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Thirty-two Arbor Acres (AA) cockerels aged 27 weeks were used to determine the effect of vitamin E (VE) on the semen characteristics and sperm quality during hot season. The birds were fed diets containing 0, 50, 100 and 150mg VE kg-1 feed. There were 4 replicates and two birds per replicate. Semen collection was done thrice a week for three weeks in all birds. Dietary vitamin E significantly (p < 0.05) increased the semen volume (SV) and number of sperm cells (NS) in AA cockerels. CONTROL birds (0.71 mL) had lower SV than birds fed 150 mg VE (0.94 mL). Birds on 100 and 150 mg VE recorded similar NS, which was higher than 0 and 50 mg VE groups. The least NS was in the CONTROL group. Sperm abnormality gradually (p < 0.05) decreased as dietary VE increased from 0 to 150 mg. Significant (p < 0.01) effect of dietary VE was recorded in percentage live sperm (PLS). Semen from cockerels on VE treatment had higher PLS than the CONTROL. In conclusion, it may be beneficial to supplement the broiler breeder cockerel diet with VE up to 150 mg kg-1 feed during hot season as it increased SV, NS and PLS and decreased sperm abnormality.(AU)

Resumo

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)

Resumo

Two experiments were carried out to evaluate the effects of digestible valine supplementation in pre-starter and starter diets on the productivity, nutrient metabolizability coefficient (NMC), and immune response of broilers from breeders of different ages. Experiments I and II were conducted with broilers in the pre-starter (1 to 7 days of age) and starter (8 to 21 days of age) phases, respectively. Broilers were fed diets that differed in their digestible valine content. In each trial, 400 male Cobb 500® chicks were randomly housed in a 2 × 4 factorial arrangement with eight treatments and five replicates of 10 birds each. The main effects were breeder age (37 vs. 52 weeks) and the digestible valine level in pre-starter (9.2, 10.2, 11.2, and 12.2 g/kg) and starter (8.3, 9.3, 10.3, and 11.3 g/kg) diets. Productive performance, intestinal histology, and immune response of broilers were evaluated. Supplementation with 11.2 g/kg valine in pre-starter diets improved NMC and increased villus height and villus:crypt ratio in the duodenum, jejunum development, and lymphocyte proliferation in the spleen of broilers at seven days of age, without improving performance (body weight gain, feed intake, and feed conversion ratio). In the starter phase, valine supplementation reduced feed intake but did not affect NMC, intestinal development, or immune response. The present results suggest that the same level of digestible valine should be used in the diet of broilers born to breeders of different ages, and the use of 9.2 and 8.3 g/kg digestible valine in pre-starter and starter diets, respectively, is sufficient to ensure satisfactory broiler performance. However, to improve the duodenum and jejunum development and immune response of broilers in the pre-starter phase, higher digestible valine levels are required.

Resumo

Objectives of the study were to investigate influence of artificial insemination (AI) in caged and floored flock in comparison to natural mating (NM) on broiler breeders welfare, productive performance and economic appraisal. To execute this experiment, a total of 1440 pullets of Ross-308 Parent Stock along with 168 males were picked from a commercial flock and divided into three groups i.e., AIC=AI in cages, AIF=AI on floor and third was NM=NM on floor. Each group carried 480 females (HH) while 168 males were divided into 41, 48 and 58 for AIC, AIF and NM, respectively. During both phases all procedures and studied parameters were the same except the sperm dose rates which were changed during post peak. According to the results, significantly (p0.05) higher levels of serum corticosterone, glucose and cholesterol were recorded in birds of AIC and respectively as compared to birds being allowed to mate naturally. Whereas, the experimental males and females of AIF and AIC kept for AI exhibited (p0.05) higher body weight, depletion % and feed consumption particularly in post peak phase. However, among the birds subjected to AI, the birds kept in the cages had better performance (p0.05) than the birds kept in the floor. Moreover, frequency rate of insemination in females and milking of males found (p0.05) reciprocal to the depletion, feed intake and body weight during peak but particularly in post peak. Perhaps, various sperm doses remained inert to implicit any impact on studied parameters. Similarly, egg weight was neither affected by housing systems nor by mating strategies during both phases. However, various insemination and milking frequencies noticeably swayed the productive traits under this study. AI in floored flock was found ineffective even in comparison to natural mating. In conclusion, AI in cages brought forth the better productive performance and lesser male depletion, hence, can be recommended.

Resumo

Present study evaluated carcass and meat quality attributes of broilers, broiler breeders and Aseel chickens. Sixty birds from each chicken genotype (broiler, broiler breeder and Aseel chickens; five-wk-old broilers and 60-wk-old Aseel chickens and broiler breeders) were evaluated. Birds were maintained under similar environment for 21 days, and then slaughtered to analyze their carcass qualitative and organoleptic characteristics. No carcass yield differences were detected among genotypes. Aseel chickens had heavier neck, followed by broiler breeder and broiler (p 0.0001). Higher liver (p 0.0001), intestine (p 0.0001), ribs and back (p=0.0014) yields were obtained in broilers than in broiler breeders and Aseel chickens. Females showed higher gizzard (p=0.0107) and intestine (p=0.0170) yield than males, which presented higher carcass (p=0.0023), thigh (p=0.0039), drumstick (p 0.0001), neck (p=0.0003) and heart (p=0.0139) yields. Broiler meat was lighter (p 0.0001) whereas Broiler breeder meat were yellower (p 0.0001) and redder (p 0.0001), ultimate-pH was lower (p=0.0001) for broiler and Aseel meat. Female meat was yellower (p 0.0001) and reddish (p=0.0482). Aseel breast meat scored lower for flavor (p=0.0121), juiciness (p=0.0178) and tenderness (p=0.0477) compared with broiler breeders and broilers, although no differences among genotypes were detected for color, aroma, taste, and acceptability, whereas for thigh meat, Aseel chickens received lower color (p=0.0344) and acceptability (p=0.0398) scores. Interaction effect were significant for carcass, meat quality and sensory evaluation. Carcass characteristics of broilers were comparable with Aseel chickens, while broiler breeder showed better meat quality traits. Broiler and broiler breeder meat scored higher for sensory evaluation. Male birds had higher carcass yield and better meat quality traits compared with females. It is concluded that meat quality attributes vary among the three chicken genotypes.

