Assessment of the metabolic effects of hydrocortisone on llamas before and after feed restriction

OBJECTIVE: To evaluate the effects of administration of hydrocortisone on plasma concentration of insulin and serum concentrations of glucose, triglyceride, and nonesterified fatty acids (NEFAs) in llamas before and after feed restriction. ANIMALS: 9 adult female llamas. PROCEDURE: Feed was withheld from llamas for 8 hours. Blood samples were collected before (0 minutes) and 120, 180, 240, and 300 minutes after IV injection of hydrocortisone sodium succinate (1 mg/kg) for determination of plasma insulin concentration and serum concentrations of glucose, triglyceride, and NEFAs. The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 21 days, after which the experimental procedures were repeated. RESULTS: Compared with llamas that were not feed-restricted, llamas after feed restriction had significantly higher plasma insulin concentration and serum concentrations of triglycerides and NEFAs. Feed-restricted llamas after hydrocortisone injection had a significantly smaller increase in serum glucose concentration, a decrease (rather than an increase) in serum concentration of NEFAs, and no change in blood concentrations of insulin or triglycerides. CONCLUSIONS AND CLINICAL RELEVANCE: Short-acting glucocorticoid hormones did not appear to increase blood lipid concentrations in healthy llamas, regardless of ongoing fat mobilization. Thus, these hormones appear unlikely to be major direct contributors to diseases such as hepatic lipidosis or hyperlipemia. Although administration of hydrocortisone reduced serum concentration of fatty acids in feed-restricted llamas, its use has not been evaluated in sick camelids and cannot be considered therapeutically useful.     

Metabolic changes and induction of hepatic lipidosis during feed restriction in llamas.

OBJECTIVES: To determine whether feed restriction induces hepatic lipidosis (HL) in llamas and to evaluate the metabolic changes that develop during feed restriction. ANIMALS: 8 healthy adult female llamas. PROCEDURE: Llamas were fed grass hay at a rate of 0.25% of their body weight per day for 13 to 28 days. Llamas were monitored by use of clinical observation, serum biochemical analyses, and ultrasound-guided liver biopsies. RESULTS: All 8 llamas lost weight and mobilized fat. Five llamas developed HL, including 4 that were nursing crias. During the period of feed restriction, mean serum concentration of bile acids and activities of aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), and gamma-glutamyl transferase (GGT) were significantly higher in llamas that developed HL, compared with llamas that did not. Mean insulin-to-cortisol concentration ratios were lower in llamas with HL before and up to 7 days of feed restriction, compared with those that did not develop HL. CONCLUSIONS AND CLINICAL RELEVANCE: HL in llamas may be induced by severe feed restriction, particularly in the face of increased energy demand. Llamas with weight loss attributable to inadequate dietary intake may develop biochemical evidence of hepatopathy and HL. Increases in serum concentration of bile acids and activities of GGT, AST, and SDH may indicate the development of HL in llamas and identify affected animals for aggressive therapeutic intervention.     

Assessment of the effects of exogenous long-acting insulin on glucose tolerance in alpacas

OBJECTIVE: To evaluate the effects of long-acting insulin on glucose clearance in alpacas. ANIMALS: 8 adult castrated alpacas. PROCEDURE: On 2 days, food was withheld from alpacas for 8 hours. Alpacas were randomly allocated to receive an SC injection of long-acting insulin (0.4 U/kg) or saline (0.9% NaCI) solution 1 hour before the first of 3 administrations of glucose (at 60, 480, and 1,200 minutes after treatment) on day 1 and the alternate treatment and procedure on day 2. Plasma glucose concentration was determined before and 15, 45, 120, and 240 minutes after each glucose administration, and fractional turnover rates were calculated. The data were compared between alpacas with and without insulin administration and among the 3 glucose administrations for each day. RESULTS: Compared with sham-treated alpacas, insulin-treated alpacas had significantly lower blood glucose concentrations from 180 to 600 minutes after treatment; they also had glucose concentrations significantly below baseline values from 120 to 480 minutes, at which time the mean glucose concentration was in the hypoglycemic range. Also, mean fractional turnover of glucose was significantly higher in insulin-treated alpacas from 105 through 300 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with known effects of regular insulin in alpacas, the action of long-acting insulin was of slower onset but longer lasting; its administration may induce hypoglycemia, even in alpacas that receive glucose. To maintain the hypoglycemic effect, long-acting insulin may have to be administered more than once daily and blood glucose concentration should be monitored to avoid hypoglycemic complications in alpacas.     

