Effect of intracerebroventricular infusion of urocortin on feed and salt intake in parotid fistulated sheep

The effect of a new peptide, brain urocortin (UCN), in the central regulation of feed and salt intake in parotid fistulated sheep was investigated through a continuous intracerebroventricular (ICV) infusion of the peptide at a small dose for 48 h. Feed and salt intake on day 1 of UCN infusion were similar to those before infusion. However, feed and salt intake on day 2 during UCN infusion decreased significantly. Water intake on days 1 and 2 during UCN infusion was the same as that before infusion. Saliva secretion from the unilateral parotid gland during UCN infusion was unchanged from that before infusion. On the other hand, urine excretion during UCN infusion increased significantly. The present results suggested that UCN acts directly on the brain mechanisms of sheep to decrease feed and salt intake, but does not alter water intake.     

Intracerebroventricular melanin-concentrating hormone stimulates food intake in sheep

Melanin-concentrating hormone (MCH) stimulates feeding when injected intracerebroventricularly (ICV) in rats. At present it is not clear whether the function of MCH is similar in ruminants, which are species with a continuous delivery of nutrients. Therefore the current investigation sought to determine the role of MCH in sheep. In the first experiment, six, castrate male sheep were satiated and received one of four treatments [saline, 0.1, or 1.0 nmol/kg MCH, and NPY (0.1 nmol/kg)] injected ICV over 30s, then infused ICV for 6 h ( approximately 500 microl/h). Food intake was measured for 2 h before and at 2, 4, 6, 8, 12 and 24 h. In this experiment, feed intake was increased (P相似文献   

The effects of artificially-induced fly-strike on food intake and liveweight gain in sheep

A single, artificially-induced fly-strike with Lucilia sericata larvae was associated with a rapid (decline in food intake in sheep, with a consequent reduction in liveweight. Loss of weight ranged from 0.5 to 5.5 kg over four to six days and recovery to pre-infestation liveweight took three to 36 days. Pair-fed, uninfested partners of these sheep also showed a reduction in liveweight, whereas uninfested sheep in some experiments fed ad libitum showed either little change or a gain in liveweight over the same period. In general, maggot infested sheep took less time to regain weight than did their pair-fed partners although the weight lost as a proportion of initial weight was similar in both groups. Loss of appetite alone would appear to account for these events.     

Effect of intracerebroventricular injection of IGF-I on circulating growth hormone concentrations in the sheep

The effect of intracerebroventricular administration of IGF-1 on circulating growth hormone (GH) concentrations has been studied in sheep. Twenty sheep were fitted with jugular vein catheters and with indwelling cerebroventricular cannulae. IGF-I was injected into a lateral cerebral ventricle and changes in the circulating concentrations of GH were measured in jugular vein blood samples. Administration of saline had no effect on circulating GH concentrations over a 3-hr period, and administration of IGF-I (at 1, 3 and 10 micrograms/sheep) also had no significant effect on circulating GH concentrations. From these data we surmise that centrally administered IGF-I does not influence GH secretion and it seems probable that cerebrospinal fluid concentrations of IGF-I do not have a role in regulating GH release in sheep.     

Effect of food intake on urine pH in cats

Ninety adult cats were fed an experimental canned meat-based cat food at levels necessary to maintain weight for 11 days. On the 12th day the cats were split into six groups of 15 cats each and fed 0, 20, 40, 60, 80 or 100 per cent of their previous food allotment. Four hours after the food was offered a urine sample was obtained via cysto-centesis. The pH of the urine sample was determined and the sample microscopically evaluated for the presence of struvite crystals. Post prandial urine pH was found to be a linear function of the amount of food consumed: (urine pH = 6–15 + [food intake (g) × 0–015]; P = 0-000). The presence of struvite crystals was dependent on urine pH while amorphous crystals were not. These data suggest that ad libitum feeding (nibble eating) may be beneficial in the management of feline struvite urolithiasis by reducing the magnitude of the post prandial alkaline tide. It also supports the suggestion that struvite crystal formation is largely a function of urinary pH.     

Effect of dietary nitrogen intake on gentamicin disposition in sheep

The effect on gentamicin pharmacokinetics of a diet high (HP) (120 g/day) or low (LP) (25 g/day) in digestible proteins was studied in sheep. Gentamicin sulphate (4 mg/kg) and inulin (40 mg/kg) were administered by the intravenous route to six ewes of local Moroccan breed. The serum gentamicin concentrations were consistently higher in ewes that received a LP diet. Clearance was 0.93 +/- 0.13 ml/mm/kg in the LP group and 1.64 +/- 0.40 ml/mm/kg in the HP group. The volume of distribution at steady state (Vss) was lower in the LP group (11% of body weight) than in the HP group (21.8% of body weight). These diet-linked variations in pharmacokinetic parameters were also obtained in the disposition of inulin following the intravenous administration of a single dose. This suggests that the protein content of the diet modifies the distribution of body water and kidney function. The therapeutic, toxicological and hygienic implications of these modifications are discussed.     

Effect of feed intake and dietary vitamin A levels on sheep performance.

