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PubMed1993

Effects of different floor types and levels of washing of waterers on broiler performance and bacteria count of drinking water.

The objective of the present experiment was to determine the effect of different flooring materials and washing of waterers on broiler performance. The floor treatments were 1) black, plastic-coated expanded metal, relatively rigid (B); 2) white plastic, semi-rigid, with rectangular openings (WR); 3) white plastic, semi-rigid, with square openings (WS); and 4) 3 cm of rice hull litter (C). One hanging waterer was placed in each pen. Wash treatments were 1) trough and bell washed every Monday, Wednesday, and Friday (AW); 2) wash trough only on Monday, Wednesday, and Friday (TW); and 3) the waterers were never washed after the 2nd wk (NW). Broilers reared on C has significantly lower BW than those broilers on B floors. Broilers reared on the B and WS floors had significantly higher breast blister scores and percentage of birds with blisters than broilers reared on C floors. Broilers reared on C had lower enlarged feather follicle scores than those reared on all raised floors and a lower percentage of enlarged feather follicles than those broilers reared on WS or WR floors. Broilers reared on WS+TW had significantly better feed conversion than WS+AW, B+TW, and B+AW treatments. Broilers reared on WR+TW treatment were significantly higher in breast blister score than broilers reared on WR+AW, C+TW, and C+AW treatments. Broilers reared on C+TW and C+AW treatments were significantly lower in breast blister score except for broilers reared on C+NW, WR+AW, and WS+AW treatments. Broilers reared on C+NW treatment were significantly lower in enlarged feather follicle score than those broilers reared on B+TW, WR+AW, and WS+NW treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Husbandry↗

PubMed2005

Changes in glutathione peroxidase and tissue selenium concentrations of broilers after consuming a diet adequate in selenium.

Three experiments (EXP) were conducted with commercial broilers to develop a low-Se diet for comparing plasma glutathione peroxidase (pGPX3) concentrations and then to compare pGPX3 and plasma and tissue Se concentrations in broilers fed this low-Se diet after being supplemented with sodium selenite (SS) or Se-enriched yeast (SY). With the exception of Se, all diets were nutritionally adequate. The EXP lasted from 0 to 20 or 22 d posthatching, and treatments were replicated with 6 to 8 pens of 6 to 15 chicks per pen. The results of EXP 1 and 2 indicated that a cornstarch-dextrose diet containing 10% torula yeast and 31% soybean meal (SBM) resulted in similar gain as a corn-SBM (C-SBM) diet, but the cornstarch-dextrose-torula yeast-SBM diet with no added Se reduced pGPX3 activity 6-fold. In EXP 3, the treatments were a C-SBM diet with 0 or 0.30 ppm added Se from SS or SY. These diets were fed from 0 to 10 d posthatching. Beginning on d 10, all broilers were fed the cornstarch-dextrose-torula yeast-SBM, low-Se diet. On d 10, 13, 16, 19, and 22, three broilers per replicate were randomly selected for plasma and tissue collection. Treatment differences were significant at P < 0.05. Daily gain, daily feed intake, and gain:feed were not affected by diet during the 0-to-10-d or 0-to-22-d periods. Plasma GPX3 activity and plasma, liver, and breast Se concentrations were greater in broilers previously fed the diets with added Se, regardless of source, than in those fed the C-SBM diet, except for liver Se concentration on d 19 of broilers previously fed the SS diet. The pGPX3 concentrations were not different in broilers previously fed either Se diet on d 10 and 13 but were greater in broilers previously fed the SY diet on d 16, 19, and 22. Plasma Se concentrations were not different in broilers previously fed diets with SS or SY on d 10 and 22 but were greater in broilers previously fed the SY diet on d 13, 16, and 19. Breast Se concentrations were greater in broilers previously fed the SY diet than in those fed the SS diet on each day. Liver Se concentrations were not different in broilers previously fed SS or SY diets on d 19 and 22 but were greater in those previously fed the SY diet on d 10, 13, and 16. These results indicated that SY supplementation in broiler diets resulted in greater tissue Se concentrations than SS and that pGPX3 and tissue Se concentrations remained greater in birds previously fed a diet with SY than in those fed SS after being fed a low-Se diet.

Animal Feed↗

PubMedDate not supplied

The detrimental effect of vaccinating parentally immune broilers with a modified liver virus vaccine for infectious bursal disease.