Resumo

O manejo adequado de ovos férteis e a mitigação dos impactos da sazonalidade de produção são extremamente importantes na avicultura. Todo planejamento de abate começa com o volume de produção de ovos férteis, espaço para incubação, índices de eclosão e mortalidades médias dos lotes. Uma prática comum é a estocagem de ovos férteis com diferentes períodos dependendo da disponibilidade de volume de ovos férteis no mercado. Portanto, o objetivo deste estudo foi avaliar os efeitos do tempo de estocagem de ovos férteis, da linhagem de matrizes pesadas e da idade de postura, sobre os índices de eclosão, mortalidades e pesos de primeira semana de pintainhos de frango de corte. Foram realizados 12 tratamentos, em arranjo fatorial com duas linhagens (Cobb MV e Ross 308AP) em duas idades de postura, sendo ovos entre 30 e 40 semanas e ovos entre 50 e 60 semanas e três diferentes períodos de estocagens de ovos férteis, sendo 4, 7 e 9 dias. Foram incubados 12.096 ovos em incubadora de estágio múltiplo e ao nascimento os pintos machos foram alojados em uma granja experimental com 96 boxes, com 40 aves por box, com oito repetições por tratamento. Foram avaliados os índices de eclosão sobre ovos férteis, mortalidades embrionárias por período de incubação, pintos descarte, percentual de ovos inférteis, mortalidade de primeira semana de pintainhos, peso de um e de sete dias de pintainhos, ganho de peso e multiplicação de peso de primeira semana. Os dados foram testados quanto à normalidade da distribuição e homogeneidade dos resíduos e analisados utilizando os procedimentos MIXED e NPAR1WAY. Houve interação entre linhagem e idade de postura da matriz sobre a eclosão de ovos férteis (P=0,0112), peso de 1 dia (P=0,0014), peso aos 7 dias (P=0,0002) e ganho de peso de 1 a 7 dias (P=0,0042). Houve interação entre tempo de estocagem de ovos férteis e linhagem da matriz sobre o peso aos 7 dias (P=0,0009), o ganho de peso de 1 a 7 dias (P=0,0005) e a multiplicação de peso (P=0,0054). Houve interação entre tempo de estocagem de ovos férteis e idade de postura da matriz sobre o peso aos 7 dias (P=0,0203), o ganho de peso de 1 a 7 dias (P=0,0286) e a multiplicação de peso (P=0,0270). Houve efeito da linhagem (P<0,0001), da idade de postura da matriz (P=0,0001) e do tempo de estocagem de ovos férteis (P=0,0236) sobre a mortalidade embrionária de primeiro período. Houve efeito da linhagem da matriz sobre a mortalidade embrionária de segundo período (P=0,0004) e os pintos de descarte (P=0,0448). Houve efeito da idade da postura da matriz sobre a mortalidade embrionária de quarto período (P=0,0144). Houve efeito da linhagem (P<0,0001) e da idade de postura da matriz (P<0,0001) sobre o percentual de ovos inférteis. O tempo de estocagem de ovos férteis não impactou na eclodibilidade, porém teve efeito negativo sobre a mortalidade embrionária de primeiro período e o peso de primeira semana. A linhagem Ross 308AP apresentou melhor eclodibilidade em matrizes entre 30 e 40 semanas e a linhagem Cobb MV melhores pesos de pintainhos ao nascimento e final da primeira semana de vida.

Proper management of fertile eggs and mitigation of the impacts of seasonality of production are extremely important in poultry production. All slaughter planning starts with the fertile egg production volume, hatching capacity, hatchability rates and average flock mortalities. A common practice is the stocking of fertile eggs for different periods depending on the availability of fertile egg volume production. Therefore, the objective of this study was to evaluate the effects of fertile egg storage time, broiler breeder strains and breeders ages on hatchability rates, mortalities and first week weights of broiler chicks. There were 12 treatments, in a factorial arrangement with two strains (Cobb MV and Ross 308AP) at two breeder ages, between 30 and 40 weeks and 50 and 60 weeks and three different fertile egg storage periods, being 4, 7 and 9 days. 12.096 were incubated in a multi-stage hatchery and at hatching, the male chicks were housed in an experimental farm with 96 boxes, with 40 birds per box, with eight replicates per treatment. Hatchability rates on fertile eggs, embryonic mortalities per incubation period, culled chicks, percentage of infertile eggs, first week chick mortality, day-old and seven-day chick weight, weight gain and first week weight multiplication were evaluated. Data were tested for normality of distribution and homogeneity of residuals and analyzed using the MIXED and NPAR1WAY procedures. There was an interaction between strain and breeder age on hatchability of fertile eggs (P=0.0112), 1-day weight (P=0.0014), weight at 7 days (P=0.0002) and weight gain from 1 to 7 days (P=0.0042). There was interaction between fertile egg storage time and breeder strain on weight at 7 days (P=0.0009), weight gain from 1 to 7 days (P=0.0005) and weight multiplication (P=0.0054). There was interaction between fertile egg storage time and breeder age on 7-day weight (P=0.0203), 1- to 7-day weight gain (P=0.0286), and weight multiplication (P=0.0270). There was an effect of strain (P<0.0001), breeder age (P=0.0001) and fertile egg storage time (P=0.0236) on first period embryonic mortality. There was an effect of breeder strain on second period embryonic mortality (P=0.0004) and culled chicks (P=0.0448). There was an effect of the breeder age on fourth period embryonic mortality (P=0.0144). There was an effect of strain (P<0.0001) and breeder age (P<0.0001) on the percentage of infertile eggs. Storage time of fertile eggs did not impact hatchability but had a negative effect on first period embryonic mortality and first week weight. Ross 308AP breeder strain showed better hatchability in breeder age between 30 and 40 weeks and the Cobb MV strain had better chick weights at hatching and at the end of the first week of life.