A study was conducted on 20 "Rahmani" male lambs of 16 kg body weight fed on normal feed level and high vitamin A level (NF-HV); normal feed level and normal vitamin A level (NF-NV); low feed level and high vitamin A level (LF-HV) or low feed level and normal vitamin A level (LF-NV) till slaughter weight of 35-40 kg. Average daily gains of lambs were 211, 148, 117 and 87 g for the NF-HV, NF-NV, LF-HV and LF-NV groups, respectively. The corresponding feed conversions were 4.3, 5.9, 5.0 and 6.4 kg DM/kg gain. Raising feed intake and vitamin A level enhanced nutrients digestibility and nitrogen balance. Rumen liquor reflected higher pH value in animals fed higher intake (NF) in the first two diets. Both feed intake and vitamin A levels enhanced volatile fatty acids and ammonia concentrations in the rumen liquor. Feed intake and vitamin A levels positively affected haemoglobin content, packed cell volume, glucose, urea, total protein, vitamin A, insulin, cholesterol, phospholipids, glutamate oxaloacetate and glutamate pyruvate transaminases and alkaline phosphatase in blood Vitamin A, insulin, cholesterol and phospholipids in blood increased gradually over the experimental period. Dressing percentages were 56.2, 49.6, 49.1 and 44.6% for the experimental groups, respectively. Liver content of glycogen and vitamin A increased with increasing feed intake and vitamin A levels. It is concluded that higher levels of vitamin A supplementation (than usually recommended) is required during fattening of lambs. Low energy and normal vitamin A levels are not recommended in lambs feeding.     

Roles of central histaminergic system in glucose metabolisms and food intake in sheep

The neurotransmitter histamine is thought to be involved in the homeostatic regulation of energy balance. The present study was conducted to examine whether the central histaminergic system is involved in the regulation glucose metabolisms and food intake in ruminants. Thioperamide, a presynaptic H3‐receptor antagonist, was intracerebroventricularly infused at a rate of 68 μg/min for 3 h, beginning at 11.00 hours, into castrated Suffolk rams (48–55 kg bodyweight) accustomed to being fed alfalfa hay cubes (2% of body weight) at 12.00 hours. The food intake was measured every 60 min for 2 h after the commencement of feeding (12.00 hours). Blood samples were taken through a jugular vein catheter every 10 or 20 min during the experiment. Plasma glucose levels were significantly (P < 0.05) greater in the thioperamide‐treated group than in the control. The post‐prandial insulin increment was significantly (P < 0.05) greater in the thioperamide‐treated group than in the saline‐treated control. The food intake of the thioperamide‐treated group was significantly (P < 0.05) less than that of the control in the period from 60 to 120 min after feeding. In conclusion, the central histaminergic system is involved in the regulation of glucose metabolisms and food intake in ruminants.     

Effect of water: food intake ratios in laying hens on food metabolisable energy

It has been hypothesised that a relatively high water intake results in a lower food digestibility. The influence of water:food ratios on the metabolisability of a diet was investigated. With ad libitum water and food the water:food ratios varied between 1.17 and 2.47 and showed a positive relationship with metabolisable energy. In groups of hens receiving 40 g food and water sufficient to provide water:food ratios of 1, 2, 3 and 4, the results showed a non-significant negative regression of apparent metabolisable energy with water:food ratios.     

The relationship of food intake during growth and food intake at maturity with lactation food intake in a mouse model

Selection for increased leanness and improved food efficiency in pigs has resulted in a decreased voluntary food intake. It has been argued that voluntary food intake during lactation should be considered in sow breeding programmes. The aim of the present study was to investigate the phenotypic correlation of food intake during growth and food intake at maturity with maximum lactation food intake in a mouse model. A total of 179 records were available on female mice selected for litter size at birth (S-line) and non-selected control females (C-line) from 3 weeks of age to 21 days in lactation. Half of the litters were standardized to eight pups per litter (s) and half were not standardized (ns). Growth intake was measured as the average intake between 21 and 42 days of age, mature intake was measured from a linear regression of food intake against age between 42 and 69 days of age, and lactation intake was measured as a linear regression of food intake against days in lactation between 5 and 14 days in lactation. In both lines, females with a higher growth intake also had a higher mature intake (r = 0.63 to 0.75, P < 0.0001). Lactation intake was related with growth intake and mature intake in Sns females (r = 0.50 and 0.46, P < 0.01) and with growth intake in Ss females (r = 0.32, P < 0.05). In both lines, lactation intake was highly correlated with litter weight (r = 0.48 to 0.94, P < 0.001). Sns and Ss females with higher growth intake supported larger litter weights during lactation (r = 0.32 and 0.30, respectively, P < 0.05) and Sns females with higher mature intakes tended to support larger litter weights (r = 0.28, P = 0.060). It is suggested that lactating C-line females eat to support a given litter size, while S-line females support the maximum litter weight that is allowed for by their intake capacity, and still produce at high levels when litters are standardized. Since lactating sows mobilise body reserves, the relationship of food intake during growth with that during lactation may be reflected in the relationship between growth intake and body condition.     

