Insulin-glucose interactions characterised in newly hatched broiler chicks

1. A study was conducted to identify the specificity of insulin-glucose interactions in newly hatched broiler chicks. 2. Plasma insulin concentrations in fed chicks at one day post-hatch were lower than those at later ages and tended to increase up to d 7, while the concentrations from 1 to 7 d of age were lower than those in chickens of 10 to 28 d of age. 3. Plasma glucose concentrations were lowered for 60 min by injection of insulin at 10 and 40 microg/kg body weight (BW) in both 1- and 21-d-old chicks, showing that the hypoglycaemic effect of exogenous insulin is of larger magnitude but shorter duration in 1-d-old chicks. 4. The decrease in plasma glucose concentration at 60 min after insulin injection (10 and 40 microg/kg BW) was larger in 1- to 7-d-old chicks than in 14- to 21-d-old chickens. 5. These results indicate that newly hatched broiler chicks are under the control of specific insulin-glucose interactions characterised by low plasma insulin concentrations with high sensitivity to insulin.     

Single injection of clenbuterol into newly hatched chicks decreases abdominal fat pad weight in growing broiler chickens

The aim of the current study was to examine the effects of clenbuterol injection into newly hatched chicks on both the abdominal fat pad tissue weight and the skeletal muscle weight during subsequent growth. Twenty‐seven 1‐day‐old chicks were divided into two groups, receiving either a single intraperitoneal (i.p.) injection of clenbuterol (0.1 mg/kg body weight) or phosphate‐buffered saline (PBS). Body weight gain, feed intake and feed conversion ratio were not affected by clenbuterol injection during the 5‐week experimental period, while the abdominal fat pad tissue weight of the clenbuterol‐injected chicks was lower than that of the control chicks at 5 weeks post‐injection. Plasma non‐esterified fatty acid concentrations were significantly increased in the clenbuterol‐injected chicks, while plasma triacylglycerol concentrations did not differ. Additionally, the enzymatic activity of fatty acid synthase was lower in the liver of the clenbuterol‐injected chicks. Conversely, the skeletal muscle weights were not affected by clenbuterol injection. These results suggest that a single clenbuterol injection into 1‐day‐old chicks decreases the abdominal fat pad tissue weight, but may not affect skeletal muscle weights during growth. © 2015 Japanese Society of Animal Science     

Necrotic hepatitis due to Clostridium perfringens infection in newly hatched broiler chicks

Multiple necrotic hepatitis lesions of 5 newly hatched broiler chicks in three flocks derived from two hatcheries were examined pathologically. The livers were brittle, and multiple yellowish or green foci were scattered on the surface and cut surface. The main histological finding was well demarcated multi-focal necrosis in the liver. Many Gram-positive large bacilli that reacted positively with polyclonal anti-Clostridium perfringens serum were observed in necrotic areas.     

Yolk utilisation in the newly hatched poult

1. Routes of yolk utilisation and some aspects of intestinal digestion and absorption were determined in the hatching poult and compared to the chick. 2. Transfer from yolk to blood was observed pre-hatch and up to 72 h post-hatch. From hatch the transport pattern was similar to the chick. 3. Transport from the yolk sac into the intestine via the yolk stalk was observed up to 120 h after hatch. Secretion was initially to the proximal ileum and reflux occurred, transporting contents to the proximal small intestine and gizzard. Antiperistaltic movements increased after hatch and secretion continued for longer post-hatch than in the chick. 4. In situ uptake of glucose per unit of duodenum did not change with age, whereas uptake of methionine and oleic acid decreased with age. In contrast, in the chick glucose and methionine uptake capacity increased slightly between hatch and 7 d. 5. The lipid class distribution of intestinal contents resembled that of yolk close to hatch, however, some lipolysis was observed in the duodenum. With age the proportion of free fatty acids increased rapidly, first in the duodenum then in the ileum and finally in the caecum. Yolk in the distal small intestine close to hatch did not appear to be utilised.     

