首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 156 毫秒
1.
In order to understand the effects of the automatic milk replacer feeding system on calf health, we examined the effect of frequent milk feeding on curd formation in the abomasum using ultrasonographic imaging. Eight male Holstein calves were divided into a milk-replacer group and a fresh milk group. Calves were fed twice a day to 12 days after birth (Period A). From 13 days, calves were fed six times a day (Period B). The abomasal fluid was taken by paracentesis. In both periods A and B, the fresh milk group formed bigger curds faster than the milk replacer group. The curd score of the milk replacer group in period B at 2 h was significant lower than those of both groups in period A. The pH in the abomasum was lower in period B than in period A. We could not identify the location of the abomasum in the milk replacer group during period B at almost time points. Our experiment suggests the possibility that frequent feeding of milk replacer causes incomplete hydrolysis of κ-casein as well as curd formation, thus reducing the digestibility compared to the feeding of the milk replacer twice per day or frequent feeding of fresh milk.  相似文献   

2.
The objective was to evaluate effects of feeding level of milk replacer on body growth, plasma metabolite and insulin concentrations, and allometric growth of visceral organs in suckling calves. Holstein bull calves (n = 8; 3–4 days of age) were fed either a low amount (average 0.63 kgDM/day, LM) or high amount (average 1.15 kgDM/day, HM) of high protein milk replacer until they were slaughtered at 6 weeks of age. Body weight (BW) at 4, 5, and 6 weeks of age, feed intake, average daily gain, and feed efficiency were higher in the HM than LM calves. The HM group had higher plasma glucose at 3 and 4 weeks of age and insulin levels after the age of 4 weeks compared with LM calves whereas no effect was detected on plasma nonesterified fatty acid or urea nitrogen concentrations. The HM calves had greater empty body weight (EBW), viscera‐free BW and most of the organs dissected than LM calves. Relative weights (% of EBW) of liver, spleen, kidneys, and internal fat were higher, whereas head and large intestine was lower in HM than LM calves. The results suggest that increased milk feeding levels would accelerate the growth of the body and specific organs.  相似文献   

3.
This study aimed at identifying changes in natural pastures during the grazing season and investigating the effects of these changes on pasture feeding potential for high yielding dairy goats. During the study, 12 dairy goats were grazed on a 1.5 ha natural pasture for three months from April to June in 2003, 2004 and 2005. The goats were fed 0.5 kg/day of concentrate as a supplement during the grazing season. Botanical composition, herbage production and intake, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the pasture were determined. Live weight, milk yield, milk dry matter (DM) and fat content of the goats were monitored. The data were analyzed using a linear model, which evaluated the effects of grazing seasons in each year. Based on the three-year average, 87% of pasture was herbaceous plants and the remaining was shrubs in DM basis with Cistus creticus , Quercus ithaburensis , Pistacia atlantica and Asparagus acutifolius being the major shrub species. The herbage yield in June was significantly lower than in other months in all years ( P  = 0.001). In all experimental years, the CP content of the pasture decreased but the structural carbohydrates increased as the grazing season proceeded. While live weight was not affected by grazing periods except for 2004 ( P  = 0.001), milk yield significantly decreased with advancing grazing period ( P  = 0.001). The results of the present study indicate that natural pasture has a supportive effect in April and May on the milk yield of lactating goats which are in mid-lactation, and suggested that supplementary feeding is required in consecutive grazing periods.  相似文献   

4.
Apelin and its mRNA are expressed in several tissues, including the supraoptic and paraventricular nuclei in the hypothalamus. Although apelin is reported to be involved in the regulation of fluid homeostasis, little is known about the postprandial dynamics of apelin in plasma and its regulatory effects on the anterior pituitary hormones of ruminants. Therefore, the aims of this study were to investigate the following: (1) changes in plasma apelin concentrations in response to food intake under conditions of hydration (free access to water) or dehydration (water restriction), and (2) the effects of intravenous administration of apelin on plasma concentrations of arginine-vasopressin (AVP), ACTH, GH, and insulin. In Experiment 1 with the use of goats, the postprandial plasma apelin concentration was significantly increased under the dehydration condition compared with the hydration condition, and this increase was accompanied by increased plasma concentrations of AVP and ACTH after 24 h of dehydration. In Experiment 2 with the use of sheep and hydration conditions, the intravenous administration of apelin ([Pyr(1)]-apelin-13; 0.5 mg/head) caused a tendency to increase or caused a significant increase in plasma concentrations of AVP, ACTH, GH, insulin, and glucose. On the basis of these findings, we concluded that apelin is involved in the feeding process, and it regulates endocrine functions in the anterior pituitary gland via AVP in ruminant animals.  相似文献   

