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1.
In young ruminants’ life, weaning often coincides with a period of growth stasis and poor welfare. The present study aimed at evaluating the effect of coping with the new diet on behavioural and haematological stress indicators in goat kids subjected to a commonly adopted weaning practice. Immediately after birth, male Saanen goat kids were divided into two groups: MILK and WMIX. All were fed colostrum for the first 3 days and then goat milk to the age of 29 days. After that, MILK kids continued to receive milk, while the WMIX kids underwent weaning and were completely weaned by day 48. Animal behaviour was recorded daily. From day 23–50, blood samples were taken weekly and analysed for indicators of stress and immune function. No abnormal behaviour, such as injurious behaviours or stereotypies, was observed in either of the experimental groups throughout the experimental period. During the last week, fasting plasma cortisol level was significantly lower, whereas plasma activity of both alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was significantly higher in WMIX kids, in relation to the MILK ones. Anyway, data were within the normal physiological range and no difference was observed neither in plasma haptoglobin, ceruloplasmin, albumin and antithrombin III, nor in plasma immunoglobulin A and G, at any time, signalling no stressful condition. Therefore, differences observed in cortisol, ALT and AST could be the consequence of the metabolic changes that occur during the transition from pre‐ruminant to ruminant state. The gradual weaning at 48 days of age did not result in any stressful condition and had no negative effect on weight gain. Results suggest that parameters commonly adopted to provide information on animal stress, such as cortisol and aminotransferase activity, can vary in relation to the physiological status of the animals and may bias stress assessment.  相似文献   

2.
This study was designed to determine whether any relationship exists between exposure to artificial long days, milk yield, maternal plasma insulin‐like growth factor 1 (IGF‐1) levels, and kid growth rate in goats. One group of lactating goats was maintained under naturally decreasing day length (control group; n = 19), while in another one, they were kept under artificial long days (LD group; n = 19). Milk yield was higher in goats from the LD group than that in the control group (P < 0.05). Maternal IGF‐1 levels at day 57 of lactation were higher (P < 0.05) in goats from the LD group than the levels in the control group and were positively correlated with the total milk yields per goat at days 43 and 57 of lactation (r = 0.77 and r = 0.84, respectively; P < 0.01). Daily weight gain at week 4 was higher (P < 0.01) in kids from the LD group than that in kids from the control group and was correlated with total and average IGF‐1 maternal levels (r = 0.60 and r = 0.60, P < 0.05). It was concluded that submitting lactating goats to artificial long days increases milk yield, plasma IGF‐1 maternal levels and the growth rate of the kids.  相似文献   

3.
The aim of the study reported here was to compare the performances of kids reared according to three different weaning programs. In the first program (T1), the dams were not milked in the evening and the kids accompanied their dams from 17.00 hours until the next morning. In the second program (T2), the dams of the kids were milked at 17.00 hours and then the kids accompanied their dams until the next morning, being separated from their dams at 08.00 hours. In the third program (T3), the kids were subjected to the T1 program for the first 4 weeks of the study, and to the T2 program for the last 4 weeks of the study. The kids in all the groups were weaned at 8 weeks of age. The weaning programs had significant effects on average daily weight gains (ADG) of the kids during weeks 1–4 and weeks 1–8 of the study (P < 0.05). In the weeks 1–8 period, the kids on the T1 program had a higher ADG than those on the T2 program (P < 0.05). However, the kids on T1, T2 and T3 programs had similar ADG post‐weaning. The dry matter intake of the starter feed of the kids of the T3 program was higher than that of the kids of the T1 and T2 programs. The results of the present study indicated that the three weaning programs did not result in any significant effect on the growth of Saanen kids. Hence, the T3 program can be used if the starter feed intake is desirable.  相似文献   

