Age Of Birds Research Articles

Infectious laryngotracheitis of chickens: Pathologic and immunohistochemistry findings.

Infectious laryngotracheitis (ILT) is an important upper respiratory disease of chickens. Gross and histologic lesions of ILT in chickens are compared to immunohistochemistry to evaluate the diagnostic test sensitivity. A total of 31 separate ILT-confirmed necropsy submissions (12 commercial meat-type flocks, 13 egg-type producers, and 6 backyard flocks) were arbitrarily selected. Each submission ranged from 1 to 18 birds, for a total of 246 chickens. Cases with available formalin-fixed tissues were selected to include a range of bird production types, ages, clinical histories, and severity of macroscopic and histologic lesions. Macroscopic findings in the respiratory tract varied from increased mucus (55.6%) to fibrinonecrotic exudate (20.3%) and hemorrhages in the larynx and trachea (13.0%). Syncytia with intranuclear inclusion bodies were present in the respiratory tract epithelium with or without hemorrhages. Sections of conjunctiva, sinus, larynx, trachea, lung, and air sac were analyzed by immunohistochemistry (IHC) to detect gallid alphaherpesvirus 1 (GaHV-1) antigen. Positive immunolabeling was detected in the cytoplasm and nuclei of syncytia and epithelial cells in 18/22 conjunctivae (82%), 12/13 sinuses (92%), 18/22 larynxes (82%), 23/25 tracheas (92%), 10/21 lungs (57%), and 3/8 air sacs (37%). Of the 34 tissues with no visible syncytia or inclusion bodies, 8 were positive by IHC. In conclusion, IHC was useful to study the viral antigen tissue distribution and support the diagnosis of ILT when the histopathologic interpretation was doubtful.

In addition to birds’ age and outdoor access, the detection method is of high importance to determine the prevalence of gastrointestinal helminths in laying hens kept in alternative husbandry systems

The prevalence of gastrointestinal helminths was investigated in sixty-six commercial non-caged layer flocks. Twenty-nine flocks were housed indoors in aviaries or floor systems, nineteen flocks were kept in conventional free-range systems with outdoor access, and eighteen flocks in organic free-range systems. Flocks were investigated at end of rearing (mean age 17 weeks), peak of egg production (mean age 38 weeks) and before slaughter (mean age 74 weeks). Four different methods were applied to determine worm infestation. During necropsies, worm infestations were recorded and mucosal scrapings were evaluated for the presence of worm eggs. Faecal samples from each flock were investigated by simple flotation method and McMaster counting technique.No gastrointestinal helminths were found in pullets. During production, 87.9 % of the layer flocks were infected with at least one nematode species at the peak of production. The prevalence further increased significantly up to 98.5 % at the end of production (p=0.05). This increase could be ascribed mainly to infections with Ascaridia (A.) galli and/or Heterakis (H.) gallinarum which were most prevalent in all husbandry systems. Furthermore, their prevalence increased significantly with the age of birds (p=0.023; p < 0.001). With regard to the husbandry system, the prevalence of Capillaria spp. was significantly higher in flocks from outdoor systems compared to flocks that were kept indoors. Cestodes were only detected at the end of production with a prevalence of 15.2 % and significantly more flocks with access to outdoor run were found positive. Interestingly, H. gallinarum was found with a high prevalence indoor and in outdoor systems. Anthelminthic treatment did not impact the prevalence of nematode infections. Comparing four different methods for the detection of helminths it was revealed that their efficiencies varied depending on the worm species. Overall, the simple flotation method was superior to detect A. galli and Capillaria spp. This method proved also very efficient for the detection of H. gallinarum but the additional evaluation of the worm infestation during necropsy increased the level of prevalence. Cestodes were mainly found during necropsies when the worm infestation was evaluated. The detection of parasite eggs in mucosal scrapings from the intestines was the least effective method for all helminths. These findings lead to the recommendation to combine faecal investigations with an evaluation of the worm infestation during necropsy of at least five birds.