Maternal pyrimidine nucleoside supplementation regulates fatty acid,amino acid and glucose metabolism of neonatal piglets

Pyrimidine nucleosides(PN) are abundant in mammalian milk and mainly involved in glycogen deposition and lipid metabolism. To investigate the effects of maternal supplementation with pyrimidine nucleoside on glucose, fatty acids(FAs), and amino acids(AAs) metabolism in neonatal piglets. Forty pregnant sows were randomly assigned into the control(CON) group(fed a basal diet, n = 20) or the PN group(fed a basal diet supplemented with PN at 150 g/t, n = 20). Litter size, born alive and birth litter...     

Effects of chromium supplementation on glucose tolerance in obese and nonobese cats

OBJECTIVE: To determine effects of dietary supplementation with chromium (Cr) picolinate on health and response to i.v. glucose tolerance testing (IVGTT) in obese and nonobese cats. ANIMALS: 7 obese and 12 nonobese cats. PROCEDURE: 6 nonobese cats were untreated controls, whereas 6 different nonobese cats and 7 obese cats received oral administration of 100 microg Cr/d for 6 weeks. All cats were evaluated before and immediately after the treatment period by use of physical examination, CBC, serum biochemical analyses, and IVGTT. Calculated values included glucose half-life, coefficient of glucose disappearance, insulin peak response, insulinogenic index, and insulin secretion rate determined at various times after start of IVGTT. RESULTS: Adverse effects on cats' health were not observed during or after treatment, and significant changes in body weight, hematologic values, or most serum biochemical values were not detected. Serum potassium concentration decreased significantly after treatment in obese cats but was within reference range. Compared with nonobese cats, obese cats had significantly higher insulin peak response, insulinogenic index, and insulin secretion rate before and after treatment. Chromium supplementation did not alter responses to IVGTT in either treatment group. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary supplementation with 100 microg of Cr/d for 6 weeks is safe but does not affect glucose tolerance in obese or nonobese cats.     

Glucose tolerance testing in llamas and alpacas

OBJECTIVE: To determine blood glucose clearance in 2 species of New World camelids after IV challenge and to examine mechanisms of this clearance. ANIMALS: 5 adult female llamas and 5 adult gelded alpacas. PROCEDURE: After food was withheld for 12 hours, camelids received 0.5 g of glucose/kg of body weight by rapid IV infusion. Serum concentrations of glucose, nonesterified fatty acids, cortisol, and insulin, and plasma concentrations of lactate were determined before and 0, 1, 2, 3, 4, 5, 15, 30, 60, 90, 120, 180, and 240 minutes after infusion. Ratios of insulin to glucose and insulin to cortisol were calculated for each time point. RESULTS: Postinfusion glucose concentrations were significantly higher in llamas than alpacas for the first 15 minutes and remained significantly higher than baseline values in both species for 180 minutes. Lactate and cortisol concentrations did not change significantly; nonesterified fatty acid concentrations decreased in both species 30 minutes after infusion. Baseline insulin concentrations were < 6 microU/ml in both species and increased only to 10.1 +/- 0.7 microU/ml in llamas. Insulin concentrations did not change significantly in alpacas. CONCLUSIONS AND CLINICAL RELEVANCE: Llamas and alpacas clear glucose more slowly than other domestic species after challenge, mainly because of a weak insulin response and slow cellular uptake. This response may impair the assimilation of exogenous glucose as well as make llamas and alpacas prone to diabetes-like disorders when an abundance of endogenous or exogenous glucogenic agents are present.     

Vomitoxin and amino acid supplements in rat feed

In Finland grain has during some years contained considerable amounts of mycotoxins depending on the weather conditions, harvesting and preservation methods. The most common of these mycotoxins are Fusariumtoxins: zearalenone and trichotechenes. The trichotechene group is large, but only a few of the toxins are of practical interest in that they cause health disorders to farm animals. The most common toxin of the trichotechenes is deoksinivalenol or vomitoxin (DON), which causes, especially in pigs, vomiting and reduction in feed palatability.     

鲑鳟鱼对饲料中蛋白质和氨基酸的需求

鲑鳟鱼指的是鲑科鱼类,一般研究较多的是虹鳟和大马哈鱼。目前挪威以成为当今世界上鲑鳟鱼类养殖的第一大国,其产量占世界总产量的50%以上。目前世界上最主要的养殖种类是虹鳟和大西洋鲑。鲑鱼又叫大马哈鱼,是浅海中的洄游种类,每年随着生长和生育迁移生活地点。鲑鳟鱼具有极高的营养价值。其肉质鲜美,含有丰富的营养成分,对人体最有益处的是它含有大量的不饱和脂肪酸(又称Omega-3),可预防心脏病和中风,每天摄食0.5～1g可使患心脏病的机会减少40%;它对神经系统和视网膜生长极为有利,对小孩的脑部和眼睛发育有极大的帮助,而且它还能有效的防…     

Dietary chromium tripicolinate supplementation reduces glucose concentrations and improves glucose tolerance in normal-weight cats