The experiment involved 392,955 broilers from breeders vaccinated with a commercially available killed infectious bursal disease (KIBD) virus vaccine (Treatments 1 and 2) and 373,371 broilers from breeders not vaccinated with a KIBD virus vaccine (Treatment 2). The broilers from the KIBD-vaccinated breeders were divided into two treatment groups: Treatment 1 consisted of 209,457 broilers and Treatment 2 consisted of 183,498 broilers. Treatment 2 broilers were vaccinated at 10 days of age intraocularly with a commercially available modified liver infectious bursal disease virus (IBD-MLV) vaccine. Broilers in all three treatments were raised on commercially contracted farms serviced by the same company representative. Broiler performance was based on mortality, body weight, feed efficiency, condemnations, and how each farm ranked with respect to contract settlements. Compared with birds in Treatments 2 and 3 respectively, Treatment 1 broilers had 1.65% and 0.89% less mortality; 0.22 lbs. and 0.09 lbs. increased weight per bird; 0.03 and 0.03 increased feed efficiency; 0.09% and 0.32% fewer air sacculitis condemnations; and 0.57% and 0.83% fewer total condemnations. Treatment 1 broilers ranked in the top 37%; Treatment 2 ranked in the bottom 36%; and Treatment 3 ranked in the lower 57% of contract settlements for all broilers processed. The results clearly showed that Treatment 1 broilers outperformed Treatment 2 amd 3 birds and that the IBD-MLV vaccine had a detrimental effect on Treatment 2 broilers.

Animal Feed↗

PubMed2002

Immunological differences between layer- and broiler-type chickens.

In commercial poultry husbandry, alternatives for the use of antibiotics and vaccines are under investigation, which preferably have to be applicable for both layer- and broiler-type chickens. There are indications that the defense mechanisms vary between layer- and broiler-type chickens. Therefore, the difference in immune response between layer- and broiler-type chickens of the same age was investigated, using TNP-KLH (trinitrophenyl-conjugated keyhole limpet hemocyanin) as antigen without adjuvant. First different routes of immunization (intravenously, intramuscular, subcutaneous and ocular) were examined to find out which immunization route gives the highest antibody titers. The intravenous immunization route resulted in higher TNP-specific antibody responses than the other immunization routes tested and therefore this immunization route was used in both following experiments. In order to investigate the optimal dose of antigen needed for immunization, a dose-response curve in broiler- and layer-type chickens was completed. The humoral immune response was measured in serum by a TNP-specific ELISA and the in vitro cellular immune response by an antigen-specific lymphocyte proliferation assay. The antibody response of layer- and broiler-type chickens appeared to differ, not only in optimal dose and response, but also in kinetics of the response itself. Broiler chickens generated higher IgM anti-TNP titers whereas layer-type chickens generated higher IgG anti-TNP titers. This specific antibody response in broiler-type chickens did not last as long as in layer-type chickens. The TNP-specific cellular immune response was detectable in layer-type chickens, but not in broilers. Both types generate a non-specific cellular immune response, although this response in broilers is lower than in layer-type chickens. From these results, we conclude that broilers primarily respond to TNP-KLH with a high IgM antibody response whereas layer-type chickens respond with a high IgG response. In addition, the cellular response of layer-type chickens is much higher than the response of broilers. The results suggest that broilers are specialized in the production of a strong short-term humoral response and layer-type chickens in a long-term humoral response in combination with a strong cellular response, which is in conformity with their life expectancy.

Animals↗

PubMed2003

Eating behaviour, and preprandial and postprandial correlations in male broiler and layer chickens.

1. It has been suggested that broiler chickens have a disturbed satiety and hunger mechanism. The satiety mechanism for eating can be expressed as the positive correlation between meal length and the length of the preceding (preprandial) interval; the hunger mechanism for eating as the positive correlation between meal length and the length of the succeeding (postprandial) interval. An experiment was conducted to investigate eating behaviour of male broiler and layer chickens by measuring meal and interval lengths. 2. Eight male broilers and 8 male layer chickens were housed individually and visually isolated in floor pens (1 m2/pen) on wood shavings. From 4 to 7 weeks of age, eating behaviour of each bird was recorded for 3 h in two conditions each week. In the first condition, the birds were not deprived from feed. In the second condition, they were 24-h food deprived and feed was provided just before the observation started. Preprandial and postprandial correlations were calculated based on data of the non-deprived condition. Before and after each observation bird and feeder were weighed to measure weight gain and feed consumption during observation. 3. Under the non-deprived condition, the broilers spent initially more, but at a later age less time on eating. The broilers had fewer meals per hour, consumed more feed per hour, and had longer meal and interval lengths than the layer chickens. After 24-h feed deprivation, the broilers had a longer first meal, consumed more feed per hour and spent more time on eating than the layer chickens. Significant preprandial correlations but no postprandial correlations were found in the broilers. In the layer chickens, both significant preprandial and postprandial correlations were found. This indicates that for regulating eating behaviour, the satiety mechanism dominates the hunger mechanism in broilers, and satiety and hunger mechanisms are equally involved in layer chickens. 4. The typical eating behaviour of broilers and the calculated preprandial and postprandial correlations have given new indications that hunger and satiety mechanisms in broilers have changed compared with layer chickens. In broilers, there is no lower set point, but only an upper set point for controlling eating behaviour, which suggests that broilers eat to their maximal physical capacity.