Pathogenicity of natural and experimental listeriosis in newly hatched chicks

The pathogenicity of Listeria monocytogenes for newly hatched chickens exposed to natural infection was examined. Organisms entered through the alimentary tract and dissemination followed bacteraemia. Among a number of symptoms recorded were unilateral and bilateral toe paralysis. In addition to gross abnormalities in the following tissues, histological lesions were seen in the liver, spleen, heart and kidneys of all infected chicks but brain lesions were observed only in birds with central nervous system involvement. The organism was recovered from some tissues derived from apparently healthy chicks as well as those with listeriosis. The use of trypsin in the isolation process increased the probability of a positive result from tissues, reduced the storage time needed and had no adverse effect on the rate of organism growth.     

Nutrient digestibility and energy utilisation of diets based on wheat, sorghum or maize by the newly hatched broiler chick

1. Two experiments were conducted to measure changes in nutrient utilisation in the newly hatched broiler chicken. The first experiment determined the nitrogen-corrected apparent metabolisable energy (AME(N)) and total tract digestibility of starch and fat in diets based on wheat, sorghum and maize during the first two weeks post-hatch. The second experiment was conducted to confirm the results of Experiment 1 using wheat- and maize-based diets and was of 21 d duration. 2. In both experiments, changes to AME(N) with age were similar irrespective of the diet type, declining from d 3 to d 5-9 and then increasing after d 9. 3. In Experiment 1, the total tract digestibility of starch and fat exhibited a pattern similar to that of AME(N). 4. In Experiment 1, cereal effects were significant, with maize- and sorghum-based diets having higher AME(N) values than the wheat-based diet. Total tract starch digestibility determined for d 5, 7 and 14 showed no cereal differences. Total tract fat digestibility on d 7 was significantly lower for the wheat- and sorghum-based diets than for the maize-based diet, but no cereal differences were observed on d 5 or 14. 5. In Experiment 2, cereal effects were significant, with the maize-based diet having a higher AME(N) than the wheat-based diet. 6. These results showed that nutrient utilisation is compromised during the first week of life of the broiler chick.     

Non-invasive determination of heart rate in newly hatched chicks.

1. Using a flexible piezoelectric probe, we detected non-invasively the cardiogenic precordial movements of domestic fowl chicks and measured heart rate (HR) daily over the first week after hatching (day 0) for comparison with previously measured embryonic HR. 2. HR of the hatchlings was much more variable than embryonic HR. The mean HR at a given age also varied among the 5 chicks measured. 3. The overall mean HR was 280 +/- 20 (SD, n = 5) bpm on day 0. This value was similar to the prepipping HR and lower than that of externally pipped embryos. It increased to 342 +/- 39 bpm 3 days later.     

Genetics of resistance to Salmonella typhimurium in newly hatched chicks

1. A survey of inbred and partially inbred lines of chickens showed pronounced differences in mortality following challenge of the newly hatched chicks with Salmonella typhimurium. Lines W, 6(1) and N were highly resistant to challenge, whereas lines C and 15I were highly susceptible. 2. This difference in susceptibility was observed with a range of 5 strains of S. typhimurium of different degrees of virulence and also following both oral and intramuscular challenge. 3. The inheritance of resistance was studied in detail by examining a series of crosses between the susceptible line C and resistant line W. The pattern of mortality in crosses and back-crosses between these lines indicated resistance is dominant and was consistent with the inheritance of a dominant autosomal resistance gene. 4. There was no evidence of maternal effects in these crosses, and no evidence of association with the major histocompatability complex.     

