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1.
Understanding how β adrenergic agonists influence the physiology of heat stress could lead to mitigation options. We sought to investigate body surface temperatures in feedlot wethers supplemented with ractopamine or zilpaterol and exposed to heat stress for 18 d. Corneal and skin temperatures were assessed via infrared thermography at 1- and 2-m distances. Rectal temperatures and circulating leukocytes, metabolites, and electrolytes were also measured. Heat stress increased (P < 0.05) rectal temperatures in unsupplemented and zilpaterol-supplemented lambs but not in ractopamine-supplemented lambs. Heat stress also increased (P < 0.05) surface temperatures of the cornea, nose, ear, and back, regardless of supplement. Observations were comparable between thermography performed at 1 and 2 m, and higher emissivity settings generally produced less variation. Heat stress tended to increase (P = 0.08) blood monocytes in unsupplemented but not ractopamine- or zilpaterol-supplemented lambs. Granulocytes were increased (P < 0.05) by heat stress in ractopamine-supplemented lambs but decreased (P < 0.05) in zilpaterol-supplemented lambs. Blood glucose, triglycerides, and cholesterol did not differ among groups, and blood lactate was reduced (P < 0.05) by heat stress in zilpaterol-supplemented lambs only. Blood Na+ was reduced (P < 0.05) and Ca2+ increased (P < 0.05) by heat stress, regardless of supplement. These findings indicate that β1- and β2-adrenergic agonists differentially relieve some but not all heat stress-induced changes in stress indicators. Moreover, corneal and skin surface temperatures measured by infrared thermography reasonably identified body temperature changes at a distance of 2 m.  相似文献   

2.
Pathogenic infections increase morbidity and reduce performance in livestock, and thus understanding the comprehensive physiological changes associated with infections can benefit production sustainability. In this study, we sought to investigate such physiological responses to an acute immune challenge in lambs. Polypay wethers received single IV injections of 1.5 µg/kg lipopolysaccharide endotoxin (LPS-injected; n = 6) or saline (controls; n = 6). Corneal temperatures (via infrared thermography), rectal temperatures, blood, plasma, and saliva were assessed every 2 hr for 10 hr after injections. Blood was also assessed at 24 hr. LPS-injected lambs exhibited elevated (P < 0.05) corneal and rectal temperatures that peaked at 4 hr but were still slightly greater (P < 0.05) than controls at 10 hr. Circulating total white blood cells, monocytes, and granulocytes were reduced (P < 0.05) in LPS-injected lambs within the first 4 hr but were subsequently greater (P < 0.05) than in controls. Lymphocytes were reduced (P < 0.05) in LPS-injected lambs over the first 8 hr and did not differ from controls thereafter. Red blood cells, hematocrit, and hemoglobin were increased (P < 0.05) in LPS-injected lambs over the first 6 hr, indicating mild dehydration. Blood glucose briefly increased (P < 0.05) in LPS-injected lambs at 2 hr but was less (P < 0.05) than in controls thereafter. Blood lactate was greater (P < 0.05) in LPS-injected lambs between 6 and 10 hr after injections, which together with reduced (P < 0.05) CO2 partial pressure indicated a metabolic shift toward glycolysis. LPS-injected lambs exhibited a transient increase (P < 0.05) in plasma TNFα at 2 and 4 hr only and sustained increases (P < 0.05) in CXCL9 and CXCL10 beginning at 6 and 4 hr, respectively. They also exhibited a mild, paradoxical increase (P < 0.05) in the anti-inflammatory sFRP3. Salivary TNFα was increased (P < 0.05) in LPS-injected lambs at 2 hr only. Regression analyses indicated that rectal temperatures were a generally poor predictor of the other inflammatory components in this study, with the exception of circulating leukocyte populations. Likewise, correlations among the 10 cytokines measured in this study were generally weak, with notable exceptions between CXCL9 and CXCL10 and between IL-21 and IFNγ. These findings demonstrate that physiological changes to even short-lived immune challenges are dynamic in nature and persist beyond the time frame of febrile responses and other common assessments.  相似文献   

