A feeding trial was conducted to evaluate house fly pupae and catabolised poultry residue as alternative protein sources to soybean meal for growing chickens.
No significant difference (P>0.05) in weight gain was observed between the control and chicks fed pupae in their diet from 1 d to 4 weeks of age. Food conversion of the chicks fed digested poultry manure was significantly (P<0.05) inferior to that of the controls. 相似文献
2. Body weight and feed intake were measured weekly. Plasma calcium and phosphorus concentration along with plasma and digestive ALP were assayed throughout the trial. Trypsin, α-amylase, lipase and total protease activity were assayed at 14 and 28 d of age. Tibia ash, calcium and phosphorus content and breaking strength were measured at 14, 28 and 42 d of age. Phosphorus digestibility was measured at 36 d of age.
3. Body weight and feed intake showed no significant differences between controls and diets containing 12 and 36 g/kg GCB. Tibia ash and tibia length were increased by supplementation of GCB (P ≤ 0.001). Tibia calcium and phosphorus content were increased by GCB inclusion at 14 d of age (P ≤ 0.001). Digestive alkaline phosphatase activity was increased and trypsin activity was reduced by inclusion of GCB (P ≤ 0.001; P ≤ 0.004). α-amylase activity decreased by inclusion of 12 and 24 g/kg GCB, whereas an increase in α-amylase activity was observed by inclusion of 36 g/kg GCB (P ≤ 0.001). Supplementation of diets with GCB increased phosphorus digestibility (P ≤ 0.01) and suppressed ileum growth during the experimental period.
4. Results of the current study showed that phosphorus from gelatin can greatly improve broiler bone characteristics and phosphorus digestibility and complete elimination of inorganic phosphate sources from broiler diets is feasible with inclusion of 36 g/kg high phosphorus gelatin. 相似文献
2. Crambe meals were prepared to differ in E‐PG (19, 36 and 40 g/kg) and CHB contents (0.1, 0.7 and 1.9 g/kg), and with either active or inactive thioglucosidase.
3. Meals were fed to 7‐d‐old broiler chicks at 50 or 100 g/kg of the diet for 12 or 13 d. In separate studies, isolated E‐PG or CHB were mixed into the diet or administered by gavage to 7‐d‐old broiler chicks in amounts equivalent to 50 or 100 g/kg crambe meal diets for 10 and 12 d, respectively.
4. Weight gain decreased (P<0.05) in chicks fed on the high glucosinolate crambe diets or isolated E‐PG. Food consumption decreased (P<0.05) in chicks fed on the diet containing the high E‐PG meal with active enzyme.
5. Mild liver lesions and increased serum aspartate aminotransferase were found in chicks fed on the diet containing the high glucosinolate meal with active enzyme. Other organs, including thyroids, were normal.
6. Commercially‐processed crambe meal appeared safe at an inclusion rate of 50 or 100 g/kg diet, but could not be recommended at this point for long term feeding. 相似文献
2. Maize and soybean meal was ground with grid sizes of 2 or 3 mm. Nine diets were prepared. The basal diet contained 500 g/kg of maize starch. The other experimental diets contained maize or soybean meal samples at concentrations of 250 and 500, and 150 and 300 g/kg, respectively, instead of maize starch. Each diet was tested using 6 replicate groups of 10 birds each. The regression approach was applied to calculate the pc AA digestibility of the test ingredients.
3. The reduction of the grid size from 3 to 2 mm reduced the average particle size of both maize and soybean meal, mainly by reducing the proportion of coarse particles. Reducing the grid size significantly (P < 0.050) increased the pc digestibility of all AA in the soybean meal. In maize, reducing the grid size decreased the pc digestibility of all AA numerically, but not significantly (P > 0.050). The mean numerical differences in pc AA digestibility between the grid sizes were 0.045 and 0.055 in maize and soybean meal, respectively.
4. Future studies investigating the pc AA digestibility should specify the particle size distribution and should investigate the test ingredients ground similarly for practical applications. 相似文献
2. A total of 936 1-d-old Ross 308 broilers were used in the study. After gender determination at the hatchery, chicks from each sex were randomly distributed into three dietary treatments. The following dietary treatments were used in the experiment from hatch to 38 d: (1) A control diet formulated to meet all of the nutrient requirements of broiler chicks according to the management guide; (2) The control diet supplemented with 18.7–15.0 µg/kg of 25OHD3; and (3) The control diet supplemented with 18.7–15.0 µg/kg of 25OHD3 plus Ca + aP.