Resumo

In broiler breeder roosters, the weight of the testes is positively associated with daily sperm production and fertility. In birds, the testes are located in the coelomic cavity, not being accessible to reproductive evaluation as mammalian testes. The reproductive evaluation of roosters is based on phenotypic traits. Any changes on testes will be reflected on fertility levels. The aim of this paper was to evaluate the potential of association of phenotypic traits as body weight (BW), comb scores (COS), cloaca scores (CLS) and feet scores (FS) with testicular morphometric parameters in adult Cobb® Mx roosters in two ages (25 and 45 weeks of age). The low BW roosters had lower testes weight (TW), smaller seminiferous tubule diameter (STD) and lower comb and cloaca scores than the medium and high BW roosters (P≤0.05). Heavy roosters had the highest COS and bigger seminiferous epithelium height (SEH). There was no statistical difference between the BW categories in FS and volumetric proportion of seminiferous tubule (ST) and interstitial tissue (IT). Considering the age effect, roosters with 45 weeks of age had lower TW and ST than 25-week roosters. Positive, moderate and significant correlation was found between testes weight and phenotypic characteristics as BW, COS and CLS in 45week roosters. A positive, moderate and significant correlation was found between body weight and histologic testicular characteristics as STD and SHE in both evaluated ages. In conclusion, there is a regression in the testes weight with age and it is more intense in Cobb® Mx roosters with lower BW. Furthermore, it is concluded that the BW positively influences the testes weight and histological quality of the testes. COS and CLS can be used with moderate potential prediction to identify roosters with low testes weight at 45 weeks of age.(AU)

Em galos de matriz pesada sabe-se que o peso dos testículos pode ser associado positivamente com a produção diária de espermatozoides e que alterações nos testículos irão refletir na fertilidade. Nas aves, os testículos estão localizados dentro da cavidade celomática, e, portanto, não são acessíveis para exame andrológico direto, como em mamíferos. A avaliação reprodutiva de galos se baseia principalmente em características fenotípicas. Buscou-se avaliar o potencial de associação de alguns parâmetros fenotípicos, como peso corporal (PC), escores de crista (ECR), escores de cloaca (ECL) e escores de pés (EP), com parâmetros morfológicos de testículos em galos Cobb® Mx em duas idades (25 e 45 semanas de idade). Galos leves apresentaram menor peso testicular (PT), menor diâmetro de túbulo seminífero (DT), e menores ECR e ECL que galos médios e pesados (P≤0.05). Galos pesados apresentaram os maiores ECR e maiores valores para altura do epitélio seminífero (AE), e DT. Não houve diferença estatisticamente significativa entre as categorias de peso para escores de pé e proporções de túbulo seminífero (TS) e interstício (INT). Considerando-se o efeito da idade, galos com 45 semanas de idade apresentaram menores PT e TS que galos com 25 semanas de idade. Correlação positiva, moderada e significativa foi encontrada entre peso de testículo e características fenotípicas como ECR, ECL e PC em galos de 45 semanas de idade. Foi encontrada correlação positiva, moderada e significativa entre PC e características testiculares como DT e AE nas duas idades avaliadas. Conclui-se que em galos Cobb® Mx ocorre regressão do testículo com o avanço da idade, e ela é mais intensa em galos com menor peso corporal. Conclui-se que o PC tem influência positiva no peso e índices histomorfométricos dos testículos, e que escores de crista e de cloaca podem ser utilizados com potencial moderado de predição para identificar galos com baixo peso de testículos em galos com 45 semanas de idade.(AU)

Resumo

ABSTRACT In order to investigate the effect of organic trace minerals premix (OTM) on the reproductive performance of breeder roosters, a total of 240 San Huang roosters (23 weeks of age) were randomly divided into two treatments with six replicates of 20 roosters each. The first group (n = 120) was fed a basal diet containing an inorganic trace minerals premix (ITM) and the other group (n = 120) was fed the basal diet in which ITM was replaced by OTM. The experiment period was 22 weeks. Semen from one randomly-selected rooster per replicate was collected two weeks after the beginning of the experiment and other 10 times every two weeks. Another rooster per replicate was randomly selected at 30, 35, and 45 weeks of age, and sacrificed. Results showed that OTM did not affect relative organ weights. There was a significant increase in semen parameters in OTM group (p 0.05), such as semen volume, semen density, and semen motility from 31 to 35 weeks. OTM-fed roosters presented higher serum testosterone levels at 45 weeks of age, as well as higher testicular mRNA expression of the genes 3-beta dehydrogenase 2 (HSD3B2) and cytochrome P450 17A1 (CYP17A1) in the OTM-fed group at 45 weeks of age compared with those fed ITM (p 0.05). Considering the results of the present study, it was concluded that feeding organic instead of inorganic trace minerals to male broilers breeders improves semen quality, which may be attributed to their better testicular development and higher expression of enzymes related to testosterone synthesis.