Animals↗

PubMed2005

Pathogenesis of ascites in broilers raised at low altitude: aetiological considerations based on echocardiographic findings.

This study reports novel insight into the aetiology of pulmonary hypertension and ascites in broiler chickens. The scope of measurements was focused on anatomical and functional parameters, and blood flow patterns in leghorns (resistant to ascites), fast-growing broilers (susceptible to ascites), broilers developing ascites, and ascitic broilers evaluated in vivo using echocardiography, and further examined in the context of postmortem findings. Both, in vivo observed features and postmortem findings, showed clear differences between broilers and leghorns, and between normal and ascitic broilers. Abnormalities in the heart chamber geometry and blood flow patterns were detected upon echocardiographic examination in all ascitic broilers. Right and left atrio-ventricular (AV) valve regurgitation were common findings in ascitic broilers and some apparently normal broilers, with left AV valve insufficiency being a predominant feature with respect to degree and frequency of occurrence. Blood flow disturbances were not detected in leghorns. Left ventricular fractional shortening (functional parameter) was considerably reduced (P < 0.01) in ascitic birds (mean: 21.7 +/- 2.0 SE) in comparison with normal broilers (mean: 39.1 +/- 3.6 SE), or leghorns (mean: 43.3 +/- 2.4 SE). The presented findings indicate that pathological and functional changes in the left ventricle and atrium play a significant role in the pathogenesis of ascites in broilers. Severe dilation of the left atrium and pulmonary veins seen on postmortem examination, as well as regurgitant blood flow in the left atrium, demonstrated by Doppler study in ascitic birds, provide evidence that chronically elevated pressure in the left atrium is involved in the aetiology of pulmonary hypertension and ascites in fast-growing broilers.

Altitude↗

PubMed1980

The use of fly ash in diets of cage and floor broilers.

Three experiments were conducted to compare limestone to fly fly ash from a coal-fired generator station as a calcium source for broilers. In Experiment 1, 5 male and 5 female broiler chicks were placed in each of 32 cages. Sixteen cages of birds were fed a ration with limestone supplying 30% of the total calcium and 16 cages were fed a ration with 30% of the total calcium supplied by fly ash. The total calcium and phosphorus levels of the rations were 1.0% and .5% respectively. In this experiment no significant difference (P < .05) was found for 8-week body weight between diets where the added calcium was from limestone or fly ash. In Experiment 2 a group of 40 male and 40 female cage reared broilers and 40 male and 40 female floor reared broilers were fed a basal diet of limestone providing 33% of the total calcium. Three diets with increasing fly ash levels were fed to three cage groups of 40 male and 40 female broilers providing 33, 46, and 45% of the total calcium of .9, 1.1, and 1.8%, respectively. Broilers fed the highest fly ash level weighed significantly less (P < .05) at 8 weeks than the caged controls but did not differ from the other treatments. Bone breaking strength as measured by the Allo Kramer Shear Press was similar between the basal and low level fly ash group and increased with higher fly fly ash levels. Humerus and radius bone strength were greatest in floor broilers when compared with cage broilers. Tibia ash content of the floor-reared broilers and higher fly ash level of caged broilers were similar and greater than that of the basal cage group. Humerus and radius ash content were higher for the higher calcium groups. In Experiment 3 four groups of 40 male broilers in cages were fed limestone diets with graded levels of limestone for the calcium source. Another four groups of 40 caged male broilers were fed fly ash diets with equivalent graded levels of fly ash for the calcium source. Both limestone and fly ash diets provided .17, .34, .51, and .68% calcium of a total calcium content of .28, .45, .62 and .79%, respectively. The four limestone groups exhibited a definite linear improvement in both 3-week body weight and bone weight (tibia and femur combined) as the dietary calcium level was upgraded. The two low fly ash groups were similar in body and bone weight to their counterpart limestone groups, but further increases in the fly ash component did not improve body or bone weight. Bone ash values for both limestone and fly ash groups showed a similar improvement with each calcium increase, except the high value for the second level of fly ash.