3. Improvement in vitamin D status by 25OHD3 supplementation, alone or in combination with Ca and aP, had no effect on body weight and feed conversion ratio of broilers.
4. The serum 25OHD3 concentration significantly increased with 25OHD3 and 25OHD3 plus Ca + aP supplementation (P < 0.05), whereas the ionised Ca and Mg concentrations remained unchanged.
5. Sternum absolute weight, ash content and the concentrations of Ca and P significantly increased (P < 0.01) with supplementation of 25OHD3, alone or in combination with Ca + aP.
6. Supplemental 25OHD3, alone or in combination with Ca + aP, slightly increased pH24 (P = 0.05) and decreased (P < 0.01) squeezable water loss in breast meat, whereas it had no significant effect on lightness, yellowness and sarcoplasmic protein solubility.
7. In conclusion, the results suggested that enhancing vitamin D status by 25OHD3 supplementation alone or in combination with Ca + aP may improve sternum structure and mineral accretion. Furthermore, supplemental 25OHD3, even in a nutritionally complete diet, may offer an effective way to improve protein solubility in female broilers. 相似文献
2. A reduction by 18% in the dietary Ca-P concentration from the recommended levels for the hen strain reduced (P < 0.01) faecal excretion of ash, Ca and P concentrations, and shear force with stress of the tibia in association with decreased feed intake, whereas improved albumen height and Haugh unit values in the egg.
3. Supplemental B significantly decreased the feed consumption, egg weight and final body weight in hens, as well as the albumen height, but had no effect on either the biomechanical characteristics of bones or the mineral profile of the bones and serum. However, there was a significant increase in the egg production rate and a reduction in the damaged and shell-less egg ratio, and in the feed conversion rate in hens fed adequate Ca-P with 150 mg/kg B compared to those of the unsupplemented controls.
4. The amount of B that accumulated in the bones and serum was correlated with the amount of B consumed. B increased the faecal excretion of ash, Ca and B. In general, dietary variables had no effect on mineral composition of serum and tibia.
5. The magnitude of the response to dietary B was much more pronounced in hens fed a diet deficient in Ca-P with 75 mg/kg B; these hens exhibited a production performance and an egg quality comparable to those given adequate Ca-P with no added B.
6. The data presented in this study describing the measured bone properties did not corroborate the hypothesis that B is a trace element playing an important role in mineral metabolism and bone strength through an interaction with Ca, P and Mg. 相似文献
2. The birds were fed on either maize- or wheat-based diets during rearing and production and on a fast- or slow-feed allocation programme from 14 to 29 weeks of age. At 22 weeks, 69 females from each pen were placed in a layer house where feeder space (FS) either remained similar or was increased.
3. Eggs produced at 33 weeks were incubated, eggshell conductance (G) was determined and a sample of 14 chicks from each treatment combination was taken to obtain bone traits at hatching.
4. Diet type did not influence G, yolk-free body weight (BW), residual yolk weight or relative asymmetry (RA) of any bilateral traits of leg bones of hatchlings. However, breeder diet type was involved on two-way and three-way interaction effects on progeny leg bone traits.
5. Breeders feed restricted according to the slow-feeding programme laid eggs with greater G compared to those managed with the fast-feeding programme, but there was no effect of feeding programme on progeny bone traits at hatching.
6. Eggs from breeders given more FS at photostimulation had greater G than those from breeders provided with similar FS. Maternal FS change did not influence hatchling yolk-free BW; however, breeders given more FS produced progeny with heavier tibias and shanks and longer femurs compared with those provided with similar FS, but only when breeders were fed on maize. Moreover, increased maternal FS at photostimulation was associated with an increased RA of femur length in the progeny.
7. It was concluded that breeder FS change at photostimulation influenced eggshell conductance and consistently affected bone development of the broiler progeny. 相似文献
2. Body weight (BW), feed intake (FI) and mortality records were collected. Two birds per replicate were killed at 24 d of age to obtain tibia samples.