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Objetivou-se avaliar os efeitos de antioxidantes suplementados às dietas de galos de matrizes pesadas em idade avançada sobre as características reprodutivas. Foram utilizados galos da linhagem Cobb com 47 semanas de idade. Estes foram distribuídos em quatros tratamentos, de acordo com a adição de antioxidante à dieta, sendo: A = grupo controle (sem suplementação antioxidante); B = suplementação de 9ppm de citranaxantina; C = suplementação de 6ppm de cantaxantina e D = 150ppm de vitamina E. Foram avaliadas as características seminais, tais como volume, vigor, motilidade e concentração, a composição de ácidos graxos do sêmen (saturados, insaturados, monoinsaturados, poli-insaturados, ômega 3, ômega 6 e ômega 9) e a correlação entre o peso dos testículos e o peso dos galos. Não foram observados efeitos das substâncias antioxidantes testadas sobre os parâmetros reprodutivos avaliados. Os antioxidantes avaliados não influenciam as respostas reprodutivas de machos reprodutores de matrizes pesadas em idade avançada.(AU)

This study aimed to evaluate the effect of antioxidant supplementation in diets of aging broiler breeder roosters on reproductive characteristics. Cobb roosters were divided into four groups, according to antioxidant addition, where: A = control group (without antioxidant supplementation); B = 9ppm of citranaxanthin; C = 6ppm of canthaxanthin, and D = 150ppm of vitamin E. Seminal characteristics (volume, force, motility and concentration), semen fatty acid composition (saturated, unsaturated, monounsaturated, polyunsaturated, ω3, ω6 and ω9), and the correlation between testis weight with rooster weight were evaluated. No effects of the antioxidants tested were observed. The antioxidants do not influence the reproductive responses of aging male broiler breeder.(AU)

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Adverse environmental conditions during rearing may negatively affect productivity and meat quality of the modern fast-growing broiler strains. Temperature manipulation during sensitive embryonic development periods may affect broilers' physiological responses to environmental conditions during rearing on commercial farms. The objective of this trial was to evaluate the effect of temperature manipulation during incubation and breeder age on the meat quality of male and female broilers submitted to heat stress during the pre-slaughter period. In this experiment, 1280 broiler chicks were distributed according to a completely randomized experimental design in a 2x2x2 factorial arrangement. Treatments consisted of two breeder ages (30 and 60 weeks), two temperature programs applied in the last four days of incubation (standard or high temperature), and sex (male and female). Birds were submitted to 32 °C for 48 hours before slaughter, on day 46.Meat quality parameters (pH, temperature, color, and weight loss) were evaluated. There was significant effect (p 0.05) of sex on meat redness (a*) and fat percentage, with females presenting higher values than males in both measurements. Males incubated at the higher temperature presented higher (p 0.05) meat weight loss by pressure than females. The thermal manipulation applied during the final stage of incubation did not affect the meat yield or meat quality of broilers submitted to heat stress.

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The aim of this study was to evaluate the effects of in-ovo vaccination on different incubation days of broiler embryos derived from young and old breeders on incubation indexes, vaccine response, and broiler performance. A number of 20,160 fertile eggs was distributed according to a completely randomized design in a 4 x 2 factorial arrangement (in-ovo vaccination on 16, 17, 18, or 19 days of incubation, and breeders of 31 or 52 weeks of age), totaling eight treatments with 15 replicates of 168 eggs each. Vaccination procedures and vaccines (strains and doses) were those routinely applied in commercial hatcheries. After hatch, 960 male chicks were housed and distributed according to the same experimental design previously applied in the hatchery. There were hatching losses (p < 0.05) when eggs were vaccinated before 18 days of incubation. Greater Marek's disease antibody titers were obtained when the in-ovo vaccination was performed on day 19 of incubation, regardless breeder age. Embryonic age at vaccination did not compromise broiler performance in the field, and the flexibility of embryonic age for in-ovo vaccination can reduces incubation costs.

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Embryo thermal stimulation has been studied as a means to promote epigenetic changes and to improve broiler health and performance. This study aimed at evaluating immunoglobulin (IgM, IgG, and IgA) titers, serum corticosterone levels, and organ integrity of day-old male Cobb(r) and Ross(r) broilers. Embryos were submitted to hot and cold stimuli (thermal stimulation) on days 14-18 of incubation. The thermal manipulation treatments did not affect immunoglobulin titers of 1 day-old Cobb(r) or Ross(r) chicks, and caused severe bursal lesions (scores 3 and 4) in both strains. However, serum corticosterone levels of Cobb(r) chicks were higher when embryos were submitted to hot stimulus (+1.39ºC) compared with cold stimulus (+36 ºC). Serum corticosterone levels of Ross(r) chicks were not affected by embryo temperature manipulation. The only effect of broiler breeder age was observed on IgM titers of Cobb(r) chicks, which were higher in chicks from 33-wk-old breeders. Further studies are needed to detect the optimal period of embryo thermal stimulation.

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Synthesis and secretion of LH and FSH takes place in the gonadotropes of the pituitary gland (adenohypophysis). The hypothalamus, in turn, controls the secretion of gonadotropins by the pulsatile secretion of gonadotropin releasing hormone. Therefore, the neuroendocrine linkage of the hypothalamic-pituitarygonadal axis provides an integrated system responsible for proper reproductive performance, including gamete development and sex steroids secretion. In broilers there is a lack of synchrony between LH and FSH pulses, and gonadotrophs reside in separate cells within the pituitary gland, suggesting that in the adult male fowl LH and FSH secretion are regulated independently. Modern male broiler breeders (selected for increased growth rate) fail to maintain testis size and semen production after 25 weeks of age. Testis size closely follows changes in FSH concentrations, suggesting that circulating FSH levels are a very good indicator of testis function in mature broiler breeder. Although cGnRH-I is believed to be the prime regulator of gonadotropin release in male birds, the role of other GnRH isoforms in the regulation of FSH remains unclear. Therefore, there is critical need to further evaluate the actual regulation of FSH, and the underlying effect FSH on testicular function in mature broilers.