4.
Ghrelin action, which stimulates growth hormone (GH) secretion, may alter during the weaning period in calves. Our objective was to compare the effects of intravenous ghrelin injection on plasma GH, insulin and glucose concentrations in calves around the weaning period. Four Holstein bull calves were fed whole milk and allowed free access to solid feeds, and weaned at 7 weeks of age. Measurements were performed at weeks 1, 2, 4, 6, 7, 9, 11 and 13, when calves were intravenously injected with ghrelin (1.0 μg/kg body weight (BW)) through a catheter, and jugular blood samples were obtained temporally relative to the injection time. Estimated digestible energy intake per metabolic BW transiently decreased at week 7 because of low solid intake immediately after weaning, and thereafter gradually increased. Plasma insulin and glucose concentrations were not affected by ghrelin injection at all ages. In contrast, plasma GH concentrations increased with ghrelin injection at all ages. The incremental area of GH at week 7 was greatest and significantly higher compared with weeks 2, 4, 6 and 9. This result suggests that nutrient insufficiency immediately after weaning enhances GH responsiveness to ghrelin.  相似文献   

5.
The aim of this study was to determine onset of puberty in Cameroon Dwarf goats (CDGs) kept as pets in northwestern Croatia by determining progesterone (PGS) and insulin‐like growth factor‐I (IGF‐I) levels in the blood by RIA methods. The first cyclic ovarian activity was estimated according to hormone profiles as determined in CDG in a moderate climate environment. Sixteen female CDG kids were kept in stables with access to pasture which provided space for exercise. The goat kids born in winter (December–January–February), spring (March–April–May), summer (June–July–August) and autumn (September–October–November) were assigned into four groups according to the season of the year of birth (n = 4 in each group). At 75 days of age at the initiation of the study, they weighed between 3.2 and 5.1 kg (4.24 ± 0.53 kg). The onset of ovulatory activity was determined by PGS and IGF‐I serum concentrations every 10 days starting from 75 days to 155 days of age. The onset of puberty in CDG kids occurred on average at 141.15 ± 2.66 days of age, but varied depending on the season of birth. All CDG kids born during summer were in heat by 155 days of age. In the other groups (kids born in autumn, winter or spring), one goat in each group was not in heat. Changes in blood serum PGS and IGF‐I concentrations during prepubertal and pubertal periods could aid in the evaluation of reproductive status and determination of the onset of puberty in CDG during all seasons of the year in a moderate climate region.  相似文献   

6.
Four goats (30.1 ± 1.3 kg) with common bile duct re‐entrant catheter and duodenal catheter were used to evaluate the effects of duodenal leucine infusion on pancreatic exocrine secretion and plasma parameters with two 4 × 4 Latin square design experiments. In the long‐term infusion experiment, goats were fed twice daily [700 g/day, dry matter (DM) basis] at 8:00 and 18:00 hours and were duodenally infused with 0, 3, 6, 9 g/day leucine for 14 days. Pancreatic juice and jugular blood samples were collected over 1‐h intervals for 6 h daily from d 11 to 14 days to encompass a 24‐h day. In the short‐term experiment, goats were infused leucine for 10 h continuously at the same infusion rate with Experiment 1 after feed deprivation for 24 h repeated every 10 days. Pancreatic juice and blood samples were collected at 0, 1, 2, 4, 6, 8 and 10 h of infusion. The results showed that the long‐term leucine infusion did not affect pancreatic juice secretion, protein output, trypsin and lipase secretion and plasma insulin concentration, but linearly increased α‐amylase secretion. No changes in pancreatic protein and lipase secretion were observed in the short‐term infusion. Pancreatic juice and α‐amylase secretion responded quadratically, with the greatest values observed in the 3 and 6 g/day leucine respectively. Trypsin secretion linearly decreased, while plasma insulin concentration increased linearly with increased leucine infusion. The results demonstrated that duodenal leucine infusion dose and time dependently regulated pancreatic enzyme secretion not associated with the change in plasma insulin concentration.  相似文献   