3.
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4.
Consumption of β-hydroxy β-methylbutyrate (HMB) alters muscle composition and metabolism leading to strength and agility improvements in human athletes. To determine if HMB affects athletic performance and muscle function in horses, Thoroughbred geldings were fed a control (CON; n = 5) or HMB (n = 6) supplement for 6 wk prior to completing a standardized exercise test (SET). Gluteus medius (GM) muscle biopsies were obtained before the SET for fiber typing. Heart rate, biceps femoris (BF) and semitendinosus (ST) surface electromyograms (EMG), and fore and hind limbs metacarpophalangeal joint angles were captured at the gallop of the SET. Results demonstrate that HMB supplementation increased (P < 0.05) the percentage of type IIA and IIA/X muscle fibers in the GM with a corresponding decrease (P < 0.05) in type IIX fibers. The percentage of type I fibers was unaffected by diet. Supplementation with HMB did not result in any measurable effects on performance or biomechanical properties by comparison to CON. Supplementation with HMB resulted in an increase (P < 0.05) in ST median frequency at speeds of 10 m/s and greater. Increasing treadmill speed resulted in an increase (P < 0.05) in stride length and the maximal proximal forelimb fetlock angle, and a decrease (P < 0.05) in stance phase time of the gait cycle. Integrated EMG (iEMG) increased (P < 0.05) with increasing treadmill speeds for both the BF and ST with the BF exhibiting greater (P < 0.05) iEMG values than the ST. In summary, HMB increased the percentage of type IIA GM fibers, which did not translate into improved performance.  相似文献   

5.
Intrauterine growth restriction (IUGR) is often observed in one of the fetuses carried by well-fed prolific ewes. This condition is the result of an insufficient placental size to cover the nutritional needs of the fetus during the near exponential growth phase of the last trimester. After birth, these IUGR offspring have an elevated appetite and lower maintenance energy requirements, suggesting dysregulation of homeostatic systems governing energy metabolism. It is also unknown whether the consequent increase in fatness occurs similarly in both visceral and carcass fractions. To address these questions, lambs differing in birth size (BS, IUGR vs. Normal, 2.6 ± 0.05 vs. 4.2 ± 0.07 kg, P < 0.001) were offered unlimited amounts of a low fat [LF; 22% of dry matter (DM)] or a high fat (HF; 38% of DM) milk replacer and slaughtered on day 14 of postnatal age (n = 7 to 8 for each BS × Diet); a second group of IUGR lambs (n = 3 for each diet) was slaughtered when they reached 8.5 kg, corresponding to the weight of Normal lambs on day 14. When normalized to body weight (BW), the DM and energy intake of IUGR lambs were higher than those of Normal lambs over the first 14 d of life (BS, P < 0.01), but contrary to expectations, the HF diet did not exacerbate these effects of the IUGR condition. Intrauterine growth restricted lambs had increased viscera fat with both diets (BS and Diet, P < 0.05) but increased carcass fat only with the LF diet (BS × Diet, P = 0.08); the fatness promoting effect of the IUGR condition was increased in both body fractions when lamb groups were compared at the fixed BW of 8.5 kg. A subset of metabolic hormones was analyzed, including the metabolic rate-setting hormone thyroxine (T4) and its possible positive regulator leptin. Plasma T4 was lower in IUGR than in Normal lambs at birth (P < 0.05) but then disappeared by day 7 of postnatal life (BS × Day, P < 0.01). On the other hand, the HF diet had no effect on plasma T4 over the first 3 d but caused an increase, irrespective of BS by day 11 (Diet × Day, P < 0.001). Plasma leptin increased with dietary fat and time (P < 0.06) but bore no relation to the effects of BS or Diet on plasma T4. These data show that IUGR and Normal lambs are similarly unable to adjust caloric intake in early life and that the fatness promoting effects of the IUGR condition are more pronounced in the viscera than in the carcass. These data also reveal dynamic regulation of plasma T4 by BS and Diet in neonatal lambs.  相似文献   