Factors affecting gene expression associated with the skin color of black-bone chicken in Thailand

The objective of this study was to investigate the effect of breed, sex, and age on the gene expression level of melanocortin 1 receptor (MC1R), DOPA chrome tautomerase (DCT), tyrosinase-related protein 1 (TYRP1), tyrosinase (TYR), and agouti signaling protein (ASIP) genes in Thai commercial chicken lines. All chicken have received Newscastle vaccination, and no antibiotics or any drugs were used in this study. Four chicken breeds including Black-Chinese, KU-Phuparn, Sri Mok, and Pradu Hang Dam were used in this study. These breeds can be classified by their skin color into 3 group including black (Black Chinese and KU-Phuparn), light black (Sri Mok), and yellowish white (Pradu Hang Dam). One hundred chickens per breed were used in this study. Breast skin tissue was randomly collected from 8 chickens (4 males, 4 females) per breed at 4, 8, 12, and 16 wk of age. The mRNA expression was analyzed using qRT-PCR and the gene expression level was calculated as 2−ΔΔCT. From the results, breed significantly (P < 0.01) affected the expression level for the 5 genes evaluated. Birds with the black skin color had greater TYRP1 and TYR gene expression when compared to chickens with light black and yellowish-white skin color, respectively. Whereas, chickens with yellowish-white skin color had greater ASIP gene expression when compared to chickens having the other skin colors. Sex significantly affected DCT, TYRP1, and TYR gene expression where the gene expression in males was greater when compared to females (P < 0.05). Age affected all gene expression levels (P < 0.01). At 4 wk of age, MC1R, DCT, TYRP1, and TYR gene expression was the highest and decreased as bird age increased (P < 0.05); however, ASIP gene expression was greatest at 8 wk of age. After 8 wk of age all gene expression for the genes evaluated in this study decreased as age increased. In addition, an interaction between breed and sex (P < 0.05) impacted DCT and ASIP gene expression. The results from this study showed that all genes evaluated can be used as candidate markers to further improve the blackness of the chicken's skin because the most desired skin color is black in the Thai black-bone chicken population.

Effect of Feeding Low Protein Diets on the Production Traits and the Nitrogen Composition of Excreta of Broiler Chickens

The main goal of the current study was to investigate the effects of feeding low protein (LP) diets on the performance parameters and excreta composition of broiler chickens. In total, 288 male Ross 308 day-old chickens were divided into two dietary treatment groups using six replicate pens with 24 chickens each. No LP diet was fed in the starter phase. The protein reduction in the grower and finisher phases were 1.8% and 2% respectively. Beside the measurements of production traits, on day 24 and 40 representative fresh excreta samples were collected, their dry matter, total N, NH4+-N and uric acid-N contents determined, and the ratio of urinary and fecal N calculated. Dietary treatments failed to cause significant differences in the feed intake, growth rate, and feed conversion ratio of animals. LP diets decreased the total nitrogen and uric acid contents of excreta significantly. The age of birds had also significant effect, resulting more reduction in the grower phase compared with the finisher. The ratio of urinary N was higher at day 40 compared with the age of day 24. The urinary N content of broiler chicken’s excreta is lower than can be found in the literature, which should be considered in the ammonia inventory calculations.

Responses of dispersing GPS‐tagged Golden Eagles (Aquila chrysaetos) to multiple wind farms across Scotland

Wind farms may have two broad potential adverse effects on birds via antagonistic processes: displacement from the vicinity of turbines (avoidance), or death through collision with rotating turbine blades. Large raptors are often shown or presumed to be vulnerable to collision and are demographically sensitive to additional mortality, as exemplified by several studies of the Golden Eagle Aquila chrysaetos. Previous findings from Scottish Eagles, however, have suggested avoidance as the primary response. Our study used data from 59 GPS‐tagged Golden Eagles with 28 284 records during natal dispersal before and after turbine operation &lt; 1 km of 569 turbines at 80 wind farms across Scotland. We tested three hypotheses using measurements of tag records’ distance from the hub of turbine locations: (1) avoidance should be evident; (2) older birds should show less avoidance (i.e. habituate to turbines); and (3) rotor diameter should have no influence (smaller diameters are correlated with a turbine’s age, in examining possible habituation). Four generalized linear mixed models (GLMMs) were constructed with intrinsic habitat preference of a turbine location using Golden Eagle Topography (GET) model, turbine operation status (before/after), bird age and rotor diameter as fixed factors. The best GLMM was subsequently verified by k‐fold cross‐validation and involved only GET habitat preference and presence of an operational turbine. Eagles were eight times less likely to be within a rotor diameter’s distance of a hub location after turbine operation, and modelled displacement distance was 70 m. Our first hypothesis expecting avoidance was supported. Eagles were closer to turbine locations in preferred habitat but at greater distances after turbine operation. Results on bird age (no influence to 5+ years) rejected hypothesis 2, implying no habituation. Support for hypothesis 3 (no influence of rotor diameter) also tentatively inferred no habituation, but data indicated birds went slightly closer to longer rotor blades although not to the turbine tower. We proffer that understanding why avoidance or collision in large raptors may occur can be conceptually envisaged via variation in fear of humans as the ‘super predator’ with turbines as cues to this life‐threatening agent.

