Beneficial Impact of Hypercapnic Conditions During Early Incubation on Broiler Hatchability. Embryo Mortality and Postnatal Performance

We assessed the extent to which CO2 levels altered different hatching and chick parameters. In Experiments 1 and 2, a total of 16,184 eggs from Cobb 500 breeders were incubated in single stage incubators under three different conditions: (a) standard ventilated incubator (CON, Exp.1 and 2); (b) increasing CO2 levels during the first 10 days of incubation until 0.7% (V7000, Exp. 1) and (c) until 0.8% (V8000, Exp. 2). High levels of CO2 improved hatchability, possibly due to lower embryo mortality from ED18 to ED21. Internal and external pipping in experiment V8000 started later than in CON; nevertheless, the hatch still occurred before in V8000 as a result of the shorter durations of external pipping and hatch. In Experiment 3, a total of 12,138 eggs from Cobb 500 were incubated in single stage incubators under three different conditions: (a) standard ventilated incubator (CON); (b) increasing CO2 levels until 1.0% with ventilation (V10000); and (c) increasing CO2 levels until 1.0% without ventilation (NV10000). Hypercapnic conditions led to better hatchability and lower embryo mortality from ED18 to ED21. Internal pipping started earlier in NV10000, but only V10000 differed from CON in terms of the average time for hatch. Hypercapnic groups also showed shorter durations of external pipping and hatch when compared to CON. Post-hatch analysis revealed no differences among incubation conditions in terms of body weight gain, feed conversion ratio, mortality by sudden death syndrome, and production factor. Nevertheless, V10000 showed a lower mortality by ascites and a better viability when compared to CON, while NV10000 presented a higher mortality by other causes. Altogether, our findings indicate that in addition to not being detrimental to embryo survival, high CO2 levels reduce embryonic mortality at 18-21 days of incubation and increase hatchability.(AU)

Artificial neural networks for the management of poultry industry: a simulation based on the broiler production chain / Redes neurais artificiais para o gerenciamento da indústria avícola: uma simulação baseada na cadeia de produção de frangos de corte

The aim of this study was to predict production indicators and to determine their potential economic impact on a poultry integration system using artificial neural networks (ANN) models. Forty zootechnical and production parameters from broiler breeder farms, one hatchery, broiler production flocks, and one slaughterhouse were selected as variables. The ANN models were established for four output variables: "saleable hatching", "weight at the end of week 5," "partial condemnation," and "total condemnation" and were analyzed in relation to the coefficient of multiple determination (R2), correlation coefficient (R), mean error (E), mean squared error (MSE), and root mean square error (RMSE). The production scenarios were simulated and the economic impacts were estimated. The ANN models were suitable for simulating production scenarios after validation. For "saleable hatching", incubator and egg storage period are likely to increase the financial gains. For "weight at the end of the week 5" the lineage (A) is important to increase revenues. However, broiler weight at the end of the first week may not have a significant influence. Flock sex (female) may influence the "partial condemnation" rates, while chick weight at first day may not. For "total condemnation", flock sex and type of chick may not influence condemnation rates, but mortality rates and broiler weight may have a significant impact.

O objetivo deste trabalho foi predizer os indicadores de produção e determinar o seu potencial impacto econômico em um sistema de integração utilizando as redes neurais artificiais (RNA). Quarenta parâmetros zootécnicos e de produção de granjas de matrizes e de frango de corte, um incubatório e um abatedouro foram selecionados como variáveis. Os modelos de RNA foram estabelecidos para quatro variáveis de saída ("eclosão vendável", "peso ao final da quinta semana", "condenações parciais" e "condenações totais") e foram analisados em relação ao coeficiente de determinação múltipla (R2), coeficiente de correlação (R), erro médio (E), erro quadrático médio (EQM) e raiz do erro quadrático médio (REQM). Os cenários produtivos foram simulados e os impactos foram estimados. Os modelos de RNA gerados foram adequados para simular diferentes cenários produtivos após o treinamento. Para "eclosão vendável", o modelo de incubadora e o período de incubação aumentaram os ganhos financeiros. Para "peso ao final da quinta semana", a linhagem também demonstrou influencia no retorno financeiro, o que não aconteceu com o peso ao final da primeira semana. O sexo do lote possui influência nas taxas de "condenação parcial", ao contrário do peso do frango no primeiro dia. As taxas de mortalidade e o peso do frango apresentaram influência na "condenação total", mas o sexo do lote e o tipo de pinto não tiverem influência.