6.
The efficacy of exogenous carbohydrases in pig diets has been suggested to depend on enzyme activity and dietary fiber composition, but recent evidence suggests other factors such as ambient temperature might be important as well. Therefore, we investigated the effect of heat stress (HS) on the efficacy of a multienzyme carbohydrase blend in growing pigs. Ninety-six (barrows: gilts; 1:1) growing pigs with initial body weight (BW) of 20.15 ± 0.18 kg were randomly assigned to six treatments, with eight replicates of two pigs per pen in a 3 × 2 factorial arrangement: three levels of carbohydrase (0, 1X, or 2X) at two environmental temperatures (20 °C or cyclical 28 °C nighttime and 35 °C day time). The 1X dose (50 g/tonne) provided 1,250 viscosimetry unit (visco-units) endo-β-1,4-xylanase, 4,600 units α-l-arabinofuranosidase and 860 visco-units endo-1,3(4)-β-glucanase per kilogram of feed. Pigs were fed ad libitum for 28 d and 1 pig per pen was sacrificed on day 28. There was no enzyme × temperature interaction on any response criteria; thus, only main effects are reported. Enzyme treatment quadratically increased (P < 0.05) BW on day 28, average daily gain (ADG) (P < 0.05), and average daily feed intake (ADFI) (P < 0.05) with the 1X level being highest. HS reduced the BW at day 14 (P < 0.01) and day 28 (P < 0.01), ADG (P < 0.01), and ADFI (P<0.001). There was a trend of increased feed efficiency (G:F) (P < 0.1) in the HS pigs. HS increased apparent jejunal digestibility of energy (P < 0.05) and apparent ileal digestibility of calcium (P < 0.01). At day 1, HS reduced serum glucose (P < 0.001) but increased nonesterified fatty acid (P < 0.01). In the jejunum, there was a trend of increased villi height by carbohydrases (P < 0.1), whereas HS reduced villi height (P < 0.05). HS increased the jejunal mRNA abundance of IL1β in the jejunum (P < 0.001). There was a trend for a reduction in ileal MUC2 (P < 0.1) and occludin (P < 0.1) by HS, and a trend for increased PEPT1 (P < 0.1). There was no effect of HS on alpha diversity and beta diversity of the fecal microbiome, but there was an increase in the abundance of pathogenic bacteria in the HS group. In conclusion, HS did not alter the efficacy of carbohydrases. This suggests that carbohydrases and HS modulate pig performance independently.  相似文献   

7.
This study evaluated the potential of mulberry leaf powder as an unconventional feed material for finishing pigs by assessing the growth performance, antioxidative properties, fatty acid profile, and lipid metabolism in 180 Xiangcun black pigs. Pigs with an initial body weight (BW) of 71.64 ± 1.46 kg were randomly assigned to 5 treatment groups, including the control diet and 4 experimental diets. The corn, soybean meal, and wheat bran in the control diet were partly replaced by 3%, 6%, 9%, or 12% mulberry leaf powder in experimental diets. There were 6 replicates (pens) of 6 pigs per replicate in each treatment. Blood and muscle samples were collected after the 50-day feed experiment. Compared with the control group, the 3%, 6%, and 9% mulberry diets had no adverse effect (P > 0.05) on the growth performance of pigs. The serum glutathione peroxidase activity and glutathione concentration increased linearly (P < 0.05) with the increase in dietary mulberry inclusion. There was no significant difference in the relative expression levels of antioxidant-related genes in muscle tissue between the control and mulberry groups. Inclusion of dietary mulberry powder increased (P < 0.05) the content of polyunsaturated fatty acids, especially in the longissimus dorsi (LD) muscle, up-regulated (P < 0.05) the relative mRNA expression level of uncoupling protein-3 in muscle tissue, but down-regulated (P < 0.05) the relative mRNA expression levels of hormone-sensitive lipase, acetyl CoA carboxylase α, lipoprotein lipase, and peroxisome proliferator-activated receptor γ in LD in a linear pattern. The nuclear respiratory factor 2 expression level in the LD muscle of pigs fed the 9% mulberry diet was higher (P < 0.01) than that in the other mulberry groups and control group. The inclusion of less than 12% dietary mulberry did not detrimentally affect the growth performance of Xiangcun black pigs, but enhanced the serum antioxidant property, increased the polyunsaturated fatty acid content, and inhibited lipid oxidation by regulating gene expression levels of lipid metabolism and mitochondrial uncoupling protein in muscle tissue. Mulberry leaves can be utilized as a forage crop in the diet of finishing pigs.  相似文献   