Prevalence and risk factors for feather-damaging behavior in psittacine birds: Analysis of a Japanese nationwide survey.

A case control study was conducted to estimate the prevalence of feather-damaging behavior and evaluate the correlation with risk factors among pet psittacine birds in Japan. Although feather-damaging behavior among pet parrots is frequently observed in Japan, its prevalence and potential risk factors have not been investigated. Therefore, we conducted an online questionnaire survey on parrot owners throughout Japan to examine regional differences in feather-damaging behavior and associated risk factors. In total, 2,331 valid responses were obtained. The prevalence of feather-damaging behavior was 11.7%, in general agreement with prior studies. The highest prevalence was among Cockatoos (Cacatua spp., etc.; 30.6%), followed by Lovebirds (Agapornis spp.; 24.5%) and African grey parrots (Psittacus erithacus; 23.7%). Multivariate logistic regression was carried out to calculate the adjusted odds ratio (ORadj) for potential risk factors and adjust the confounding of the variables. The odds of feather-damaging behavior were significantly higher for Conures (Aratinga spp., Pyrrhura spp., Thectocercus acuticaudatus, Cyanoliseus patagonus) (ORadj = 2.55, P = 0.005), Pacific parrotlets (Forpus coelestis) (ORadj = 3.96, P < 0.001), African grey parrots (ORadj = 6.74, P < 0.001), Lovebirds (ORadj = 6.79, P < 0.001) and Cockatoos (ORadj = 9.46, P < 0.001) than Budgerigars (Melopsittacus undulatus), and for young adults (ORadj = 1.81, P = 0.038) and adults (ORadj = 3.17, P < 0.001) than young birds, and for signs of separation anxiety (ORadj = 1.81, P < 0.001). Species, bird age and signs of separation anxiety were significantly higher risk factors for feather-damaging behavior than any other potential risk factors. Our findings, which include broad species diversity, are a good source of data for predicting risk factors for feather-damaging behavior and could be useful in preventing declines in welfare.

Comparing the efficacy of stimbiotic and a combination of xylanase and beta-glucanase, in broilers fed wheat-barley based diets with high or low AME

A stimbiotic is defined as a product that stimulates a fiber-degrading microbiome to increase fiber fermentability. The aim of this study was to examine if it is more advantageous to feed a stimbiotic (xylanase + xylo-oligosaccharides [STB]) or a combination of xylanase and beta-glucanase (Xyl + BG) to broilers fed wheat-barley based diets with differing AME levels. Cobb 500 broilers (n = 480, 80 birds per treatment) were fed 6 dietary treatments in a 2 × 3 factorial arrangement; 2 AME levels, ‘High’ or ‘Low’, which differed by 100 kcal ME/kg, and 3 additive supplementations, with no supplemental additives, STB or Xyl + BG. Diets were fed as 3 phases, starter (d 0–14), grower (d 14–21) and finisher (d 21–35). On bird age d 14, 21 and 35, total pen body weight and feed intake were determined, and feed conversion ratio corrected for mortality (cFCR) was calculated. On d 21 and d 35 ileal viscosity and beta-glucan content and caecal SCFA concentration were determined. Additive suplementation had no impact on cFCR in birds fed the low AME diet, but in birds fed the high AME diet the cFCR value was reduced in the presence of the additives (P = 0.001 and P = 0.015, at d 14–21 and d 21–35, respectively). At d 21, cecal SCFA concentration was consistently higher (P = 0.015), and ileal beta-glucan level lower (P = 0.002), in birds fed the diet supplemented with STB compared to those without additives. At d 35, ileal viscosity was lower in birds fed STB compared to those fed the diet without supplementation of additives, irrespective of diet AME level (P = 0.017). These results suggest that both STB and Xyl + BG ameliorate the antinutritive effects of the non-starch polysaccharides (NSP) present in wheat-barley based diets, resulting in improved bird performance. However, supplementation with STB induces a comparatively greater positive effect on NSP hydrolysis and SCFA production.

