Effects of delta 9-tetrahydrocannabinol and diazepam on feeding behavior in mice.

The present study examined effects of diazepam (DZP) alone or in combination with delta 9-tetrahydrocannabinol (THC) on feeding behavior as well as body weight in male ddY strain mice at 5 weeks of age. Because we saw no hyperphagic effect of DZP with or without THC in mice, we explored the hyperphagia elicitable by DZP. THC [2 (THC2) or 4 (THC4) mg/kg/day s.c.] was given daily for 7 days. For the last day the mice were starved and injected i.p. with DZP (2 mg/kg) 10 min prior to a food or maze test. Controls received vehicle injections. Feeding behavior was measured after giving food for 2 hr. THC4 significantly reduced body weight gain. DZP, with or without THC, induced hyperphagia. THC4 alone also induced hyperphagia that was not significantly affected by DZP. Time taken to find food was extended by DZP and further with THC. Both DZP and THC can therefore interact on food ingestion but synergize on food seeking in mice through different mechanisms.     

Behavioral reactivity of cattle toward novel food: effects of testing time and food type of neighbors

In order to improve methods to investigate individual variation in responses of cattle toward novel food, the influence of food type offered to neighbors and time of testing were investigated in tethered heifers. Twenty-four Danish Friesian heifers were used in two 2 x 3 factorial experiments, using 8 kg of a mixed ration (grass silage and concentrates) and 4.5 kg of carrots as a novel food. The factors were 1) time of testing: heifers tested at usual feeding time (1000) vs after 30 min with access to their usual food; and 2) food type of neighbors: either no food, novel food, or usual food. During the 30-min period with novel food in front of them, the behavior of the experimental heifers was video recorded. Testing at usual feeding time led to a tendency to increase the latency to eat the mixed ration (P = 0.08), a tendency to reduce intake of the mixed ration (P = 0.08), increased frequency and duration of sniffing carrots (P = 0.1 and P = 0.02, respectively), increased duration of sniffing the mixed ration (P = 0.05), and decreased frequency and duration of disturbance from neighbors (carrots: P = 0.0002 and P = 0.003). The food type of the neighbors did not have major influence on the behavioral reactivity. For both the mixed ration and carrots, the frequency of eating was increased when the neighbors got novel food rather than their usual food (P = 0.01 and P = 0.02). However, the frequency and duration of disturbance from neighbors was increased when no food was offered to the neighbors (carrots: P = 0.001; mixed ration: P = 0.01 and P = 0.09, respectively). It is concluded that time of testing is an important factor for the behavioral response toward novel food, leading to increased responses when tested at the usual feeding time compared with testing after 30 min of access to usual food. The minor effects of food type of neighbors indicate that it is possible to perform individual testing in a home environment, where the animals have limited possibility for contact with neighbors.     

Digestibility,fecal characteristics,and plasma glucose and urea in dogs fed a commercial dog food once or three times daily

Digestibility, fecal characteristics, and levels of glucose and urea in the plasma were determined in 8 dogs that received 2 different dog foods once or 3 times daily. One dog food (A) was 5 times more expensive than the other (B). Fecal pH and consistency, digestibility of dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) were determined. Blood samples were taken from 30 min before to 60 min after a meal. Digestibilities of DM, OM, and CP, and fecal consistency were higher, and daily fecal excretion and fecal pH were lower when dogs were fed food A (P < 0.001). The feeding schedule had no effect on plasma glucose and urea. Neither feeding frequency nor food × frequency interactions was significant for the parameters studied.     

Effects of dopamine receptor agonists on food intake and rumen motility in dwarf goats

