157:H7. Concentrations of NEFA tended (P = 0.12) to be greater in HI-E ewes than in LO-E ewes, whereas cortisol was similar (P = 0.49) for HI-E and LO-E ewes. We conclude that short-term feeding of HI-E tall fescue seed may alter the concentrations of prolactin and NEFA, and may increase fecal shedding of E. coli O157:H7 in experimentally inoculated ewes.  相似文献   

17.
高酮血症造成奶牛中性粒细胞先天免疫机能受到抑制,本研究探讨 β-羟丁酸(BHBA)是否抑制脂多糖(LPS)诱导的奶牛中性粒细胞核因子-κB(NF?κB)信号通路的激活.分离健康奶牛中性粒细胞,采用LPS(100 ng/mL)和不同浓度(0.5、1.0、2.0和4.0 mmol/L)BHBA作用于中性粒细胞,收集细胞,应...  相似文献   

18.
选择经同期发情且同期受孕,在妊娠90d时健康的苏尼特母羊49只,以4种营养水平(MEMJ/kgW0.75·d):0.2(G1);0.33(G2);0.44(G3);0.86(CG),分组限制饲养,研究妊娠后期不同营养水平限制饲养母羊对其体贮动员及利用的影响。结果表明:整个限制期,CG、G3、G2、G1组母羊随着摄入外源能量的降低,分别动员了试验开始时平均母体净重的2.4%、11.3%、17.9%、27.9%,差异极显著(P<0.01)。在此期间,G1、G2、G3组的胰岛素浓度有降低的趋势。6￣34d,各组血清中游离脂肪酸浓度都不同程度的有所降低,其中G1组与G3、CG组差异显著(P<0.05),仅为262.22μmol/L。到了54d时,尽管各组血清中游离脂肪酸浓度有所回升,但仍低于限制开始时浓度。其中G1组为793.98μmol/L,而G2、G3、CG组分别为1072.29、1048.19、1011.25μmol/L。从54d到分娩后,G1组血清中游离脂肪酸浓度基本维持在同一水平,而G2、G3、CG组血清中游离脂肪酸浓度有不同程度的降低。  相似文献   

19.
近年来高产奶牛围产期维生素E(VE)缺乏较为普遍,但这一问题在牛场最易被忽视。为此,本试验在某一大型集约化牛场,选取VE缺乏组奶牛40头,健康组奶牛40头,对试验奶牛的抗氧化、肝功、能量代谢、矿物元素和其他维生素指标进行显著性分析、Pearson相关性分析和回归分析及ROC分析。结果显示:与健康组相比,VE缺乏组血浆中总抗氧化能力(T-AOC)、高密度脂蛋白(HDL)、白蛋白(ALB)水平极显著降低,与VE水平呈正相关;而血浆中丙二醛(MDA)、过氧化氢酶(CAT)、谷草转氨酶(AST)、低密度脂蛋白(LDL)、游离脂肪酸(NEFA)、肌酐(CREA)水平极显著升高,与VE呈负相关;血浆中谷丙转氨酶(ALT)、β-羟丁酸(BHBA)水平显著升高,与VE呈负相关。并且,确立了血浆中HDL、T-AOC、ALB、LDL、AST、NEFA和MDA可作为VE缺乏症的预警指标,其预警值分别为HDL<1.495 mmol/L,T-AOC<0.305 mmol/L,LDL>4.09 mmol/L,ALB<51.7 g/L,MDA>11.19 mmol/L,AST>37.2 U/L和NEFA>713μmol/L。结论:VE缺乏与氧化应激、肝功、能量代谢有密切关系,7项生化指标可用于奶牛围产期VE缺乏症的预警,为今后更有效地监控和预防奠定理论基础。  相似文献   

20.
Ketosis was diagnosed in a flock of Merino ewes that conceived from synchronised oestrus in the early autumn period. On day 140 of pregnancy the ewes were sampled for determination of betaOH-butyrate (BHB), AST, glucose, non-esterified fatty acids (NEFA), total cholesterol (TCH), insulin, T4, T3, cortisol, IGF-1 and leptin. The results were evaluated according to the number of fetuses born some days later and the presence of hyperketonaemia (BHB: > or = 1.60 mmol/l). In May, about 3 months after lambing, cyclic ovarian function was induced (Cronolone + eCG), and the ewes were inseminated artificially (AI) 48 h after the removal of gestagen-containing sponge. At the time of AI and 10 days later blood samples were collected again to check the plasma levels of the same constituents as previously (in samples taken at AI), and to monitor the ovarian response by assaying progesterone (in both samples). On day 140 of gestation significantly lower BHB levels were detected in dams with single (n = 41) than in those with twin (n = 57) pregnancies. Hyperketonaemia was found only in ewes bearing twins (n = 27). These animals had higher NEFA and cortisol, and lower TCH, insulin, IGF-1, leptin and T3 levels than their normoketonaemic twin-bearing flock-mates, and those with single pregnancy. The blood glucose concentrations varied within a wide range, and the means of groups did not exhibit any significant differences. The formerly hyperketonaemic individuals were characterised by lower leptin level 3 months after lambing, and they showed a poorer response to the cycle-induction procedure than the others. The non-responders had lower IGF-1 and leptin levels than those ovulated after this treatment. It was concluded that the subclinical form of ovine ketosis is characterised by complex endocrine alterations, reflecting an obvious form of negative energy balance. If attempts to induce cyclic ovarian function outside the breeding season are made soon after lambing, the ovarian response and fertility of these ewes may also be depressed.  相似文献   

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