7.
Our objective was to determine the effects of calcium salts of long-chain fatty acids (CLFAs) and rumen-protected methionine (RPM) on plasma concentrations of ghrelin, glucagon-like peptide-1 (7 to 36) amide, and pancreatic hormones in lactating cows. Four Holstein cows in midlactation were used in a 4 by 4 Latin square experiment in each 2-wk period. Cows were fed corn silage-based diets with supplements of CLFAs (1.5% added on dry matter basis), RPM (20 g/d), CLFAs plus RPM, and without supplement. Jugular blood samples were taken from 1 h before to 2 h after morning feeding at 10-min intervals on day 12 of each period. CLFAs decreased dry matter intake, but RPM did not affect dry matter intake. Both supplements of CLFAs and RPM did not affect metabolizable energy intake and milk yield and composition. Plasma concentrations of NEFAs, triglyceride (TG), and total cholesterol (T-Cho) were increased with CLFAs alone, but increases of plasma concentrations of TG and T-Cho were moderated by CLFAs plus RPM. Calcium salts of long-chain fatty acids increased plasma ghrelin concentration, and the ghrelin concentration with CLFAs plus RPM was the highest among the treatments. Plasma concentrations of glucagon-like peptide-1, glucagon, and insulin were decreased with CLFAs, whereas adding RPM moderated the decrease of plasma glucagon concentration by CLFAs. These results indicate that the addition of methionine to cows given CLFAs increases plasma concentrations of ghrelin and glucagon associated with the decrease in plasma concentrations of TG and T-Cho.  相似文献   

8.
Although studies in rodents and humans have evidenced a weaker effect of fat in comparison to carbohydrates on the suppression of food intake, very few studies have been carried out in this field in dogs. This study investigates the effects of a high‐carbohydrate (HC ) and a high‐fat (HF ) diets on subsequent food intake and blood satiety‐related hormones in dogs. Diets differed mainly in their starch (442 vs. 271 g/kg dry matter) and fat (99.3 vs. 214 g/kg dry matter) contents. Twelve Beagle dogs received the experimental diets at maintenance energy requirements in two experimental periods, following a cross‐over arrangement. In week 7 of each period, blood concentrations of active ghrelin, glucagon‐like peptide (GLP ‐1), peptide YY , insulin, and glucose were determined before and at 30, 60, 120, 180, and 360 min post‐feeding. The following week, intake of a challenge food offered 180 min after the HC and HF diets was recorded over two days. In comparison to the dogs on the HC diet, those on the HF diet had a higher basal concentration of GLP ‐1 (p  = .010) and a higher total area under the curve over 180 min post‐prandial (tAUC 0–180) (p  = .031). Dogs on the HC diet showed a higher elevation of ghrelin at 180 min (p  = .033) and of insulin at 360 min (p  = .041), although ghrelin and insulin tAUC 0–180 did not differ between the two diets (p  ? .10). Diet had no effect on challenge food intake (p  ? .10), which correlated with the tAUC 0–180 of ghrelin (r = .514, p  = .010), insulin (r = ?.595, p  = .002), and glucose (r = ?.516, p  = .010). Feeding a diet high in carbohydrate or fat at these inclusion levels does not affect the feeding response at 180 min post‐prandial, suggesting a similar short‐term satiating capacity.  相似文献   