A síntese e secreção de LH e FSH acontece nos gonadotropos da glândula pituitária (adenohipófise). O hipotálamo, por sua vez, controla a secreção de gonadotropinas pela secreção pulsátil do hormônio liberador de gonadotropina. Portanto, a ligação neuroendócrina do eixo hipotálamo-pituitária-gonodal fornece um sistema integrado responsável pelo desempenho reprodutor correto, incluindo desenvolvimento de gametas e secreção de esteroides sexuais. Em frangos há uma falta de sincronia entre pulsos LH e FSH, e gonadotropos residem em células separadas na glândula pituitária, sugerindo que a secreção de LH e FSH do macho adulto é regulada de forma independente. Reprodutores modernos de frango macho (selecionados para taxa de crescimento aumentada) falham na manutenção do tamanho dos testículos e produção de sêmen após 25 semanas de idade. Apesar de que se acredita que o cGnRH-I é o regulador primário da liberação de gonadotropina em pássaros macho, a função de outras isoformas de GnRH na regulação de FSH não é clara. Portanto, há uma necessidade crítica de se avaliar melhor a real regulação de FSH, e o efeito basal do FSH na função testicular em frangos maduros.

Resumo

The objective of the present study was to evaluate the supply of a specific-male diet on rooster body weight, hatchability, and fertility. Two diets were supplied during the egg production period: treatment 1, diet formulated for females and containing, in average, 2,830 kcal ME/kg and 15% CP; and treatment 2, diet specifically formulated for male broiler breeders, containing 2,750 kcal ME/kg and 13.5% CP. In the experiment, 26 flocks, with approximately 7,000 females and 840 males each, belonging to the same broiler breeder commercial strain, were distributed into 26 houses (1200m²) on the same farm, and submitted to the same management practices. Body weight was evaluated in 13 flocks per treatment and for five weeks (45, 50, 55, 60, 65), and hatchability and fertility in four incubation lots per treatment and for the same weeks. Data were evaluated by the analysis of mixed models for repeated measurements, using the PROC MIXED of SAS 9.3 (SAS Institute Inc., Cary, NC, USA), and means were compared by the test of Tukey-Kramer at 5% significance level. The specific-male diet allowed body weight control during all analyzed weeks and promoted high hatchability and egg fertility. The increase in the number of chicks hatched demonstrates the economic viability of feeding a specific diet for male broiler breeders.

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The objective of the present study was to evaluate the supply of a specific-male diet on rooster body weight, hatchability, and fertility. Two diets were supplied during the egg production period: treatment 1, diet formulated for females and containing, in average, 2,830 kcal ME/kg and 15% CP; and treatment 2, diet specifically formulated for male broiler breeders, containing 2,750 kcal ME/kg and 13.5% CP. In the experiment, 26 flocks, with approximately 7,000 females and 840 males each, belonging to the same broiler breeder commercial strain, were distributed into 26 houses (1200m²) on the same farm, and submitted to the same management practices. Body weight was evaluated in 13 flocks per treatment and for five weeks (45, 50, 55, 60, 65), and hatchability and fertility in four incubation lots per treatment and for the same weeks. Data were evaluated by the analysis of mixed models for repeated measurements, using the PROC MIXED of SAS 9.3 (SAS Institute Inc., Cary, NC, USA), and means were compared by the test of Tukey-Kramer at 5% significance level. The specific-male diet allowed body weight control during all analyzed weeks and promoted high hatchability and egg fertility. The increase in the number of chicks hatched demonstrates the economic viability of feeding a specific diet for male broiler breeders.

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Em galos de matriz pesada, o peso dos testículos se associa positivamente com a produção diária de espermatozoides e com a fertilidade. Contudo, os testículos de aves se localizam na cavidade abdominal, não sendo acessíveis para exame andrológico como os testículos de mamíferos. A avaliação reprodutiva de galos de matriz pesada é subjetiva e se baseia em características como peso corporal (PC), qualidade de pés e pernas e morfologia de cloaca e crista. Estudos que validem o potencial de associação dessas características fenotípicas com parâmetros da morfometria testicular são raros, principalmente quando se consideram galos de matriz pesada manejados em lotes comerciais. Escores de cloaca e de crista e parâmetros da morfometria testicular foram avaliados em galos Cobb 500 Slow adultos das categorias de PC leve (<4,300kg), médio (entre 4,300 e 5,250kg) e pesado (≥5,250kg). O coeficiente de variação para PC foi de 12%. Os galos da categoria de PC pesado apresentaram testículos mais pesados e maiores escores de cloaca e de crista do que os galos da categoria de PC leve. Não houve diferença estatística entre as categorias de PC, considerando-se índice gonadossomático, porcentagens de túbulo seminífero e de tecido intersticial, diâmetro de túbulo seminífero e altura de epitélio seminífero. Correlação positiva, moderada e significativa foi observada entre peso de testículo e características de PC, escores de cloaca e de crista, diâmetro de túbulo seminífero e altura de epitélio seminífero. Um dos seis galos da categoria de PC leve avaliados quanto à histologia de testículo apresentou atrofia testicular. Em galos Cobb 500 Slow, conclui-se que o PC influencia o peso e a qualidade histológica de testículos e que os escores de cloaca e de crista podem ser utilizados com potencial moderado de predição para identificar galos com baixo peso de testículos...