Kaya, F., Van Duin, C.T.M. & Van Miert, A.S.J.P.A.M. Food intake and rumen motility in dwarf goats. Effects of some dopamine receptor agonists. J. vet. PharmacolTherap, 17 , 120–126. In ruminants, the dopaminergic regulation of feeding behaviour has not been investigated. Therefore, the effects of dopamine receptor agonists and antagonists on food intake and forestomach motility were studied in dwarf goats Goats treated i.v. with bromocriptine (1 μg or 2.5 μg/kg body wt/min during 10 min) ate less food than when treated with saline. This inhibitory effect on food intake could not be prevented by the peripheral dopamine receptor antagonist domperidone (0.5 mg/kg body wt i.v.). In contrast, dopamine (i.v. 20 μg/kg body wt/min during 15 min), levodopa (i.v. 40 μg/kg body weight during 10 min), apomorphine (i.v. 2 μg/kg body wt/min during 10 min) and lisuride (i.v. 0.2 μg/kg body wt/min during 15 min and 0.5 μg/kg body wt during 10 min) failed to modify food intake. Given in association with benserazide, a decarboxylase inhibitor (i.v. 20 μg/kg body wt/min during 10 min), levodopa was still inactive as an anorectie agent. Levopoda, bromocriptine and lisuride administered at similar dose rates to those which were used in the food intake experiments, induced some clinical signs including inhibition of forestomach contractions. The inhibition of rumen contractions induced by these drugs was completely antagonized by domperidone pretreatment. These results, together with earlier in vivo and in vitro observations, suggest that the inhibitory effects of dopamine receptor agonists on forestomach contractions are due to interactions with peripheral dopaminergic receptors. The change in smooth muscle tension, which leads to a change in the signals transmitted via vagal afferents to the central nervous system, probably does not modify feeding behaviour in dwarf goats. Furthermore, i.v. infusion of lisuride induced rumination when the inhibition of the forestomach contractions was prevented by domperidone; this effect may involve α₂-adrenoceptor activation.     

Myoelectric activity of the ileum, cecum, and right ventral colon in ponies during interdigestive, nonfeeding, and digestive periods

Myoelectric activity of the ileum, cecum, and right ventral colon (RVC) was studied in 4 mature ponies. Eight Ag-AgCl bipolar recording electrodes were sutured to the seromuscular layer of the ileum (2 electrodes), cecum (4 electrodes), and RVC (2 electrodes). Myoelectric activity was studied beginning 10 days after surgery. Eight, 60-minute recording sessions were performed in each pony during the interdigestive period, which was the period 3 to 7 hours after the morning feeding. On separate days, food was withheld for 24 hours, and 90-minute recordings were obtained during the nonfeeding period. Ponies were then fed a normal ration, and recordings were continued to obtain data for the digestive (feeding) period. All phases of the migrating myoelectric complex were seen at both ileal electrodes during the interdigestive period, including the periods of no spiking activity (phase 1), irregular spiking activity (phase 2), and regular spiking activity (phase 3). Phase 2 occupied 77% of the total recording time, and the mean duration of phases 1, 2, and 3 was 3.4 +/- 0.2, 12.8 +/- 1.2, and 6.7 +/- 0.7 min, respectively. Frequency of ileal slow waves was 11.8 +/- 0.1/min, and spike burst conduction velocity was 4.7 +/- 0.3 cm/s. A complete migrating myoelectric complex was seen in 11 of 32 tracings (34%) and had a mean duration of 24.2 +/- 2.6 min. The ileal migrating action potential complex, most often seen in phase 2, had a frequency of 4.8 +/- 0.5 spike bursts/h and a conduction velocity of 13.6 +/- 0.4 cm/s.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of interrupted lighting regimens on the feeding activity of the laying fowl

Segmentation of the main light period of an 8L:4D:2L:10D regimen into 30 min light, 30 min dark did not affect total feeding activity, rate of feeding or total intake of laying hens. When 15 min light and 45 min dark was provided each hour feeding activity and food intake were reduced, while rate of feeding and feeding during the dark periods increased. No feeding occurred in the 10 h 'night'. Hens subjected to interrupted lighting showed less feeding activity than those on a 14L:10D regimen. Insertion of a 4 h dark period in the 14 h subjective day of laying hens increased their rate of feeding, but reduced total intake. The pattern of feeding activity depended on the position of the 4 h dark period. The largest modification of feeding activity occurred on a 8L:4D:2L:10D regimen; 20% of activity occurred in the last 2 h of the apparent day. Feeding occurred during the 4 h dark period, but not during the 10 h 'night'.     

Salivary secretory IgA concentrations in beagle dogs

The normal concentrations of salivary secretory IgA (sIgA) were examined, and the response of sIgA to acute stress was evaluated in dogs. Ten clinically healthy beagle dogs familiarized with the method of saliva sampling were used. During the non-stress period, saliva samples were collected between 0800 hr and 1700 hr at 1-hr intervals for 7 consecutive days and analyzed for sIgA concentration. After a 1-day control period, a noise stressor was presented for 15 min between 0845 hr and 0900 hr on 2 consecutive days. Saliva was collected at pre-stress, immediately after, 30 min after and 60 min after the stress. The average sIgA concentration over the 2-day period was compared with the control value. Environmental stimuli were restricted. During the non-stress period, significant variations were observed during the diurnal pattern, in which sIgA increased in the morning and then decreased; and the day-to-day variations were significant except at 0800 hr and 0900 hr. During the stress experiments, the sIgA concentration decreased significantly, immediately after and 30 min after the noise stress, and then increased to the same level as the control value by 60 min after the stress. When estimating the effectiveness of salivary sIgA as a marker of stress in dogs, the appropriate time for saliva sampling appears to be in the morning. Salivary sIgA was deemed potentially useful as a marker of stress in dogs.     