5.
In order to evaluate the effects of an elevated amount of modified milk replacer on body weight, daily gain, starter intake, plasma endocrine parameters and expression of nutrient transporters in small intestinal epithelia, Holstein bull calves (n = 24) were fed for 60 days either with the usual amount of 24% crude protein (CP) and 20% fat milk (CF) replacer (C group), or with a double amount of a modified milk replacer of 28% CP and 16% CF (E group). Body weight from D20 to D60 and daily gain before D40 was greater or tended to be greater for the E group than the C group. Plasma concentrations of insulin‐like growth factor‐1 (IGF‐I) and insulin were greater for the E group than the C group on D28 but not on D56, without changing plasma growth hormone levels. Gene expression for sodium‐dependent glucose transporter 1 and fatty acid translocase (CD36) was altered in day‐ and intestine‐dependent manners. From these findings, we conclude that an elevated intake of milk replacer given up to 40 days old is sufficient to enhance body weight, which may be associated with increased plasma IGF‐I concentrations, in Holstein bulls.  相似文献   

6.
This study was conducted to determine the effect of feeding high milk volumes on the growth rate, health and cross-sucking behaviour in group-fed Jersey calves. Three-day-old heifers (n = 120) in a seasonal calving dairy herd were randomly assigned to one of 6 treatment groups. Three groups received high milk volumes (HMV), consisting of ad libitum milk or milk replacer feeding twice a day, while 3 groups received restricted milk volumes (RMV), consisting of 2 l twice daily, during the pre-weaning period. After a pre-weaning period during which feeding was reduced to once daily, all calves were weaned at 42 days and monitored until 60 days of age. Adjusting for birth mass, birth date, dam parity and sire, average daily mass gain (ADG), both pre-weaning (days 0-42) and overall (days 0-60), was higher in HMV than in RMV calves (P < 0.001). After weaning, growth rates showed no differences and at 60 days of age the HMV calves maintained a 6.74 kg advantage in mean body mass (P < 0.001). The mean intake of dry starter feed was higher in RMV than in HMV calves. Overall feed conversion rate of HMV calves was 9.6 % better than RMV calves. However, the variable cost per kg mass gain was 12 % higher for HMV calves. In the RMV groups 75 % of calves showed cross-sucking behaviour pre-weaning and 18 % post-weaning, whereas in HMV calves the proportions were 2 % and 7 %, respectively. There was no significant effect of milk volume on the incidence of diarrhoea. We conclude that the feeding of high volumes of milk to Jersey calves has a positive effect on growth rate, without compromising health or reducing solid feed intake after weaning. However, the higher cost of such a feeding system may limit its implementation.  相似文献   