Stress and fear responses of slow-growing broiler chickens to light stimulation initiated at different phases of embryonic development

Photo-incubation can influence the fear and stress responses of poultry. However, it is unclear how photostimulation initiated at different phases of development influences the welfare status of slow-growing broiler birds. 500 Sasso eggs were assigned to 4 treatments; some were incubated in the dark throughout incubation (TA), while TB, TC and TD were photo-stimulated (12L:12D) from days 1, 7, and 14 of incubation, respectively, until hatch using a 6,500k LED at 788 clux intensity. Birds were raised in 5 replicates per treatment with 16 birds per replicate using a 6,500k LED (at 28 clux) and a photoperiod of 16L:8D. Fear (emergence, tonic immobility, isolation and inversion tests) and stress response (physical asymmetry) of 10 birds per treatment were examined. At the end of the three-week brooding, all parameters measured were not significantly influenced (P > 0.05) by the onset of photo-incubation. At slaughter age (12 weeks), physical asymmetry was significantly higher (P < 0.05) in TA compared to the other treatments. The frequency of isolation vocalisation was significantly lower (P < 0.05) in TB compared to TA, and latency to rightness during tonic immobility was significantly higher (P < 0.05) in TA compared to the other treatments. Latency to emerge was significantly longer (P < 0.05) in TA compared to TC and TD. The frequency of wing flaps during inversion was significantly higher (P < 0.05) in TA and TD. Conclusively, photo-incubating eggs reduce stress and fear, and initiating photo-incubation during the first phase of incubation is more beneficial.

Molecular investigations of the effect of thermal manipulation during embryogenesis on muscle heat shock protein 70 and thermotolerance in broiler chickens

The objective of this study was to elucidate the optimum protocol timing of thermal manipulation (TM) during embryogenesis, which underline genetic improvement of muscle thermotolerance acquisition. For the present study, 1,440 fertile eggs were divided randomly and equally into control (37.8 °C with 56% relative humidity) and four thermally manipulated groups (TM1, TM2, TM3, and TM4) subjected to 39 °C for 18 h with 65% relative humidity daily during different embryonic periods. Then, at day 35 post-hatch, all groups were subjected to thermal challenge at 43 °C for 6 h to identify the level of thermotolerance acquisition differences between them. Hsp70 mRNA expression was evaluated by using a relative quantitatively RT-qPCR. Single nucleotide polymorphisms sequence of the Hsp70 gene was evaluated by Sanger's sequencing method. Pectoral and thigh muscles samples were subjected to immunohistochemistry to detect Hsp70. Among TM conditions that were investigated, TM1 (39 °C for 18 h during embryonic days (ED) 7­11) induced a significant improvement in thermotolerance parameters (body temperature and T3 levels) during thermal challenge combined with an increase in the levels of Hsp70 mRNA and its protein with a high stability of nucleotide sequences in both pectoral and thigh muscles. The partial DNA sequence of Hsp70 gene in TM1 was reported, and nucleotide sequences were deposited in NCBI GenBank database with the accession numbers (MK852579) and (MK852580). Thigh muscle thermotolerance acquisition was higher than pectoral muscle during thermal challenge at 43 °C for 6 h. Thus, TM during ED7­11 may improve thermotolerance acquisition without adversely affecting performance.(AU)

Rate of Transfer of Infectious Anaemia Maternal Antibodies from Broiler Breeders To the Progeny: a Field Evaluation

Clinical manifestation of the disease caused by the chicken anaemia virus (CAV) occurs when chicken chicks are vertically contaminated or before the second week of life. CAV control is based on the vaccination of broiler breeders in order to promote progeny protection through maternal antibodies. This work aims to evaluate, under field conditions, the antibody title in commercial broiler breeders at 28, 48, and 68 weeks of age, the rate of transference to the progeny, as well as the duration of antibodies in the progeny up to 21 days of age. Thus, a total of 92 sera samples from 93,000 broiler breeders vaccinated with a live vaccine for CAV at 14 weeks of age and 366 sera samples from their respective progeny were analyzed using ELISA. Breeders' antibody title for CAV ranged between 5051 and 8660, and these titles may provide sufficient protection for their progeny. On average, 63% of the maternal antibodies were transferred to the progeny and lasted up to the second week of chick's life. It is possible to conclude that the vaccine and the vaccination procedure used by this company for breeders against CAV seems to be effective in inducing high antibody levels in the breeders and transfering protective maternal antibodies to the progeny.(AU)

