No description available.

O presente estudo teve como objetivo avaliar as principais características de desempenho e qualidade interna e externa dos ovos de poedeiras comerciais brancas submetidas ao fracionamento de cálcio da dieta e diferentes granulometrias de calcário calcítico. Foram utilizadas 270 galinhas ISA-Babcock B-300 N de 40 semanas de idade por quatro períodos de 28 dias cada. O delineamento experimental foi o inteiramente casualizado em arranjo fatorial 3x3, com o fatores: fracionamento de cálcio (2 g Ca manhã e 2 g Ca tarde, 1 g Ca manhã e 3 g Ca tarde, e 3 g Ca manhã e 1 g Ca tarde) e granulometrias de calcário calcítico (mista, grossa e fina) totalizando 9 tratamentos com 5 repetições de 6 aves cada. As características de desempenho zootécnico não foram influenciadas pelos tratamentos com exceção do consumo de ração e de cálcio. O fracionamento de cálcio resultou em maior consumo de ração e cálcio no período da manhã para as aves alimentadas com 3 g de Ca neste período do dia. Para o período da tarde, o maior consumo de ração foi observado em aves alimentadas com 3 g de cálcio em comparação à aves alimentadas com 1 e 2 g de cálcio. Não houve diferença significativa quando avaliou-se o consumo de ração total do dia. O fator granulometria do calcário não influenciou nenhum dos parâmetros estudados com exceção da densidade aparente dos ovos. A utilização de calcário calcítico fino resultou em menor densidade dos ovos em comparação ao calcário calcítico misto ou grosso. Conclui-se que a utilização de calcários com granulometria mista ou grossa beneficia a qualidade da casca dos ovos e que a prática de fracionar o oferecimento de cálcio ao longo do dia não se mostrou vantajosa. No entanto, futuras pesquisas são recomendadas envolvendo o fracionamento de outros nutrientes como fósforo, energia e proteína. / This study was carried out to evaluate the performance and internal and external egg qualities of white commercial laying hens fed diets with different calcium levels and limestone particle sizes. Two hundred seventy ISA-Babcock B-300N hens, 40 weeks of age, were used by four – 28 days period. The experimental design was randomly in a 3x3 factorial arrangement: calcium fractionation (2g Ca morning + 2g Ca afternoon, 1g Ca morning + 3g Ca afternoon, 3g Ca morning + 1g Ca afternoon) and limestone particle size (blended, coarse and fine) with a total of nine treatments with five replicates of six hens each. Performance characteristics were not influenced by the treatments, except feed intake and calcium intake. It was observed higher calcium and feed intake for hens fed 3g Ca in the morning. Also, in the afternoon was verified higher calcium and feed intake for hens fed 3g Ca. There was no effect of the treatments on total daily intake. The limestone particle size improved egg specific gravity when blended or coarse particle size was benefical to eggshell quality. The calcium fractionation did not show be adventageous. However, further researches are indicate to evaluate other nutrients fractionation as phosphorus, energy, and protein.

No description available.

No description available.

No description available.

O presente estudo teve como objetivo avaliar as principais características de desempenho e qualidade interna e externa dos ovos de poedeiras comerciais brancas submetidas ao fracionamento de cálcio da dieta e diferentes granulometrias de calcário calcítico. Foram utilizadas 270 galinhas ISA-Babcock B-300 N de 40 semanas de idade por quatro períodos de 28 dias cada. O delineamento experimental foi o inteiramente casualizado em arranjo fatorial 3x3, com o fatores: fracionamento de cálcio (2 g Ca manhã e 2 g Ca tarde, 1 g Ca manhã e 3 g Ca tarde, e 3 g Ca manhã e 1 g Ca tarde) e granulometrias de calcário calcítico (mista, grossa e fina) totalizando 9 tratamentos com 5 repetições de 6 aves cada. As características de desempenho zootécnico não foram influenciadas pelos tratamentos com exceção do consumo de ração e de cálcio. O fracionamento de cálcio resultou em maior consumo de ração e cálcio no período da manhã para as aves alimentadas com 3 g de Ca neste período do dia. Para o período da tarde, o maior consumo de ração foi observado em aves alimentadas com 3 g de cálcio em comparação à aves alimentadas com 1 e 2 g de cálcio. Não houve diferença significativa quando avaliou-se o consumo de ração total do dia. O fator granulometria do calcário não influenciou nenhum dos parâmetros estudados com exceção da densidade aparente dos ovos. A utilização de calcário calcítico fino resultou em menor densidade dos ovos em comparação ao calcário calcítico misto ou grosso. Conclui-se que a utilização de calcários com granulometria mista ou grossa beneficia a qualidade da casca dos ovos e que a prática de fracionar o oferecimento de cálcio ao longo do dia não se mostrou vantajosa. No entanto, futuras pesquisas são recomendadas envolvendo o fracionamento de outros nutrientes como fósforo, energia e proteína. / This study was carried out to evaluate the performance and internal and external egg qualities of white commercial laying hens fed diets with different calcium levels and limestone particle sizes. Two hundred seventy ISA-Babcock B-300N hens, 40 weeks of age, were used by four – 28 days period. The experimental design was randomly in a 3x3 factorial arrangement: calcium fractionation (2g Ca morning + 2g Ca afternoon, 1g Ca morning + 3g Ca afternoon, 3g Ca morning + 1g Ca afternoon) and limestone particle size (blended, coarse and fine) with a total of nine treatments with five replicates of six hens each. Performance characteristics were not influenced by the treatments, except feed intake and calcium intake. It was observed higher calcium and feed intake for hens fed 3g Ca in the morning. Also, in the afternoon was verified higher calcium and feed intake for hens fed 3g Ca. There was no effect of the treatments on total daily intake. The limestone particle size improved egg specific gravity when blended or coarse particle size was benefical to eggshell quality. The calcium fractionation did not show be adventageous. However, further researches are indicate to evaluate other nutrients fractionation as phosphorus, energy, and protein.