7.
This study aimed at investigating the effects of weaning kids abruptly at an average of 55 ± 13 days of age on intake, behavioral and serum parameters and, lasted for a total of six weeks; two weeks pre-weaning and four weeks post-weaning. Sixteen single kids with equal gender were used. Kids were only allowed to stay with their mothers for suckling (45 min/period) both in the morning and in the evening period during pre-weaning. Grower concentrate and hay were offered ad libitum . The duration of the study was divided into three periods for the sampling of behavioral and serum parameters; (i) pre-weaning period lasting for two weeks (P-BW) (ii) early post-weaning period lasting for one week (P-AW1) and (iii) late post-weaning period lasting for three weeks (P-AW2). Daily weight gain of kids gradually decreased as the observation period progressed ( P  = 0.001). However concentrate feed intake increased from 0.154 kg/day in P-BW to 0.479 kg/day in P-AW1 and 0.499 kg/day in P-AW2. Water intake, rumination and standing behaviors decreased in P-AW2 ( P  < 0.001), whereas activity towards concentrate feed (CF) ( P  < 0.001) and roughage ( P  = 0.012) increased as compared to P-BW and P-AW1. Abnormal oral activity was not affected by the periods ( P  = 0.906). CF was significantly higher in females ( P  = 0.003), whereas males displayed higher lying behavior ( P  = 0.007). Glucose, total protein, urea, cholesterol, HDL-cholesterol, LDL-cholesterol concentrations ( P  = 0.001) and ALP activity ( P  = 0.003) were significantly affected by the periods. The results of the present study suggest that behavioral and serum parameters across the periods describe changes in the nutritional conditions as a result of the transition from milk to solid feed in association with weaning.  相似文献   

8.
In an initial experiment we observed postprandial changes in plasma concentrations of growth hormone (GH), insulin, glucagon, and somatostatin (SRIF) in sheep. We then examined whether increasing the rumen concentration of volatile fatty acids (VFA) by infusing a VFA mixture at three rates (53.5, 107, and 214 micromol/kg/min for 4 hr) mimicked the postprandial changes in hormone secretion. Feeding significantly (P < 0.05) suppressed the plasma GH concentration for 6 hr, whereas it significantly (P < 0.05) increased plasma concentrations of insulin, glucagon, and SRIF. Plasma glucose levels tended to decrease after feeding but then gradually increased over the prefeeding level (P < 0.05). Intraruminal infusion of the VFA mixture at 107 micromol/kg/min caused similar changes in ruminal VFA concentrations to those seen after feeding. The infusion significantly (P < 0.05) suppressed GH secretion in a dose-dependent manner, whereas it caused a significant (P < 0.05) increase in insulin and glucose concentrations without changing glucagon concentrations. From these results, we conclude that the postprandial change in ruminal VFA concentration may be a physiological signal which modifies GH and insulin secretion in sheep.  相似文献   

9.
The effect of dry, soft moist, and canned dog foods on immediate postprandial plasma glucose and insulin concentrations was evaluated in clinically normal dogs. Dogs were fed either dry (10 dogs; group I), soft moist (10 dogs; group II), or canned (8 dogs; group III) dog food for 5 consecutive days. On the fifth day, plasma glucose and insulin concentrations were determined in each dog prior to, during, and at 5, 10, 15, 30, 45, 60, 90, 120, 180, and 240 minutes after ingestion of the food. The alterations in plasma glucose concentrations were not significantly different from prefeeding values until 240 and 180 minutes after feeding for groups I and III, respectively. In contrast, the increments in plasma glucose were significantly (P less than 0.01) increased from basal concentrations at 30 and 45 minutes after feeding in group-II dogs. The maximal mean postprandial plasma glucose concentration was significantly (P less than 0.0001) less for group III, compared with concentrations for groups I and II, but there was no significant difference between concentrations for groups I and II. Although a biphasic insulin secretory response was found in all 3 groups of dogs, the patterns of phase-2 insulin secretion and the total amount of insulin secreted during the study were significantly different. There was a rapid increase in the plasma insulin concentration immediately after phase 1 in group II, with maximal plasma insulin concentrations occurring 30 minutes after feeding, followed by a gradual decrease in concentrations throughout the remainder of the study.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Eight male Holstein calves 7 to 10 d of age were fed a milk replacer containing a skim milk powder subjected to low-temperature drying either with or without addition of an oxalate-NaOH buffer known to prevent curd formation. The calves were used in a completely randomized design to study the effect of milk clotting on digestibility and blood parameters. Plasma glucose and plasma insulin were similar (P greater than .05) for the clotting and the nonclotting milk replacers. For both treatments, concentrations of glucose and insulin reached a peak 2 h postfeeding (P less than .01). Plasma triglycerides were higher (P less than .01) postfeeding for the nonclotting than for the clotting milk replacer. Plasma essential amino acids and plasma urea were higher, whereas plasma calcium was lower, for the nonclotting milk (P less than .01). Digestibility of dry matter, protein and fat was similar (P greater than .05) between clotting and nonclotting milk. The dry matter content of feces was not affected by clotting (P greater than .05). The data are interpreted to indicate that clotting of the milk replacer modifies blood concentrations of triglycerides, essential amino acids and urea without changing the digestibility of the diet.  相似文献   