Animals↗

PubMedDate not supplied

Echocardiographic study of pulmonary hypertension syndrome in broiler chickens.

Echocardiography was used to study cardiovascular structure and function during the development of pulmonary hypertension syndrome (PHS) in broiler chickens. Body weight-normalized right and left ventricular diameters at both end-diastole (RVDD, LVDD) and end-systole (RVDS, LVDS) were determined weekly in broilers reared under either normobaric (altitude, 96.7 m) or hypobaric conditions (simulated altitude, 2900 m) until 5 wk of age. Hypobaric-exposed broilers had larger RVDD at 3 and 4 wk of age and larger RVDS at 3, 4, and 5 wk of age. Hypobaric-exposed broilers also had larger LVDD at 2, 3, 4, and 5 wk of age and larger LVDS at 4 wk of age. Right (RVFS) and left ventricular fractional shortening (LVFS) were smaller in hypobaric- vs. normobaric-exposed broilers at 3, 4, and 5 wk of age and at 4 wk of age, respectively. Among hypobaric-exposed birds, PHS-positive (+) broilers had larger RVDD and RVDS than PHS-negative (-) broilers on week 3 and on weeks 1 and 3 after hypobaric exposure, respectively. PHS-positive (+) broilers also had smaller RVFS on week 1 after hypobaric exposure. Electrocardiographic and post-mortem data indicated that PHS+ broilers also developed right ventricular hypertrophy when compared with PHS-negative (-) broilers. These results are consistent with the hypothesis that PHS develops as a result of pulmonary hypertension and cardiac overload and suggest that PHS+ broilers have a greater and more persistent reaction to hypoxia than PHS- broilers.

Air Pressure↗

PubMed2003

Relative bio-availability and utilisation of phosphatic fertilisers as sources of phosphorus in broilers and layers.

1. Different concentrations of non-phytate phosphorus (NPP, 2.5, 3.0, 3.5, 4.0 and 4.5 g/kg diet) were given to broilers (8 to 42 d of age) to establish regressions between dietary NPP concentration and body weight gain and tibia ash content. Second and third experiments were conducted to study the feasibility of utilisation of different phosphatic fertilisers [ammonium phosphate (AP), ammonium polyphosphate (APP), single super phosphate (SSP), NPK (17:17:17, NPK) and NP (28:28:0, NPK)] in commercial broilers (8 to 42 d) and White Leghorn layers (252 to 364 d). 2. Phosphatic fertilisers were incorporated both in broiler (10 g calcium and 4.5 g NPP/kg) and layer (35 g calcium and 3.5 g NPP/kg) diets by replacing dicalcium phosphate (DCP) in toto. 3. The logarithmic curves obtained for predicting the body weight gain and tibia ash content at different levels of NPP used in experiment 1 were Y = 156.27 + 2,468.8 logX (r2= 0.958) and Y = 530.82 + 144.26 log X (r2 = 0.916), respectively. 4. Body weight gain and food intake in broilers given APP- or NP-supplemented diets were comparable to these in the DCP-fed group. Feeding of NPK, AP or SSP resulted in significant depression in weight gain and food intake and high excreta moisture content. Food/gain, Ca and P contents in tibia ash and serum were not influenced by the use of phosphatic fertilisers as P sources in broiler diets. 5. Tibia ash content in broilers fed on diets containing fertilisers was either similar to or significantly higher than that in the DCP-fed group. Broilers on AP or SSP retained more P and had higher tibia ash content than those on DCP. AP, SSP or NPK caused degenerative and necrotic changes in liver, kidney and intestine of broilers. 6. Relative bio-availability of P from APP or NP was better for body weight gain than AP, SSP or NPK, while the reverse was true for bone calcification. 7. APP and NP gave hen-d egg production similar to that of DCP-fed layers. Food intake was significantly reduced in layers fed on diets containing fertilisers. However, food/egg mass, egg weight and serum Ca and inorganic P contents were not influenced by inclusion of fertilisers in layer diets. 8. Except for AP, inclusion of fertilisers in layer diets reduced shell weight and shell thickness compared with the DCP-fed group. However, no apparent eggshell defects were found which could be attributable to diet. 9. Results of these experiments suggest that APP and NP can be used as the sole source of P both in broiler and layer diets, replacing DCP in toto. However, when utilising these P sources in layers, due attention should be given to shell quality. Fertilisers containing high F (AP and SSP) or K (NPK) reduced performance in broilers and layers and caused microscopic changes in liver, kidney and intestine in broilers.