Effect of Dietary Growth Promoter Supplementations on the Serum Biochemistry and Morphometric Characteristics of Tibia Bone in Broiler Chicken

Bone mineralization is considered an essential source of minerals for metabolic needs that provide strength and hardness to the bone tissues and in birds its development can be enhanced by the use of dietary supplements. The present study was executed to evaluate the influence of prebiotic, probiotic and antibiotic on the morphometric aspects of tibia bone in broilers. One-hundred and sixty-one-day-old broiler chick were divided randomly into four groups (n=40) with 4 replicates (n=10 in each replicate). Group-I fed with only corn based basal diet and served as controlled group. Group-II with antibiotic supplement (Zinc bacitracin 0.04%), Group-III with probiotic supplement (lactobacillus 0.1%) & Group-IV with prebiotic supplement (mannan oligosaccharide 0.1%). On the 35th day, two birds were selected randomly from each replicate and slaughtered to record the morphometric parameters of both right and left tibia bones from each bird. The findings showed that the length, weight, thickness of lateral and medial wall, tibiotarsal index of bone and bone ash percentage of supplemented groups have had significant (p<0.05) difference when compared to that of the controlled group. The weight/length index in birds supplemented with prebiotic and probiotic was significantly higher (p<0.05) than in the antibiotic supplemented and control group. Medullary canal diameter of all the supplemented groups was significantly lower (p<0.05) than the control group. No significant (p>0.05) difference of robusticity index and diaphysis diameter was observed among various groups. A significant (p<0.05) low level of Alkaline Phosphatase while higher level of Calcium and Phosphorus was recorded in the supplemented groups compared to that of the control group. In conclusion, the use of prebiotic and probiotic as growth promoter can exhibit some underline mechanisms in the form of enhancement of bone quality, density and characteristics in broiler chicks as compared to common antibiotics.(AU)

Investigation of different levels of cholecalciferol and its metabolite in calcium and phosphorus deficient diets on growth performance, tibia bone ash and development of tibial dyschondroplasia in broilers

This experiment was conducted to examine the effects of 1-α(OH)D3 alone or in combination with different levels of cholecalciferol on performance, and tibia parameters of one-d–old male broilers fed a tibial dyschondroplasia (TD)-inducing diet. A total of three hundred male broilers were randomly allocated to 5 treatment groups with 4 replicates. The dietary treatments consisted of TD inducing diet, TD inducing dietsupplemented with 5μg per kg of 1-α(OH)D3; TD inducing dietsupplemented with 5 μg per kg of 1-α(OH)D3and 1,500; 3,000 or 5,000 IU cholecalciferol kg-1of diet. At 42 d of age, broiler chickens fed diets containing 1-α(OH)D3 and 1,500 IU cholecalciferol kg-1of diet had higher body weight (p < 0.05).In the complete experimental period the best FCR and the highest daily weight gain were obtained in broilers supplemented with1-α(OH)D3 and 1,500 IU cholecalciferol kg-1of diet. Broilers supplemented with 1-α(OH)D3 and 1,500 IU cholecalciferol kg-1of diet had significantly lower incidence and severity of TD in comparison with other groups. In conclusion, the results indicated that the supplementation of 1-α(OH)D3 in combination of 1,500 IU cholecalciferol kg-1of diet could maximize tibia bone ash, performance and prevent TD in broilers fed TD inducing diet.(AU)

Investigation of different levels of cholecalciferol and its metabolite in calcium and phosphorus deficient diets on growth performance, tibia bone ash and development of tibial dyschondroplasia in broilers