3. Increasing Ca level significantly reduced the FI and body weight gain (BWG) between hatch and 10 and 24 d, especially with the phytase-supplemented diets. However, phytase supplementation of the diet containing 4 g NPP/kg improved the FI and BWG at d 10 and 24. At d 24, phytase supplementation improved feed conversion ratio (FCR) of birds that consumed diets containing high NPP. The overall FCR was better in birds offered the phytase-supplemented, medium-Ca diet.
4. There was a significant reduction in length, width and breaking strength of the tibia bone in birds fed on a diet with high Ca and low NPP. Phytase supplementation improved the tibia ash content and bone breaking strength of chicks fed on the diet containing 8 and 4 g/kg Ca and NPP, respectively. The Ca content of the tibia bone was low in birds fed on diets with 6 and 4 g/kg Ca and NPP, respectively, but this was counteracted by phytase supplementation.
5. Birds fed on diets with 4 g/kg NPP had the best carcass percentage and parts yield. Phytase supplementation to high-Ca diets significantly reduced the carcass yield of birds.
6. These results confirmed the detrimental effect of high dietary Ca on phytase activity and subsequent growth and bone development of birds, especially when NPP is in short supply. 相似文献
2. A total of 300 male broiler chicks (Ross 308) were randomly allotted to 5 dietary treatments in a completely randomised design during 1–15 and 15–35 d rearing periods. Experimental treatments consisted of a basal diet with a reduction in Arg content (CON?; starter: 12.1 g/kg and grower: 11.3 g/kg Arg), a CON? diet supplemented with synthetic Arg equal to the required Arg level (CON+; starter: 13.80 g/kg; grower: 12.37 g/kg) and CON? diet supplemented with three levels of GAA (GAA0.6; GAA1.2; and GAA1.8; g/kg).
3. Supplemental GAA at 0.6 and 1.2 g/kg reduced the adverse effects of the CON? diet on weight gain and feed conversion ratio in the starter period, equal to the effect of CON+ diet. During the entire rearing period, such an effect was only seen for broilers fed CON? diet supplemented with 1.2 and 1.8 g/kg GAA (P < 0.05). Proportional weights of liver and abdominal fat were decreased in birds fed diets containing supplemental Arg and 1.8 g/kg GAA compared to the CON? broilers (P < 0.05). Jejunal villus height and villus height to crypt depth ratio were increased in broilers receiving the CON? diet (P < 0.05). Serum concentration of nitric oxide increased when the CON? diet was supplemented with either Arg or 1.8 g/kg GAA (P < 0.05).
4. Dietary inclusion of GAA had an Arg-sparing effect, whereby 1.2 and 1.8 g/kg of supplemental GAA resulted in greater growth performance during the starter and entire rearing periods, respectively. Supplementation with 1.8 g/kg GAA had significant effects on some carcass and physiological parameters. 相似文献
2. Growth rate, food intake, food utilisation and proportion of dietary nitrogen retained were much poorer in chicks receiving salseed meal.
3. The chicks receiving salseed meal developed pathological lesions in liver and kidney.
4. The red blood cell count, white blood cell count, haemoglobin concentration and packed cell volume of the chicks receiving salseed meal were lower than those of chicks receiving maize.
5. The apparent metabolisable energy value of salseed meal was determined as 6.83 MJ/kg. 相似文献
2. Thirteen farms participated, all housing Lohmann LSL layers in systems allowing 8 or 10 hens per cage.
3. Each flock was visited at three different ages: 32, 62 and 77 weeks. During each visit, 100 hens were examined for keel bone fractures and deviations, plumage damage, body wounds, foot pad lesions, bumble feet, missing toes and toe wounds.
4. A deterioration with age of the condition of the plumage and keel bone was found (P < 0.001). At 77 weeks of age, 16% of the birds had poor plumage, and 43% of the birds had keel bone damage. In contrast, foot pad lesions were most prevalent at 32 weeks of age (13%), whereas the other foot injuries and body wounds remained at a relatively low level throughout the three ages examined.
5. Prevention of damage to the keel bone, plumage and foot pads should therefore be considered when aiming to improve welfare of laying hens housed in small furnished cages. 相似文献
2. A total of 480 3-d-old broiler chickens were randomly allocated to 4 treatments with 4 cages per treatment and 30 bird (15 males and 15 females) chicks per cage. All birds were fed on commercial basal diet. The control birds (HS0) received drinking water with no additions, whereas birds in the other treatment groups received a drinking water with 7.5 (HS7.5), 15.0 (HS15.0) and 22.5 (HS22.5) g/kg HS. Mush feed were provided on an ad libitum basis. Body weight and feed intake of broilers were determined at d 0, 21, and 42, and feed conversion ratio was calculated. On d 42, 4 broilers (2 males and 2 females) from each cage were slaughtered and the breast and thigh meats were collected for mineral composition and quality measurements.