9.
Two separate experiments were carried out to establish the effects of the protein:energy ratio in milk replacers on growth performance, plasma lipid concentrations and fatty acid composition in adipose tissue of male goat kids. In the first experiment there were 211 3-day- old goat kids and in the second experiment there were 121 kids aged 3-7 days. The animals were fed ad libitum for a period of 4 weeks on milk replacers containing either 11.5 or 9.5 g crude protein/MJ metabolizable energy. In essence, protein was exchanged with fat on a weight basis. Milk concentrations were increased from 160 to 190 g/l in experiment 1, from 150 to 180 g/l in experiment 2. There were significant increases in body weight and feed intake when the milk replacer with high protein : energy ratio was fed. Group mean average daily weight gain was 168 and 203 g for the groups with low and high dietary protein:energy ratio in experiment 1; for experiment 2 the values were 139 and 160 g. Average dry matter intake was 18 and 14% higher for the diet with high protein:energy ratio in experiments 1 and 2, respectively. There was no change in either feed conversion (feed:gain ratio) or energy conversion (weight gain:energy intake ratio). There were no consistent diet effects on plasma lipid concentrations. Dietary fatty acid composition was reflected by that of adipose tissue. The milk replacer with high protein:energy ratio produced a small increase in the contents of myristic and palmitic acid in adipose tissue.  相似文献   

10.
The aim of the study was to evaluate the influence of soybean trypsin inhibitor (TI) on immunoglobulin G (IgG) serum levels and growth in neonatal goat kids. Twenty‐four newborn kids were fed with natural colostrum (group A), and 24 kids received the same colostrum with 1 g of TI per litre (group B). Blood samples were obtained at birth and on days 1, 2 and 4 of life to analyze serum proteins, IgG and haematological parameters. There were no clinical signs of disease and no significant differences in body weight between the groups. Haematological parameters were not affected by treatment. The peak of serum IgG was reached at 24 h of life, but no effects of soybean TI was observed on serum IgG levels. The apparent efficiency of absorption of IgG was similar in both groups (group A 24.5% vs. group B 25.2%, p > 0.05). The addition of TI to colostrum did not change the concentration of serum proteins and their fractions in goat kids. The correlation between serum IgG and γ‐globulin was positive and significant (p < 0.01, r = 0.64) in group A, but not in group B (p > 0.05, r = 0.08), suggesting a negative influence of soybean TI on γ‐globulin absorption. These results show that addition of soybean TI to colostrum did not improve the performance or immunological status in goat kids.  相似文献   

11.
The objective of this study was to investigate the effects of substituting 1 kg of a standard lactation diet with 1 kg of a sugar‐rich (15.75 DE MJ/kg) or fat‐rich (23.85 DE MJ/kg) diet during late lactation on blood glucose and insulin changes in primiparous sows. During a 4‐week lactation period, 21 primiparous sows were fed to appetite with a standard lactation diet (14.10 DE MJ/kg). At 9 days before weaning, sows were assigned to a control (C, n = 7), fat (F, n = 6) or sugar (S, n = 8) treatment. During the treatment period (from 8 days before weaning until weaning), 1 kg of the lactation diet was substituted with 1 kg of a sugar‐rich or fat‐rich diet for S and F sows. At 3 days before weaning, serial blood samples were collected for a total of 228 min around feeding to establish pre‐ and postprandial plasma glucose and insulin concentrations. Preprandial plasma glucose and insulin concentrations did not differ between treatments (p > 0.05); however, mean plasma glucose and insulin concentrations were higher for S compared to F (p < 0.05) and intermediate for the C sows. Postprandial plasma concentrations of glucose and insulin were higher for the S sows than for C and F sows (p < 0.05). Sow body weight loss during late lactation did not differ between treatments (p > 0.05). The results from our study suggest that a sugar‐enriched diet during the last week of lactation elevates circulating glucose and insulin concentrations and may potentially improve post‐weaning fertility in primiparous sows.  相似文献   

12.
The effects of corn replacement by cassava dreg in diets of crossbred goat kids were evaluated. We tested the impacts of 0, 33, 66 and 100% replacement on intake, digestibility, feeding behaviour, performance and carcass characteristics. Thirty-six goat kids, aged between 4 and 5 months and with initial body weights of 17.61 ± 1.98 kg, were used in a completely randomised design. Analysis of regression revealed a negative linear effect on neutral detergent fibre (NDF) intake and a positive linear effect on non-fibrous carbohydrates (NFC) and hydrocyanic acids (HCN) intake. Cassava dreg use had a positive linear effect on organic matter digestibility and non-fibrous carbohydrates. Based on our results, cassava dreg use did not negatively impact animal performance, feeding behaviour and carcass characteristics, suggesting that it may replace corn up to 100% in the diets of confined goat kids.  相似文献   