A Comparison of Morphometric Indices, Mineralization Level of Long Bones and Selected Blood Parameters in Hens of Three Breeds

Abstract The aim of the study was to compare morphometric indices and the mineralization level of humerus, femur and tibia in Leghorn (H-22), Sussex (S-66) and Rhode Island Red (R-11) hens at different age (weeks 6, 16, 45 and 64), as well as some blood parameters. The material for the experiment was one-day old chicks of breeds: Leghorn (H-22), Sussex (S-66) and Rhode Island Red – RIR (R-11), which were separated into three groups. At 6, 16, 45 and 64 weeks of the study, 10 birds selected from each group were weighed, slaughtered, and their right femurs, tibiae and humeri were dissected. After removing soft tissues, the bones were weighed and measured for length, diameter, and the Seedor index (SI) was calculated. The bones were analysed for the content of calcium (Ca), phosphorus (P) and crude ash (CA). At 64 weeks, blood was collected from the hens and analysed for the concentration of Ca, P, pyridinoline and deoxypyridinoline. The study showed that hen breed had an effect mostly on morphometric indices of the bones such as bone weight and diameter, and the Seedor index (SI), while the age of birds had an effect on the bone mineralization level up to 45 weeks of age. The bone mineralization did not decrease in the studied breeds of hens at the end of the laying period. It was also found that heavier birds (RIR) had greater diameter bones and a higher SI, but the content of ash and minerals in the bones of that breed was generally similar to the Leghorn and Sussex hens. RIR hens exhibited higher plasma phosphorus concentration compared to Sussex hens. This may suggest that RIR birds have a slightly stronger bone system compared to Leghorn and Sussex hens.

Flight altitudes of a soaring bird suggest landfill sites as power line collision hotspots

Anthropogenic structures are increasingly encroaching wildlife habitats, creating conflicts between humans and animals. Scaling up renewable energy requires new infrastructures such as power lines, that cause high mortality among birds since they act as obstacles to flight and are used for perching and nesting, which can result in collisions or electrocutions. These interactions often endanger wildlife populations and may also result in high financial costs for companies. Flight behaviour plays a crucial role in collision risk, and the study of flight altitudes enables us to understand what drives birds to fly at collision risk altitudes. This allows the identification of high-risk areas, conditions and bird behaviours, and the implementation of mitigation measures by power line companies. In this study, we use boosted random tree modelling to identify drivers of white stork (Ciconia ciconia) flight altitudes and to investigate the factors that lead them to fly at collision risk altitudes. We found that the main drivers of flight altitude for this soaring bird species were time of day, distance to the nearest landfill site and cloud cover density. Bird age, habitat type and season were comparatively less important. Collision risk increases during crepuscular hours near landfill sites, also in days with high cloud cover density and during the breeding season. In recent years, hundreds to thousands of storks congregate daily at landfill sites to take advantage of the predictability and superabundance of anthropogenic food waste. Some of these sites have high density of power lines, becoming collision risk hotspots for storks and other landfill users. Despite being susceptible to collision, our results suggest that white storks can avoid power lines to a certain extent, by changing their flight altitude at ca. 80 m from these structures. This study shows that the implementation of mitigation measures for existing power lines should be prioritized in areas in the vicinity of landfill sites within white stork distribution ranges, and the projection of new lines should avoid those areas. These measures would benefit species vulnerable to mortality due to power line collision, and it would also reduce associated power outages and economic costs.

Molecular and Cultures based Diagnosis of Infectious Bursal Disease Virus (IBDV) in Vaccinated and Non Vaccinated Poultry Flocks

Background: In recent years, Infectious bursal disease is continuously occurring even after vaccination in India and requires an inclusive diagnosis. Therefore, the present study was undertaken to diagnose IBD through molecular and culture methods. Methods: One pooled sample, from each of 54 flocks having birds with IBD like symptoms, was collected. History of bird type, age and vaccination was recorded. Samples were subjected to RT-PCR, egg embryo culture and chicken fibroblast cells culture. Result: A total of 49669 out of 517900 (9.59 %) of birds, aging 3-6 weeks, were displaying the signs similar to IBD.In RT-PCR, 21 (38.88%) samples were found positive which belonged to11 (52.38%) vaccinated and 10 (47.62%) unvaccinated flocks.The RT-PCR positive samples were successfully cultivated for the virus through egg embryo and cell culture. The CEF culture was found least sensitive compared to egg embryo culture and RT-PCR.