Animal Feed↗

PubMed2004

Effect of hypothalamic electrolytic lesions in White Leghorn and broiler male cockerels.

1. This study compared the effect of bilateral electrolytic lesions of the basomedial hypothalamus (HL) in broiler and White Leghorn (WL) males. 2. Hypothalamic lesions were placed in WL at 10 weeks of age (body weight 1.1 kg) and in broilers, either at 6 weeks (body weight 1.5kg) or at 10 weeks of age (body weight 3.4kg). They were fed ad libitum until autopsy at 16 and 17 weeks of age for broilers and WL, respectively. 3. Hypothalamic lesions caused obesity (high percentage weight of abdominal adipose tissue) in both strains. Obese fowls with unimpaired reproductive systems were classified as OB and those with functional castration as FC (functionally castrated) or FCLC (functionally castrated with large comb). 4. All post-HL syndromes-OB, FC and FCLC-were present in WL, whereas all obese broilers (which are immature at this age) were classified as OB. 5. The percentage weight of abdominal adipose tissue in OB broilers was lower than in OB WL (3% vs 5%, respectively). 6. Daily food intake of OB broilers was higher than control at 12 to 15 weeks of age, regardless of time of placement of HL, whereas daily food intake of OB WL was significantly higher than that of control WL only during the first 2 weeks following HL. 7. Body weight of OB broilers at autopsy was 20% higher than control broilers, whereas body weight of OB WL was not significantly affected. 8. An additional group of broilers was reared to sexual maturity under food restriction until 28 weeks of age. HL were placed at 10 weeks of age (body weight 1.7 kg). Autopsy was performed after a 4-week period of ad libitum feeding. 9. There were OB as well as FC and FCLC among the HL, food-restricted broilers. Percentage weight of testes and spleen were reduced in OB fowls of both strains, but more so in OB WL. 10. Hyperphagia and weight gain were not observed during the ad libitum feeding period of those obese broilers after HL, indicating that hyperphagia and weight gain are secondary to obesity.

Abdomen↗

PubMed1998

Changes in the somatosensory evoked potentials and spontaneous electroencephalogram of broiler chickens during exposure to gas mixtures.

1. Six week-old broiler chickens implanted with electroencephalogram (EEG) recording and somatosensory stimulating electrodes were exposed to either 90% argon in air, a mixture of 30% carbon dioxide and 60% argon in air or a mixture of 30% oxygen and 40% carbon dioxide (balance nitrogen) for 2 min, to determine the times to onset of changes in spontaneous EEG and the loss of somatosensory evoked potentials (SEPs) and thus unequivocal loss of consciousness. 2. In addition, after a 2 min exposure to the carbon dioxide-oxygen mixture, some broilers were allowed to recover in air and their EEGs and SEPs were continuously recorded until the return of normal EEG and SEPs. During this period, the time to return of response to comb pinching was also determined in 10 broilers. 3. All broilers exposed to either argon or the carbon dioxide-argon mixture died within 2 min, whereas, only 3 out of 17 broilers died during the 2 min exposure to the carbon dioxide-oxygen mixture. 4. During exposure to argon, unlike the other 2 gas mixtures, the majority of broilers showed high amplitude, low frequency electrical activity in the EEG on average at 10 s. The mean times to onset of EEG suppression were 17, 19 and 40 s after exposure to argon, the carbon dioxide-argon mixture and the carbon dioxide-oxygen mixture, respectively. An isoelectric EEG occurred on average at 58 and 41 s after exposure to argon and the carbon dioxide-argon mixture, respectively. An isoelectric EEG did not occur in broilers which were exposed to the carbon dioxide-oxygen mixture. 5. The SEPs were abolished in broilers on average 32 and 24 s after exposure to argon and the carbon dioxide-argon mixture, respectively. During exposure of broilers to the carbon dioxide-oxygen mixture the SEPs were abolished in the majority of birds on average at 47 s, however, 2 out of 14 birds retained their SEPs for the entire period of 2 min exposure to this gas mixture. 6. During the recovery after exposure to the carbon dioxide oxygen mixture, response to comb pinching and SEPs returned either at the time of, or soon after, the onset of high frequency electrical activity in the suppressed EEG of broilers. The mean times to return of response to comb pinching and SEPs were 52 and 43 s, respectively. 7. Based on the time to onset of EEG suppression or loss of SEPs, exposure of broilers to either 90% argon in air, or a mixture of 30% carbon dioxide and 60% argon in air, resulted in quicker loss of consciousness than during exposure to a mixture of 40% carbon dioxide, 30% oxygen and 30% nitrogen. The time to return of consciousness after a 2 min exposure to the carbon dioxide-oxygen mixture was also found to be rapid.