13.
《Livestock Science》2006,99(1):29-38
There are contradicting data in the literature regarding condensed tannins content in carobs. In this study, urea (0.5 g/ml) under reflux conditions increased dramatically the yield of condensed tannins to 17% of dry matter, as compared to 3.5% in acidic methanol extraction. This shows that carob pods are rich source of nonextractable condensed tannins. The effect of PEG in diet rich in carob pods on voluntary feed intake, digestibility and growth in weaning kids was studied during 15 days of balance trials in 24 kids distributed into three dietary treatments. The corn grain and wheat bran components in the control diet (diet 1) were replaced by carob in treatments 2 and 3; treatment 3 was supplemented by 3.3% of PEG of molecular weight-4000. Food intake, diet utilization and growth rate of weaning kids fed a diet containing 52% carob pods were decreased considerably in comparison to kids fed the control commercial diet. Supplementing the kids fed the carob-based diet with PEG increased feed intake, crude protein digestibility and growth to the rate obtained with the control diet. The nutritional experiment highlights the following aspects relevant to all mammals consuming carob pods rich diets: (i) tannins increased the variability in feed intake between days, (ii) hypocholesterolemic effect of carob pods is related to lipid binding capacity of nonextractable condensed tannins in the digestive tract, (iii) supplementing high level of carob pods to animals with normal blood cholesterol level may induce hypocholesterolemia.  相似文献   

14.
During epidemic outbreaks in two goatherds clinical symptoms and deaths occurred in five (14%) of the 3‐week‐old goat kids in farm A, and in six (33%) of those in farm B. In the latter farm, three female goats aborted before the clinical symptoms in the kids emerged. Mycoplasma could be isolated from both healthy and sick goat kids and from female goats, which had diseased kids or had aborted. Three goat kids (one from herd A and two from herd B) were sent for post‐mortem examination. In all these cases septicaemia caused by Mycoplasma was diagnosed. Based on the bacteriological examination the Mycoplasma strains proved to be Mycoplasma mycoides subsp. capri (Mmc). This was confirmed by the PCR examination. Mmc was isolated from several locations includingfrom the rectum of one healthy female goat, and from two diseased kids. In addition, bacteria were detected in the small intestine in two of the necropsied kids by bacteriological and/or immunohistochemical methods. The finding suggests that Mmc may be transmitted via faeces in goatherds, kept under conventional conditions.  相似文献   

15.
P Bas 《Journal of animal science》1992,70(12):3857-3866
The lipogenic capacity of omental adipose tissue and liver was measured in vitro from samples obtained at slaughter from 33 young male goats. The animals were slaughtered either on the day of weaning (d 0) or 2, 14, or 56 d after weaning. Ages at weaning were 4 wk (early weaning) or 6 or 8 wk (late weaning). Blood samples from the jugular vein were taken before slaughter to measure the concentrations of plasma glucose and nonesterified fatty acids. There was a 30% decrease in glucose concentration after weaning. Nonesterified fatty acid concentration increased fourfold between d 0 and 2 after weaning. By d 14 after weaning, nonesterified fatty acids returned to basal concentration. The lipoprotein lipase (LPL) activity of adipose tissue declined markedly (90%) on d 2 after weaning. Lipoprotein lipase activity returned to preweaning values by d 56 after weaning in those goats that had ad libitum access to feed. In adipose tissue, nicotinamide adenine dinucleotide phosphate (NADP)-malate dehydrogenase activity fell by only 17% by d 2 after weaning and to 63% by d 14 after weaning. Lipoprotein lipase activity was closely related to metabolizable energy intake the day before slaughter. Acetyl-coenzyme A carboxylase activity was low in adipose tissue and it increased only slightly by d 56 after weaning. The data indicated that LPL played a preponderant role in the restoration of lipid stores after weaning. High NADP-malate dehydrogenase activity together with a high concentration of plasma glucose by d 56 after weaning suggested that this enzyme activity could be enhanced by high glucose availability in goat kids. Activities of lipase, acetyl-coenzyme A carboxylase, NADP-malate dehydrogenase, and glucose-6-phosphate dehydrogenase in liver were essentially unaffected by weaning. The extent and rapidity of change of lipogenic enzymes of goat kids was much more pronounced in adipose tissue than in liver.  相似文献   