Campylobacter colonization of the crops of newly hatched leghorn chicks

We have studied colonization of crops in newly hatched leghorn chicks (a layer breed) by wild-type and mutant strains of Campylobacter jejuni. We established that the wild-type parent strain forms a stable population level within the crop and that the mutant strains will do likewise. Concentrations of mutant strains in the crop were usually below that of the wild-type parent strain and ranged from 10(3) to 10(5) colony-forming units. These results differ from results we have previously reported concerning cecal colonization, where these same mutant strains lacked colonizing ability. The present results, therefore, indicate that bacterial factors necessary for colonization of the crop are not the same as those needed for colonization of the cecum.     

Simultaneous measurements of instantaneous heart rate and breathing activity in newly hatched chicks

1. Among three types of fluctuations of instantaneous heart rate (IHR) found previously in newly hatched chicks, a high frequency oscillation with a mean frequency of about 0.7 Hz (Type I) appeared to be concurrent with breathing (Moriya et al., Comparative Biochemistry and Physiology, 124A: 461-468, 1999). 2. In order to confirm that Type I HR fluctuation is respiratory sinus arrhythmia (RSA), breathing activity was measured by a condenser microphone, simultaneously with IHR. 3. The microphone detected pressure changes caused by breathing (acoustorespirogram, ARG) and also unexpectedly movement, probably twitch, of hatchlings. 4. Simultaneous measurements of IHR and ARG demonstrated that oscillatory frequency of Type I HR fluctuation coincided with breathing frequency and IHR increased with inspiration, confirming that Type I HR oscillation is RSA. 5. In addition, large transient HR accelerations (Type III HR fluctuation) simultaneously occurred with movement or twitch of the hatchlings, suggesting that Type III HR fluctuation and movement of hatchlings have the same origin, probably sympathetic nerve function.     

A cell wall preparation of Enterococcus faecalis strain EC-12 stimulates β-defensin expression in newly hatched broiler chicks

In our previous study, a cell wall preparation of Enterococcus faecalis strain EC‐12 (EC‐12) prevented the colonization of vancomycin‐resistant enterococci (VRE) in newly hatched broiler chicks. Relatively early prevention against VRE colonization by EC‐12 administration may be related to the enhanced innate immune system. In this study we examined the effect of EC‐12 on the kinetics of immunoglobulin A (IgA) concentration in the cecal digesta of chicks from 1 day to 14 days old to evaluate humoral immunity. We also examined the effect of EC‐12 on β‐defensin mRNA expression and lysozyme production. The IgA concentration in the cecal digesta showed a decline in chicks from 2 to 8 days old and then a recovery up to when they were 14 days old. The concentration tended to be higher in EC‐12‐administered chicks than in control chicks at 14 days old. EC‐12 administration did not stimulate the lysozyme activities in the alimentary tract. However, β‐defensin mRNA expression in the tongue and the bursa of Fabricius was higher in chicks administered EC‐12 than in the control chicks at 5 days old. These results indicate that β‐defensin may be one of the major defense mechanisms inhibiting VRE colonization in young chicks.     

Energy metabolism of cocks and broiler chickens fed on diets with different carbohydrate sources.

Energy balances of cocks and chickens were measured using the nitrogen-carbon-balance method. In Experiment 1 twelve adult White Leghorn cocks were fed alternately on a basal ration or on a supplemental ration composed of 75% basal diet and 25% carbohydrate source as a supplement. In Experiment 2 six groups of 12 male broiler chickens were fed successively on two diets each with different carbohydrate sources (40% of DM) and on two energy levels. The investigated carbohydrate sources were glucose, fructose, sucrose, maize starch, raw and steamed potato starch, dried sugar beet pulp, tapioca, wheat, maize, rye and barley. In both experiments the energy digestibility of the diets with raw potato starch, beet pulp and barley was significantly lower compared to the other diets. Digestibility of those ranged from 88 to 81%. By simple linear regression no significant differences in efficiency of utilisation of ME of the diets between the carbohydrate sources sugars, starches and cereal grains could be proved. The corresponding MEm values agreed very close among the diets (411 to 429 kJ.kg BW-0.75.d-1).     

