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1.
The commercial broiler chicken strains are the result of successful selection programmes. Most of the problems related to welfare arise from the high growth rate and body weight. The use of environmental enrichments in intensive farming could have a positive effect on birds by increasing animal welfare. The aim of the study was to evaluate the effects of Hermetia illucens (HI) and Tenebrio molitor (TM) live larvae in the diets of broiler chickens on growth performance, carcass yield and health status. A total of 180 four-day-old male broiler chickens (Ross 308) were randomly allotted to 18 pens. Each pen was assigned to one of the three dietary treatments (6 replicates/treatment, 10 birds/replicate) as follows: (i) control diet (C): commercial feed (two feeding phases: starter [4–11 days] and grower [12–38 days]), (ii) HI: C + 5% of the expected daily feed intake (DFI) HI live larvae (calculated on dry matter [DM]) and (iii) TM: C + 5% of DFI TM live larvae (DM). At 39 days of age, birds were slaughtered. Growth performance parameters were overall not affected by dietary treatments, except for the grower phase feed conversion ratio (FCR) and the overall FCR being better in the TM broilers than the others (p < 0.01). No differences were observed for slaughtering performance and haematological and serum parameters, except for the spleen relative weight being higher (p < 0.01) in the birds administered with larvae when compared to the C group. Gut morphometric indexes and histopathological alterations were not influenced by insect larvae administration. In conclusion, the administration in limited quantities of HI and TM live larvae as environmental enrichment has no negative effects on broiler chicken growth performance and health status. A behavioural study could confirm that live insect larvae represent a novel natural environmental enrichment in broiler farming.  相似文献   

2.
The general histological features of the small intestine are well known. However, histological intestinal alterations induced by ingested feeds have not been established. To demonstrate such a relationship; (i) the post‐hatching development of intestinal villi in chickens was observed; (ii) histological intestinal differences were compared in White Leghorns and broilers; and (iii) histological intestinal alteration was investigated in fasting and refeeding treatments, using chickens and piglets. Histological intestinal recovery responses; (iv) to luminal nutrient absorption, intraluminal physical stimulation, or intravenous parenteral alimentation in fasted chickens, as well as; (v) to particle size and nutritional level of refed diets in fasted chickens and piglets were also compared. To induce compensatory enlargement of ileal villi; (vi) the jejunum was surgically resected. To reconfirm the histological intestinal alterations induced artificially; (vii) conventional feeding experiments were enforced in chickens and piglets. These fundamental investigations demonstrate that the high values of villus height, cell area and cell mitosis numbers as well as protuberated epithelial cells are hypertrophied by ingested feeds . Finally, as examples of practical use in the animal production field; (viii) useful feed resources to improve the growth performance by activating the intestinal function in chickens and piglets; and (ix) an effective forced molting method are introduced. Based on the histological intestinal alterations related with growth performance in chickens and piglets, this article reviews progress in the establishment of a histological intestinal index to assess the intestinal function.  相似文献   

3.
This study was conducted to evaluate the effects of dietary Tenebrio molitor larvae meal (TM meal) inclusion on the performance, carcass traits, caecum microbiota and blood parameters of broiler chickens. A total of 180-day-old chickens were allocated to three dietary groups with five replicate pens (12 birds/pen). Experimental diets were included a corn-soybean basal diet, and two diets with 2.5% and 5% TM. TM-included diets have been administered for periods of starter (1–10 days) and grower (11–25 days). A regular finisher diet was given to all groups during the 26–42 days of age. Diets containing TM meal did not influence feed intake and mortality percentage. Feed conversion ratio was lower with the 2.5% TM meal diet compared with the control group at starter period (p < .05). Besides, broiler chickens fed TM meal included diet had a higher body weight gain than the control group during 1–10 days of age (p < .05). The carcass characteristics and length and weight of different parts of small and large intestines were not influenced by diets. TM meal inclusion decreased the albumin-to-globulin ratio compared with the control group (p < .05). Additionally, lower total count of aerobic and Escherichia coli bacteria was observed in response to diet inclusion of 5% TM meal. Overall, the inclusion of TM meal in broilers' diet improved body weight gain and feed conversion ratio in the starting period, decreased albumin-to-globulin ratio and E. coli bacteria content.  相似文献   