8.
This study aimed to evaluate the effect of dietary yerba mate (Ilex paraguariensis) extract (YME) on muscle metabolomics and physicochemical properties of lamb meat. Thirty-six uncastrated male lambs (90 d old) were fed experimental diets, which treatments consisted of 0%, 1%, 2%, and 4% inclusion of YME. Animals were fed for 50 d before slaughter. Muscle and meat samples were collected for metabolomics and meat quality analysis, respectively. The experiment was carried out in a randomized block design and analyzed using orthogonal contrasts. There was a quadratic effect of YME inclusion in tenderness (P < 0.05) and a positive linear effect on meat lightness (P < 0.05). No qualitative changes (P > 0.05) on individual metabolites were observed; however, changes in the quantitative metabolic profile were observed, showing that animals fed 1% and 2% of YME have a greater concentration of desirable endogenous muscle antioxidants, with direct impact on metabolic pathways related to beta-alanine metabolism and glutathione metabolism. Therefore, YME dietary supplementation up to 2% of the diet to lambs had little to no effects on the majority of meat quality traits evaluated; moreover, 4% of YME inclusion negatively affected feed intake and meat quality traits.  相似文献   

9.
This study evaluated the effects of dietary energy levels on growth performance, carcass traits, meat quality, and serum biochemical of female Hu lambs. Seventy female Hu lambs (aged 4 months) were randomly allotted to 5 dietary treatments. Lambs were fed diets with 5 levels of metabolizable energy (ME): 9.17 (E1), 9.59 (E2), 10.00 (E3), 10.41 (E4), and 10.82 MJ/kg (E5). The lambs were adapted to the experimental diets for 10 d and the experiment period lasted for 60 d. Dry matter intake and feed conversion ratio linearly (P < 0.001) increased and decreased (P < 0.001), respectively, with increasing dietary ME levels. Average daily gain (ADG) linearly (P < 0.001) increased with increasing dietary ME levels, with the highest final body weight (P = 0.041) observed in E4 group. Moreover, dietary energy level was associated with linear increases in serum total protein (TP) (P < 0.001), albumin (ALB) (P = 0.017), glucose (GLU) (P = 0.004), and low-density lipoprotein cholesterol (LDLC) (P = 0.006) concentrations, and it was associated with a quadratic decrease in serum triglyceride (TG) concentration (P = 0.002). Serum ammonia concentration, which was firstly decreased and then increased, was quadratically affected by dietary ME levels (P = 0.013). Compared with E1 group, lambs in E4 group had higher (P < 0.05) live weights, carcass weights, mesenteric fat ratio, non-carcass fat ratio, and larger loin muscle area, but lower (P < 0.05) meat colour a∗ and b∗ values, and lesser (P < 0.05) C17:0, C20:0, C18:1n-9t, C18:3n-3, and n-3 polyunsaturated fatty acids (PUFA), but greater (P < 0.05) C18:3n-6 and n-6:n-3 ratios in longissimus dorsi (LD) muscle tissue, and lesser (P < 0.05) C17:0, C18:3n-3, C22:6n-3, and n-3 PUFA in the biceps femoris (BF) muscle tissue. The results demonstrated that increasing dietary energy level improved the growth performance and affected carcass traits, serum biochemical indexes, and fatty acid profiles in different muscles of female Hu lambs. For 4-month-old female Hu lambs, the recommended fattening energy level is 10.41 MJ/kg.  相似文献   