3. Performance, carcass and GIT traits and caecal microbial population of broiler chicks at d 42 were not affected by the dietary treatments. The lightness (L*) of breast and thigh meat decreased in broilers supplemented with 15 and 22.5 g/kg HS in drinking water. Although the redness (a*) of breast meat increased, yellowness of thigh meat decreased in broilers supplemented with 15 and 22.5 g/kg HS in drinking water (P < 0.05).
4. In conclusion, the 15 and 22.5 g/kg HS administration in drinking water can be applied for broiler chicks to maintain growth performance and improve meat quality without changing caecal microflora. 相似文献
2. In the present study, control mash rye-based diets (CON) or Bacillus-DFM supplemented diets (TRT) were administered ad libitum to male broilers in three independent experiments.
3. In Experiments 1 and 2 (n = 25/group), liver samples were taken to evaluate bacterial translocation, digesta samples were used for viscosity measurements and the intestinal microbial flora was evaluated from different intestinal sections to enumerate total recovered gram-negative bacteria (TGB), lactic acid bacteria (LAB) and anaerobic bacteria (TAB). Additionally, both tibias were removed for assessment of bone quality.
4. In Experiment 3, each experimental group had 8 replicates of 20 chickens (n = 160/group). Weekly, body weight (BW), feed intake (FI) and feed conversion ratio (FCR) were evaluated. At d 28-of-age, samples were taken to determine bacterial translocation, digesta viscosity and bone quality characteristics.
5. In all experiments, consumption of Bacillus-DFM reduced bacterial translocation to the liver and digesta viscosity. Additionally, DFM supplementation improved BW, bone quality measurements and FCR. Moreover, chickens fed on the Bacillus-DFM diet in Experiments 1 and 2 showed a significant reduction in the number of gram-negative and anaerobic bacteria in the duodenal content compared to control.
6. In summary, chickens fed on a rye-based diet without DFM inclusion showed an increase in bacterial translocation and digesta viscosity, accompanied by reduced performance and bone quality variables relative to the Bacillus-DFM candidate group. Hence, incorporation into the feed of a selected DFM ameliorated the adverse anti-nutritional effects related to utilisation of rye-based diets in broilers chickens. 相似文献
2. Poults fed on diets with no supplementary riboflavin had poor gait scores, decreased times to sit and higher rates of culling compared to poults fed on the control diet (20 mg biotin and 0.3 mg riboflavin/kg diet). Histologically, riboflavin deficiency was associated with a peripheral neuropathy similar to that described previously in chicks and, unexpectedly, in growth plate abnormalities.
3. Tibiae of poults fed on the control diet were larger, more dense, stronger and stiffer than the diets with no supplementary riboflavin.
4. Increasing supplementary biotin in poults fed on diets with no supplementary riboflavin was associated with a decrease in tibia weight, density, strength and stiffness.
5. The results demonstrated that riboflavin deficiency in fast-growing turkey poults was associated with growth retardation, growth plate disturbance and peripheral nerve dysfunction leading to an inability to walk. 相似文献
2. Compared with ad libitum‐fed counterparts, a marked increase in the relative weight of the storage organs (crop and gizzard) was observed in the meal‐fed birds. The relative weight of the intestine was not affected by meal feeding but the ileal wall became thinner.
3. After food deprivation for 14 or 22 h, respectively, for the ad libitum and the meal‐fed chicks, the weights of contents in the gastrointestinal tract (GIT) segments did not differ between treatments except for those of the gizzard and caecum. Food restoration resulted in an increase in the contents of the GIT of meal‐fed chicks. The increments in the crop and gizzard contents were related to the severity of food restriction. The contents of the intestinal segments were quite similar in all treatments.