This experiment was conducted to examine the effects of 1-α(OH)D3 alone or in combination with different levels of cholecalciferol on performance, and tibia parameters of one-d–old male broilers fed a tibial dyschondroplasia (TD)-inducing diet. A total of three hundred male broilers were randomly allocated to 5 treatment groups with 4 replicates. The dietary treatments consisted of TD inducing diet, TD inducing dietsupplemented with 5μg per kg of 1-α(OH)D3; TD inducing dietsupplemented with 5 μg per kg of 1-α(OH)D3and 1,500; 3,000 or 5,000 IU cholecalciferol kg-1of diet. At 42 d of age, broiler chickens fed diets containing 1-α(OH)D3 and 1,500 IU cholecalciferol kg-1of diet had higher body weight (p < 0.05).In the complete experimental period the best FCR and the highest daily weight gain were obtained in broilers supplemented with1-α(OH)D3 and 1,500 IU cholecalciferol kg-1of diet. Broilers supplemented with 1-α(OH)D3 and 1,500 IU cholecalciferol kg-1of diet had significantly lower incidence and severity of TD in comparison with other groups. In conclusion, the results indicated that the supplementation of 1-α(OH)D3 in combination of 1,500 IU cholecalciferol kg-1of diet could maximize tibia bone ash, performance and prevent TD in broilers fed TD inducing diet.

Effects of breeder age and short-term temperature stimulation during incubation on performance, organ weight, and carcass yield in male and female broilers / Efeitos da idade da matriz e de alterações curtas de temperatura de incubação no desempenho, peso dos órgãos e rendimento de carcaça em frangos de corte machos e fêmeas

Birds develop thermoregulatory control during the last days of incubation. Different temperature conditioning programs have been proposed to prepare broiler chicks for post-hatch life. This study aimed to investigate the effects of short-term temperature (STT) stimulation and breeder age on hatching performance, embryo development, yolk absorption, and post-hatch performance of male and female broilers. A 2 × 2 factorial completely randomized design was used, with two breeder ages (30 and 60 wk), two temperature incubation programs (control and STT), and 2,520 eggs per treatment. Eggs were distributed in two large-scale commercial incubators with a capacity of 120,960 eggs. The control group was subjected to a standard single-stage incubation program (37.2-37.4 °C), whereas the STT group was subjected to a temperature increment of 1 °C for 4 h on embryonic days 16, 17, 18, and 19. Embryos were analyzed at 16 and 19 days of incubation, and chicks at hatch. At 19 days of incubation, STT conditioning resulted in lower yolk sac weight in embryos from 60-wk-old breeders and higher relative weight of the gastrointestinal tract in embryos from 30-wk-old breeders. At hatch, males had lower residual yolk weight, females had greater length, and chicks from 60-wk-old breeders subjected to STT had higher body weight and relative weight of the gastrointestinal tract. Eggs from 30-wk-old breeders showed higher fertility and hatchability and lower infertility, mortality, and second-grade chick percentages. Regarding performance, it was found that males had higher body weight from 7 to 42 days of age and higher whole leg yields. Females, on the other hand, had higher fat yields. Breeder age and sex influenced gastrointestinal tract development, carcass yield, and performance. A 1 °C increase in incubation temperature for 4 h from days 16 to 19 of incubation affected yolk absorption and digestive tract development in chicks from 60-wk-old breeders without, however, influencing performance results.(AU)

As aves desenvolvem o controle do sistema termorregulatório durante os últimos dias de incubação, dessa forma, diferentes programas temperatura de incubação têm sido descritos para preparar os pintos de corte para a vida pós-eclosão. Objetivou-se nesse estudo, estabelecer os efeitos de alterações curtas na temperatura de incubação e da idade da matriz no desempenho de eclosão, desenvolvimento embrionário, absorção da gema e desempenho pós-eclosão de frangos de corte machos e fêmeas. O delineamento experimental foi inteiramente casualizado em fatorial 2 x 2 com 2 idades de matriz (30 e 60 semanas) e 2 programas de incubação de temperatura, controle (CT) e grupo de treinamento de temperatura de curto prazo (STT) e 2.520 ovos em cada tratamento. Os ovos foram distribuídos em 2 incubadoras comerciais de grande escala com capacidade para 120.960 ovos. O grupo CT seguiu um programa de incubação de estágio único padrão (37,2-37,4°C) e o STT teve um incremento em + 1 ° C por 4 hs nos dias 16, 17, 18 e 19 de incubação. Os embriões foram analisados aos 16 e 19 dias e pintinhos na eclosão. Aos 19 dias de incubação, embriões de matrizes com 60 semanas apresentaram menor peso do saco vitelino e embriões de matrizes com 30 semanas apresentaram maior porcentagem de trato gastrointestinal quando em STT. Na eclosão, os machos apresentaram menor vitelo residual, e as fêmeas apresentaram maior comprimento, pintinhos mais pesados e maior trato gastrointestinal quando originárias de matrizes de 60 semanas de idade e expostos ao STT. Na eclosão, os ovos com 30 semanas de idade apresentaram maior porcentagem de fertilidade e eclodibilidade e menor infertilidade, mortalidade e pintos de secunda categoria. No desempenho, os machos apresentaram maior peso corporal do 7° ao 42° dia e maiores valores de porcentagem de pernas e as fêmeas maiores valores de porcentagem de gordura. A idade das matrizes e o sexo influenciaram o desenvolvimento visceral, o rendimento de carcaça e o desempenho dos frangos de corte. O aumento de 1°C durante 4 horas entre os dias 16 e 19 de incubação afetou a absorção da gema e o trato digestivo em pintos de matrizes com 60 semanas de idade, sem refletir nos resultados de desempenho.(AU)