Animals↗

PubMed1998

Typhaea stercorea (Coleoptera: Mycetophagidae), a carrier of Salmonella enterica serovar Infantis in a Danish broiler house.

In December 1994, Salmonella enterica serovar Infantis (S. Infantis) was accidentally introduced into a Danish broiler house by stocking an S. Infantis-infected broiler flock of 39,900 day-old chicks. At the time of the study, the infection had persisted through 6 broiler cycles. Typhaea stercorea (L.), the hairy fungus beetle, was found in large quantities inside and around the broiler house. Various attempts to control the beetle had failed; T. stercorea had been uncontrollable on the farm since Alphitobius diaperinus (Panzer), the lesser mealworm, was eradicated approximately 10 yr earlier. We investigated the ability of T. stercorea to act as a carrier of S. Infantis in the broiler house between 2 broiler cycles. We examined the empty, cleaned, and disinfected broiler house for S. Infantis 3 d before stocking the 7th broiler flock, and S. Infantis was isolated from the beetles only. Of 20 singly examined T. stercorea, 9 (45%) were S. Infantis positive. A rapid spread of the infection was seen in the 7th broiler flock; 100% of the culled chicks were S. Infantis positive 3 d after stocking. Under experimental conditions chicks were observed eating beetles, and when 5 d-old, specified pathogen-free chicks were fed with S. Infantis-positive T. stercorea collected from the broiler house, all 5 chicks became infected in 4 d. We conclude that T. stercorea may act as a potential carrier of S. Infantis between successive broiler cycles.

Animal Feed↗

PubMed1997

The influence of complex carbohydrates on Salmonella typhimurium colonization, pH, and density of broiler ceca.

Salmonella typhimurium colonization, pH, and density of ceca were measured in 3-, 5-, and 6-wk-old broilers fed either a control ration or rations with added fructooligosaccharides (FOS) or lactose derivatives (LD). The purpose was to compare dietary crude FOS from Jerusalem artichokes with refined FOS and two LD for ability to reduce Salmonella colonization as determined by semi-quantitative procedures. Chicks were challenged commencing at 5 d, by exposure to chicks orally infected with S. typhimurium. With the exception of chicks fed crude FOS, the high prevalence of Salmonella infection at 3 wk declined as chicks aged. At 6 wk, broilers fed crude FOS had higher Salmonella counts than all other broiler groups, whereas broilers fed refined FOS had lower infections than control broilers. The decline of Salmonella infection of broilers fed either refined FOS or LD ceased after dietary additives were discontinued at 5 wk of age. At 6 wk, infection rates of the latter groups were at least as high as those of control broilers. Both FOS and LD reduced cecal pH and density. Broilers fed the control ration had higher pH at 5 and 6 wk and higher cecal densities at 3 and 5 wk than those of broilers fed rations containing 5% (wt/wt) carbohydrates. Treatment differences for cecal pH and density disappeared within 1 wk of withdrawal of carbohydrates from 5-wk-old broilers. No consistent effect of cecal pH and density on Salmonella infection was observed. Density was dependent on cecal volume, and at 6 wk of age, on broiler size.

Aging↗

PubMed1998

Salmonella prevalence in crops of Ontario and Quebec broiler chickens at slaughter.