New Perspectives on Avian Models for Studies of Basic Aging Processes.

Avian models have the potential to elucidate basic cellular and molecular mechanisms underlying the slow aging rates and exceptional longevity typical of this group of vertebrates. To date, most studies of avian aging have focused on relatively few of the phenomena now thought to be intrinsic to the aging process, but primarily on responses to oxidative stress and telomere dynamics. But a variety of whole-animal and cell-based approaches to avian aging and stress resistance have been developed—especially the use of primary cell lines and isolated erythrocytes—which permit other processes to be investigated. In this review, we highlight newer studies using these approaches. We also discuss recent research on age-related changes in neural function in birds in the context of sensory changes relevant to homing and navigation, as well as the maintenance of song. More recently, with the advent of “-omic” methodologies, including whole-genome studies, new approaches have gained momentum for investigating the mechanistic basis of aging in birds. Overall, current research suggests that birds exhibit an enhanced resistance to the detrimental effects of oxidative damage and maintain higher than expected levels of cellular function as they age. There is also evidence that genetic signatures associated with cellular defenses, as well as metabolic and immune function, are enhanced in birds but data are still lacking relative to that available from more conventional model organisms. We are optimistic that continued development of avian models in geroscience, especially under controlled laboratory conditions, will provide novel insights into the exceptional longevity of this animal taxon.

Energetic values of animal by-products for broiler chickens of different ages

The objective of this study was to determine the chemical composition and apparent metabolizable energy (AME), AME corrected for nitrogen balance (AMEn) and its respective metabolizable coefficients of animal byproducts for broiler chickens with different ages. Meat and bone meal, poultry by-product meal, tilapia processing residue and poultry fat were evaluated. A total of 760 male broiler chickens were used and evaluated and the phases: pre-starter (1 to 8 d of age); starter (11 to18 d); grower 1 (21 to 28 d); grower 2 (31 to 38 d), and finisher (41 to 48 d). Total excreta collection method was performed in five metabolism assays. The experimental design was completely randomized, and data were submitted to analysis of variance, posteriorly, the four feeds were compared by Tukey test and a regression analysis was performed with broiler chickens age. The significance was considered at 5% probability. The values of AME and AMEn were higher in older birds for all ingredients. The lesser CAME and CAMEn were obtained for meat and bone meal, for the regression analysis poultry by-product meal, tilapia processing residue and poultry fat had an increased linear effect with birds age and there was no adjust for meat and bone meal for regression analysis.

Estimating the age of domestic fowl (Gallus gallus domesticusL. 1758) cockerels through spur development

AbstractDetermining the age of bird remains after the cessation of growth is challenging due to the absence of techniques such as tooth eruption and wear available for mammals. Without these techniques, it is difficult to reconstruct hunting strategies, husbandry regimes, and wider human–animal relationships. This paper presents a new method, developed from a collection (n = 71) of known‐age specimens of domestic fowl (Gallus gallus domesticusL. 1758), for assessing age based on the fusion and size of the tarsometatarsal spur. Using this method, we reconstruct the demographics of domestic fowl from Iron Age to Early Modern sites in Britain to reveal the changing dynamics of human–domestic fowl relationships. We highlight the advanced age that cockerels often attained in their early history and how their life expectancies have subsequently declined.

Effect of Dietary Supplementation with L-Arginine and Vitamin C on Egg Production Performance for Matrouh Strain Hens