The effect of flavour on the growth and feed utilisation of broiler chicks

The results of four experiments testing the effect of a flavour made up of ethyl butyrate and other esters, phenylacetic acid and other organic acids, oil of juniper and other essential oils, diacetyl, and maltol on the feed utilisation and growth of broiler chicks to 8 weeks of age have shown small but consistent improvements in feed conversion. This improvement was significant (P>0.05) when the 8‐week results of the four tests were pooled, but were not significant when tested within each experiment. The 4‐week results of the combined experiments indicated a highly significant (P<0.01) improvement in feed utilisation following the use of the flavour.     

Energy utilisation in germ-free and conventional chicks fed diets containing sorbose

1. In experiment 1, growing conventional (CV) chicks were fed on diets containing graded amounts (0, 100, 200 and 300 g/kg diet) of sorbose from 4 to 14 d. Protein, fat and energy deposition were determined after carcase analysis. The values for growth, food efficiency, metabolisable energy (ME) and fat and energy depositions declined as the dietary sorbose content increased. 2. In experiment 2, the performances of germ-free (GF) and CV chicks fed on diets with (100 g sorbose/kg diet) or without sorbose were investigated. On both diets, body weight gain, food consumption and protein accumulation in GF chicks were significantly higher than those in CV birds. No significant differences were observed between the dietary treatment except for ME values, which were significantly lower for the sorbose diet. 3. It is suggested that dietary sorbose decreased energy utilisation, and that the microbial contribution to the utilisation of dietary sorbose was negligible in the chicken.     

Skeletal muscle protein turnover in broiler and layer chicks

Dietary infusion of L-[U-14C]tyrosine was used to estimate the fractional protein synthesis rates (FSR) in broiler and layer chickens. Six 2-wk-old birds of each strain were placed in individual metabolism cages and given a purified diet in agar-gel containing 2 microCi L-[U-14C]tyrosine for 6 h. The birds were sacrificed and the pectoralis major (PM) and two combined leg (LM) muscles (gastrocnemius and peroneous longus) were removed for analysis. Subgroups of chickens were sacrificed 3 d before and 3 d after infusion to observe changes in muscle composition to calculate fractional protein accretion rates (FAR). Fractional protein breakdown rates (FBR) were calculated by difference (FBR = FSR-FAR). Protein, ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) concentrations were determined to observe relationships between these cellular constituents and FSR. Fractional whole body growth rate and FSR in PM was greater (P less than .05) in broiler than layer birds. The FSR in LM of the layer was not different (P greater than .05) from that of broilers, and from the FSR of the PM in each bird-type. The calculated FBR in the layer PM was at least 17% higher than that of the other muscles. Ratios of FSR to FBR indicated that 16% of the protein synthesized in the layer PM was retained, compared with 45% in the broiler PM. The RNA activity of the layer PM was less (P less than .05) than that of the other muscles investigated. Deoxyribonucleic acid activity was lower (P less than .05) in the PM than LM of either bird-type.(ABSTRACT TRUNCATED AT 250 WORDS)     

Control of Salmonella enteritidis phage type 4 experimental infection by fosfomycin in newly hatched chicks

One hundred and twenty 1-day-old broiler chickens were divided into four groups: group I unmedicated and orally challenged with 1.5×10⁸ cfu of Salmonella enteritidis phage type 4; group F infected and treated with 300 ppm of fosfomycin in their drinking water; group CF uninfected and treated, and group C maintained as a control group. Their performance, clinical signs, S. enteritidis PT4 reisolation and biochemistry variables were compared. Group F showed fewer symptoms and gross lesions than those from group I. Fosfomycin treatment at 300 ppm improved body weight at 7 days of age by 42.3%. S. enteritidis PT4 reisolation in group I was higher than in the treated group, but total decontamination of challenged birds was not achieved. There was an increase in the levels of total protein and globulins in group I but not in the treated group. Fosfomycin caused no adverse effects on chickens from group CF, assessed by performance and biochemical variables. The results indicate that fosfomycin could be used in the treatment of S. enteritidis PT4 experimental infection.     