Opioid modulation of feeding and drinking in fowls

1. D-ala2-methionine enkephalinamide (DME), the stable analogue of met-enkephalin (an opioid agonist), stimulated food intake of immature hens in the first 30 min after intracerebroventricular injection (2 and 8 micrograms/kg), but had no effect on either food or water intake when injected intravenously (15 and 60 micrograms/kg). 2. Naloxone (an opioid antagonist) had no effect on food intake after either intracerebroventricular (50 and 200 micrograms/kg) or intravenous (1 and 4 mg/kg) injection, but inhibited water intake in the second 30 min after intravenous injection. 3. Water intake was not measured after the intracerebroventricular injections of DME and naloxone. 4. Both feeding and drinking were inhibited in a dose-related way in the 7 h after intramuscular injection of nalmefene (0.2, 0.4, 0.8 and 1.6 mg/kg), a more potent and longer-lasting antagonist than naloxone. 5. These data are compared with published results from similar work with birds and mammals. It is concluded that central release of endogenous opioids may reinforce both feeding and drinking in fowls, but whereas opioid blockage affects feeding more than drinking in pigeons and quail, the opposite appears to be the case in fowls.     

Factors affecting the circadian rhythm in plasma cortisol concentrations in the horse

In horses, a circadian rhythm in plasma cortisol concentrations has been reported in some but not all studies. When a rhythm occurred, horses were accustomed to a management routine, comprising stabling, feeding and sometimes exercise, which may entrain a circadian pattern. In this work, we monitored plasma cortisol by collecting jugular blood through indwelling cannulae from four groups: 1): 10 untrained, unperturbed mares grazing excess pasture, bled hourly for 26 hr; 2) 4 mares housed in a barn for 48 hr before sampling every 15 min for 20–24 hr; 3) 5 mares placed in an outdoor yard for sampling every 30 min from 0930–2100 hr; and 4) 4 stabled racehorses in training, bled every 30 min from 0730–2000 hr and once the following morning at 0830 hr.Plasma cortisol showed a similarly-timed circadian rhythm (P<0.0001) in all Group 1 horses, with a peak at 0600–0900 hr, and a nadir at 1800–2100 hr. By contrast, cortisol concentrations did not vary with time in either Group 2 or 3. Neither daily mean nor peak cortisol values differed in Group 1 and 2 (i.e. bled for ≥ 20 hr); however nadir values were higher (P<0.05) in Group 2. In Group 4, cortisol declined (P=0.004) during the sampling period but had returned to initial concentrations the next morning. Values did not differ from those for Group 1, except between 1000 and 1300 hr when cortisol in Group 4 was lower (P<0.05).We conclude that a circadian cortisol rhythm exists in horses in the absence of any known cues imposed by humans. However, this rhythm can be obliterated by the minor perturbation of removing the horse from its accustomed environment. By contrast, the rhythm occurs in trained racehorses, suggesting either that they have adapted to their environment thereby allowing an endogenous rhythm to emerge, or that the rhythm is entrained by their daily routine. These observations highlight the difficulties in determining the cortisol status of a horse, since measurements will be affected by time of day, the occurrence of short-term fluctuations, and how accustomed the horse is to its environment.     

Metabolic and behavioral adaptation of light-bodied chicks to meal feeding.

1. Two-week-old male chicks of a light-bodied strain were fed one (1M) or two (2M) 2-h meals per day. An additional group was pair-fed (P1M) the amount consumed by the 1M group on the previous day. 2. After 21 days, final body weight of the 1M and 2M chicks attained 65% and 80%, respectively, of that of the control group fed ad libitum. The weight gain of the P1M chicks was equal to that of the 1M chicks. 3. Food consumption of chicks adapted to meals was not even throughout the feeding period. On day 16 of the experiment, the 1M birds consumed 65% of the meal during the first 30 min. P1M chicks behaved similarly to the 1M ones. The intake of the 2M chicks during each meal was exactly half of their daily consumption, despite the uneven time period between meals. 4. The time during which food remained in the gastrointestinal tract (GIT) was longer under the meal feeding regimes than in the ad libitum-fed groups. 5. Although neither body composition nor metabolisable energy was affected by meal regime, food utilisation was poorer in the 1M and P1M than in the ad libitum and 2M-fed chicks.     