The effect of dietary chromium supplementation on glucose and insulin metabolism in healthy, non-obese cats was evaluated. Thirty-two cats were randomly divided into four groups and fed experimental diets consisting of a standard diet with 0 ppb (control), 150 ppb, 300 ppb, or 600 ppb added chromium as chromium tripicolinate. Intravenous glucose tolerance, insulin tolerance and insulin sensitivity tests with minimal model analysis were performed before and after 6 weeks of feeding the test diets.During the glucose tolerance test, glucose concentrations, area under the glucose concentration-time curve, and glucose half-life (300 ppb only), were significantly lower after the trial in cats supplemented with 300 ppb and 600 ppb chromium, compared with values before the trial. Fasting glucose concentrations measured on a different day in the biochemistry profile were also significantly lower after supplementation with 600 ppb chromium. There were no significant differences in insulin concentrations or indices in either the glucose or insulin tolerance tests following chromium supplementation, nor were there any differences between groups before or after the dietary trial.Importantly, this study has shown a small but significant, dose-dependent improvement in glucose tolerance in healthy, non-obese cats supplemented with dietary chromium. Further long-term studies are warranted to determine if the addition of chromium to feline diets is advantageous. Cats most likely to benefit are those with glucose intolerance and insulin resistance from lack of exercise, obesity and old age. Healthy cats at risk of glucose intolerance and diabetes from underlying low insulin sensitivity or genetic factors may also benefit from long-term chromium supplementation.     

Assessment of the effects of epinephrine and insulin on plasma and serum biochemical variables in llamas and alpacas

OBJECTIVE: To describe the metabolic effects of epinephrine administration in New World camelids and investigate whether these effects are influenced by administration of insulin. ANIMALS: 6 llamas and 8 alpacas (all adult castrated males). PROCEDURE: Prior to each experiment, food was withheld from camelids for 8 hours. On each of 2 consecutive days, alpacas were administered epinephrine (10 mg/kg, IM; time 0); alpacas were randomly assigned to receive regular insulin (0.2 U/kg, IV) immediately after epinephrine administration on one of those days. In llamas, the experiment was performed once after administration of epinephrine only. At 0, 30, 60, 90, 120, 150, 180, 210, and 240 minutes after treatment, blood samples were collected and several serum or plasma biochemical variables were assessed; in addition, plasma samples from llamas were assessed for insulin concentrations. Data were compared between days (alpacas only) and between time points. RESULTS: Administration of epinephrine induced mobilization of glucose, triglycerides, nonesterified fatty acids, and beta-hydroxybutyrate. A small increase in endogenous insulin concentration was detected in epinephrine-treated llamas, compared with baseline values. Overall, insulin administration decreased, negated, or delayed the epinephrine-associated increases in serum or plasma concentrations of circulating energy substrates, except that it augmented the epinephrine-associated increase in concentration of triglycerides. CONCLUSIONS AND CLINICAL RELEVANCE: Epinephrine appeared to mobilize energy substrates in camelids and hence may be involved in the pathogenesis of disorders of glucose and fat metabolism. Insulin appeared to antagonize most of these effects, and its administration may have therapeutic value in camelids.     

The effects of grit supplementation and feed type on steel-shot ingestion in mallards

Lead poisoning by shot-pellet ingestion is an important cause of death in waterfowl from wetlands that have high densities of lead-shot pellets and low availabilities of grit in their sediments. To evaluate grit supplementation when mixed with baited grain as a method of reducing shot ingestion in waterfowl, 24 mallards (Anas platyrhynchos) were kept in captivity to study the relationship between steel-shot, grit and grain ingestion in four experiments. Steel-shot ingestion was more related to seeking grit than to feeding on grain, and it did not differ between two types of grain offered (rice or sorghum). Grit ingestion increased with grit supplementation and shot ingestion was only slightly reduced. Calcareous grit used in the experiments had a shorter half-life (1.4 days) in the gizzard than values reported for siliceous grit (3.1 days).     

Starch supplementation improves the reproductive performance of sows in different glucose tolerance status