4.
The purpose of this study was to verify the ability of a probiotic in the feed to maintain the stability of the gut microbiota in chickens after antibiotic therapy and its association with growth performance. One thousand six hundred twenty 1‐day‐old Cobb male were housed in floor pens (36 pens, 45 birds/pen) and were fed corn‐/soya bean meal‐based diets supplemented with or without probiotic (Bacillus subtilis) during the entire rearing phase. From 21 to 24 days of age (three consecutive days), the chickens were submitted to antibiotic therapy via drinking water (bacitracin and neomycin) in order to mimic a field treatment and induce dysbiosis. Growth performance was monitored until 42 days of age. At 2, 4 and 6 days after antibiotic therapy, three chickens from each pen were euthanized and the contents of the small intestine and caeca were collected and pooled. The trial was conducted with four treatments and nine replicates in a 2 × 2 factorial arrangement for performance characteristics (with and without probiotic × with and without antibiotic therapy); for the intestinal microbiota, it was in a 2 × 2 × 3 factorial arrangement (with and without probiotic × with and without antibiotic therapy × 2, 4 and 6 days after the antibiotic therapy) with three replicates per treatment. Terminal restriction length polymorphism (T‐RFLP) analysis showed that the structure of gut bacterial community was shaped by the intestinal segment and by the time after the antibiotic therapy. The number of 16S rDNAs copies in caecum contents decreased with time after the therapeutic treatment. The antibiotic therapy and dietary probiotic supplementation decreased richness and diversity indexes in the caecal contents. The improved performance observed in birds supplemented with probiotic may be related to changes promoted by the feed additive in the structure of the intestinal bacterial communities and phylogenetic groups. Antibiotic therapy modified the bacterial structure, but did not cause loss of broiler performance.  相似文献   

5.
Increased intestinal permeability (IP) can lead to compromised health in chickens. As there is limited literature on in vivo biomarkers to assess increased IP in chickens, the objective of this study was to identify a reliable biomarker of IP using DSS ingestion and fasting models. Male Ross chickens (n = 48) were reared until day 14 on the floor pen in an animal care facility, randomized into the following groups: control, DSS and fasting (each with n = 16), and then placed in metabolism cages. DSS was administered in drinking water at 0.75% from days 16 to 21, while controls and fasted groups received water. All birds had free access to feed and water except the birds in the fasting group that were denied feed for 19.5 h on day 20. On day 21, all chickens were given two separate oral gavages comprising fluorescein isothiocyanate dextran (FITC‐d, 2.2 mg in 1 ml/bird) at time zero and lactulose, mannitol and rhamnose (LMR) sugars (0.25 g L, 0.05 g M and 0.05 g R in 2 ml/bird) at 60 min. Whole blood was collected from the brachial vein in a syringe 90 min post‐LMR sugar gavage. Serum FITC‐d and plasma LMR sugar concentrations were measured by spectrophotometry and high‐performance ion chromatography respectively. Plasma concentrations of intestinal fatty acid binding protein, diamine oxidase, tight junction protein (TJP), d ‐lactate and faecal α‐antitrypsin inhibitor concentration were also analysed by ELISA. FITC‐d increased significantly (p < 0.05) after fasting compared with control. L/M and L/R ratios for fasting and L/M ratio for DSS increased compared with control chickens (p < 0.05). TJP in plasma was significantly increased due to fasting but not DSS treatment, compared with controls. Other tests did not indicate changes in IP (p > 0.05). We concluded that FITC‐d and LMR sugar tests can be used in chickens to assess changes in IP.  相似文献   

6.
A feeding experiment was conducted to evaluate the effects of dietary sesame meal (SM) on growth performance and histological intestinal alterations of layer chickens. Thirty-two White Leghorn male chickens were divided into 4 groups of 8 birds. They were fed 0, 10, 20, or 30% dietary SM for 28 d. After the feeding experiment, average villus height, epithelial cell area, and crypt cell mitosis numbers were morphometrically compared with an image analyzer, and the results were analyzed with Duncan's multiple range test. The morphological changes of epithelial cells on the villus apical surface were observed morphologically using scanning electron microscope. The growth performance data revealed no significant differences in birds fed up to 20% dietary SM, significantly lower values were revealed in the 30% dietary SM group. At 10% dietary SM, growth performance tended to be improved. Most values of the intestinal villus height, epithelial cell area, and crypt cell mitosis numbers were not different among groups for each intestinal segment. Flat epithelial cells were on the intestinal villus apical surface in the group fed 0% dietary SM. Those cells developed into protuberated cells in the group fed 10% dietary SM, and these protuberated cells disappeared gradually with increasing dietary SM levels. Considerations for current growth performance and histological intestinal alterations suggest that the SM would have no detrimental effect on the growth performance with up to 20% dietary SM nor on the intestinal villi with up to 30% dietary SM, but hypertrophy was observed in the epithelial cells of bird fed up to 20% dietary SM. In conclusion, up to 20% SM could be incorporated into diets fed under commercial conditions to male birds of laying strains in the developer period.  相似文献   