家蚕止桑、饷食时间的研究 Ⅱ.家蚕止桑、饷食时间与生长发育和代谢的关系

探讨了小蚕期止桑、饷食时间与大蚕期生长发育和代谢的关系,发现一至三眠迟饷食12小时,一至二眠或一至三眠早止桑60％,迟饷食24小时处理区的四至五龄食下量和消化量减少,五龄指数生长期缩短,体重减轻,处理结束龄和五龄中肠组织碱性磷酸酶、五龄肠液蛋白酶、五龄后部丝腺谷丙转氨酶活力降低、而一至三眠早止桑60％,一至二眠迟饷食12小时,对上述性状无明显作用,消化率和食物转化率不受止桑、偏食时间的影响。认为起蚕期长时间饥饿会损伤中肠机能,使蚕陷于营养不良,生长机能减弱,丝蛋白合成能力下降,表现出经济性状和抗病性的降低。     

Biphasic disruption of fasting equine gut motility by dopamine – a preliminary study

Dopamine was infused intravenously (1, 5 and 10 micrograms/kg/min) for 60 min in three fasted ponies. A dose-dependent increase in heart rate occurred that was rapid in onset and termination at the start and end of the infusions, respectively. Dose-dependent changes in gastric and small intestinal motility were observed. An initial marked inhibition of gastric contraction amplitude was followed by a secondary prolonged period of activity. At the same time the small intestine showed a prolonged period of irregular activity (phase II) and a marked increase in the interval between successive phase IIIs. The left dorsal colon and small colon exhibited variable responses. The normal fasting motility pattern was therefore disrupted by dopamine biphasically, an initial inhibition of the stomach being followed by a period of increased activity in the stomach and small intestine which resembled the postprandial motility pattern. Although the cardiovascular effects of dopamine were transient, the increases in gastrointestinal motility persisted long after the infusion was terminated.     

Effects of food restriction during the finishing period on the performance of broiler chickens

1. Three hundred 4-week-old commercial Hibrow broiler chicks were fed ad libitum , 85% and 70% of ad libitum or ad libitum for 5 d per week with 3rd and 5th days of food withdrawal for 28 d to examine the effects of food restriction on liveweight, growth rate, food conversion efficiency, dressing percentage, abdominal fat and mortality. 2. Quantitative food reduction to 85% and 70% of ad libitum , and reduction in feeding time by 2 d/week significantly reduced final body weight and rate of growth. 3. Food restriction (to 70% ad libitum ) resulted in lower abdominal fat than ad libitum feeding, 15% food restriction or reduction in feeding time by 2 d/week. 4. There were no significant differences between the effects of 15% food restriction and 2-d reduction in feeding time per week on final body weight, growth rate and abdominal fat. 5. Reduction in feeding time by 2 d/week resulted in the same food efficiency as ad libitum feeding and quantitative food restriction by 15% and a significantly better food efficiency than 30% quantitative food reduction. 6. Reducing feeding time by 2 d/week seemed to have less severe effects on the birds than quantitatively reducing food supply by 30%.     

The regulation of food intake and correlated energy balance in mice.

In order to study the regulation of food intake and correlated body energy metabolism, the effect of restricted feeding during the light period in female IVCS mice was investigated. Access to food and water was restricted (RF group) for 3 weeks only from 10:00 hr to 17:00 hr, and that in the control group remained ad libitum. After starting food restriction (day 1), mean food intake decreased to 10% of the control value, then rose sharply, over the next 3 days, to reach 70% of the control value. Then, it decreased gradually to about 50% of the control value and remained at this low level thereafter. There was no significant difference between mean body weights for the two groups. Feed-efficiency was considered, therefore, to be higher in the RF than in the control group. RF-treatment increased plasma corticosterone levels and decreased locomotor activity. However, the diurnal patterns of plasma corticosterone levels and locomotor activity observed suggest that the circadian rhythm, synchronized with the light-dark cycle, persisted during RF-treatment. These findings suggest that restricted feeding during the naturally inactive phase (light period) induces a decrease in food intake. Animals seem to adapt to underfeeding, at least partly, by increasing feed-efficiency and plasma corticosterone levels and decreasing locomotor activity.     