11.
  相似文献   

12.
The plasma concentration of glucose was monitored for six hours in lambs fed either ewe colostrum, cow colostrum or milk replacer by stomach tube at one hour of age. The feeding of ewe colostrum resulted in an elevation of the mean (+/- se) plasma glucose concentration from 2 . 6 +/- 0 . 3 mmol/litre before feeding to 7 . 3 +/- 0 . 92 mmol/litre three hours after feeding and this elevation was maintained. A similar rise was observed in the lambs fed cow colostrum but this was of shorter duration. A marked hyperglycaemia was observed after the feeding of milk replacer with a maximum value of 23 . 4 +/- 1 . 33 mmol/litre three hours after feeding. The practical implications of these results are discussed.  相似文献   

13.
In order to examine the relationship between white scour and fatty acids, we added fatty acids to the milk replacer. Twenty healthy Holstein calves were divided into 4 groups, five calves per group; a control group with no fortified fatty acid, and 3 groups fed either with oleic, stearic, or palmitic acid, respectively. The calves were fed milk replacer (5% of the calf's body weight) twice a day but the fatty acids (2 wt % of milk replacer) were added only once. The fecal and blood samples were obtained at 0, 12, 24, 36, and 48 h after feeding of the acids. All five calves in the palmitic acid group, and 3 out of 5 calves each in the stealic and the oleic acid groups had whitish feces after feeding fatty acid. The stearic acid group had a significantly elevated stearic acid concentration in the feces during 24–36 h compared to the pre-feeding level. The fecal concentration of palmitic acid increased significantly at 24–36 h in the palmitic acid group. We concluded that the long-chain saturated fatty acids are one of the causes of white scour in calves.  相似文献   

14.
Plasma concentrations of prolactin (PRL), growth hormone (GH), insulin, glucagon, glucose, urea and free fatty acids (FFA) were measured in Holstein calves, yearlings, bred heifers and primiparous cows, either sired by bulls with high predicted differences (PD) for milk (selection group) or by bulls from an unselected random bred control population (control group; n = 6). Serial blood samples were collected before and after feeding for an 8-h period from 0900 to 1700 h. All animals were fed a complete feed at 1100 h and administered insulin (.6 IU/100 kg body weight) at 1400 h. Mean plasma PRL was greater in control animals after feeding and insulin administration, while GH was greater overall in selection cattle. Insulin remained elevated longer in selection animals after exogenous administration, and plasma glucagon was increased in the control group. While plasma glucose and urea were unaffected by genetic group, plasma FFA were elevated in selection group calves and primiparous cows compared with the control group. All hormones and metabolites differed among the pre- and post-feeding and insulin administration periods and also with age. Mean PRL and GH increased after feeding, while glucagon decreased after exogenous insulin. Plasma FFA declined after feeding, while urea and glucose were similar before and after feeding. Mean PRL increased and glucagon decreased with advancing age and plasma GH and insulin showed inverse relationships at different ages. Plasma FFA changes closely followed GH changes with age, while plasma glucose more closely followed insulin changes with age. Results indicate that all hormones measured and FFA responded to genetic selection for milk, and increases in GH are uniformly associated with increased genetic potential for milk yield.  相似文献   