In broiler breeder roosters the weight of the testes is positively associated with daily sperm production and fertility. However, the avian testes are located in the abdominal cavity, not being accessible for reproductive evaluation as mammalian testes. The reproductive evaluation of broiler breeder roosters is subjective and is based on characteristics such as body weight (BW), quality of feet and legs and morphology of cloaca and comb. Studies that validate the potential of associating these phenotype characteristics with testicular morphometric parameters are rare, especially when broiler breeder roosters of commercial flocks are considered. Cloaca and comb scores and testicular morphometric parameters were evaluated in adult Cobb 500 Slow roosters with low (<4.300kg), medium (between 4.300 and 5.250kg) and high (≥5.250kg) BW categories. The coefficient of variation for BW was 12%. The high BW roosters have heavier testes and higher cloaca and comb scores than the low BW roosters. There was no statistical difference between the BW categories in gonadosomatic index, percentage of seminiferous tubule and interstitial tissue, diameter of the seminiferous tubule and height of the seminiferous epithelium. Testis weight is positive, moderate and significantly correlated with BW, cloaca and comb scores, diameter of seminiferous tubule and height of seminiferous epithelium. One of six low BW roosters evaluated for histology of the testis had testicular atrophy. We conclude that in Cobb 500 Slow roosters BW influences the weight and histological quality of the testes. Besides this, cloaca and comb scores can be used with moderate prediction potential to identify roosters with underweight testes...

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This study investigated the effects of arginine (Arg) supplementation on broiler breeder egg production and egg quality. Male (30) and female (360) Ross® breeders, totaling 390 birds, were studied. A completely randomized design with five Arg levels (0.943%, 1.093%, 1.243%, 1.393%, 1.543% digestible Arg) and six replicates of 12 females and one male per experimental unit was applied. The following performance and egg quality were evaluated: lay percentage, albumen and yolk contents, average egg weight, egg specific gravity, and eggshell percentage and thickness. Hatchability and and embryo mortality were also determined. The applied dietary digestible Arg levels quadratically influenced egg production (p<0.05), with the highest production obtained when 1.262% digestible Arg was supplemented. Egg weight linearly increased (p<0.05) with digestible Arg dietary level; however, egg specific gravity linearly decreased (p<0.05). Hatchability was not affected (p<0.05) by digestible Arg level. The supplementation of broiler breeder diets with Arg improved egg production and egg weight without any effect on hatchability. Further research is needed to determine the effect of dietary Arg supplementation on the performance of the progeny.(AU)

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O tradicional método dose-resposta usado para determinar a relação ideal dos aminoácidos essenciais (IAAR) tem sido considerado muito oneroso, principalmente quando reprodutores são usados, pois é necessário um ensaio para cada aminoácido essencial (EAA). Por outro lado, o método da deleção tem sido considerado um meio rápido e prático para determinar a IAAR, pois apenas um ensaio é necessário. Dessa forma, o objetivo desta tese foi determinar a relação ideal dos aminoácidos essenciais para reprodutores (matrizes e galos) e frangos de corte utilizando o método da deleção. O primeiro estudo teve como objetivo estimar o perfil de aminoácidos essenciais e a relação ideal para a mantença de aves pelo método da deleção. Um ensaio de balanço de nitrogênio foi realizado utilizando 198 galos adultos, alojados individualmente em gaiolas metabólicas. Os tratamentos foram 33 dietas purificadas sendo 11 dietas com uma mistura de aminoácidos que fornecem alto consumo de proteínas de 500 mg N /BWkg0.75 por dia, 11 dietas