10.
We conducted 3 independent experiments to demonstrate functional G-coupled protein receptor 43 (GPR43) and GPR120 in bovine intramuscular (i.m.) and subcutaneous (s.c.) adipose tissues. We hypothesized that media volatile fatty acids and long-chain fatty acids would affect cAMP-activated protein kinase-alpha (AMPKα) protein expression and cAMP concentrations differently in i.m. and s.c. adipose tissue. Experiment 1: oleic acid (18:1n-9) decreased phosphorylated AMPKα protein (p-AMPKα) and the p-AMPKα/AMPKα protein ratio in i.m. preadipocytes, increased the p-AMPKα/AMPKα protein ratio in bovine satellite cells, and had no effect in s.c. preadipocytes. Experment 2: ex vivo explants from the 5th to 8th longissimus thoracic rib muscle section of Angus crossbred steers were cultured 48 hr in media containing 0.25 µM ciglitizone, 5 mM glucose, and 5 mM acetate, in the absence or the presence of 100 µM oleic acid. Oleic acid increased acetate incorporation into fatty acids and GPR43 gene expression in i.m. adipose tissue (P < 0.05), but oleic acid had no effect on fatty acid synthesis or GPR43 expression in s.c. adipose tissue. Experiment 3: fresh s.c. and i.m. adipose tissue from the 5th to 8th longissimus thoracic rib muscle section of Angus crossbred steers was transferred immediately to 6-well culture plates containing 3 mL of KHB/Hepes/5 mM glucose. Samples were preincubated with 0.5 mM theophylline plus 10 μM forskolin for 30 min, after which increasing concentrations of acetate or propionate (0, 10−3, 10−2.3, and 10−3 M) in the absence or the presence of 100 μM oleic acid or 100 µM palmitic acid (16:0) were added to the incubation media. Acetate had no effect on forskolin-stimulated cAMP production in s.c. adipose tissue but decreased cAMP in i.m. adipose tissue (P < 0.05); this indicates a functional GPR43 receptor in i.m. adipose tissue. The combination of 10−2 M acetate and oleic acid decrease cAMP production in s.c. adipose tissue, consistent with GPR120 receptor activity, but oleic acid and palmitic acid attenuated the depression of cAMP production caused by acetate in i.m. adipose tissue. Palmitic acid depressed cAMP production in s.c. adipose tissue, and increased cAMP production in i.m. adipose tissue (P < 0.05). Propionate had no effect on cAMP production in s.c. or i.m. adipose tissue. These results provide evidence for functional GPR43 receptors in i.m. adipose tissue and GPR120 receptors in s.c. adipose tissue, both of which would suppress lipolysis.  相似文献   

11.
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12.
The objective of this study was to determine the effect of offering animals a multiforage choice (MF) of fresh herbages on dry matter intake (DMI), live weight gain, and animal welfare, in comparison with a monotonous diet of ryegrass (Lolium perenne L.). Twenty ram lambs (30.5 ± 0.9 kg initial live weight; mean ± SEM), were randomly allocated to either a diet consisting of diverse MF choice or a single forage ryegrass (SF) diet (n = 10 per treatment) for 35 d. Both diets were fed ad libitum; however, the MF diet was composed of set dry matter ratios of 24% chicory (Cichorium intybus L.), 30% lucerne (Medicago sativa L.), 25% plantain (Plantago lanceolata L.), and 21% ryegrass. The DMI of the MF lambs was 48% greater (P < 0.01) and the within animal day-to-day coefficient of variation (CV) of intake was 26% lower (P < 0.01) than the SF lambs. The average daily gain (ADG) of lambs offered the MF diet was 92% greater (P < 0.01) than the lambs offered the SF diet. The within-animal day-to-day CV of intake was negatively related to ADG (r = −0.59; P < 0.01). The MF lamb’s urinary N concentration was 30% lower (P < 0.01) than that of the SF lambs. The SF lambs spent more time (P < 0.05) exhibiting stereotypic behaviors in the afternoon and spent more time observing other animals than the MF. Overall, allocating an MF choice of fresh herbages as opposed to a single forage diet of ryegrass increases DMI and thereby animal performance, while potentially reducing urinary N excretion.  相似文献   