Swabs of crop contents of 635 broiler chickens were obtained from 9 Ontario and 12 Quebec processing plants and cultured for Salmonella to determine prevalence in broiler crops. Serotypes of positive cultures were determined to evaluate the serotype profile. The overall prevalence of contamination was low (4.3%). Prevalence was higher in broilers sampled in Quebec (5.8%) than in those sampled in Ontario (2.2%). In Quebec, there were differences in prevalence among the groups of broilers sampled at the various plants. These differences were believed to be attributable to differences in Salmonella prevalence among groups of flocks delivered to the plants due to the limited exposure of the chickens to the plant. The serotype profile of Salmonella isolated from the crops of broilers in this study was similar in several respects to profiles obtained from other surveys of Canadian broiler flocks using either environmental samples or cloacal swabs. Similarities included: predominance of Salmonella hadar and Salmonella heidelberg; several other common serotypes at a low prevalence; little Salmonella enteritidis isolated in other studies, and no S. enteritidis isolated in this study. Results of this field survey of Salmonella in crops of broilers are similar to those of Canadian studies of other internal and environmental sites of broilers. The similarity indicates that monitoring of Salmonella environments of flocks of live broiler chickens should define profiles of Salmonella contamination of the carcasses and would also aid in determination of Salmonella contamination status of broiler flocks. Such information would assist efforts to reduce Salmonella contamination in broiler chickens.

Abattoirs↗

PubMed2002

Carbohydrate-based cocktails that decrease the population of Salmonella and Campylobacter in the crop of broiler chickens subjected to feed withdrawal.

The efficacy of various carbohydrate-based cocktails in reducing the number of enteropathogens in the crops of broilers subjected to feed withdrawal was examined. Market-aged broilers that had been orally challenged with Salmonella typhimurium were provided the cocktails during a 12-h feed withdrawal. After feed withdrawal, the broilers were processed, and their crops were aseptically removed and weighed. Crops were then blended in distilled water, and the pH of the suspensions was measured electronically. Populations of S. typhimurium, Campylobacter, and lactic acid bacteria in the crop suspensions were enumerated. Findings indicated that significantly fewer S. typhimurium and Campylobacter were recovered from the crops of broilers that had been provided cocktails supplemented with sucrose than from the (Key words: crop, carbohydrate, feed crops of broilers provided cocktails supplemented with equal concentrations (wt/vol) of glucose. Furthermore, significantly fewer S. typhimurium were recovered from the crops of broilers provided cocktails supplemented with 2 to 10% sucrose than from the crops of broilers provided water or cocktails that were not supplemented with carbohydrates. The pH of the crop contents of broilers provided carbohydrate cocktails were lower than the pH of the crops of broilers provided water or cocktails that were not supplemented with carbohydrates. Consumption of the cocktails did not produce significant changes in the crop weights. Findings indicate that altering the composition of carbohydrate-based cocktails provided to broilers during feed withdrawal may affect the efficacy of cocktails in reducing the number of enteropathogens recovered from the crops of broilers.

Animal Feed↗

PubMed2004

Comparison of embryo physiological parameters during incubation, chick quality, and growth performance of three lines of broiler breeders differing in genetic composition and growth rate.

In broiler breeder management, stringent feed restriction is practiced to reduce body size in order to improve egg production and meet broiler production demand, but this practice has raised welfare issues. The potential for the dwarfing (dw) gene to reduce feed intake and body size of breeders under ad libitum feeding or less stringent restriction while maintaining improved egg production has been reported. In this study, we compared embryo physiology, quality of chicks, and performance of broilers from eggs of dwarf breeders with those from a standard broiler breeder. Hatching eggs from 3 commercial lines of broiler breeders were compared for incubation parameters, 1-d-old chick weight, chick quality, and broiler growth to 41 d of age. The lines included a standard heavy (S) line, an experimental (E) line, and a label-type (L) line. The E and L line breeders carry the sex-linked dw gene and are being used to assess the potential for dw to reduce feed intake or lower feed restriction and improve reproductive performance in heavy female broiler parent stock. Two separate experiments were conducted. All female parent stocks were mated to Cornish males, and fertile eggs were collected. In the first experiment, eggs were incubated for 21 d under standard conditions to determine, during final stages of incubation, corticosterone and thyroid hormone levels (triiodothyronine, T3; thyroxine, T4) in embryos and hatchlings, CO2 partial pressure (pCO2), and O2 partial pressure (pO2) in air cells, heat production by eggs and 1-d-old weights. In the second experiment, eggs were incubated for 21 d to compare chick quality, chick weights at 1 d of age, and broiler growth to 7 and 41 d. Average egg weights were higher for the S and L lines than the E line, but weight loss during incubation was lowest for the E line. Plasma T3 and T3/T4 ratio was similar between lines at IP, but corticosterone was higher in the S line. At hatch, T3/T4 ratio was higher in the S line compared with the E and L lines, but corticosterone was higher in the S and E lines than in the L line. Heat production by embryos was different among lines (S > E > L). The pCO2 was also higher in the S line than the E and L lines. These incubation parameters suggest different metabolic rates among lines (S > E > L). Incubation duration was shortest for the S line. Chick weights at 1 d old were not different between lines. Chick quality scores were also not different when expressed as a percentage of high-quality chicks or as an overall average score of each line. However, broiler BW at 7 and 41 d were different among lines (S > E > L). Chicks of higher quality (score of 100) in all lines had higher BW than those of lower quality (score of < 100). For corresponding quality groups between lines, the S line had higher BW, and those of the L had the lowest. These data suggest a link between the levels of embryo metabolism and growth potentials of the lines. We concluded that the dw gene has potential for reducing feed intake in heavy broiler parent stock (as in the E line), improving reproductive performance (as in the L and E lines), and maintaining progeny broiler chick weights at 1 d of age and quality but with lower weight at slaughter.