The traditional dose-response method used to determine the ideal essential amino acid ratio (IAAR) has been considered too costly, especially when breeders are used, because an assay for each essential amino acid (EAA) is necessary. On the other hand, the deletion method has been considered a quick and practical way to determine the IAAR, because only one assay is required. Thus, the aim of this thesis was to determine the optimal ratio of essential amino acids for breeders (broiler breeder hens and roosters) and broilers using the deletion method. The first study aimed to estimate the essential amino acid profile and the ideal ratio for maintenance of poultry by deletion method. A nitrogen (N) balance trial was conducted using 198 adult roosters, housed individually in metabolic cages. The treatments were 33 purified diets being 11 diets with an EAA mixture providing high protein intake of 500 mg N/BWkg0.75 per day, 11 diets providing medium protein intake of 250 mg N/BWkg0.75 per day (in each diet one EAA tested was reduced 50%) and 11 diets providing low protein intake of 125 mg N/BWkg0.75 per day (made by omitting the EAA tested). Each treatment had six replicates. After 48 h of fasting receiving water plus sucrose, the roosters were fed 40 g of the diets by tube once a day for three days. The excreta were collected within 72 h after the first feeding. The diets and excreta were analyzed for nitrogen content. For each EAA studied, a linear regression was fitted by N balance and EAA intake. The maintenance requirements were estimated as the EAA intake to maintain the N balance equal to zero. The daily EAA requirements for maintenance were estimated to be: Lys 11, Met 29, Thr 23, Trp 5, Arg 50, Val 29, His 6, Gly 54, Phe 49, Leu 78 and Ile 21 mg/BWkg0.75 per day. Therefore, the EAA ratio for maintenance was concluded to be Lys 100, Met 276, Thr 220, Trp 48, Arg 467, Val 275, His 60, Gly 511, Phe 467, Leu 735 and Ile 198% independent of the scale. The EAA profile and the ideal ratio for maintenance of poultry estimated in this study contribute to improve factorial model for estimating EAA requirements for poultry. In the second study, two approaches using amino acid deletion method, one with comparative slaughter and another with N balance, were used to re-evaluate the actual assumptions of ideal ratios between the EAA: lysine (Lys), methionine+cystine (Met+Cys), threonine (Thr), tryptophan (Trp), arginine (Arg), valine (Val), isoleucine (Ile), leucine (Leu), phenylalanine+tyrosine (Phe+Tyr), glycine+serine (Gly+Ser), and histidine (His) for growing broilers of Cobb 500 genotype during three periods (I: 6 to 21, II: 22 to 37, and III: 38 to 53 d). Per trial, 120 male chickens were housed in metabolic cages for assessment of individual N-balance and AA efficiency data. An AA balanced diet (BD) was formulated according to recommendations of Brazilian tables (Rostagno et al., 2011) for the ideal protein in growing broilers. The diets with different limiting AAs were created by dilution of BD with corn starch to achieve 0.70 of the AA level in BD and supplemented with crystalline AAs, except the AA under study. The AA diluted diets led to significant impairment of protein utilization and indicated valid limiting position of these AAs. Also, at start and the end of the trial a group of birds with mean body weight of each replicate was killed with no blood loss to determine nitrogen deposition by comparative slaughter technique. The mean value of the optimum ratios of the eleven tested EAAs determined by comparative slaughter in the three periods are: Lys100, Met+Cys 65, Thr 66, Trp 17, Arg 108, Val 79, Ile 61, Leu 122, Phe+Tyr 128, Gly+Ser 155, and His 41. Based on observed AA efficiency data, the optimum ratios determined by nitrogen balance are: Lys 100, Met+Cys 72, Thr 65, Trp 17, Arg 106, Val 76, Ile 67, Leu 107, Phe+Tyr 115, Gly+Ser 137, and His 35. There are some differences among the results obtained by the two methods (Louvain and Goettingen approach), but the Goettingen approach provided result in accordance with the literature and less variation in the results. The third study aimed to determine the model parameters for maximum nitrogen retention (NRmaxT), nitrogen maintenance requirement (NMR) and the efficiency of lysine utilization (bc-1) to determine the lysine (Lys) requirements of broiler breeder hens. The N balance trials were performed in two periods (I: 31-35 wks and II: 46-50 wks). Seven treatments were used with eight replicates and one hen per cage; the treatments consisted of seven diets with protein levels ranging from 58.8 to 311.9 g/kg of feed, with Lys being limiting in the dietary protein (c = 3.91 g of Lys in 100 g of CP). For each period, the data of nitrogen intake (NI), nitrogen excretion (NEX), nitrogen in egg mass (NEM), nitrogen deposition (ND, ND=NI-NEX) and nitrogen retention (NR, NR=ND+NEM+NMR) were obtained in a balance trial of 25 days. The NMR was calculated by the exponential relationship between NEX and NI. The NRmaxT and b (slope related to protein quality) were estimated by the exponential fit between NR and NI. The bc-1 was obtained dividing b by c. Based on the likelihood ratio test for the model parameters, the obtained values were 255 mg/BWkg0.67 for NMR, 0.000117 for b and 1684 mg/BWkg0.67 (period I) and 1484 mg/BWkg0.67 (period II) for NRmaxT. The Lys intakes were estimated by the function Lys = (ln(NRmaxT)-ln(NRmaxT-NR)):(16×bc-1)), which resulted in the Lys intakes of 915 and 876 mg/d for breeder hens in the periods I and II, respectively. The current study concludes that the optimal Lys requirement is in range with literature data, but the recommendations can be adapted according to feed intake, aimed protein deposition and dietary AA efficiency. The fourth study aimed to apply the individual AA efficiency data (bc-1) for lysine (Lys), methionine+cystine (Met+Cys), threonine (Thr), tryptophan (Trp), arginine (Arg), valine (Val), isoleucine (Ile), leucine (Leu), phenylalanine+tyrosine (Phe+Tyr), glycine+serine (Gly+Ser) and histidine (His) to derive an ideal AA ratio (IAAR) for breeder hens. N-balance trials were performed from 31 to 35 wks and from 46 to 50 wks. Twelve treatments with eight replicates and one hen per cage were used. A balanced diet (BD) was formulated to meet the IAAR and the requirement of other nutrients for breeder hens. The limiting diets were formulated diluting BD with corn starch and refilled with crystalline AAs and other feed ingredients, except for the AA under study. In each period, the data of N-intake (NI), N-excretion (NEX), N in egg mass (NEM), N-deposition (ND, ND=NI-NEX) and N-retention (NR, NR=ND+NEM+NMR) were obtained in a balance trial of 25 days. The b values (protein quality) were estimated by b = (ln(NRmaxT)-ln(NRmaxT-NR)):(NI)), where NRmaxT is the potential for maximum nitrogen retention of breeder hens. The bc-1 values were obtained dividing b by the dietary AA concentration (c, g AA/16g N). The limiting position of each AA was confirmed and the bc-1 values were used to obtain an average IAAR: Lys (100), Met+Cys (83), Trp (24), Thr (81), Arg (114), Val (90), Ile (93), Leu (105), Phe+Tyr (109), Gly+Ser (95), and His (35). The IAAR was in the line with the recommendation from the literature, validating this alternative procedure for predicting dietary IAAR for broiler breeder hens. Finally, the aim of the fifith study was to apply the deletion method to derive an IAAR for broiler breeder hens. The nitrogen balance trials were performed from 31 to 35 wks and from 46 to 50 wks. Twelve treatments with eight replicates and one hen per cage were used. A balanced diet (BD) was formulated to strictly meet the IAAR and the requirement of other nutrients. The limiting diets were formulated diluting BD with corn starch and refilled with crystalline amino acids (AA) and other feed ingredients, except for the AA under study. Each feeding trial lasted 25 days. The feather losses, egg production and egg weight were recorded daily and the samples were stored to further determine NEM and nitrogen in feather losses (NDFL), respectively. At the start and the end of each period, a group of breeder hens were slaughtered to further determine nitrogen deposition in the body (NDB) and feathers (NDF). The NR was calculated as the sum of NDB, NDF, NDFL, NEM, and the nitrogen maintenance requirement (NMR=255 mg/BWkg0.67 per day). The percent reduction in NR resulting from the individual AA deletions relative to BD and the percent of the AA to delete from the BD were used to calculate the optimum in-feed AA requirement. The average IAAR determined was: Lys (100), Met+Cys (86), Trp (23), Thr (80), Arg (113), Val (90), Ile (91), Leu (133), Phe+Tyr (108), Gly+Ser (94), and His (35). The IAAR determined in this study corroborate with the recommendations for broilers in the literature, particularly when using the Goettingen approach, validating the deletion method for determining the IAAR. In addition, the method has been standardized for broiler breeder hens and the results of this study allowed updating the ideal ratio for these birds. Likewise, the deletion method for determining the IAAR for maintenance was also standardized and the ideal profile updated. Finally, the standardization of these methods will allow Brazilian research enjoy a rapid and low-cost procedure to estimate and evaluate the IAARs.