15.
To determine the effect of supplemental feeding of Diamond V-XP yeast (XPY) alone or in combination with propionibacteria strain P169 on milk production, milk components, body weight, days to first and second ovulation, plasma insulin, and plasma and milk glucose, 31 primiparous and multiparous (MP) Holstein cows were fed one of three dietary treatments between 2 weeks prepartum to 30 weeks postpartum: (i) control (n = 10), fed a corn silage-based total mixed ration (TMR); (ii) XPY (n = 11), fed control TMR plus XPY (at 56 g/head/day); and (iii) P169+XPY (n = 10), received control TMR plus XPY plus P169 (at 6 x 10(11) cfu/head/day). After parturition, daily milk weights were recorded, and milk samples were collected twice weekly for milk component analyses. Daily uncorrected milk, solids-corrected milk, and 4% fat-corrected milk production for MP cows fed P169+XPY was 9-16% greater than control MP cows, but these increases were only evident during mid lactation (9-30 weeks). The percentage of milk fat was 8-18% greater in control than XPY and P169+XPY groups. Milk lactose percentage in MP cows fed P169+XPY was 3-5% greater than in control and XPY MP cows. Primiparous and MP cows fed P169+XPY had 28-32% greater milk glucose levels than control and XPY-fed cows. Diurnal plasma glucose concentration was not affected by diet in MP cows. Plasma insulin levels in MP cows fed P169+XPY were 30-34% greater than in other groups of MP cows. Milk glucose and plasma insulin responses to P169+XPY feeding suggest that P169+XPY might have enhanced gluconeogenesis and increased glucose uptake by the mammary gland in Holstein cows. Thus, a combined feed supplement of P169 and XPY may hold potential as a natural feed alternative to hormones and antibiotics to enhance lactational performance.  相似文献   

16.
The blood glucose and the plasma non-esterified fatty acids (NEFA) and insulin concentrations were estimated in jugular blood samples from 18 Alpine×Beetal and Sannen×Beetal goats during pregnancy and compared with samples from non-pregnant goats and from goats during the periparturient period. The blood glucose levels in the pregnant goats rose to a peak of about 60±1.36 mg/ml at 42–56 days and then declined to about 46±2.37 mg/ml at 112–126 days. In non-pregnant goats, the blood glucose levels were significantly (p<0.01) higher than in pregnant goats, except between days 42 and 70 (59±1.36 mg/ml). On the day of kidding, the levels declined significantly (p<0.01), increasing again thereafter. The plasma NEFA concentrations were significantly higher in pregnant than in non-pregnant goats from days 56 to 126. The NEFA concentration increased on the day of kidding, followed by a transient fall by day 3. The plasma insulin concentration was usually higher in pregnant than in non-pregnant goats, except between days 56 and 70 and from day 126 onwards. The insulin concentration fell late in pregnancy, but there was a transient increase 2 days after parturition. The blood glucose and plasma NEFA concentrations can be used as indices of nutritional status during pregnancy in goats.  相似文献   

17.
Ingestions of a moderately ketogenic silage twice daily were followed by transient increments in plasma insulin and ketone bodies and decreases in plasma glucose. Ketone bodies and glucose were negatively correlated throughout the day, but the insulin elevations culminated before the maximal effects on ketone bodies and glucose were established. Cows with varying glucose levels before morning feeding reacted to a highly ketogenic silage by decreasing their glucose level uniformly to about 3 mmol/l, in spite of a widely varying feeding-induced insulin increment. Hay-feeding caused insulin increments of the same magnitude as silage-feeding, but the glucose decrease and the ketone increment was much smaller. The results indicate some direct action of ketone bodies on blood sugar regulation, in addition to effects mediated by insulin. The role of ketone bodies as the insulinotropic factor was not confirmed. The insulin level after feeding seems to be determined by the carbohydrate status of the animal before feeding. No significant changes in plasma glucagon were observed after feeding, and no consistent differences in plasma levels of this hormone were found when non-ketonemic, ketonemic, and clinically ketotic cows were compared. The plasma level of enteroglucagon (GLI) was positively correlated to the relative amount of concentrates consumed, but no relation to plasma glucose was found.  相似文献   

