Effects of different crating periods on selected biochemical indices in broiler chickens

Effects of different crating periods on selected biochemical indices were monitored in a group of unsexed ROSS 308 broiler chickens aged 42 days. 120 randomly selected chickens were weighted and placed in 15 heavy duty plastic crates with reduction in floor space approx. 160 cm2/kg of body weight of broilers (average body weight was 2.75 kg). Five crates were kept for 4 hours (Group 4h), another five crates for 8 hours (Group 8 h) and another five crates for 12 hours (Group 12h). After tested periods of crating the broilers were released and blood samples were withdrawn from Vena bosilico in 24 randomly selected birds from each group (Groups 4 h, 8 h, 12 h respectively) and also in other 24 randomly selected non-crated control birds. The results of our experiment proved that duration of crating significantly influenced the stress response in broiler chickens. The duration of crating period was positively correlated with the plasma corticosterone level and negatively correlated with the lactate dehydrogenase, cholesterol, triglycerides, glucose and lactate levels in the blood of broiler chickens.     

Attachment of some bacterial strains to the skin of broiler chickens

Attachment of micro‐organisms proved to be dependent to a large extent on the presence of flagella and their activity. From the results it is evident that non‐flagellated bacteria rarely attach. The attachment rate of flagellated bacteria is greatly dependent on temperature and pH. The optimal temperature for attachment of different flagellated bacteria lies around 20 °C, whether or not the organisms are psychrophilic or mesophilic.     

Screening of in vitro nutrient digestibility coefficients of selected insect meals in broiler chickens,black-meat chickens and quails

The objective of this study is to identify potential insect species comparing with commonly used protein sources based on efficiency of the in vitro digestibility on dry matter (DMd), organic matter (OMd) and crude protein (CPd) in broiler chickens, black-meat chickens (Native breed) and quails. Each of gastric mucosa, pancreas and duodenal mucosa were obtained from proventriculus, pancreas and duodenum, respectively. Crude digestive enzyme extracts (CTE) were extracted from these organs to perform in vitro digestibility. Eighteen insect samples and six commonly used protein sources were served as substrates which were evaluated on DMd, OMd and CPd in triplicate for each substrate. The CTE from gastric mucosa was used to simulate proventriculus, whereas small intestine was simulation by adding the CTE from pancreas and duodenum. The large variation of chemical composition between insect meals was presented. For commonly used protein sources, animal proteins were higher on digestibility than plant proteins (p < .001). Quails represented a great potential to digest insect meals comparing other animals. Based on CPd results, there were potential insect species for broiler chickens (Achroia grisella: AG, Tenebrio molitor: TM and Musca domestica), black-meat chickens (Patanga succincta, TM and AG) and quails (Hermetia illucens, Acheta domesticus and Locusta migratoria; p < .001). The evidences from this study suggest that these insect species contain a great potential to use as alternative protein sources promoting an animal production with sustainability. However, the in vivo experimentation must be performed to confirm in further study.     

The efficacy of selected probiotic and prebiotic combinations in reducing Campylobacter colonization in broiler chickens

Campylobacter is one of the leading causes of foodborne illness worldwide and is associated with consumption of poultry products. One potential strategy to reduce Campylobacter colonization in poultry is the use of probiotics. In an attempt to reduce Campylobacter in poultry, we isolated 117 GRAS (generally recognized as safe) bacterial isolates from the ceca of healthy birds and evaluated their efficacy against Campylobacter, using a soft agar overlay technique. Twenty-six isolates (Bacillus and Lactobacillus spp.) with greatest ability to inhibit Campylobacter in vitro, were tested in birds. In these studies, bacterial isolates were administered orally on day-of-hatch and, chicks were challenged with a four-strain mixture of wild type C. jejuni (∼10⁶ CFU/mL) on day 7. Cecal samples were collected on day 14 for Campylobacter enumeration. Out of 26 isolates, 3 isolates demonstrated a reduction in Campylobacter counts (1 to 2 logs). In an attempt to improve the efficacy of these 3 isolates, follow-up studies were conducted with various doses of 2 prebiotics (fructooligosaccharide [FOS] or mannan oligosaccharide [MOS]) in the feed. Campylobacter counts were not reduced for any of the FOS treatments (0.125%, 0.25%, or 0.5%) or the MOS treatments (0.04%, 0.08%, or 0.16%), but were reduced for the combination of isolate 3 with 0.04% MOS in feed. The results of this study indicate that the selection and administration of bacterial isolates in combination with selected prebiotics may reduce enteric Campylobacter counts in preharvest poultry.     