Influence of dose, frequency, and duration of infused gonadotropin-releasing hormone on secretion of luteinizing hormone and follicle-stimulating hormone in nutritionally anestrous beef cows.

Nutritionally induced anovulatory cows were ovariectomized and used to determine the relationships between dose, frequency, and duration of exogenous gonadotropin-releasing hormone (GnRH) pulses and amplitude, frequency, and concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in serum. In Experiment 1, cows were given pulses of saline (control) or 2 micrograms of GnRH infused i.v. during a 0.1-, 1.25-, 5-, 10-, or 20-min period. Concentrations of LH and FSH during 35 min after GnRH infusion were greater than in control cows (P < 0.01), and FSH concentrations were greater when GnRH infusions were for 10 min or less compared with 20 min. In Experiment 2, the effect of GnRH pulse frequency and dose on LH and FSH concentrations, pulse frequency, and pulse amplitude were determined. Exogenous GnRH (0, 2, or 4 micrograms) was infused in 5 min at frequencies of once every hour or once every 4th hr for 3 d. There was a dose of GnRH x frequency x day effect on LH and FSH concentrations (P < 0.01), indicating that gonadotropes are sensitive to changes in pulse frequency, dose, and time of exposure to GnRH. There were more LH pulses when GnRH was infused every hour, compared with an infusion every 4th hr (P < 0.04). Amplitudes of LH pulses were greater with increased GnRH dose (P < 0.05), and there was a frequency x dose x day effect on FSH pulse amplitude (P < 0.0006). We conclude that LH and FSH secretion in the bovine is differentially regulated by frequency and dose of GnRH infusions.     

Absence of Feeding-Induced Variations in Plasma Insulin in Hypoglycaemic-Ketonaemic Cows

The effects of food intake on plasma insulin levels were studied in 38 cows with plasma sugar ranging from 41 to 86 mg/100 ml and acetoacetate (Acac) ranging from 0.2 to 18 mg/100 ml, measured before morning feeding. The animals were fed concentrates, silage and hay. Blood samples were taken immediately before feeding in the morning and at intervals of % to 1 hr. during the following 4 hrs.In animals with low blood Acac, plasma insulin concentrations began to increase as early as 1/2 hr. after the start of feeding and reached maxima after 2 hrs. Simultaneously Acac increased and sugar decreased markedly. Animals with Acac levels > 1 mg/100 ml had low pre-feeding insulin concentrations, and the level of the hormone did not increase after feeding. They did not show systematic changes in Acac. But plasma sugar tended to decrease when food was given, even in the absence of insulin increments in peripheral blood.Glucose was infused at a low rate (0.9 g/min.) for 18 hrs. into a hypoglycaemic, ketonaemic cow. As her glucose and ketone levels became normalized, she also responded to feeding with insulin increments. But throughout the experiment her plasma insulin remained considerably lower than in an identically treated control animal which had low Acac levels before the infusion. It appears that the endocrine adjustments during ketonaemia in cows include, beside low basal (pre-feeding) insulin levels, an inhibition of the normally occurring elevation of plasma insulin after feeding.     

肉仔鸡生长过程中行为与产热的变化

研究肉仔鸡成长过程中行为变化对产热量的影响 ,将 2日龄肉仔鸡 36只分为自由摄食、 50 %摄食和绝食 3组进行观测。立位行为集中在明期 ,特别是摄食 30min前后 ,暗期几乎没有出现立体行为。 2日龄时 ,每天约有 70 0min是立位的 ,其后 ,随着日龄的增加而减少。在自由采食区 ,公雏比母雏摄食时间长。 50 %摄食区较自由采食区的摄食时间少。在绝食区 ,随着日龄的增加 ,公母的立位时间呈现减少倾向。 2 1日龄之前随着日龄的增加其摄食时间也增加 ,其后呈现相反倾向。产热 (HP ,kJ/kg0 75)与摄食时间有相同倾向。在 2 1日龄前公雏的HP比母雏低 ,2 1日龄后母雏比公雏低。 1天中各个区的HP活动规律是摄食后 1h内最高 ,暗期降低 ;限制摄食量后 ,HP降低 ,明期和暗期的HP差也随之减小     

Circadian variation in heart rate, blood pressure, body temperature and EEG of immature broiler breeder chickens in restricted-fed and ad libitum-fed states