开食时间对雏鸡早期生长和内脏器官发育的影响

本试验旨在研究不同开食时间对雏鸡早期的生长性能及内脏器官发育的影响.试验选取1080只0日龄、体重相近的新扬州鸡雏鸡,根据开食时间不同,随机分成6个组,每个组3个重复,每个重复60只(30只公鸡,30只母鸡).出壳后一周内,每天从每个重复中随机挑选8只雏鸡(4公4母),分别称其活重后致死,取卵黄囊、肝脏、心脏、胰腺、法氏囊和小肠分别称重,测量小肠长度.结果表明,出壳后禁食36h对7日龄鸡体重没有显著负面影响,出壳后最长禁食时间不应超过60h.     

Effect of L-carnitine supplementation on utilisation of energy and protein in broiler chicken fed different dietary fat levels.

Effects of a supplementation of 80 mg L-carnitine per kg diet were studied in broiler chicken at two dietary levels of fat (4 and 8%) and different feeding levels (ad libitum in a growth trial, 95 and 85% of ad libitum in a balance trial). A low-carnitine basal diet adequate in amino acid concentration was used. In the growth trial, each diet was fed to 9 groups of 10 birds each for 16 days from day 5 of live onwards. Growth and feed intake were determined. At the end of the trial, birds were killed and homogenised for subsequent empty body analysis. Accretion of protein and energy was determined using a representative blank group killed at the beginning of the trial. In the balance trial, 8 individual birds were used per treatment. Birds were offered the feed at approximately 85 and 95% of ad libitum intake, which was determined with separate birds for both fat levels. Excreta were quantitatively collected three times daily for 8 consecutive days beginning on day 17 individually for each bird. Supplemented L-carnitine did not significantly affect any response criterion. However, growth and feed conversion tended to be improved by about 5% in the carnitine supplemented diets when fed ad libitum. An interaction between carnitine and fat level occurred with regard to feed conversion, indicating that carnitine had a positive effect at the high fat level, but not at the low fat level. L-carnitine did not positively affect the metabolisability of energy (ME/GE) and the efficiency of energy utilisation (RE/GE or RE/ME). Similarly, no significant carnitine effect was determined with regard to N accretion and the efficiency of utilisation of dietary protein in both trials. It is concluded that endogenous carnitine synthesis is not the limiting factor for energy utilisation in broiler chicken, even at high dietary fat concentration. Occasionally reported positive effects of supplemental carnitine were likewise caused by reasons other than improved energy or protein utilisation. Further studies on amino acid utilisation and catabolism should consider marginal amino acid supply.     

Effects of dietary protein concentration and corticosterone injections on energy and nitrogen balances and fat deposition in broiler chicks

Reducing dietary protein concentration in isocaloric diets consistently decreased nitrogen and energy excretion, and increased dry matter (DM), non-protein DM (NPDM), energy retention and fatness. There were significant correlations, negative between dietary energy-to-protein (E:P) ratio and nitrogen excretion and positive between the E:P ratio and the retention of DM, NPDM and energy. Nitrogen excretion was correlated with energy excretion, and NPDM retention with energy retention. Corticosterone injections increased fatness despite significantly increasing nitrogen and energy excretion. A positive relationship was observed in corticosterone-treated birds between nitrogen excretion on the one hand and the retention of DM and NPDM on the other. Increased food intake because of a low dietary protein concentration was not evident when a sorghum-based diet was used. Moreover, corticosterone injections increased neither the food intake nor the fatness of chicks fed this diet. Decreasing the protein concentration in diets containing identical metabolisable energy (ME) levels slightly, but significantly increased apparent ME values in three out of four experiments. Corticosterone injection did not affect this variable.