The present work was aimed to study the effect of dietary L-arginine level, vitamin C, and their interaction between them on some productive performance of Matrouh laying hens during the summer season. A 4X3 factorial treatment arrangement was carried out including four levels of dietary L-Arg (0.0, 0.4, 0.8, and 1.2 g/kg diet) and three VC concentrations (0, 150, and 300 mg/kg diet). A total number of 108 Matrouh hens (Egyptian local strain) aged 64 weeks were randomly distributed into twelve treatment groups (three replicate each). The results obtained showed a significant (p < 0.05) effect in live body weight due to dietary L-Arg and VC supplementation at 72 weeks of age only. Significant (p < 0.05) differences were observed in feed intake and feed conversion ratio due to dietary L-Arg levels during all periods of estimation. Dietary L-Arg levels had significant (P<0.05) effects on the rate of egg prodction during the periods from 68-71 and 64-75 weeks of birds age. Significant (p < 0.05) differences were observed in egg weight due to dietary L-Arg and VC levels during all periods of estimation except at 72-75 weeks of age. Dietary L-Arg levels had significant (P<0.05) effect on egg mass during the periods from 68-71,72-75 and 64-75 weeks of bird’s age. The VC supplementation didn't have any significant effects on feed conversion ratio, egg production rate, egg weight, and egg mass. The interaction effects between dietary L-Arg and VC levels had a major influence (p < 0.05) on body weight, feed consumption, feed conversion ratio, egg production rate, egg weight and egg mass. In conclusion, it could be concluded that Matrouh laying hens supplemented diet with L-Arg at a level of 1.2 g or VC at a level of 300 mg/kg diet, seemed to be adequate to achieve the favorite results and is recommended.

Apparent metabolizable energy of cereal grains for broiler chickens is influenced by age

The current study was conducted to investigate the influence of broiler age on the AME and AMEn of 4 common cereal grains (wheat, sorghum, barley, and corn). Four experimental diets with the same inclusion (962 g/kg) of each grain were developed and fed to groups of broiler chickens aged 1 to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35, or 36 to 42 d post-hatch. Each diet, in pellet form, was randomly allocated to 6 replicate cages in each age group. Except for the 0 to 7 d age group, the birds were fed a starter (d 0–21) and/or a finisher (d 21–35) diet before the introduction of experimental diets. The number of birds per cage were 10 (d 1–7) and 8 (d 8–42). Excreta were collected over the last 4 d of each age period. The AME and AMEn of the grains were determined by the total excreta collection. Bird age influenced (P < 0.001) the AME and AMEn of all cereal grains. The AMEn of wheat declined quadratically (P < 0.01) with advancing age, from 3,461 kcal/kg in wk 1 to 3,219 kcal/kg in wk 2 and then plateaued. The AMEn of sorghum grain declined linearly (P < 0.001) with advancing age, from 3,762 kcal/kg in wk 1 to 3,614 kcal/kg in wk 2, plateaued to wk 5 and then declined to 3,556 kcal/kg in wk 6. A quadratic (P < 0.001) reduction in the AMEn of barley was observed as birds grew older, with the AMEn decreasing between wk 1 (3,286 kcal/kg) and wk 2 (2,988 kcal/kg), increasing in wk 3 (3,117 kcal/kg) and then plateauing. The AMEn of corn declined quadratically (P < 0.05) with advancing broiler age; the highest AMEn was observed in wk 1 and 5, the lowest AMEn in wk 2, with the other weeks being intermediate. In conclusion, the present results showed that broiler age has a substantial impact on the AME and AMEn of cereal grains and the effect varied depending on the cereal grain. These data suggest that age dependent AME and AMEn values may need to be considered when formulating broiler diets to improve the precision of feed formulation and production efficiency.

Use of extruded eggshell as a calcium source substituting limestone or oyster shell in the diet of laying hens.

The nutritional values of limestone, oyster shell and extruded eggshells were evaluated using different methods. In total, 120 ready‐to‐lay pullets, 18‐week‐old ISA Brown were distributed into six dietary groups, namely D1 (4% limestone), D2 (8% limestone), D3 (4% oyster shell), D4 (8% oyster shell), D5 (4% eggshell) and D6 (8% eggshell), to assess the effect of calcium sources on egg production, egg quality, dry matter and cholesterol content of the egg. Kitchen‐extruded eggshell contained 98.52, 4.24, 29.75 and 14.82% DM, CP, Ca and P, whereas hatchery‐extruded eggshell contained 99.20, 13.80, 25.53 and 13.87% DM, CP, Ca and P, respectively. Limestone and Oyster shells contained 99.60 and 99.51% DM, and 37.12 and 35.20% Ca, respectively. Body weight, egg, hen day and egg mass production, and FCR did not differ among diets (p > .05). Egg production tended to increase with the increase of hen‐housed egg production (p < .001) in D6, followed by D2, D5, D3, D4 and D1, respectively. The lowest production cost and the highest net profit were observed in D6, followed by D2, D4, D5, D1 and D3, respectively. Diet with 8% Ca sources performed better than the diets with 4% Ca sources in terms of egg quality and dry matter content, where D6 was comparable to D2 or D4. The weight of egg, albumen, yolk, eggshell, dry yolk and yolk–albumen ratio increased, while dry albumen and eggshell weight, eggshell strength and thickness, Haugh unit, yolk index and egg‐specific gravity decreased with the increase in bird's age. The cholesterol content of yolk was statistically similar among diets. Therefore, no adverse effect of calcium sources on the production of laying hen was observed. Of these, extruded eggshell especially the 8% extruded eggshell may be beneficial to use in the diet of laying hen for producing a quality, safe and profitable egg.