16.
This study has been carried out in the Western Mediterranean Region of Turkey on seven different Honamli goat flocks. The aim of this study was to determine the growth characters, survival rate (till weaning, 105th day), some reproductive characteristics and marketable milk yield. The data were collected from 516 does and 210 kids (125 buckling and 85 doelings). The results indicate that the numbers of multiple birth and litter size were 32.8 % and 1.35 respectively. Survival rates of kids at the 30th, 90th, and 105th days were 98.5, 97.2, and 97.2?%, respectively. The average birth weight for the buckling and doelings was 4.1 and 3.7?kg, respectively. The average weaning weights for buckling and doelings were 26.9 and 23.4?kg, respectively. The effects of dams?? age, on sex and birth type on the growth of Honamli kids were statistically significant (p?<?0.05, p?<?0.01, and p?<?0.001). While the diameters of erythrocytes of Honamli goats are smaller, the density of hemoglobin in the erythrocytes is more than Asian, Indian, and American caprine breeds. The average lactation length and marketable milk yield was assessed to be at 210.3?days and was 89?L, respectively. The growth characteristics of Honamli kids at weaning age were assessed to be higher than most of the other goat breeds in Turkey. The results further indicated that there is a significant variation in the production traits among the different Honamli goat flocks. Production traits of Honamli goats at different breeding conditions should further be investigated to come to a definite conclusion.  相似文献   

17.
Twenty-two Angora kids were used to study the effect of a dietary supplementation with field bean (Vicia faba L. var. minor) on hair follicle activity, mohair characteristics and plasma total thyroxine (T4), triiodothyronine (T3), insulin (INS) and insulin-like growth factor-1 (IGF-1) concentrations. At birth, their mothers were divided in two groups (S: supplemented, C: control), the S group being supplemented with 300 g/head/day of whole field bean. At weaning, diet of kids from S group was supplemented with 80 g/head/day of whole field bean. At weaning, secondary hair follicle activity (S: 0.91 ± 0.01, C: 0.84 ± 0.02, p < 0.01) and staple length (S: 5.82 ± 0.13 cm, C: 5.16 ± 0.14 cm, p < 0.001) were greater in the S group. At 155 days of age, secondary fibre diameter (S: 16.54 ± 0.35 μm, C: 18.09 ± 0.31 μm, p < 0.01) was higher in the C kids. Concentrations of total plasma T4 and T3 were higher (p < 0.001) in S (120 ± 12 and 4.87 ± 0.92 ng/ml respectively) than in C kids (92 ± 8 and 2.97 ± 0.77 ng/ml respectively). At weaning, T4 values were negatively correlated (p < 0.05) with the secondary fibre diameter and the T3/T4 ratio was positively correlated (p < 0.05) with the secondary to primary hair follicle ratio. At 155 days of age, both T3 and T3/T4 values were positively correlated (p < 0.01) with staple length. Plasma INS (0.11 ± 0.03 ng/ml) and total IGF-1 concentrations (232 ± 13 ng/ml) were not affected by diet. Improvements of diet quality in kids positively affected fibre diameter and length and follicle activity rate. We suggest that increased circulating thyroid hormones concentrations, but not those of INS and IGF-1, may contribute to the beneficial actions of nutritional supplementation on anatomical growth and mohair production of kids.  相似文献   