13.
Regression of the corpus luteum (CL) is characterized by a decay in progesterone (P4) production (functional luteolysis) and disappearance of luteal tissues (structural luteolysis). In mares, structural luteolysis is thought to be caused by apoptosis of luteal cells, but functional luteolysis is poorly understood. 20α-hydroxysteroid dehydrogenase (20α-HSD) catabolizes P4 into its biologically inactive form, 20α-hydroxyprogesterone (20α-OHP). In mares, aldo-keto reductase (AKR) 1C23, which is a member of the AKR superfamily, has 20α-HSD activity. To clarify whether AKR1C23 is associated with functional luteolysis in mares, we investigated the expression of AKR1C23 in the CL in different luteal phases. The luteal P4 concentration and levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) mRNA were higher in the mid luteal phase than in the late and regressed luteal phases (P<0.05), but the level of 3β-HSD protein was higher in the late luteal phase than in the regressed luteal phase (P<0.05). The luteal 20α-OHP concentration and the level of AKR1C23 mRNA were higher in the late luteal phase than in the early and mid luteal phases (P<0.05), and the level of AKR1C23 protein was also highest in the late luteal phase. Taken together, these findings suggest that metabolism of P4 by AKR1C23 is one of the processes contributing to functional luteolysis in mares.  相似文献   

14.
Constipation in gestating and lactating sows is common and the inclusion of dietary fiber may help to alleviate this problem. We investigated the effects of inulin (INU) and isomalto-oligosaccharide (IMO), two sources of soluble dietary fiber, on gastrointestinal motility-related hormones, short-chain fatty acids (SCFA), fecal microflora, and reproductive performance in pregnant sows. On day 64 of gestation, 30 sows were randomly divided into three groups and fed as follows: a basal diet, a basal diet with 0.5% INU, and a basal diet with 0.5% IMO. We found that INU and IMO significantly modulated the levels of gastrointestinal motility-related hormones, as evidenced by an increase in substance P (P < 0.05), and a decrease in the vasoactive intestinal peptide concentrations (P < 0.05), indicating the capacity of INU and IMO to alleviate constipation. Furthermore, IMO enhanced the concentrations of acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids in the feces (P < 0.05). High-throughput sequencing showed that IMO and INU increased the fecal microflora α- and β-diversity (P < 0.05). Methanobrevibacter was more abundant (P < 0.05), whereas the richness of Turicibacter was lower in the INU and IMO groups than in the control group (P < 0.05). In addition, IMO significantly increased litter size (P < 0.05). Overall, our findings indicate that INU and IMO can relieve constipation, optimize intestinal flora, and promote reproductive performance in pregnant sows.  相似文献   

15.
An experiment was conducted to test the hypothesis that reducing crude protein (CP) in starter diets for pigs reduces post-weaning diarrhea and improves intestinal health. In total, 180 weanling pigs were allotted to 3 diets containing 22, 19, or 16% CP. Fecal scores were visually assessed every other day. Blood samples were collected from 1 pig per pen on days 1, 6, 13, 20, and 27, and 1 pig per pen was euthanized on day 12. Results indicated that reducing dietary CP reduced (P < 0.01) overall average daily gain, gain to feed ratio, final body weight, and fecal scores of pigs. Pigs fed the 16% CP diet had reduced (P < 0.01) serum albumin compared with pigs fed other diets. Blood urea nitrogen, haptoglobin, interleukin-1β, and interleukin-6 concentrations in serum were greatest (P < 0.01) on day 13, whereas tumor necrosis factor-α and interleukin-10 concentrations were greatest (P < 0.01) on day 6. Villus height in the jejunum increased (P < 0.05) and crypt depth in the ileum was reduced (P < 0.01) if the 19% CP diet was fed to pigs compared with the 22% CP diet. A reduction (P < 0.05) in mRNA abundance of interferon-γ, chemokine ligand 10, occludin, trefoil factor-2, trefoil factor-3, and mucin 2 was observed when pigs were fed diets with 16% CP. In conclusion, reducing CP in diets for weanling pigs reduces fecal score and expression of genes associated with inflammation.  相似文献   

16.