Effects of Different Scratch Mat Designs on Hen Behaviour and Eggs Laid in Enriched Cages.

Simple SummaryEnriched cages for laying hens must contain litter so that pecking and scratching are possible. This is typically provided using layer’s feed dispensed onto a scratch mat, however, there are no regulations on the size or materials of the mat. This study examined how different scratch mat designs and bird age affected behaviours on the mat at three times of day, and their influence on where eggs were laid and shell quality. The proportion of hens at the scratch mats did not increase during or shortly after the application of scratch feed, however, they were more likely to be foraging then. Most eggs collected were clean and laid in the nest. Of the small proportion of eggs that were cracked or dirty, the mat type did not affect dirty eggs, but eggs laid opposite the Big Dutchman mats were more likely to be cracked at 79 weeks of age than at any other mat type or age. There appeared to be no optimal scratch mat design (of those studied) and their use (during observations) was low, suggesting that mat designs were not major influencers on bird behaviour.Laying hens in the UK and EU must be provided with litter for pecking and scratching. In enriched cages, this is commonly provided by dispensing layer’s feed onto a scratch mat. Mats vary in design and size, which might affect hen behaviour and egg quality, since eggs are sometimes laid at the mats. We investigated if four different scratch mats (BD, K, V, Z) provided to hens in enriched cages resulted in differences in behaviour on the mats and external egg quality. Twenty-four 60-bird cages (6 cages/bank × 4 banks) with 2 mats/cage at one tier of a commercial enriched cage unit were used. Mats were allocated to cages in a balanced design prior to the flock arriving. Hens and eggs were studied at 30, 50 and 79 weeks of age, with three behaviour observations (before, during or after scratch feed application). The data were analysed by GLMMs or LMMs. The vast proportions of birds on the mats were standing (0.720) or sitting (0.250). Bird proportions on the mats were low overall and declined from 0.028 (30 weeks) and 0.030 (50 weeks) to 0.020 (79 weeks) (p < 0.001). The greatest proportion of hens were observed on Z (p < 0.001), which had the largest area, but relative to the available area least birds were on Z and most were on K (p < 0.001). Foraging was not affected by bird age or mat type but was greater at the second observation (p < 0.001). Most eggs were laid in the nest box and were clean. Clean eggs declined, and dirty eggs increased, significantly with age, particularly at the scratch mat (p < 0.001). Dirty eggs were not affected by mat design. Cracked eggs were highest at 79 weeks of age, particularly with BD mats (p < 0.001). Overall, scratch mat designs had minimal effects on behaviour (but few hens were seen there) and egg quality.

Effects of hydrated sodium calcium aluminum silicates (HSCAS) in experimentally induced cadmium toxicity in male Japanese quail (Coturnix japonica)

Cadmium (Cd) is an environmental pollutant and is toxic to animal species. The objective of this study was to evaluate the toxico-pathological effects of Cd and the effects of hydrated sodium calcium aluminum silicates (HSCAS) on Cd-induced pathological alterations in male Japanese quails (Coturnix japonica). A total of 180 male C. japonica at 25 d of age were divided into nine equal groups, i.e. A–I. Group A was kept as control while groups B and C were administered with Cd @ 100 and 200 mg/kg feed. Groups D and E were fed HSCAS @ 5 and 10 g/kg feed. Groups F, G, H, and I were administered with HSCAS along with Cd in different combinations. The total duration of the experiment was 35 d (at experimental day 0, bird age was 21 d). Gross changes in Cd-fed groups included enlargement of the liver and atrophied testes. Histopathological picture of groups B (100 mg Cd/kg) and C (200 mg Cd/kg) showed fatty change, individual cell necrosis, and proliferation of bile ducts at hepatic triad. Testes showed testicular degeneration which included absence of spermatogenesis, pyknotic, and dark nuclei between the spermatids and absence of spermatids and spermatozoa. No parameter studied showed any adverse effect of HSCAS given to the quail @ 5 and 10 g/kg feed. Groups of quail-fed Cd and HSCS concurrently in different combinations did not show any adverse effect suggesting an amelioration of Cd-induced pathological changes in the birds. It was concluded that concurrent administration of HSCAS and Cd protected the quail from adverse effects of Cd toxicity.