Data mining as a hatchery process evaluation tool

The hatchery is one of the most important segments of the poultry chain, and generates an abundance of data, which, when analyzed, allow for identifying critical points of the process . The aim of this study was to evaluate the applicability of the data mining technique to databases of egg incubation of broiler breeders and laying hen breeders. The study uses a database recording egg incubation from broiler breeders housed in pens with shavings used for litters in natural mating, as well as laying hen breeders housed in cages using an artificial insemination mating system. The data mining technique (DM) was applied to analyses in a classification task, using the type of breeder and house system for delineating classes. The database was analyzed in three different ways: original database, attribute selection, and expert analysis. Models were selected on the basis of model precision and class accuracy. The data mining technique allowed for the classification of hatchery fertile eggs from different genetic groups, as well as hatching rates and the percentage of fertile eggs (the attributes with the greatest classification power). Broiler breeders showed higher fertility (> 95 %), but higher embryonic mortality between the third and seventh day post-hatching (> 0.5 %) when compared to laying hen breeders eggs. In conclusion, applying data mining to the hatchery process, selection of attributes and strategies based on the experience of experts can improve model performance.

Data mining as a hatchery process evaluation tool

The hatchery is one of the most important segments of the poultry chain, and generates an abundance of data, which, when analyzed, allow for identifying critical points of the process . The aim of this study was to evaluate the applicability of the data mining technique to databases of egg incubation of broiler breeders and laying hen breeders. The study uses a database recording egg incubation from broiler breeders housed in pens with shavings used for litters in natural mating, as well as laying hen breeders housed in cages using an artificial insemination mating system. The data mining technique (DM) was applied to analyses in a classification task, using the type of breeder and house system for delineating classes. The database was analyzed in three different ways: original database, attribute selection, and expert analysis. Models were selected on the basis of model precision and class accuracy. The data mining technique allowed for the classification of hatchery fertile eggs from different genetic groups, as well as hatching rates and the percentage of fertile eggs (the attributes with the greatest classification power). Broiler breeders showed higher fertility (> 95 %), but higher embryonic mortality between the third and seventh day post-hatching (> 0.5 %) when compared to laying hen breeders eggs. In conclusion, applying data mining to the hatchery process, selection of attributes and strategies based on the experience of experts can improve model performance.(AU)

In ovo feeding: a review / Alimentação in ovo: uma revisão

The poultry industry plays a large role in the Brazilian economy. In fact,Brazil ranks as the worlds leading exporter and second largest producer ofpoultry meat as the result of genetic improvement, animal nutrition,management, and biosecurity. During the development of bird embryos, thenutrients are stored within the egg, but carbohydrate supplementation isunsatisfactory upon hatching. Poor carbohydrate supplementation candamage the embryo development and negatively affect poultry weight. Inovo feeding is a promising technique to improve the quality of newly hatchedchicks as it uses systems for feeding the embryos by inoculating nutrientsinto the egg amniotic fluid. However, further studies are needed in order toimprove this technique and create effective implementations and protocolsthat can be widely used in the industry. This study aims to both review theliterature on the use of in-ovo feeding and understand the perspectives ofits use in the broiler production chain.