18.
This experiment was conducted to investigate the effects of vanadium (V) supplementation on performance, some plasma metabolites (cholesterol and triglycerides) and glucose metabolism in Mahabadi goat kids. Twenty‐eight male kids (15 ± 2 kg body weight) were fed for 14 weeks in a completely randomized design with four treatments. Treatments were supplemented with 0 (control), 1, 2, and 3 mg V as vanadyl sulfate/animal/daily. On day 70, an intravenous glucose tolerance test (IVGTT) was conducted. Dry matter intake did not change by V supplementation, but adding V quadraticaly improved feed efficiency (p = .03) and tended to increase average daily gain (Quadratic, p = .09). Blood metabolites were unaffected by V supplementation, except for concentration of glucose in plasma, which decreased linearly as supplemental V level increased (p = .02). Plasma glucose concentrations at 15, 30, 45 and 60 min after glucose infusion were decreased in a quadratic fashion in response to increasing supplemental V level (p < .01). The IVGTT indicated that the kids supplemented with 2 mg V had higher glucose clearance rate (K) and lower glucose half‐life (T½; p < .05). Glucose area under the response curve from 0 to 60 min and 0 to 180 min after glucose infusion were decreased linearly (p = .04) by supplemental V. The results suggested that moderate supplementation of V may improve glucose utilization and feed efficiency in fattening kids.  相似文献   

19.
Ghrelin is a gut peptide which participates in growth regulation through its somatotropic, lipogenic and orexigenic effects. Synergism of ghrelin and growth hormone-releasing hormone (GHRH) on growth hormone (GH) secretion has been reported in humans and rats, but not in domestic animals in vivo. In this study, effects of a combination of ghrelin and GHRH on plasma GH and other metabolic parameters, and changes in plasma active and total ghrelin levels were studied in Holstein bull calves before and after weaning. Six calves were intravenously injected with vehicle (0.1% BSA-saline), ghrelin (1 microg/kg BW), GHRH (0.25 microg/kg BW) or a combination of ghrelin plus GHRH at the age of 5 weeks and 10 weeks (weaning at 6 weeks of age). Ghrelin stimulated GH release with similar potency as GHRH and their combined administration synergistically stimulated GH release in preweaning calves. After weaning, GH responses to ghrelin and GHRH became greater compared with the values of preweaning calves, but a synergistic effect of ghrelin and GHRH was not observed. The GH areas under the concentration curves for 2h post-injection were greater in weaned than in preweaning calves (P<0.05) if ghrelin or GHRH were injected alone, but were similar if ghrelin and GHRH were injected together. Basal plasma active and total ghrelin levels did not change around weaning, but transiently increased after ghrelin injection. Basal plasma insulin, glucose and non-esterified fatty acid levels were reduced after weaning, but no changes by treatments were observed. In conclusion, ghrelin and GHRH synergistically stimulated GH release in preweaning calves, but this effect was lost after weaning.  相似文献   

20.
Thirty new born male kids were allotted into three groups to evaluate the effects of diet and age on complement system activity in serum. After the colostrum feeding period, the control group (C) received a commercial milk replacer; the CLA group received 20 g/kg milk replacer DM of conjugated linoleic acid; and the GMK group was fed with goat milk. The kids were fed colostrum for 2 days and then either milk replacer or goat milk from days 3 to 60. Blood samples were taken at 1, 10, 20, 30, 40, 50 and 60 days of age. The complement system activity was higher (P < 0.05) in the GMK group throughout the whole experiment through alternative pathway. C kids did not present complement activity at any time. CLA group complement activity was statistically higher than that of C kids from 30 to 60 days, through alternative pathways. In conclusion, the milk replacer formula should be reformulated because it did not induce any complement system activity in the first two months of life.  相似文献   

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