7.
The present experiment was conducted to investigate the effects of fiber and threonine (Thr) on growth performance, intestinal morphology and immune responses of broiler chickens. A total of 420 one-day-old mixed sex broiler chicks (Ross 308) were randomly divided into 6 experimental diets and 5 replicates of 14 chicks based on a factorial arrangement (2 × 3) from 1 to 42 d of age. Experimental factors included dietary supplemental fiber type (no supplemental fiber [NSF], 30 g/kg sugar beet pulp [SBP] or 30 g/kg rice hull [RH]) and Thr inclusion level (100% or 110% of Thr requirement recommended by breeder company [Ross 308]). Growth performance of broilers was assayed at different periods of the experiment. Intestinal morphometric features were measured at 21 d of age. Antibody titer against sheep red blood cells (SRBC), Newcastle and influenza disease viruses were measured on d 30 of trial. Dietary inclusion of SBP and RH significantly decreased feed intake and weight gain during the entire rearing period (P < 0.05). Interaction of fiber and Thr had no beneficial effects on the performance of chickens across the entire rearing phase. Dietary supplementation of 110% Thr required level improved jejunal morphometric features (P < 0.05), whereas its inclusion with fibrous materials failed to show the same effects. Dietary supplemental Thr together with SBP significantly increased antibody production against SRBC (P < 0.05). In conclusion, although supplemental 30 g/kg fibrous materials impaired growth performance, inclusion of SBP along with 110% Thr level improved the humoral immunity in broiler chickens.  相似文献   

8.
1. The effect of intestinal digesta viscosity on bird performance in chickens with coccidiosis was compared to those without coccidiosis. 2. Six hundred chicks were divided into five groups: one control group was fed a basal maize/soyabean-based diet and the other groups were fed the basal diet supplemented with 2, 4, 6 or 8 g carboxymethyl cellulose (CMC) per kg of feed. At 14 d of age half the birds were individually inoculated with sporulated oocysts of Eimeria acervulina and Eimeria praecox. 3. Intestinal digesta viscosity increased with increasing inclusion of CMC. This effect was considerably less pronounced in inoculated than in non-inoculated birds. 4. There was a significant negative effect on live weight gain and feed conversion ratio (FCR) with increasing CMC inclusion in non-inoculated birds, but in inoculated birds there was no clear relation between CMC inclusion and performance. Neither intestinal lesion scores, nor numbers of Clostridium pefringens in the caeca, were significantly affected by CMC inclusion. 5. Across all diets inoculation impaired growth rate by 9% and FCR by 8%, but did not affect the amount of C. perfringens in the caeca.  相似文献   

9.
The utilization of copra meal as a feed ingredient is limited because it contains a high level of mannan. However, recent findings indicate that the effect of copra meal on growth performance in broiler chickens can be improved by the supplementation of mannanase in the diet. In the present study, we examined the effect of mannanase‐hydrolyzed copra meal (MCM) on growth performance and muscle protein metabolism in growing broiler chickens (Gallus gallus domesticus). Forty 8‐day‐old male broiler chicks were assigned to two groups (four birds in each pen, five replicates) and fed either a commercial diet (as a control diet) or a diet containing MCM at 0.2% until 22 days of age. Dietary MCM significantly increased the weights of body, breast muscle, and thighs in chickens, whereas the weights of abdominal adipose tissue and liver were not affected. Cumulative feed intake was significantly increased by MCM. Dietary MCM significantly decreased plasma 3‐methylhistidine level. The messenger RNA and protein levels of muscle protein metabolism‐related factors were not altered by MCM. These findings suggest that the growth‐promoting effect of MCM is related to the suppression of muscle proteolysis in growing broiler chickens.  相似文献   