A avicultura tem tido papel expressivo na economia brasileira, estando o país classificado como o segundo maior produtor e o maior exportador do mundo. Esse resultado é proveniente de avanços no melhoramento genético, nutrição, manejo e biosseguridade. Nas aves, os nutrientes utilizados durante o desenvolvimento embrionário estão contidos no ovo, sendo escassa a reserva de carboidratos logo após a eclosão do pintainho. Essa restrição pode causar prejuízos ao desenvolvimento embrionário, impactando negativamente no peso das aves. Diante disso, a nutrição in ovo mostra-se como uma técnica promissora, que visa prover nutrientes ao embrião por meio da inoculação de soluções com efeitos benéficos ao seu desenvolvimento. Contudo, são necessários mais estudos no intuito de aprimorar a técnica e criação de protocolos efetivos que possam ser amplamente utilizados pela indústria. Nesse contexto, o objetivo desta revisão de literatura foi abordar e depreender as perspectivas da utilização da técnica nutrição in ovo na cadeia produtiva de frangos de corte.

In ovo feeding: a review / Alimentação in ovo: uma revisão

The poultry industry plays a large role in the Brazilian economy. In fact,Brazil ranks as the worlds leading exporter and second largest producer ofpoultry meat as the result of genetic improvement, animal nutrition,management, and biosecurity. During the development of bird embryos, thenutrients are stored within the egg, but carbohydrate supplementation isunsatisfactory upon hatching. Poor carbohydrate supplementation candamage the embryo development and negatively affect poultry weight. Inovo feeding is a promising technique to improve the quality of newly hatchedchicks as it uses systems for feeding the embryos by inoculating nutrientsinto the egg amniotic fluid. However, further studies are needed in order toimprove this technique and create effective implementations and protocolsthat can be widely used in the industry. This study aims to both review theliterature on the use of in-ovo feeding and understand the perspectives ofits use in the broiler production chain.(AU)

A avicultura tem tido papel expressivo na economia brasileira, estando o país classificado como o segundo maior produtor e o maior exportador do mundo. Esse resultado é proveniente de avanços no melhoramento genético, nutrição, manejo e biosseguridade. Nas aves, os nutrientes utilizados durante o desenvolvimento embrionário estão contidos no ovo, sendo escassa a reserva de carboidratos logo após a eclosão do pintainho. Essa restrição pode causar prejuízos ao desenvolvimento embrionário, impactando negativamente no peso das aves. Diante disso, a nutrição in ovo mostra-se como uma técnica promissora, que visa prover nutrientes ao embrião por meio da inoculação de soluções com efeitos benéficos ao seu desenvolvimento. Contudo, são necessários mais estudos no intuito de aprimorar a técnica e criação de protocolos efetivos que possam ser amplamente utilizados pela indústria. Nesse contexto, o objetivo desta revisão de literatura foi abordar e depreender as perspectivas da utilização da técnica nutrição in ovo na cadeia produtiva de frangos de corte.(AU)

Effects of placement time on performance and gastrointestinal tract growth of male broiler chickens

The main objective of this study was to evaluate the effect of placement time on the performance of broiler chickens and the development of their gastrointestinal tract. Two methodologies for measuring broiler performance were compared, one considering day of pulling as the first day, the other considering day of placement as the first day. A total of 1,056 one-day old male Cobb® 500 broiler chicks were subjected to treatments of different placement times after pulling from the hatchery: 3, 24, 48, and 72 h. The studied traits were: feed intake, body weight, feed conversion, viability, and gastrointestinal tract development. When day of pulling was considered the first day, feed intake and body weight at 39 days decreased as placement time increased. However, when day of placement was considered the first day, fasting up to 72 h did not have any negative effect on broiler performance at 39 days post-placement. Placement time did not affect yolk sac utilization or liver weight. At nine days post-placement, weights of gizzard + proventriculus, pancreas, and small intestine increased with increasing placement time. At seven days of age, there was no effect of placement time on villus height or crypt depth. It is possible to place broiler chicks up to 72 h post-hatching with no negative effects when day of placement is considered the first day for evaluating broiler performance.(AU)

Effects of stocking density and climate region on performance, immunity, carcass characteristics, blood constitutes, and economical parameters of broiler chickens