Background

Insulin secretion and tissue sensitivity to insulin is considered to be one of the factors controlling lipid metabolism post partum. The objective of this study was to compare glucose-induced blood insulin and metabolite responses in Estonian Holstein (EH, n = 14) and Estonian Red (ER, n = 14) cows.

Methods

The study was carried out using the glucose tolerance test (GTT) performed at 31 ± 1.9 days post partum during negative energy balance. Blood samples were obtained at -15, -5, 5, 10, 20, 30, 40, 50 and 60 min relative to infusion of 0.15 g/kg BW glucose and analysed for glucose, insulin, triglycerides (TG), non-esterified fatty acids (NEFA), cholesterol and β-hydroxybutyrate (BHB). Applying the MIXED Procedure with the SAS System the basal concentration of cholesterol, and basal concentration and concentrations at post-infusion time points for other metabolites, area under the curve (AUC) for glucose and insulin, clearance rate (CR) for glucose, and maximum increase from basal concentration for glucose and insulin were compared between breeds.

Results

There was a breed effect on blood NEFA (P < 0.05) and a time effect on all metabolites concentration (P < 0.01). The following differences were observed in EH compared to ER: lower blood insulin concentration 5 min after glucose infusion (P < 0.05), higher glucose concentration 20 (P < 0.01) and 30 min (P < 0.05) after infusion, and higher NEFA concentration before (P < 0.01) and 5 min after infusion (P < 0.05). Blood TG concentration in ER remained stable, while in EH there was a decrease from the basal level to the 40th min nadir (P < 0.01), followed by an increase to the 60th min postinfusion (P < 0.01).

Conclusion

Our results imply that glucose-induced changes in insulin concentration and metabolite responses to insulin differ between EH and ER dairy cows.  相似文献   

17.
Beta-glucan has been shown to have a beneficial effect on gastrointestinal health. This experiment was conducted to investigate the effects of β-glucan isolated from Agrobacterium sp. ZX09 on growth performance and intestinal health of weaning pigs. A total of 108 weaned pigs (21 d of age; 6.05 ± 0.36 kg) were randomly divided into 3 groups (6 pens/group; 6 pigs/pen), and the groups were each treated with the following diets: 1) basal diet, 2) basal diet supplemented with 20 mg/kg olaquindox, 3) basal diet supplemented with 200 mg/kg β-glucan, for 21 d. Compared with the control group, pigs fed with 200 mg/kg β-glucan had greaterBW, average daily gain and duodenal villus height to crypt depth ratio (P < 0.05). Olaquindox increased the duodenal or jejunal villus height of pigs compared with β-glucan. Compared with the control group, β-glucan tended to increase the occludin mRNA expression in the jejunum (0.05 < P < 0.10). Beta-glucan enriched the beneficial microbiota in the ileum of pigs (P < 0.05). In conclusion, β-glucan may promote growth performance by improving intestinal health and increasing beneficial microbiota of weaned pigs. The study results will provide valuable theoretical guidance for the utilization of β-glucan in weaned pigs.  相似文献   

18.
This study aimed to evaluate innate immune responses of mammary glands induced by intramammary infusion of Bifidobacterium breve in dairy cows. Somatic cell counts in quarters of cows showed a marked increase following B. breve infusion on days 1 and 2. Opsonized-stimulated chemiluminescence response in quarter milk was significantly (P<0.05) increased by B. breve infusion on days 1 to 3 compared to that of pre-infusion. Lactoferrin concentrations in B. breve-infused quarter milk increased significantly (P<0.05) on days 2 to 4 and 6 compared to those of pre-infusion. IgG and IgA concentrations in B. breve-infused quarters significantly (P<0.05) increased on days 2 to 4 for IgG and days 3, 4, 6 and 8 for IgA compared to those of pre-infusion. Interleukin (IL)-1β and IL-8 mRNA levels in somatic cells from B. breve-infused quarters were significantly (P<0.05) upregulated on day 1 compared to those on days 0 and 14. Conversely, IL-6 mRNA levels in somatic cells from B. breve-infused quarters on days 0, 1 and 14 and NF-κB mRNA levels on day 0 were significantly (P<0.05) down-regulated compared to those of control. IL-1β, tumor necrosis factor (TNF)-α and IL-6 concentrations increased on days 1, 3 and 7 after B. breve infusion in quarters. Intramammary infusion of B. breve (3 × 109 cfu) induces a massive influx of leukocytes and enhances innate immune response in mammary glands. This event may contribute to the enhancing host defense in the mammary gland.  相似文献   