10.
This study was conducted to investigate the effects of free‐range system (FRS) and conventional cage‐rearing system (CRS) on growth performance, carcass yield, meat quality, lymphoid organ indices, and serum biochemistry of Wannan Yellow chickens. At 56 days of age, a total of 640 male chickens were randomly allocated to FRS and CRS groups, each of which included 4 replicates with 80 chickens in each replicate. The experiment lasted from 56 to 112 days of age. The results showed that CRS chickens exhibited better final body weight, average daily feed intake, average daily gain, and feed conversion ratio, whereas FRS chickens showed better breast and leg yields, shear force, meat color, lower drip loss, and decreased abdominal fat deposition. Moreover, the absolute thymus weight and thymus to body weight ratio of FRS birds were significantly higher than those of CRS birds (p < 0.05). Additionally, FRS chickens had significantly reduced glucose, total protein, triglyceride, and cholesterol contents, but enhanced levels of high‐density lipoprotein cholesterol (p < 0.05). In conclusion, the FRS has advantages in breast and leg yields, meat quality, and some serum biochemical parameters of Wannan Yellow chickens, whereas it has negative effects on growth performance.  相似文献   

11.
The aim of the study was to determine the effect of dietary supplementation of a probiotic and a synbiotic on the morphometric parameters of the small intestine of broiler chickens. The experiment was conducted on three hundred sixty, one‐day‐old female Ross 308 chicks, which were randomly selected from 20,000 birds and divided into three treatment groups (n = 120) with ten replicates per treatment. The control group (C) was fed a commercial diet, the probiotic group (PRO) was fed the same diet with an added 1% of the probiotic Lavipan® (Lactococcus lactis, Carnobacterium divergens, Lactobacillus casei, Lactobacillus plantarum and Saccharomyces cerevisiae), and the synbiotic group (SYN) was fed the commercial diet with an added synbiotic: 0.8% of the prebiotic RFO (extracted from lupin seeds) and 1% Lavipan®. According to the manufacturer's data, apart from the typical probiotic action,microorganisms contained in the preparation release anti‐bacterial substances (hydrogen peroxide and bacteriocins) and, therefore, are antagonistic towards pathogenic bacteria present in the gut of animals. Supplementation took place in the first seven days of rearing, and all birds had ad libitum access to water and feed during the 42 days of the experiment. On the last day, all birds were slaughtered and samples from three segments of the small intestine were taken. Villi area, height, width and crypt depth ratios were read using Multiscan software. Synbiotic supplementation increased the BWG of broilers from first to tenth day of rearing, compared to the control group. The PRO group had improved villi morphometric parameters of the duodenum. In the jejunum and ileum, both bioactive substances improved villus width and villus surface area. Crypts were deeper in the small intestine of birds supplemented with bioactive substances, which allows greater renewal of the villi. As expected, the intestinal morphometric parameters of broiler chickens benefited from bioactive substance supplementation.  相似文献   

12.
Effects of sex and strain of bird on factors influencing welfare in chickens were investigated in 288 21-week-old Potchefstroom Koekoek (PK), Ovambo (OV), and Naked Neck (NN) chickens. The birds were allocated to 4 paddocks of Chloris gayana and a house subdivided into 4 pens. There were 12 males per strain and 12 females per strain in each paddock. Similarly, 12 males per strain and the same number of females were placed in each pen in the house. Twelve birds, 4 each of NN, OV, and PK, were randomly selected per paddock and per pen, and tonic immobility (TI) was determined. Ambient temperature and humidity were recorded and fitted into a PROC MIXED model as random effects, with strain and sex as main effects. On the last d of the trial, blood samples were collected from 9 (3 of each strain) randomly selected birds per paddock, via brachial venepuncture, using 5 mL syringes and 22 gauge needles. At slaughter, the liver and spleen were recovered and weighed immediately. Organ weights were expressed relative to body weight (BW) of each bird. Sex of bird influenced (P < 0.05) BW, spleen, and relative liver weights and heterophil to lymphocyte (H/L) ratio. Strain did not influence (P > 0.05) TI but affected (P < 0.05) all other parameters. Rearing system (P < 0.05) influenced all parameters. Strain × sex interactions were significant (P < 0.05) on all organ weights. Males appeared more stressed than females. The free-range system could minimize stress in birds though mechanisms should be devised to prevent attacks by predators. Perhaps future research could be designed to study similar parameters over a longer observation period using younger slow-growing chickens.  相似文献   

