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ResumoO experimento foi conduzido com o objetivo de avaliar o efeito de diferentes idades de matrizes sobre a biometria de órgãos e a morfometria intestinal de pintos de corte à eclosão. Foram incubados 200 ovos provenientes de matrizes pesadas da linhagem comercial Ross 308, com as idades de 32, 40, 48, 56 e 64 semanas. À eclosão 20 pintinhos de cada idade de matriz foram pesados individualmente e sacrificados para avaliação do peso do peito, bolsa cloacal, saco da gema e intestino delgado e do comprimento do intestino delgado. O segmento do duodeno foi coletado para mensuração da altura de vilo e da profundidade de cripta. Houve efeito linear positivo da idade da matriz (p<0,05) sobre o peso vivo, peso absoluto e relativo do saco da gema, peso absoluto da bolsa cloacal e peso absoluto e relativo do peito. Para o peso absoluto, peso relativo do intestino delgado observou-se efeito quadrático da idade da matriz (p<0,05), sendo o melhor desenvolvimento do intestino em pintos provenientes de matrizes entre 40 e 50 semanas. O peso do pinto apresentou correlação positiva com o peso do saco da gema, bolsa cloacal e peito (p<0,05). Para vilo e cripta obteve-se um efeito significativo da idade das matrizes (p<0,05) sobre a profundidade das criptas, cujo comportamento foi linear decrescente e inverso à idade das matrizes enquanto a relação vilo:cripta, apresentou comportamento linear crescente (p<0,05) de acordo com a idade das matrizes. Conclui-se que a idade da matriz tem influência na biometria dos órgãos e na morfometria da mucosa do intestino delgado de pintos de corte à eclosão. Palavras-chave: Altura de vilo, peso de órgãos, frango de corte, saco da gema AbstractThe objective of the conducted experiment was the evaluation of effect of multiple age breeders on the organs biometry and the intestinal morphometry of chicks at hatching. There were incubated 200 eggs provided from Ross 308 breeders at the ages of 32, 40, 48, 56 and 64 weeks. At hatching, 20 chicks of each breeder age were individually weighted and sacrificed in order to evaluate breast, cloacal bursa, yolk sack and small intestine weight, besides the small intestine length. The duodenum portion was collected in order to measure the villus height and the crypt depth. There were a positive linear effect of the breeder age (p<0,05) on the live weight, absolute and relative yolk sack weight, cloacal bursa

This study aimed to assess the influence of thermal conditioning during the first week, and to verify the effect of this, upon the heat challenge by the end of the productive period on performance, heart morphology and carcass yield. A total of 980 Ross male broiler chicks randomly assigned according to a completely randomized design with 4 treatment and 8 replications totaling 32 experimental units. The treatments consisted of different temperature ranges in the first week of life: thermal comfort temperature, temperature below the comfort zone, temperature above the comfort zone and thermal oscillation. At 35 days of age four replicates of each treatment were submitted or not to heat stress in last week's rearing (27 and 32°C). Animals submitted to thermal conditioning in the first week of life showed no adaptation to heat capable of increasing production and carcass characteristics when submitted to chronic heat stress during the final rearing period. Metabolic disorders such as ascites syndrome and sudden death syndrome can occur in both broilers reared above the temperature of thermal comfort in the first week, as those submitted to heat stress from 35 days of age, considering the heart morphometric analysis performed on these birds.

Incubation management can have direct effects on neonate health and consequently affect post-hatching development. The effects of incubation in multiple and single stage incubators with different concentrations of CO were evaluated in terms of the vessel density in the chorioallantoic membrane, hatching, heart morphology, and body development of the neonate up to the tenth day. A total of 2,520 fertile eggs were used and distributed in a completely randomized design with 4 levels of CO in 4 single-stage incubators (4,000; 6,000; 8,000; and 10,000 ppm) and a control treatment based on multiple-stage incubation, totaling 5 treatments. The levels of CO were used during the first 10 d of the incubation period, and after this period, all eggs were submitted to the same level of CO (4,000 ppm). Eggs that were incubated in multiple-stage incubators presented a lower percentage of vessels in the chorioallantoic membrane, lower yolk absorption by the embryo, wall depth of the right ventricle, and greater humidity losses in the eggs when compared to eggs in the single-stage incubators. The eggs submitted to hypercapnia, between 5,000 and 6,000 ppm of CO, had a higher percentage of vessels in the chorioallantoic membrane; the embryos originating from these eggs had higher weight, with higher relative weight of the liver. However, the same levels reduced the yolk absorption. Single-stage incubation with moderate levels of hypercapnia is an efficient tool to be adopted by the hatcheries when attempting to improve chick quality.