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This study analyzed broiler breeder age (29 or 60 wk-old) effects on physical characteristics of eggs (initial mass, mass loss, volume, diameter, surface area and density) and of eggshells(weight, volume, thickness, conductance, and porosity ), as well as the influence of embryo sex on hematological parameters and body, liver and heart weights during incubation (at days 13, 15, 18 and 21). Physical parameter values were lower in 29-wk-old broiler breeder eggs than those of 60-wk-old breeders, except for relative eggshell weight, which was higher. In both male and female embryos, erythrocytic parameters and the body, liver, and heart weights increased during the incubation. The embryos and their organs were heavier when derived from 60-wk-old breeder eggs as compared to 29-wk-old breeder eggs. At hatching, hematocrit values were higher in males than in females. Thrombocytes were the most frequent leukocytes in the blood. Thrombocyte percentage decreased and lymphocyte percentage increased during the last days of incubation. The results showed maternal age influence only on body, heart and liver weights, focal sex-related influence the hematocrit at hatching, and temporal effect of incubation on body and organ weights, as well as on red blood cell count, hematocrit, hemoglobin, plasma glucose, and lymphocytes, which increased during the incubation period, while mean corpuscular volume and thrombocyte values decreased.

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O presente trabalho teve como objetivo avaliar a utilização de minerais orgânicos e inorgânicos, na alimentação de matrizes de corte Cobb500. Foram utilizados 4 tratamentos: PI - composto por 100% de inclusão de premix mineral inorgânico; tratamento PO - 100% de inclusão de premix mineral orgânico; tratamento PI+PO - 70% de inclusão de premix mineral inorgânico e 30% de premix mineral orgânico e o tratamento PI+Zn - 100% de premix mineral inorgânico (exceto zinco 70%), somado a 30% de zinco orgânico. Os microminerais testados foram: zinco, manganês, selênio, cobre e ferro, sendo o iodo acrescentado ao sal em seu estado inorgânico. A dieta fornecida às aves foi a base de milho e farelo de soja. Foram utilizadas 440 galinhas e 40 galos com 51 semanas de idade. O período experimental foi compreendido entre a 51 e a 65 semana de idade do lote. Os parâmetros de produção e qualidade analisados foram: taxa de postura, eclosão de ovos, gravidade especifica, peso de ovos, mortalidade embrionária e qualidade da progênie. Os parâmetros da progênie analisados formam: ganho de peso corporal, conversão e consumo alimentar e mortalidade. As aves foram alojadas em um galpão experimental do Laboratório de Avicultura (LAVIC) da Universidade Federal de Santa Maria que possui 20 boxes de 4,61m2. O delineamento experimental foi o inteiramente casualizado com quatro tratamentos e cinco repetições de 22 fêmeas e 2 machos cada. Para avaliar o desempenho das progênies, foram realizadas duas avaliações de 1 a 21 dias. Em cada uma foi utilizado 320 pintos machos de um dia, provenientes de ovos produzidos nas semanas 55 e 60 de idade do lote. Foi adotado o mesmo delineamento utilizado na avaliação das matrizes, totalizando quatro tratamentos com 10 repetições de 8 aves machos cada. Nas condições e época que os experimentos foram conduzidos, o uso de minerais orgânicos não resultou efeitos significativos (P>0,05), sobre os parâmetros avaliados nas matrizes de corte, tão pouco sobre os parâmetros das duas avaliações realizadas na progênie

This study was conducted to investigate the effect of organic and inorganic minerals, in broiler breeders Cobb500. It was used 4 treatments: PI= 100% mineral inorganic premix; PO= 100% mineral organic premix; PI+PO= 70% mineral inorganic premix + 30% mineral organic premix and PI+Zn= 100% mineral inorganic premix, except zinc mineral, that was 70% inorganic form and 30% organic form. The trace minerals were: zinc, manganese, selenium, copper and iron, Iodine is added to the inorganic salt in its state. Corn and soybean meal diets were used. 440 hens and 40 roosters with 51 weeks of age were used. The experiment was conducted between 51st and 65th weeks of age of birds. The production parameters and quality parameters analyzed were: laying rate, hatching rate, egg weight, specific gravity, embryonic mortality and quality progeny. The parameters of progeny analyzed were: body weight gain, feed intake, feed conversion and mortality. The birds were housed in an experimental house at Poultry Laboratory (LAVIC) of the Federal University of Santa Maria with 20 floor pens of 4.61m2. The design was completely randomized with four treatments and five pen replicates with 22 hens and two roosters each. To evaluate the progenies two evaluations were performed of 1 the 21 days. Each evaluation used 320 male chicks one day of age, from eggs produced with the arrays of 55 and 60 weeks of age. For each evaluation, was adopted the same design used in the evaluation of the broiler breeders, resulting in four treatments groups with 10 replicates of 8 males birds each. Under the conditions and time that the experiment was conducted, the use of organic minerals had no significant effect (P>0.05) on the parameters evaluated in the broiler breeders and progeny, during the study period. Keywords: Zootechnical indexes. Minerals. Broiler breeders