4. The activities of the digestive enzymes in the pancreas, expressed as units/g pancreas or units/kg body weight, were not significantly affected by feeding regime. In the small intestine of the meal‐fed birds, marked increases in specific (units/g content) and relative (units/kg body weight) activities were observed of amylase and chymo‐trypsin when compared with their ad libitum‐fed counterparts. The effect of meal feeding on trypsin activities was less pronounced. 相似文献
2. A 2 × 3 × 2 factorial experiment consisted of a positive control diet with adequate Ca and a negative control diet (Ca concentration reduced by 30%), three concentrations of WS (0, 75 and 150 mg/kg diet), and two concentrations of 1, 25 (OH)2 D3 (0 and 0.5 μg/kg diet).
3. A total of 600 male one-d-old Ross 308 broiler chicks were randomly distributed into 60 floor pens, with 10 birds each. Each treatment was replicated 5 times (50 birds). Diets were given ad libitum from one to 42 d of age. On d 21 and 42, one bird per replicate was killed and tibiae were removed.
4. Dietary treatments did not affect feed intake and feed conversion. The maximum body weight gain (2475 g) was noted in birds fed on a diet adequate in Ca and supplemented with 75 mg/kg WS.
5. The Ca and P retentions were significantly higher in birds that were given a diet with 30% less Ca. Supplementation of 150 mg/kg WS significantly improved Ca retention in birds receiving a negative control compared to those given a positive control diet (83.0% vs. 66.3%). Ca retention was significantly improved with the addition of 0.5 μg/kg 1, 25 (OH)2 D3 to the diet containing 75 mg/kg WS, regardless of dietary Ca concentration (79.5 vs. 73.3 and 77.9 vs. 68.9).
6. On d 21, birds that received WS had significantly higher tibia Ca compared to those of controls. No significant effects on tibia Ca were noted at 42 d. Birds given a negative control diet supplemented with 75 mg/kg WS and 0.5 μg/kg 1, 25 (OH)2 D3 displayed a similar tibia Ca compared to those given only 150 mg/kg WS. Dietary supplementation of 1, 25 (OH)2 D3 significantly increased tibia Ca and tibial mineralised zone width in birds at 42 d of age.
7. Tibia shear force and stiffness were significantly increased by supplementation of WS. Administration of 1, 25 (OH)2 D3 resulted in a significantly lower width of the proliferative zone at 21 d of age. Reduction of the Ca supply significantly reduced the mineralised zone and cortical thickness at this age.
8. The present study showed that WS supplementation improved Ca retention, bone calcification and mechanical properties with no adverse effects on performance. Also, synergistic effects of WS and 1, 25 (OH)2 D3 were observed on Ca retention and bone calcification. 相似文献
2. A ‘linear–plateau’ model successfully described the efficiency of protein utilisation (ep) as a function of AMEn:DCP in all three experiments. In Experiment 1, with both sexes being both ad libitum and control fed, the breakpoint was at 58.6 MJ AMEn/kg DCP. In Experiment 2, both sexes were fed balanced and unbalanced protein series, and at different rates, the slopes of the ascending part of the linear–plateau relationships for the different treatments were the same for all treatments (0.0204), and the inflection point was at 71 MJ AMEn/kg DCP. Using similar treatments in Experiment 3, the breakpoint for the balanced protein was 72 MJ/kg and for the unbalanced, 64, with a combined slope of 68 MJ AMEn/kg DCP.
3. The three experiments provide adequate evidence that ep is a linear–plateau function of the dietary AMEn:DCP ratio with a breakpoint of around 66.2 ± 1.98 MJ AMEn/kg DCP. Below this critical ratio, food intake declines as does protein and lipid retention.
4. That broilers, like pigs, exhibit an energy-dependent phase when high-protein feeds are offered is of practical importance when formulating pre-starter feeds for broilers and starter feeds for turkey poults as the ep of such feeds may well fall below the maximum due to the lack of dietary energy required to process the high dietary protein contained in such feeds resulting in poorer performance than expected. 相似文献
2. A total of 540 one-d-old Ross 308 broiler chicks were allotted to 9 experimental diets, including three ME levels (control, or 0.42 or 0.84 MJ/kg higher ME) and three types of supplemental lipotropic factors (control, 1000 mg/kg of choline or 100 mg/kg of carnitine) as a 3 × 3 factorial arrangement of treatments. Average daily feed intake (ADFI), average daily gain (ADG) and feed conversion ratio (FCR) were recorded during the starter (1–14 d of age), grower (15–28 d of age) and finisher (29–42 d of age) periods.
