Objetivou-se a avaliação dos efeitos dos níveis de suplementação de vitamina E na ração para frangos de corte sobre o desempenho na fase inicial (um a 21 dias de idade) e de crescimento (21 a 39 dias de idade). Os tratamentos foram definidos pelos níveis de suplementação de vitamina E (DL-α tocoferol). As quantidades adicionadas às rações foram: 10; 30; 50; 75 e 100mg de vitamina E para cada kg de ração. Na fase inicial (experimento I), o menor nível de suplementação de vitamina E mostrou-se superior aos demais, apresentando efeito significativo (P≤0,05) sobre o peso médio aos 21 dias de idade e ganho de peso de um a 21 dias de idade. Na fase de crescimento (experimento II), não houve efeito significativo (P>0,05) dos níveis de suplementação de vitamina E sobre as variáveis estudadas. O nível mínimo de suplementação de vitamina E testado (10mg/kg) é suficiente para atender às exigências dos frangos de corte machos sobre o desempenho.

This study aimed to evaluate the effect of vitamin E supplementation on the performance of broiler chickens in the initial and growth phase, from one to 21 and 21 to 39 days of age, respectively. Five increasing levels of DL-α tocopherol supplementation (10, 30, 50, 75 and 100mg to each kg of diet) were added to the diet. In the initial phase (experiment I), the lowest vitamin E level was superior by presenting significant effect (P≤0.05) on body weight at 21 days of age and weight gain from one to 21 days old. In the growth phase (experiment II), there was no significant effect (P>0.05) of vitamin E supplementation on the variables studied. The minimum level of vitamin E supplementation tested is sufficient to attend the requirements of male broiler chickens.

The objective of this study was to evaluate the quality of pellets from the end of the pelletizer machine until the end of the line feed plate, using two methods of analysis: pellet durability index (PDI) and EMBRAPA pelletizing method (MEP). Furthermore, the effect of the discharging methods at the broiler farm on the physical quality of pellets using MEP as a method of analysis was evaluated. The first phase of the experiment was a randomized block with six treatments: A - pellets at the end of the pelletizer machine; B - pellets inside the truck; C - truck's discharging at the feed silo; D - place inside the warehouse after the feed silo; E - the middle of the feed plate line and F - the end of the feed plate line. The experiment was carried out in seven replicates (blocks). The second phase of the experiment was a randomized block with two treatments: A - smaller discharge opening (for pellets feed); B - bigger discharge opening (for mashed feed). The experiment was performed with twelve replicates (blocks). The discharge of the pellets feed at broilers farm is the point that worsens the pellets quality. The discharge of pellets feed by the truck should be done with the bigger discharge opening. Moreover, MEP showed to be a better method than PDI to evaluate the integrity of the pellets for broiler chickens.

Foram avaliados os efeitos do momento de transferência dos ovos da incubadora para o nascedouro e da idade da matriz pesada sobre o rendimento de incubação. Os tratamentos foram definidos pela idade das matrizes Cobb®, sendo considerados ovos de matrizes novas (33 semanas) e ovos de matrizes velhas (63 semanas), e pelos momentos de transferência da câmara de incubação para os nascedouros (aos 15, 17 e 19 dias). O delineamento experimental foi inteiramente ao acaso em parcelas subdivididas, sendo o fator da parcela os três momentos das transferências e as subparcelas as duas idades das matrizes, com 18 repetições por tratamento. A bandeja com 96 ovos foi considerada a repetição, totalizando 1.728 ovos para cada tratamento. Ovos de matrizes velhas são mais pesados, perdem mais peso durante a incubação e têm percentual de fertilidade menor (P<0,05), qualquer que seja o momento de transferência dos ovos. Independentemente da idade das matrizes, a transferência dos ovos da incubadora para o nascedouro aos 15, 17 ou 19 dias de incubação não interfere na mortalidade embrionária, eclodibilidade e peso dos pintos ao nascimento. É possível adaptar o manejo de transferência à necessidade logística do incubatório ou reduzir o período dos ovos na máquina de incubação para aumentar o fluxo de produção, sem prejuízo ao rendimento de incubação.