1. Heart rate, intra-aortic blood pressure, deep body temperature and telencephalic EEG were monitored by radiotelemetry in 6 freely moving immature broiler breeders (three in each of two years), during routine food restriction and then ad libitum feeding, over two 24-h periods in each feeding state.2. Heart rate, blood pressure and body temperature were all higher during ad libitum than restricted feeding, and heart rate and body temperature were higher by day (12 h) than at night (12 h). The decreases in heart rate and body temperature at night were greater during restricted than ad libitum feeding. Blood pressure tended to be higher at night, except in year 2 during restricted feeding. Body temperature and ambient temperature were higher in year 2 than year 1.3. During restricted feeding, marked peaks in heart rate, blood pressure and body temperature in the 15 min after provision of the daily food ration at 09:00 h, when birds were eating, were equivalent to corresponding values seen during ad libitum feeding.4. Relative powers in delta (1 to 4 Hz) and theta (4 to 8 Hz) frequency bands of the EEG power spectrum were higher at night in year 2 only, while power in the alpha (8 to 12 Hz) band was higher at night in both years.5. It is concluded that most of the variation in heart rate, blood pressure and body temperature between feeding states and times of day/night can be accounted for in terms of variation in food intake and energy expenditure. The greater slow wave (delta, theta) EEG activity seen after lights-off in year 2 may reflect non-paradoxical sleep at that time.     

Food intake and rumen motility in dwarf goats. Effects of atipamezole on the inhibitory effects induced by detomidine,medetomidine and romifidine

The effects of some ₂-adrenoceptor agonists and of the ₂-adrenoceptor antagonist atipamezole on food intake and ruminal contractions were studied in dwarf goats. Detomidine, 0.2 µg/kg per min for 10 min, failed to modify food intake during either the first or second observation period (0–30 min and 180–210 min after drug infusion, respectively). Given at a higher dose rate (0.4 µg/kg per min for 10 min), the drug inhibited food consumption during the first observation period, but stimulated food intake during the second period. A similar pattern was observed after IV infusion with medetomidine (0.2 µg/kg per min for 10 min), romifidine (0.4 µg/kg per min for 10 min) or xylazine (1 µg/kg per min for 10 min). The ₂-antagonist atipamezole (2 µg/kg per min for 10 min) failed to modify food intake during either the first or second observation period. After treatment with atipamezole, the effects of ₂-agonists on feeding behaviour were completely antagonized.The ₂-agonists administered at similar dose rates to those used in the food intake experiments induced bradycardia, decreases in body temperature and inhibition of ruminal contractions. The inhibition of ruminal contractions induced by romifidine was partly antagonized by atipamezole pre-treatment. These findings demonstrate that the ₂-agonist-induced changes in ruminal contractions do not simply cause changes in feeding behaviour. The drop in body temperature induced by ₂-agonists was prevented by atipamezole pre-treatment, whereas the induced bradycardia was not modified by this ₂-antagonist.Abbreviations IV intravenous - SEM standard error of the mean     

Feed intake and serum GH, LH and cortisol in gilts after intracerebroventricular or intravenous injection of urocortin

In three experiments (Exp), ovariectomized gilts received intracerebroventricular (ICV; Exp 1 - with restraint, Exp 2 - without restraint) or intravenous (i.v.; Exp 3) injections of urocortin or saline to assess effects on feed intake and serum GH, LH, and cortisol. Following a 20-hr fast, feed was presented at 1 hr (Exp 1) or 30 min (Exp 2 and 3) after injection (time = 0 hr) of saline or 5 (U5) or 50 (U50) μg/pig (Exp 1 and 2) or 5 μg/kg BW (Exp 3) of urocortin. Blood samples were collected every 15 min from –2 to 6 hr relative to injection and hormone data pooled 2 hr before and hourly after treatment. Treatment with U50 decreased feed intake, relative to saline (treatment x time interaction; P < 0.05), when delivered ICV but not i.v. A treatment by time interaction was detected for GH (Exp 1, 2, 3) and LH (Exp 1 and 2; P < 0.01). Serum GH increased over time (relative to −2 hr; P < 0.05) following treatment with urocortin but not saline regardless of route of administration. Conversely, in Exp 1 (U5 and U50) and Exp 2 (U50), LH decreased relative to −2 hr with a delayed decrease during Exp 1. Serum cortisol was not affected by treatment in Exp 1, but increased following urocortin in Exp 2 and 3 (treatment by time interaction, P < 0.01). These data provide evidence that urocortin modulates GH and LH concentrations and suppresses feed intake in gilts via mechanisms which may be independent of cortisol and may depend upon dose and route of administration.