19.
Myocardial ischemia-reperfusion injury (IRI) is one of the most leading concerns for public health globally. Diazepam, a local anesthetic, has been reported for its cardioprotective potential. The present investigation aimed to evaluate the possible mechanism of action of diazepam against left anterior descending ligation-induced myocardial IRI in experimental rats. IRI was induced in healthy male rats by ligating coronary artery for 30 min and then reperfused for 60 min. The animals were pre-treated with either vehicle or diltiazem (10 mg/kg) or diazepam (1, 2.5, and 5 mg/kg) for 14 days. Compared to the IRI group, diazepam (2.5 and 5 mg/kg) markedly (P<0.05) attenuated IRI-induced alterations in cardiac function and oxido-nitrosative stress. In addition, diazepam prominently (P<0.05) improved cardiac Na+K+ATPase, Ca2+ATPase levels and hypoxia-inducible factor-1 alpha (HIF-1α) mRNA expression. It also significantly (P<0.05) down-regulated cardiac mRNA expressions of cardiac troponin I (cTn-I), C-C chemokine receptor type 2 (CCR2), tumor necrosis factor-alpha (TNF-α), interleukins (IL)-1β, and IL-6. In western blot analysis, IRI-induced myocardial apoptosis was reduced by diazepam treatment reflected by a marked (P<0.05) decreased in Bcl-2-associated X protein (Bax) and Caspase-3 protein expression. Diazepam also efficiently (P<0.05) improved IRI-induced histological aberration in cardiac tissue. In conclusion, diazepam exerts cardioprotective effect by inhibiting inflammatory release (CCR2, TNF-α, and ILs), oxido-nitrosative stress, and apoptosis (Bax and Caspase-3) pathway during myocardial IRI in experimental rats.  相似文献   

20.
The aim of this study was to investigate the involvement of prolactin (PRL) on development of secondary skin follicles in cashmere goats. Goats were randomly assigned to either a bromocriptine treatment or control group. Samples of cashmere fiber, blood, and skin were collected from all goats after 1 mo. The results indicated that the length, growth rate, and diameter of fibers were not influenced (P > 0.05) by the inhibition of PRL resulting from the treatment with bromocriptine. There was a tendency for increases in total follicle number, primary and secondary follicle numbers, and in the ratio of secondary to primary follicles following treatment with bromocriptine, but these differences were not significant (P > 0.05). The percentage of active secondary follicles in anagen was increased (P < 0.05) in the bromocriptine-treated goats, but there was no effect of treatment on the percentage of active primary follicles. Bromocriptine decreased (P < 0.05) circulating concentrations of PRL and Insulin-like growth factor 1 (IGF1) and increased (P < 0.05) those of melatonin (MT), but there was no effect of this treatment on the serum concentrations of cortisol, growth hormone, tetraiodothyronine, and triiodothyronine. In bromocriptine-treated goats, mRNA expressions of PRL and MT membrane receptor 1a (MTNR1a) were decreased (P < 0.05) and mRNA expression of MT nuclear receptor (RORα) was increased (P < 0.05), but there was no effect of the treatment on expression of long PRL receptor, short PRL receptor, MT membrane receptor 1b and IGF1. It is concluded that inhibition of PRL promotes secondary hair follicle development in the anagen phase, possibly by downregulating MTNR1a and up-regulating RORα gene expression in the skin.  相似文献   

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