13.
AIM: To compare the effects of four stocking densities (5, 10, 15 or 20 birds per m2) on the performance, carcass characteristics and selected welfare indicators of broiler chickens. METHODS: A total of 756 day-old male broiler chicks were assigned as six replicates of 13, 25, 38 and 50 birds per pen, to stocking densities of 2,000, 1,000, 667 and 500 cm2 floor space per bird, respectively. The birds were housed in floor pens in an environmentally controlled room. Normal commercial diets were fed ad libitum and fresh water was freely available throughout the 5-week study period. Liveweights of birds and feed intake were recorded at weekly intervals. Data on carcass parameters and welfare indicators (moisture, gait scores, feather scores, breast and hip lesions, and foot pad and hock burns) were obtained on Day 35. Adrenal glands were removed at slaughter, weighed and examined histologically to determine the total proportion of cortical and medullary tissues. RESULTS: During the study, the birds at the lowest density grew faster (p<0.001-0.01) and consumed more (p<0.001- 0.01) feed than those at the other three stocking densities. The liveweight gains and feed intake of birds reared at densities of 10, 15 and 20 birds per m2 were similar (p=0.11-0.83 and p=0.17-0.57, respectively). Stocking density had no influence on the feed/weight gain, mortality or carcass characteristics. No breast or hip lesions were observed in carcasses from any of the groups. The weight and structure of the adrenal glands were similar across all groups although the staining of medullary tissue of birds was most intense in the highest stocking density group. As stocking density increased, so did moisture and gait score, hock and foot pad burn scores, and the feather score was adversely affected. CONCLUSIONS: The data showed that the relationship between stocking density and productivity traits was not linear in nature, in accordance with other studies. Under the conditions of the current study, the performance, mortality and carcass characteristics of broilers grown at densities of 10, 15 and 20 birds per m2 were similar. There were some welfare implications at high population densities as indicated by adverse effects on litter quality, gait scores and the incidence of hock and foot pad burns.  相似文献   

14.
Two experiments were conducted to investigate the effects of phytonutrients (PN) on growth performance, antioxidant status, intestinal morphology, and nutrient utilization of birds fed low energy diets. In Exp. 1, a total of 1,440 one-day-old Ross 308 male broiler chickens were randomly divided into 3 treatment groups, with 16 replicates per treatment (48 pens; 30 birds per pen). Birds in treatment 1 were fed diets with normal energy content (NE). Birds in treatment 2 were fed NE diet but with 60 kcal removed (LE). Birds in treatment 3 were assigned to LE diet supplemented with PN (LE + PN). Results indicated that LE diet increased feed conversion ratio (FCR) compared with NE from d 1 to 38, while LE + PN diet prevented this response (P = 0.02). At d 26, birds in the LE + PN group had the highest ileal and jejunal villus height to crypt depth (VH:CD) ratio. At d 39, PN supplementation improved ileal and jejunal VH:CD ratio, compared with LE group. Moreover, birds fed PN diets received a better economic profit. In Exp. 2, 360 one-day-old Ross 308 male broiler chickens were used in a metabolism study. The treatments used in Exp. 2 were the same as those in Exp.1, with 4 replicates (pens) and 30 birds in each replicate. Dietary apparent metabolism energy (AME), energy and protein digestibility were determined between 21 and 28 d of age. Results showed that chickens fed LE + PN diet tended to have greater AME (P = 0.02) and nitrogen-corrected apparent metabolism energy (AMEn) (P = 0.03) than birds fed LE diets. It was concluded that LE + PN showed a potential advantage to improve feed conversion and gut health of broilers, as well as economic profits.  相似文献   

15.
This study aimed to determine the effect of different dietary levels of a Chlorella by‐product (CBP) on the growth performance, immune response, intestinal microflora and intestinal mucosal morphology of broilers. In total, 480 one‐day‐old broiler chickens were randomly allotted to four dietary treatments with four replicated pens consisting of 30 chicks. The basal diet was formulated to be adequate in energy and nutrients. Three additional diets were prepared by supplementing 25, 50 or 75 g/kg of CBP to the basal diet. The diets were fed to the broilers ad libitum for 35 days. Result indicated that increasing inclusion level of CBP improved BW gain (linear, p < 0.05). There was no effect of inclusion level of CBP in diets on total cholesterol, triglyceride, aspartate aminotransferase and alanine aminotransferase levels during the 35 days. Plasma IgG, IgM and IgA concentrations increased (linear, p < 0.05) with inclusion level of CBP in diets. Supplementation of CBP in the diets increased (linear, p < 0.05) the concentrations of Lactobacillus in the caecal content and decreased (linear, p < 0.05) the concentrations of Escherichia coli and Salmonella in the caecal content. Villus height increased (linear and quadratic, p < 0.05) with inclusion level of CBP in diets. Crypt depth increased (quadratic, p < 0.05) with inclusion level of CBP, and a decreased villus height: crypt depth ratio (quadratic, p < 0.05) was observed as inclusion level of CBP in diets increased. The results of the current experiment indicate that dietary supplementation of CBP improves growth performance of birds. Dietary CBP has improving Lactobacillus spp. concentrations in the gastrointestinal tract, plasma immunoglobulin concentrations and intestinal mucosal morphology.  相似文献   