We evaluated the effects of the moment of egg transfer to the hatcher and broiler breeder age on the incubation yield. The treatments were defined by Cobb ® broiler breeder age, separating young breeders (33 weeks old) from older breeders (63 weeks old) and the moment of transfer from incubation chamber to the hatcher (at 15, 17 and 19 days). The experimental design was completely randomized split plot. The plots factor was the three times of transfers and the subplots the two breeder ages, with 18 replicates per treatment. A tray of 96 eggs was considered replay, totaling 1728 eggs for each treatment. Eggs from older breeders are heavier, lose more weight during incubation and fertility rate is lower (p<0.05), regardless of the moments of eggs transfer. Regardless of the breeder age, the transfer of eggs from the incubator to the hatcher at 15, 17 or 19 days of incubation does not interfere in embryonic mortality, hatchability and chick weight at hatch. You can adapt the transfer management to the logistic needs of the hatchery or reduce the period of egg incubation in the machine to increase the flow of production with no losses in incubation yield.

The effects of oviposition time, which represents different positions of the follicles in a sequence of posture, were studied on egg weight, chick weight, egg weight loss during incubation, hatchability, embryo mortality and infertility . A total of 19, 820 eggs, layed on the same day, from Cobb® broiler breeders aging 46-week-old were used. The eggs were classified according to the oviposition time posture (corresponding to the time of collection) from 8:30 am, 10:30 am, 12:30 pm, 14:30 pm and 16:30 pm, which represented the folowing treatments: 1st, 2nd, 3rd, 4th and 5th collects, respectively. The experimental design was completely randomized with five treatments and 36 repetitions, and each tray of 96 eggs was considered a repetition. The normal and homogeneous data were submitted to analysis of variance and means compared by Tukey test. The non-normal and non-homogeneous averages were compared by Kruskal-Wallis test. It is concluded that the time of egg laying has influence on egg weight and chick weight, but does not affect hatchability, fertility and embryonic development.

Foi realizado um estudo sobre qualidade da casca dos ovos incubáveis provenientes de matrizes pesadas com diferentes idades, por meio da avaliação da relação entre peso da casca e peso do ovo e análises de peso específico, espessura, porosidade, resistência e microscopia eletrônica. Os dois tratamentos foram definidos pela idade da matriz, sendo considerados ovos de matrizes novas - 33 semanas - e de matrizes velhas - 63 semanas. Os ovos de matrizes com 33 semanas foram mais leves, e o número de poros por cm² foi menor que o de ovos das aves mais velhas. Ovos de aves com 63 semanas apresentaram menor percentual de casca em relação ao peso do ovo, menor peso específico e menores resistência e espessura da casca. A proporção das membranas da casca em relação à sua espessura total foi maior nas matrizes mais novas. Concluiu-se que ovos de matrizes velhas têm qualidade de casca inferior aos ovos das matrizes novas e que as membranas da casca nos ovos de matrizes novas desempenham papel relevante em sua estrutura.

We conducted a study on eggshell quality from Cobb® broiler breeders at different ages by assessing the relationship between eggshell weight and egg weight and analysis of specific weight, thickness, porosity, strength and electron microscopy. Both treatments were defined by broiler breeder age, considering eggs from young breeders (33 weeks) and eggs from old breeders (63 weeks). It was observed that eggs from breeders at 33 weeks have lower weight and number of pores per cm² compared with eggs from older birds. 63 weeks broiler breeders had lower percentage of eggshell in relation to egg weight, lower specific weight, strength and thickness, when compared with eggs from young breeders. The proportion of shell membranes in relation to its total thickness was significantly higher in young breeders. It was concluded that eggs from older broiler breeders have lower eggshell quality than the young breeders. The shell membranes in young breeder's eggs play a significant role in its structure, making it necessary to focus on this layer in future studies on eggshell quality and their relationship between breeder age and incubation yield.

Male sex determination in humans is controlled by the SRY gene, which encodes a transcriptional regulator containing a conserved high mobility group box domain (HMG-box) required for DNA binding. Mutations in the SRY HMG-box affect protein function, causing sex reversal phenotypes. In the present study, we describe a 19-year-old female presenting 46,XY karyotype with hypogonadism and primary amenorrhea that led to the diagnosis of 46,XY complete gonadal dysgenesis. The novel p.E89K missense mutation in the SRY HMG-box was identified as a de novo mutation. Electrophoretic mobility shift assays showed that p.E89K almost completely abolished SRY DNA-binding activity, suggesting that it is the cause of SRY function impairment. In addition, we report the occurrence of the p.G95R mutation in a 46,XY female with complete gonadal dysgenesis. According to the three-dimensional structure of the human SRY HMG-box, the substitution of the conserved glutamic acid residue by the basic lysine at position 89 introduces an extra positive charge adjacent to and between the positively charged residues R86 and K92, important for stabilizing the HMG-box helix 2 with DNA. Thus, we propose that an electrostatic repulsion caused by the proximity of these positive charges could destabilize the tip of helix 2, abrogating DNA interaction.