This study was to evaluate the effects of glucose tolerance status, maternal starch supplementation and soybean substitution in diets on the performance of dams and their offspring. Eighty-eight pregnant sows (Landrace × Large White) were selected from an initial total of 120 sows, based on blood glucose test values, and assigned to 4 experimental treatments in a 2 × 2 factorial design. The factors were glucose tolerance status (glucose intolerant [GIT] vs. normal glucose tolerant [NGT]) or dietary treatments (corn starch diet [CS] vs. soybean substitution diet [SS]). A higher area under the curve (AUC) for post-meal glucose was observed (P < 0.05) in the GIT group than in the NGT group on d 109 of gestation. The CS group had a lower value of homeostasis model assessment-insulin resistance than the SS group (P < 0.05) on d 109 of gestation. Corn starch supplementation for sows decreased the stillbirth rate (P < 0.05), regardless of the sows' glucose tolerance status. The villus height of the jejunum and the villus height to crypt depth ratio of the ileum were greater in normal birth weight piglets from the CS group than from the SS group (P < 0.01), and so was the activity of sucrase in the jejunum and ileum (P < 0.01). Compared with the SS group, the CS group showed a reduction in pre-weaning mortality rate, an increase in the number of high-birth-weight piglets, and a decrease in the number of low-birth-weight piglets (P < 0.05) under GIT status. In conclusion, sows fed CS decreased stillbirth rate and improved insulin resistance, as well as improving the intestinal morphology and digestive enzyme activities of their progeny, regardless of glucose tolerance status. Additionally, the CS group improved birth weight distribution and decreased pre-weaning mortality rate of piglets under GIT status.     

可利用氨基酸饲料新技术的发展状况与应用

动物营养学研究的深入发展,单以粗蛋白质含量的高低来决定某种蛋白质饲料的营养价值已显得十分片面,特别是蛋白质的消化代谢率、生物学效价和可利用氨基酸概念的提出和应用使这种评价方法受到严重的挑战。在畜禽用蛋白质饲料中,鱼粉中的赖氨酸在家禽体内的利用率为89％,而在生长育肥猪体内的利用率为88％;就赖氨酸而言,鱼粉在生长育肥猪体内的消化利用率为93％,豆粕在生长育肥猪体内的消化利用率为88％。综上所述,不同的畜禽对同一饲料的同一种氨基酸的消化利用率有所不同,不同饲料的同一种氨基酸在同一种畜禽体内的消化利用率也不相同。     

氨基酸螯合铁与仔猪补铁

铁在动物营养中是最重要的微量元素之一。它是红细胞中血红蛋白的组成成分 ,保证氧在机体内的正常运输 ;它以肌红蛋白形式存在于肌肉中 ,以乳铁蛋白形式存在于乳中 ,以铁蛋白和含铁血黄素形式存在于肝中。铁在动物体内还作为多种酶的组成成分影响能量代谢、蛋白质合成和免疫机能。因此 ,铁是仔猪出生后快速发育及维持身体代谢与生理作用所必需的重要元素。1　仔猪贫血及常规补铁由于母猪体内铁转运系统中存在胎盘屏障和乳腺屏障 ,致使初生仔猪体内铁贮较低 (仅2 9ｍｇ/ｇ无脂肪组织 ) ,同时 ,母猪乳汁中铁的含量很低 (1 3 3ｍｇ/Ｌ)。仔猪…     

猪饲料氨基酸消化率测定方法的研究进展

氨基酸的消化率作为评定猪饲料蛋白质营养价值的重要参数,已日益引起学者们的重视。文章就目前氨基酸的测定方法进行了综述,并对各种方法的优缺点进行了评述。     

合成氨基酸在水产饲料中的应用

<正>鱼粉由于氨基酸平衡、适口性佳、消化率高,一直是水产饲料尤其是肉食性水产动物饲料的主要蛋白原料。但由于世界鱼粉资源有限,世界水产养殖产量保持高速增长,所以替代蛋白的应用研究已成为水产动物营养研究的热点。Alam等(2004)认为,蛋白原料     

The effect of weight loss by energy restriction on metabolic profile and glucose tolerance in ponies

In nine initially obese ponies, a weekly weight loss according to 1% of their ideal body weight was evaluated for its impact on insulin sensitivity and metabolic profile. Weight loss was obtained solely through energy restriction, initially at 70% of maintenance energy requirements, but to maintain constant weight loss, feed amount had to be decreased to 50% and 35% of maintenance energy requirement during the course of the trial. An oral glucose tolerance test (OGTT) was performed at weeks 0, 10 and 17. Fasted blood samples were taken on weeks 0, 3, 10, 17 for analysis of triglycerides (TG), non‐esterified fatty acids (NEFA), creatine phosphokinase (CPK), lactate dehydrogenase (LDH), T₃, T₄ and leptin. Total average weight loss was 18.2%. When the OGTT was performed at weeks 0, 10 and 17, ponies had lost 0.22%, 9.9% and 16.3% of their initial weight respectively. Weight loss was associated with a decreased AUC for glucose and insulin. Moreover, greater % weight loss was associated with a significantly lower glucose peak and a lower area under the curve (AUC glucose). The lower glucose response after an OGTT in lean ponies was not the result of an increased insulin secretion, but an improved insulin sensitivity. Restricted feeding led to mobilization of TG and NEFA and to a reduced basal metabolism, with lower LDH, CPK, T₃ and leptin. In conclusion: in obese Shetland ponies, weight loss at a rate of 1% of ideal body weight per week through restricted energy intake, ameliorated insulin sensitivity.