Evaluation of different antigenic preparations against necrotic enteritis in broiler birds using a novel Clostridium perfringens type G strain

ObjectiveKeeping in view, the constraints faced by the Indian broiler industry with lack of a suitable vaccine against Necrotic Enteritis (NE), a study has been proposed to explore the prevalence and detail characterization of C. perfringens type G in NE suspected broiler chicken in the process of suitable vaccine development. MethodsIntestinal scrapings/faecal contents of NE suspected broiler chickens were screened to establish the prevalence of C.perfringens type G in broiler birds. A most pathogenic, highly resistant type G isolate of C. perfringens, bearing both tpeL and gapC gene was selected for preparation of three different vaccine formulations, and to evaluate their immunogenic potential in broiler birds. ResultsScreening of clinical samples of NE suspected broiler birds revealed C. perfringens type G, bearing gapC gene in 51.22% samples, of which 47.62% revealed tpeL gene. Seven of the tpeLpos type G isolates were comparatively more pathogenic for mice, of which, one exhibited multidrug resistance towards ciprofloxacin, norfloxacin, tetracycline and levofloxacin. The sonicated supernatant (SS) prepared from the selected tpeL and gapC positive isolate could maintain a significantly higher protective IgG response than toxoid and bacterin preparation from the 21st to 28thday of age in immunized birds. ConclusionThe additional TpeL toxin in C. perfringens type G has been proved to be an additional key biological factor in the pathogenesis of NE in broiler chickens. Considering the release of more immunogenic proteins, the SS proved to be a better immunogenic preparation against NE with a multiple immunization dose.

The Variability of Quality Traits of Table Eggs and Eggshell Mineral Composition Depending on Hens' Breed and Eggshell Color.

Simple SummaryThe quality of the bird’s eggshell is extremely important because it constitutes a barrier that protects the developing embryo from external conditions. The shell color is a characteristic for a specific breed and its intensity is one of the basic selection criteria, especially among ornamental breeds of hens. The presence or absence of a specific dye is genetically determined, and environmental conditions or nutrition affect it only to a negligible degree. The shell is an inorganic part of the egg. Differences in the mineral composition are determined mainly by the feeding system and the age of birds, although differences are also observed between the lines or breeds, so probably also due to the color. The content of given elements affects the shell quality, determining its strength, thickness, or preventing the appearance of defects that affect the hatching results. In case of table eggs the variability of colors is attractive for consumers, particularly if the differences are extreme (white, green, brown). Based on the study, it was clearly visible that genetically determined eggshell color affects not only the quality of shell itself but also the whole egg parameters.The aim of the study was to evaluate the relationship between the eggshell color parameters and its mineral composition as well as the internal quality of eggs derived from various breeds of hens, varied by eggshell color: seledine from Araucana, brown from Marans, and white from Leghorn. The sample consisted of 180 eggs (60/group) The eggshell color was measured using CIE L*a*b* system. The quality evaluation included traits of whole egg (weight, specific gravity, proportions of elements, shape index), yolk (weight, color, index, pH), albumen (weight, height, pH), and shell (color, strength, weight, thickness, density). The mineral composition of eggshells was analyzed. The eggs origin affected the quality characteristics of particular egg elements (p < 0.001). However, the impact of analyzed colors on the egg quality traits varied, and in the case of whole egg and albumen traits the most favorable was the white color (p ≤ 0.05), while in the case of the strength of shell or its thickness it was the dark brown color (p ≤ 0.05). The eggshell color influenced variations in its mineral composition (p < 0.001) except potassium and sodium content, while the proportion of particular mineral elements in shell was correlated with the L*a*b* color space coordinates (p ≤ 0.05).