Animals↗

PubMed2004

Differential expression of mitochondrial electron transport chain proteins in cardiac tissues of broilers from pulmonary hypertension syndrome-resistant and -susceptible lines.

Pulmonary hypertension syndrome (PHS) is a metabolic disease associated with the rapid growth rate of modern broilers. Broilers susceptible to PHS experience sustained elevation of pulmonary arterial pressure leading to right ventricular hypertrophy and ultimately heart failure. Previous studies have shown that mitochondrial function is defective in broilers with PHS; they use oxygen less efficiently than broilers without PHS. In this study mitochondrial electron transport chain (ETC) protein levels were compared in cardiac tissues from PHS resistant and susceptible line broilers using quantitative immunoblots. Seven of 9 anti-mammalian mitochondrial ETC protein antibodies tested exhibited cross-species reactivity. Six ETC proteins were differentially expressed in the right ventricles of broilers raised under simulated high altitude conditions (2,900 m above sea level). Four ETC proteins were present at higher levels in resistant line birds without PHS than in resistant line birds with PHS or in susceptible line birds with or without PHS. One ETC protein was present at higher levels in broilers without PHS than in broilers with PHS in both lines, and one ETC protein was present at lower levels in susceptible line birds without PHS than in susceptible line birds with PHS or in resistant line birds with or without PHS. Interestingly, differential expression of mitochondrial ETC proteins was not observed in the right ventricles of broilers raised at local altitude (390 m above sea level) nor was it observed in the left ventricles of broilers exposed to simulated high altitude. These results suggest that higher levels of mitochondrial ETC proteins in right ventricle cardiac muscle may be correlated with resistance to PHS in broilers.

Animals↗

PubMed2005

Preharvest feed withdrawal affects liver lipid and liver color in broiler chickens.

An Iowa grain processor attempted to alter the typical 12-h preharvest fasting period by giving broilers cornstarch derivative pellets and water for 6 h followed by 6 h of no feed or water. After slaughter, plant food inspectors determined that livers from the treatment group were lighter in color than normal, and consequently a significant number of chicken carcasses were condemned for human consumption. The study reported herein was conducted to determine the effects of fasting or 3 feeding programs applied before processing on liver color, liver lipids, and liver glycogen of broilers. Dietary treatment groups consisted of 1) full-fed control broilers, 2) fasted broilers, 3) maltodextrin-fed broilers, and 4) and chickens given maltodextrin and methionine. Full-fed chickens had lighter liver coloration than chickens without access to feed for 6 or 12 h immediately prior to slaughter (P < 0.05). Lightness values for livers from full-fed control chickens (L* = 54.41) were 38% higher than those for livers from fasted broilers (L* = 39.30). Lighter liver colors in full-fed broilers were associated with higher hepatic lipid concentrations (6.38%) and more total liver lipid (4.96 g/liver) than was found in broilers without feed for 12 h. In contrast, darker livers from fasted broilers had lower levels of lipid (4.42%) and less total lipid (2.68 g/liver) than the full-fed broilers. Feeding maltodextrin pellets resulted in liver colors that were lighter (P < 0.05) than those found in fasted chickens but darker (P < 0.05) than livers from full-fed broilers. If carbohydrate supplements are fed prior to slaughter, producers should notify processing plant officials so that inspectors do not interpret light livers as an abnormal physiological state.

Animals↗