This experiment was conducted to evaluate the effects of stocking density and climate region on performance, immunity, carcass characteristics, blood plasma, and economic parameters of the Ross strain of broiler chickens. The effects of four climates (mild and humid, semi-arid, alpine, and hot and dry) and four densities (10, 15, 17, and 20 chicks/m2) were studied as a completely randomized design with 4×4 factorial arrangement of treatments. The results showed that the density had a significant effect on feed intake and feed conversion ratio in the starter period and on body weight gain in the grower and the whole periods of the experiment. Moreover, both climate and density had a significant impact on economic performance (live weight, survival rate, production index, meat production/m2, and profitability). The mild and humid climate and the density of 17 chicks/m2 had the most economic benefit compared with other treatments. The climate type had a significant effect on the relative weights of the breast, wings, neck, proventriculus, and ileum. The effects of climate and density on glucose, triglyceride, very low-density lipoproteins (VLDL), high-density lipoproteins (HDL), LDL/low-density lipoproteins (HDL), total protein and globulin were significant. In addition, the effect of climate on the antibody titer against sheep red blood cells (except for immunoglobulin G on day 28) was significant.(AU)

Feather and blood meal at different processing degrees in broiler pre-starter and starter diets

The objective of this study was to evaluate the inclusion of feather and blood meal (FBM) in broiler pre-starter and starter diets according to the processing method used. Performance, digestibility, and intestinal morphometry of broilers fed diets containing FBM were evaluated in two experiments, in the pre-starter (1-7 d) and starter (8-21 d) phases in a randomized block design with four treatments and five replicates of 12 birds, totaling 20 experimental units per trial. The criteria used for block formation was the battery floor. The meal was processed under different degrees of hydrolysis pressure (2.0 kgf/cm2 for 40 min; 2.5 kgf/cm2 for 30 min; and 3.0 kgf/cm2 for 20 min) and added at 9% to the pre-starter (Experiment I) and starter (Experiment II) diets. In each experiment, 480 male Cobb 500® chicks were allocated to batteries. The following variables were measured: live weight, weight gain, feed intake, feed conversion ratio, and digestibility and retention of dry matter, nitrogen, and ether extract. Performance was not influenced by the dietary inclusion of the ingredient. However, FBM subjected to the highest hydrolysis pressure resulted in the worst overall nutritional balances. The chickens were more susceptible to FBM processing in the pre-starter phase, when the hydrolysis pressure of 2.5 kgf/m2 for 30 min provided the best results. In the starter diet, FBM processed at a hydrolysis pressure of 2.0 kgf/m2 for 40 min provided the best performance results up to 14 days of age, without changing nutrient metabolism. Up to 9% feather and blood meal can be included in broiler pre-starter and starter diets as long as the ingredient processing method is well-known.(AU)

Morphological Investigations of the Effect of Thermal Manipulation During Embryogenesis on Body Performance and Structure of Pectoral and Thigh Muscle of Ross Broiler Chicken

The aim of this study was to determine the optimum timing of thermal manipulation during early, mid, late and long lasting embryogenesis that may result in improvement of body performance and myofiber development (fiber diameter and thickness of perimysium) of pectoral and thigh muscles by a comparative morphometrical investigation on post-hatch day 35. 1440 fertile Ross broiler eggs were divided randomly and equally into 5 treatment groups: control (no TM), TM1, TM2 TM3 and TM4 were thermally subjected to 39ºC for 18h with 65% relative humidity daily during embryonic days ED 7-11, ED 11-15, ED 15-18 and ED 7-18 respectively. Out of TM conditions that were investigated, TM1 resulted in a significant improvement of hatchability rate (95.14%)and body performance when compared to the control. On post-hatch day 35, there were significant differences in BW, skinned carcass, breast, thigh and gut weight for all groups when compared to each other with a higher significant in TM1 and TM2 when compared to those of the control. FCR in this study was lower in TM groups when compared to the control group. In TM3 and TM4 the chicks show a significantly lower value of body performance when compared with those of the control group, TM1 and TM2.The histological evaluation of Pectoral muscle revealed myofibers of different diameter (38.39-40.27 µm) and perimysial thickening (17-30.5 µm), while myofibers diameter of thigh muscle ranged between (29-32.9 µm) and the perimysial thickening ranged between (14.36-22.15 µm). Thus, these results indicate that TM duringED7-11 improved muscle growth and body performance and this finding may be applied by commercial breeders to produce more enhanced broiler chickens.(AU)

Morphological Investigations of the Effect of Thermal Manipulation During Embryogenesis on Body Performance and Structure of Pectoral and Thigh Muscle of Ross Broiler Chicken