3. Results showed that the increase in dietary ME level had no impact on ADFI during the starter and grower periods. In the finisher period, increasing dietary ME decreased (P < 0.001) ADFI. Raising dietary ME level by 0.84 MJ/kg resulted in the greater ADG during the grower (P < 0.05) and finisher (P < 0.001) periods. Moreover, an improvement in FCR was observed with feeding the +0.84 MJ/kg diet. Dietary supplementation of lipotropic factors improved FCR values in birds fed the control and +0.84 MJ/kg diets during the grower and finisher periods (P < 0.01).
4. Dietary supplementation of both choline and carnitine increased (P < 0.05) moisture content of leg muscle, although malondialdehyde content of leg muscle was decreased (P < 0.01) in the presence of both lipotropic factors. Dietary supplementation of carnitine decreased (P < 0.01) leg fat content, and this effect was more obvious with higher ME levels, giving a significant ME × lipotrope interaction (P < 0.05). Higher dietary ME level (+0.84 MJ/kg) reduced (P < 0.05) protein content of breast muscle, but this factor was increased (P < 0.05) by dietary supplementation of choline.
5. Although dietary ME level had no marked effect on carcass yield and internal organ weight, supplemental choline increased (P < 0.01) carcass yield.
6. The results from this trial indicated that dietary supplementation with lipotropic factors can improve feed efficiency in high energy diets. In addition, oxidative stability of leg/breast muscles was improved as a result of dietary supplementation with choline or carnitine. 相似文献
2. Ambadi meal, either expeller‐processed (135.5 g and 271 g/kg) or solvent‐extracted (130.5 g and 261 g/kg), was incorporated at the expense of the peanut meal protein used in the reference diet (180 g/ kg) into diets which were fed to WL pullets (experiment 1) from 1 to 56 d of age. The weight gains and food efficiencies of the chicks fed on the ambadi meal and reference diets were similar.
3. With broilers (experiment 2) the weight gains were also similar, at all dietary concentrations of ambadi meal (89 to 356 g/kg), to those on the reference diet (235 g/kg peanut meal) from 14 to 35 d of age. However, food intake was higher on the ambadi meal diets and this resulted in significantly poorer food efficiency when compared to the reference diet.
4. High food intake and consequently low food efficiency was still evident in birds given ambadi meal diets even when ambadi meal replaced peanut meal on a digestible protein basis (experiment 4) or when ambadi meal (expeller or solvent‐extracted) was subjected to physical treatments such as soaking, autoclaving and pelleting (experiment 5).
5. The transit time of food through the gastro‐intestinal tract of broilers was faster when the diet contained ambadi meal than peanut meal. The higher food intake seen in broilers given diets containing ambadi meal could be the consequence of the fast rate of food passage.
6. Ambadi meal in diets for broilers resulted in significant increase (P<0.05) in the lengths of jejunum plus ileum and caecum. Fibre from the ambadi meal might have influenced the changes in the dimensions of gastro‐intestinal tract as well as in the transit time of food. 相似文献
2. In this study, seven experiments were designed, each with four treatment groups (n = 44 in each experiment). In Experiment 1, chicks received control solution and 0.5, 1 and 2 nmol of somatostatin through intracerebroventricular (ICV) injection. In experiments 2, 3 and 4, chickens were ICV injected with control solution and 1.25, 2.5 and 5 μg of B5063 (NPY1 receptor antagonist), SF22 (NPY2 receptor antagonist) and SML0891 (NPY5 receptor antagonist), respectively. In experiment 5, 6 and 7 chickens received ICV injection of B5063, SF22, SML0891, with a co-injection of + somatostatin, control solution and somatostatin. The cumulative feed intake was measured until 120 min post injection.
3. Somatostatin significantly increased feed intake in FD3 chicks. Both B5063 and SML0891 dose-dependently decreased feed intake compared with the control group, while SF22 led to a dose-dependent increase in feed intake. In addition, the hyperphagic effect of somatostatin significantly decreased with co-injection of B560 plus somatostatin (p < 0.05), but SF22 and SML0891 had no effect on feed intake induced by somatostatin in chicks (p > 0.05).
4. Based on the results of this study, it is likely that somatostatin increased feed intake and NPY1 receptor acts as a mediator in hyperphagic effect of somatostatin in neonatal chicks. 相似文献