Effect of laying on food and water intake in dwarf and normal hens

1. Irrespective of whether the hen carried the dwarfing gene, dw, food intake on days when there was ovulation and oviposition was higher than on days when there was only oviposition.

2. The “ overconsumption “ in dw hens was greater than in the Dw hens.

3. Food intake and shell thickness were correlated, the relationship being particularly close in dw hens.

4. There was a consistent and positive correlation between food intake and weight of egg laid on the same day in both Dw and dw hens.     

Effect of oral administration of L-pipecolic acid on food intake in chicks and mice

It has been demonstrated that L-pipecolic acid (L-PA), a major metabolic intermediate of L-lysine (L-Lys) in the brain, is involved in the functioning of the γ-aminobutyric acid-ergic system. Previous study has shown that intracerebroventricular injection of L-PA suppressed feeding and induced sleep-like behavior in neonatal chicks. The present study examines whether the action of L-PA was induced by gavage in both chicks and mice. Oral administration of L-PA significantly inhibited food intake at 2 h after treatment in neonatal chicks, although no significant effect of L-Lys was detected. In mice, oral L-PA suppressed food intake compared to the control after 2 h of treatment. It was concluded that L-PA was effective for suppression of food intake after oral administration in both avian and mammalian species.     

Effects of intracerebroventricular infusions of corticotropin‐releasing hormone in sheep

To provide new insights into the neural mechanisms of physiological and behavioral responses to stressors in sheep, acute changes in endocrine, autonomic and behavioral functions following 30 min infusions of ovine‐corticotropin‐releasing hormone (oCRH; 0, 0.5, 5 or 50 µg/0.5 mL of artificial cerebrospinal fluid/30 min) into the third ventricle of sheep (n = 7–8) were examined. Serial blood samples were collected through indwelling jugular catheters to determine plasma cortisol concentrations (CORT). Heart rate (HR) and rectal temperature (RT) were obtained via telemetry systems. The behaviors of the animal were monitored simultaneously. Intracerebroventricular infusions of CRH dose‐dependently induced an increase in CORT; there was a time–treatment interaction in CORT (P < 0.001). There was not a time–treatment interaction either in HR (P = 0.29) or in RT (P = 0.28). That RT showed a tendency to decrease with higher doses of CRH in sheep was in contradiction to previous reports in rats and pigs. As to changes in behavioral function, only the induction of bleating was marked. These results suggest that in physiological and behavioral responses of sheep to stressors, CRH regulates the increase in CORT and the induction of bleating. However, CRH might have little function in sympathetic nervous activation during physiological responses to stressors in sheep.     

Effect of mild restriction of food intake on the speed of racing Greyhounds

OBJECTIVE: To determine whether mild restriction of food intake affects clinicopathologic variables, body composition, and performance of dogs undertaking intense sprint exercise. ANIMALS: 9 trained healthy adult Greyhounds. PROCEDURE: Dogs were offered food free choice once daily for 9 weeks until body weight and food intake stabilized. Dogs were then randomly assigned to be fed either 85% or 100% of this quantity of food in a crossover study (duration of each diet treatment period, 9 weeks). Dogs raced a distance of 500 m twice weekly. Clinicopathologic variables were assessed before and 5 minutes after racing; food intake, weight, body composition, body condition score, and race times were compared at the end of each diet period. RESULTS: Compared with values associated with unrestricted access to food, there were significant decreases in mean body weight (by 6%) and median body condition score (from 3.75 to 3.5 on a 9-point scale) and the mean speed of the dogs was significantly faster (by 0.7 km/h) when food intake was restricted. Body composition and most clinicopathologic variables were unaffected by diet treatment, but dogs given restricted access to food had slightly fewer neutrophils, compared with values determined when food intake was unrestricted. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that the common practice among Greyhound trainers of mildly restricting food intake of racing dogs to reduce body weight does improve sprint performance. A body condition score of approximately 3.5 on a 9-point scale is normal for a trained Greyhound in racing condition.     

Effects of intracerebroventricular corticotropin-releasing hormone and intravenous morphine on cortisol, prolactin and growth hormone secretion in sheep.

It has previously been demonstrated that naloxone and morphine modify the adrenocortical and pituitary responses of sheep to stress. Since CRH acts within the brain to co-ordinate the stress response, the present experiment was conducted to determine whether morphine has similar effects in sheep given oCRH centrally. Plasma concentrations of cortisol, prolactin and growth hormone were measured in blood samples collected at 10 min intervals from sheep (N = 5) over a 3-hr period. Intravenous injections of saline vehicle or morphine sulphate (0.4 mg/kg) were given after 40 min and intracerebroventricular injections of oCRH (0, 5 or 20 micrograms) were administered after 60 min. Sustained, dose-related, increases in cortisol were induced by oCRH and, in agreement with findings in stressed sheep, these responses were reduced by pretreatment with morphine. Prolactin levels appeared to increase after morphine but oCRH, on its own, did not increase prolactin secretion in this study. There was no change in growth hormone concentrations after oCRH whereas morphine transiently stimulated release.