16.
This study evaluated the effects of globin and spray-dried porcine plasma (SDPP) on growth performance, digestibility, nitrogen retention, energy retention efficiency (ERE) and intestinal morphology of broiler chickens. A total of 336-day-old male broiler chickens were reared from 1 to 40 days of age and fed 3 diets (8 replicates/diet, 14 birds/replicate) during 3 feeding phases: starter (1–12 days), grower (12–25 days) and finisher (25–40 days). Isonitrogenous diets were formulated by replacing gluten protein isolate contained in the control diet (C diet) with 2% (starter) or 1% (grower and finisher) spray-dried porcine plasma in the plasma diet (SDPP diet). The globin diet (G diet) was obtained by adding globin on the top of C diet at a dose of 0.08% for the whole rearing period. Total tract apparent digestibility (aD), nitrogen retention and ERE were assessed during the three growing phases. At 12  and 40 days of age, one bird per pen was slaughtered to sample gut, liver, spleen and bursa of Fabricius for histomorphological investigations. The SDPP diet increased body weights of chickens at 12 (+60 g; p < .001), 25 (+101 g; p < .001) and 40 days (+130 g; p = .018) of age compared to C and G diets. Also SDPP improved crude protein aD (+9.7%) and ERE (+12.3%) during the starter phase (p < .001). Dietary globin and SDPP inclusion did not affect either the gut morphology or the histopathological findings in birds at 12 and 40 days of age, despite a numerical (+6.90% and +7.40% respectively) villus height improvement in the SDPP group. Overall, these results confirm that dietary supplementation with SDPP and, to a lesser extent, with globin can improve growth performance and dietary protein and energy utilization in broiler chickens without effect on gut functionality.  相似文献   

17.
Foot pad dermatitis (FPD), a condition of inflammation and necrotic lesions on the plantar surface of the footpads, is commonly observed in fast‐growing broiler chickens and turkeys. FPD negatively affects the welfare of birds, performance indices and the economic profit of poultry meat production. Nutrition is an important factor affecting water intake, excreta moisture and litter quality and, in this way, the occurrence and intensity of FPD in birds. This article reviews and discusses the recent results published in the literature on the effects of nutritional factors on litter quality and FPD severity in broiler chickens and turkeys. Literature data on the efficacy of nutritional methods on the litter quality and FPD occurrence are not consistent. However, the results of several experiments indicate that the optimal level of crude protein, biotin and electrolytes (Na, K) in the diet, as well as feed additives such as feed enzymes hydrolysating non‐starch polysaccharides and organic sources of microelements (zinc), may reduce the litter moisture as well as FPD incidence and severity in broiler chickens and turkey.  相似文献   

18.
Fasting of up to 24 hr has been shown to increase intestinal permeability (IP) in chickens. The aim of this study was to determine whether fasting duration of 4.5 and 9 hr increased IP and whether l ‐glutamine (a non‐essential amino acid) supplementation before fasting provided some protection of barrier function as shown in other species. Ross 308 male broilers (n = 96) were fed either a control diet or the same diet supplemented with 1% glutamine from d0 to d38 post‐hatch. On d37, the birds were assigned to single‐bird metabolism cages and were fasted for either 0, 4.5, 9 or 19.5 hr. This study design was 2 × 4 factorial with two levels of glutamine and four levels of fasting. Birds in the 0‐hr fasting group had free access to feed. All birds had ad libitum access to water. To measure IP on day 38, following their respective fasting periods, birds were administered two separate oral gavages of fluorescein isothiocyanate dextran (FITC‐d) followed by lactulose, mannitol and rhamnose (LMR) sugars, 60 min apart. Whole blood was collected from the jugular vein 90 min post‐LMR sugar gavage. FITC‐d and L/M/R ratios were measured by spectrophotometry and high‐performance ionic chromatography respectively. Lipopolysaccharide (LPS) endotoxins in plasma of the birds fed the control diet were also measured using chicken‐specific LPS antibody ELISA. Serum FITC‐d and plasma L/M and L/R ratios for 4.5, 9 and 19.5 hr were significantly (p < .05) higher compared to the non‐fasting group. However, IP was not different in the glutamine‐supplemented group (p > .05) compared to the control group. LPS concentrations measured by the ELISA were below the detectable range. We conclude that fasting periods of 4.5 and 9 hr increased IP compared to non‐fasted birds and dietary glutamine supplementation did not ameliorate changes in IP.  相似文献   