Antimicrobial therapy of selected diseases in turkeys,laying hens,and minor poultry species in Canada

This paper identifies common poultry diseases requiring antimicrobial therapy, antimicrobials deemed efficacious to treat these diseases, and antimicrobial resistance (AMR) in these commodity-pathogen combinations, and describes current residue issues and minor use minor species (MUMS) guidelines. Veterinarians with turkey/layer expertise and diagnosticians were surveyed to determine the bacterial and protozoal diseases diagnosed in the last 5 years. Avian pathogenic Escherichia coli, Staphylococcus aureus, and Ornithobacterium rhinotracheale were the 3 most frequently diagnosed pathogens of turkeys. In layers, E. coli-peritonitis, and Clostridium perfringens/Eimeria spp. infections were the most common diagnoses. A literature review identified 32 antimicrobials as efficacious and/or recommended for treating these diseases. Surveillance and monitoring indicate the presence of enteric resistant organisms from some of these avian species (including resistance to antimicrobials of very high importance to human medicine). This paper highlights the need for surveillance of pathogen frequency, antimicrobial use (AMU), and AMR particularly in turkeys.     

The avian major histocompatibility complex influences bacterial skeletal disease in broiler breeder chickens

This study evaluated bacterial skeletal disease in conjunction with the major histocompatibility complex (MHC) in a genetically pure line of broiler breeder chickens. Chickens from six broiler breeder flocks were examined for skeletal lesions, bacterial pathogens, and MHC genotype. During a 10-week period, eighty-eight, 9- to 21-week-old lame chickens and 34 normal, age-matched controls were selected. Tenosynovitis, arthritis, and femoral or tibiotarsal (or both) osteomyelitis occurred in 86 of 88 (97.7%) lame chickens. Ninety-five bacterial isolates were obtained from 83 of 88 (94.3%) lame birds and 4 of 34 (11.8%) controls. Staphylococcus spp. was isolated from 72.6% of the skeletal lesions, predominantly Staphylococcus aureus (38.9%). MHC B complex genotypes were determined by hemagglutination for 88 lame birds, 34 controls, and 200 randomly selected birds from each of the six flocks (1,200 total). Combined chi-square analysis revealed that the homozygous MHC genotypes B(A4/A4) (chi(2) = 14.54, P = 0.0063) and B(A12/A12) (chi(2) = 42.77, P = 0.0001) were overrepresented in the sample of symptomatic birds compared with random samples from the same flocks. The homozygous A4 and A12 MHC genotypes influenced flock chi-square values more than the corresponding heterozygotes. An MHC B complex influence on bacterial skeletal disease was apparent in this line of broiler breeders.     

Salt poisoning in broiler chickens

The incident occurred on a small, owner-operated broiler unit that used home-mixed feed. Two flocks of broilers, one aged 6 weeks and one aged 6 days, developed signs of watery diarrhoea, thirst and weakness. Over 3 days the mortality increased considerably and many birds were noticed to show laboured breathing. The majority of dead birds had an excess of clear fluid in the pericardial sac, oedematous lungs and pale swollen kidneys. Cystic dilation of the testes was conspicuous in several birds from the younger flock killed at 12 days of age. This lesion is a specific indication of sodium toxicity in young broilers. Histological lesions were those associated with cardiovascular collapse and hypoxia. Liver levels of sodium chloride were 4 g/kg of wet weight. Broiler feed samples contained more than 7% sodium chloride whereas the nutritional specifications were for 0.4%. The rations had been correctly mixed and the problem was traced to a faulty batch of meatmeal that had been contaminated by salt used for curing hides.     