18.
The effect of cracked corn grain supplementation (3.5 kg/day) during 3 weeks before the expected calving date on milk production and composition, body condition score (BCS), metabolic and hormonal profiles and length of postpartum anoestrus was evaluated in multiparous Holstein dairy cows under grazing conditions (Energy supplemented group, n = 10; Control group, n = 10). Body condition score was weekly recorded during the peripartum period, from days −21 to +35 (parturition = day 0). Non-esterified fatty acids, β-hydroxybutyrate, cholesterol, urea, insulin, insulin-like growth factor I (IGF-I), leptin, thyroxine (T4) and 3,3'5-triiodothyroinine (T3) were weekly determined in plasma from days −21 to +35. The reinitiation of ovarian cyclicity was twice weekly determined by ovarian ultrasonography and confirmed by plasma progesterone concentrations. Cows fed energy concentrate prepartum had higher BCS during the prepartum and postpartum and produced more milk. Non-esterified fatty acids plasma concentrations were significantly higher in the energy group, while cholesterol was higher in the control group. Treated cows had higher levels of plasma insulin, IGF-I and leptin pre-calving. IGF-I, leptin and T4 were diminished during the early postpartum period in both groups. Insulin levels were also diminished in the control group, but levels remained high in the energy-supplemented group. Treated cows ovulated sooner after parturition than controls. We conclude that Energetic supplementation prepartum in cows under grazing conditions increased milk production and reduced the reinitiation of ovarian activity, consistent with a better EB (BCS), higher prepartum levels of IGF-I, leptin and insulin, and higher insulin levels during early postpartum.  相似文献   

19.
本试验旨在研究长期饲喂高精料饲粮下添加复合缓冲剂(碳酸氢钠20 g/d、氧化镁12 g/d、丁酸钠20 g/d)对奶山羊乳成分、血浆生化指标及激素含量的影响。选择8头安装门静脉及肝静脉瘘管处于泌乳中期的奶山羊随机分为2组,分别饲喂基础饲粮(高精料饲粮组,HG组)和基础饲粮+复合缓冲剂(高精料饲粮+复合缓冲剂组,BG组)。预试期为7 d,正试期为143 d。结果显示:与HG组相比,复合缓冲剂显著升高采食后010 h瘤胃液p H平均值(P0.05);复合缓冲剂显著降低肝静脉血浆中非酯化脂肪酸的含量(P0.05),对门静脉和肝静脉血浆中葡萄糖、β-羟丁酸含量无显著影响(P0.05),对肝脏组织中甘油三酯和总蛋白含量无显著影响(P0.05);复合缓冲剂显著降低门静脉血浆中胰岛素和胰高血糖素的含量(P0.05),对门静脉和肝静脉血浆中胰岛素样生长因子1和生长激素的含量无显著影响(P0.05);复合缓冲剂显著或极显著升高产奶量、乳脂率、乳蛋白率、乳非脂固形物率(P0.05或P0.01)。综合得出,在长期高精料饲粮饲喂条件下,由碳酸氢钠、氧化镁、丁酸钠组成的复合缓冲剂能通过影响奶山羊血浆生化指标及激素含量,影响体机营养物质代谢,最终有效提高产乳量与改善乳品质。  相似文献   

20.
Fructo-oligosaccharides (FOS) are soluble fibres which exert various effects in the gastrointestinal tract, and induce metabolic and endocrine changes. The effects are favourable in diabetes mellitus, and may be favourable in veal calves, which during late periods of fattening often develop hyperglycemia, glucosuria and insulin resistance, especially during high lactose intake. Based on this we have studied metabolic, endocrine and haematological traits in veal calves (Simmental x Red Holstein) fed FOS (10 g/day; group GrF) or no FOS (group GrC). Whole milk and milk replacer in both groups, on a kg body weight basis, were fed in identical amounts. Experiments, lasting for 3 weeks, started when calves were 10 weeks old and weighed 117 kg. During week 3 lactose was supplemented to enhance post-absorptive glucose loads. Feed intakes were similar in both groups, but weight gain tended to be higher in GrF than GrC. The post-prandial increase of glucose concentrations was significantly smaller, of lactate tended to be smaller, and growth hormone peak frequency tended to be lower, whereas maximal insulin concentrations reached post-prandially were significantly higher in GrF than GrC. Eosinophil granulocytes increased during FOS feeding. In conclusion, FOS had basically similar effects on metabolic and endocrine traits in veal calves as in animals and humans with diabetes mellitus, but changes were small, albeit more prominent after lactose loads.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号