19.
1. An experiment was conducted to compare and explain the incidence of spontaneously occurring subclinical necrotic enteritis in broiler chickens that were fed on two practical broiler diets that differed in the major protein concentrates (soya bean meal or potato protein concentrates) and examine the relationships between the severity of the disease and the growth performance and physiological responses of the chickens. 2. A total of 840, 20-d-old birds were randomly allocated to 12 pens. Two maize-based nutritionally complete diets that either contained some potato protein or soya bean meal as the major protein supplement were fed for 16 d. Twelve birds were randomly sampled from each pen at the end of the feeding period and their blood sampled and intestinal tracts and livers dissected. 3. The birds fed on the potato protein diet had a significantly 7·7% lower feed intake and a significantly 7·8% lower growth rate compared with the birds fed on the soya-based diet. There were no significant differences in feed conversion efficiency or mortality. There were no differences in the determined apparent metabolisable energy concentrations, however, the apparent dry matter digestibility of the potato protein diet was significantly higher than that of the soya based diet and the apparent crude protein digestibility of the potato protein diet was significantly lower. 4. A significantly higher alpha toxin antibody titre was found in the birds fed on the potato protein diet compared with those fed on the soya protein diet. There was a significantly increased incidence of hepatic lesions in the birds fed on the potato protein diet compared with the birds fed on the soya diet. The mean incidence of intestinal necroses tended to be greater in the birds fed on the potato protein diet (23·6%) compared with the birds fed on the soya-based diet (15·3%). 5. There was a significant linear relationship between ileal digesta sialic acid concentration and serum alpha toxin antibodies, although there were a considerable number of outliers to this relationship. Measurement of sialic acid concentration may be a useful variable to indicate the severity of necrotic enteritis in broiler flocks.  相似文献   

20.
This study was designed to evaluate the effects of dietary inclusion of zinc‐methionine (ZnMet) as a replacement for conventional inorganic zinc sources on performance, tissue zinc accumulation and some plasma indices in broiler chicks. A total of 450‐day‐old Ross male broiler chicks were randomly assigned to five pen replicates of nine experimental diets. Dietary treatments consisted of two basal diets supplemented with 40 mg/kg added Zn as feed‐grade Zn sulphate or Zn oxide in which, Zn was replaced with that supplied from ZnMet complex by 25, 50, 75 or 100%. At 42 days of age, three randomly selected birds from each pen were bled to measure plasma metabolites; then, the chicks were slaughtered to evaluate carcass characteristics. Results showed that dietary treatments affected (p < 0.05) feed intake during the starter period, and chicks on Zn oxide diets consumed more feed than sulphate counterparts. Furthermore, dietary substitution of inorganic Zn sources by ZnMet caused improvements (p < 0.01) in body weight gain during all experimental periods. Dietary supplementation of ZnMet improved feed conversion efficiency during 1–21 and 1–42, but not in 21–42 days of age. Complete replacement of inorganic Zn by that supplied from ZnMet caused an increase (p < 0.05) in relative liver weight. Similarly, dietary inclusion of ZnMet increased breast meat and carcass yields and reduced abdominal fat percentage (p < 0.05). Incremental levels of ZnMet increased (p < 0.05) zinc concentrations in liver and thymus, and the highest zinc accumulations were seen in 100% ZnMet‐supplemented birds. Interestingly, introduction of ZnMet into the diets partially in place of inorganic sources resulted in decreases (p < 0.01) in plasma uric acid and triglycerides concentrations. The present findings indicated that dietary ZnMet inclusion in replacement of inorganic sources in addition to improving growth performance, reduced plasma uric acid and triglycerides concentrations, consequently decreased abdominal fat pad and increased carcass meat yield.  相似文献   

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