Swollen-head syndrome in broiler chickens

Swollen-head syndrome is a disease seen in broiler chickens between 4 and 6 weeks of age in Southern Africa. It appears to be caused by a mixed coronavirus and Escherichia coli infection. The coronavirus appears to be of a hitherto unrecorded serotype. The disease is controlled by an attenuated live-virus vaccine and antibacterial medication.     

Salt poisoning in broiler chickens

The clinical signs of salt poisoning in young chickens are thirst, diarrhoea and weakness. When 13 500 broilers are simultaneously affected, the deterioration that occurs in their physical condition and in the litter beneath their feet is dramatic. Two flocks of meat chickens on a small unit in North Otago were affected in this way.     

Campylobacter succession in broiler chickens

The competitive ability of Campylobacter coli OR12 over C. jejuni OR1 has been examined in experimental broiler chickens following the observation that C. coli replaced an established C. jejuni intestinal colonisation within commercial chicken flocks reared outdoors [El-Shibiny, A., Connerton, P.L., Connerton, I.F., 2005. Enumeration and diversity of campylobacters and bacteriophages isolated during the rearing cycles of free-range and organic chickens. Appl. Environ. Microbiol. 71, 1259-1266]. Co-cultures of C. coli OR12 with C. jejuni OR1, revealed that the two species were able to grow together at similar growth rates in exponential growth phase but if the disparity of the inoculum ratios were >log(10)4 in favour of C. coli OR12, C. jejuni OR1 was observed to prematurely enter decline phase. Chickens were pre-colonised with C. jejuni OR1 at 21-days-old to examine succession in vivo. The birds were inoculated between 2 and 12 days later with C. coli OR12, to determine if the second isolate could efficiently colonise and compete with an established C. jejuni strain. C. coli OR12 were able to co-colonise before replacing C. jejuni OR1 as the dominant species when the birds were more than 27 days of age at the time of administration over a 4-day period. If these criteria were met C. coli OR12 became the dominant isolate otherwise co-colonisation occurred until they were met. C. coli OR12 was also found to displace three alternative C. jejuni strains from pre-colonised chickens challenged with C. coli OR12 at 30 days of age and tested at 40 days. These data raise the possibility of manipulating populations of Campylobacter colonising chickens through competition.     

An epizootiological study of acute death syndrome and leg weakness in broiler chickens in western Canada

In a survey of 51 broiler chicken flocks, the incidence of chickens dying from acute death syndrome and of those with skeletal deformities varied from 0.71 to 4.07% and from 0.46 to 4.08% among the flocks, respectively. The average incidence of those with skeletal deformities was 1.72%; 1.10% were culled in the field, and 0.62% were condemned or downgraded as carcasses. The major types of skeletal deformities were valgus deformation of the intertarsal joint (70%), varus deformation of the intertarsal joint (9%), tibial rotation (7%), and spondylolisthesis (14%). The strain and source of chickens and the management and nutritional practices were recorded for each flock. Statistical analyses were conducted in an attempt to identify factors that might correlate with the incidence of either chickens dying from acute death syndrome or those with skeletal deformities. Results of these analyses are discussed.     

Energy and nitrogen retention and loss in broiler chickens genetically selected for leanness and fatness

1. A breeding programme based on the assessment of the body fat content of broilers by measurement of plasma very low density lipoprotein concentration has resulted in 2 lines with significantly different body fat contents. 2. Energy and nitrogen intake and retention were measured in 63- to 70-d-old females from each line during 5-d periods of indirect chamber calorimetry. Results obtained by this technique were compared with results from a previously published growth trial incorporating carcase analysis at 49 d. 3. Body weight, metabolisable energy intake, heat production, energy retention and efficiency of energy retention did not differ significantly between the fat and lean lines. 4. The proportion of energy retained as crude protein and the efficiency of crude protein retention were significantly greater in the lean line. 5. In terms of whole-body energy and nitrogen exchanges, the essential difference between the lines was therefore in the partition of the same quantity of retained energy between fat and protein deposition. 6. The results were consistent with a higher rate of breakdown of amino acids in the fat line; because heat production did not also increase, a greater proportion of retained energy therefore became available for storage as fat.