The aim of this study was to determine the optimum timing of thermal manipulation during early, mid, late and long lasting embryogenesis that may result in improvement of body performance and myofiber development (fiber diameter and thickness of perimysium) of pectoral and thigh muscles by a comparative morphometrical investigation on post-hatch day 35. 1440 fertile Ross broiler eggs were divided randomly and equally into 5 treatment groups: control (no TM), TM1, TM2 TM3 and TM4 were thermally subjected to 39ºC for 18h with 65% relative humidity daily during embryonic days ED 7-11, ED 11-15, ED 15-18 and ED 7-18 respectively. Out of TM conditions that were investigated, TM1 resulted in a significant improvement of hatchability rate (95.14%)and body performance when compared to the control. On post-hatch day 35, there were significant differences in BW, skinned carcass, breast, thigh and gut weight for all groups when compared to each other with a higher significant in TM1 and TM2 when compared to those of the control. FCR in this study was lower in TM groups when compared to the control group. In TM3 and TM4 the chicks show a significantly lower value of body performance when compared with those of the control group, TM1 and TM2.The histological evaluation of Pectoral muscle revealed myofibers of different diameter (38.39-40.27 µm) and perimysial thickening (17-30.5 µm), while myofibers diameter of thigh muscle ranged between (29-32.9 µm) and the perimysial thickening ranged between (14.36-22.15 µm). Thus, these results indicate that TM duringED7-11 improved muscle growth and body performance and this finding may be applied by commercial breeders to produce more enhanced broiler chickens.

Is the eggshell quality influenced by the egg weight or the breeder age?

For a long time, it has been said that eggshell quality decreases as eggs increase in size, but this increase is seen as the breeder age advances. Therefore, the present study aimed to evaluate the age and egg weight effect on Cobb 500 broiler breeders on eggshell quality. The quality measures tested were eggshell and mineral matter percentage, eggshell surface, shape and eggshell index, eggshell and membrane thickness and specific gravity. Eggs from 27, 31, 36, 40, 46, 48, 53, 58 and 63 week-old breeders were classified as eggs with a constant weight ranging from 63.8 ± 0.2; and eggs with increasing weight, according to age, being: 55.8g; 60g; 62.2g; 64.2g; 65.2g, 66.6g, 68.1g, 69.9g and 72.5g, respectively. The eggs weight did not influence the eggshell percentage and the specific gravity in seven of the nine tested ages, while for mineral matter in six of the nine studied ages. The shape and shell index, shell and membrane thickness are characteristics independent of egg weight. As the Cobb 500 broiler breeder age advanced, the mineral matter concentration and specific gravity maintained constant, the membrane thickness (R2>70) reduced, and other studied variables were influenced in the same way for both treatments. Thus, the eggshell quality decrease with the advancing age cannot be attributed solely to the increase of egg weight with consequent increase in the eggshell volume and the surface, but there are also age-related factors.(AU)

Is the eggshell quality influenced by the egg weight or the breeder age?

For a long time, it has been said that eggshell quality decreases as eggs increase in size, but this increase is seen as the breeder age advances. Therefore, the present study aimed to evaluate the age and egg weight effect on Cobb 500 broiler breeders on eggshell quality. The quality measures tested were eggshell and mineral matter percentage, eggshell surface, shape and eggshell index, eggshell and membrane thickness and specific gravity. Eggs from 27, 31, 36, 40, 46, 48, 53, 58 and 63 week-old breeders were classified as eggs with a constant weight ranging from 63.8 ± 0.2; and eggs with increasing weight, according to age, being: 55.8g; 60g; 62.2g; 64.2g; 65.2g, 66.6g, 68.1g, 69.9g and 72.5g, respectively. The eggs weight did not influence the eggshell percentage and the specific gravity in seven of the nine tested ages, while for mineral matter in six of the nine studied ages. The shape and shell index, shell and membrane thickness are characteristics independent of egg weight. As the Cobb 500 broiler breeder age advanced, the mineral matter concentration and specific gravity maintained constant, the membrane thickness (R2>70) reduced, and other studied variables were influenced in the same way for both treatments. Thus, the eggshell quality decrease with the advancing age cannot be attributed solely to the increase of egg weight with consequent increase in the eggshell volume and the surface, but there are also age-related factors.