Abstract Female ability to exploit conspecifics in reproduction may have unusual expressions. I studied the reproductive behaviour of the golden egg bug (Phyllomorpha laciniata; Heteroptera, Coreidae) experimentally in the field and in the laboratory. Female golden egg bugs lay their eggs mainly on the backs of conspecific males and other females. Non-parental eggs are often carried. Occasionally, the eggs are laid on the food plant (Paronychia spp; Polycarpea, Caryophyllaceae) of the species but typically, those eggs survive poorly due to egg parasitism and predation. I explored the dependence of female reproduction on conspecific presence and encounter rate. I also studied female current reproductive state (which depends on if she has recently oviposited) in relation to her activity as well as male choice of a female. Female bugs preferred to oviposit on conspecifics when presented with a choice between a bug and a food plant. When alone females often did not lay eggs. Increased encounter rate with others increased female egg laying rate. Survival of carried eggs among bugs did not vary significantly although males received more eggs than females. Females with high current fecundity (mature eggs accumulated to reproductive tract) were more active than females with lower current fecundity (recently oviposited). Females with high current fecundity seemed to search for conspecifics to lay eggs on. Males also preferred to court females with high current fecundity. These females were more likely to oviposit immediately after mating, lowering the risk of female remating before oviposition. To conclude, conspecifics are important egg-laying substrates for female golden egg bugs. Conspecific availability affects female egg laying and the rate of egg production in short term. In particular, males are necessary for egg-laying females and they typically receive unrelated eggs when they court females. Sexual interactions resulting from female polyandry are crucial factors that maintain female egg laying on the backs of males and other females in the unique reproductive system of the golden egg bug.

MSCAGR (Animal Science) / Department of Animal Science / The aim of the study was to investigate the effects of feed withdrawal and strain on laying performance and egg quality of White and Brown Hy-line layers. Fifty four hens for each strain (White Hy-Line and Brown Hy-line) aged 18 weeks (point of laying stage) were used in the investigation. Feed withdrawal had no effect (P>0.05) on laying performance, mortality rate, egg internal and external quality, but significantly affected (P<0.01) average feed intake, body weight, small and extra-large eggs percentages. Hens under ad libitum consumed more feed than hens under four hours and eight hours feed withdrawal. High body weight was observed on ad libitum fed hens, intermediate on eight hours feed withdrawn hens and lower at four hours feed withdrawn hens. High percentage of small graded eggs was observed on four hours feed withdrawn hens, intermediate on eight hours feed withdrawn hens and lower on ad libitum fed hens. High percentage of extra-large graded eggs was observed on ad libitum fed hens, intermediate on eight hours feed withdrawn hens and lower four hours feed withdrawn hens. Strain had a significant effect on average egg weight, median egg weight, albumen weight, extra-small, small, medium and large graded eggs percentages (P<0.01) and on body weight, egg height , egg width, average egg shell colour (P<0.05). Strain did not affect (P>0.05) average feed intake, body weight change, egg output, feed conversion ratio, mortality rate, egg shell breaking force, albumen height, yolk height, yolk weight, extra-large and jumbo graded eggs percentage. Brown Hy-Line layers had high average egg weight, median egg weight, egg height, egg width, and average egg shell colour and albumen weight than White Hy-Line layers. Small sized eggs percentage and body weight were high on White Hy-Line layers compared to Brown Hy-Line layers. Medium and large sized eggs were high on Brown Hy-Line layers than White Hy-Lines. Feed withdrawal by strain interaction effect was observed on body weight, average egg weight and median egg weight, albumen weight and egg height, percentage of small, medium and large graded eggs (P<0.05). Brown Hy-Line hens under eight hours feed withdrawal had high egg weight, median egg weight, egg height, albumen weight and under eight hours feed withdrawn White Hy-Line hens had lower albumen height compared to other interactions. In all interactions White Hy-Line had high percentage of small graded eggs whereas Brown Hy-line had high percentage of large and medium graded eggs. / NRF

The use of antibiotics as growth promotors in the food animal industry has led to the generation of antibiotic resistant microorganisms, which are a major health risk to humans. Therefore, bans and limitations, including the FDA’s veterinary feed directive, have been placed on the use of antibiotics as growth promotors, and there has been a push to find an adequate alternative. In the laying hen, probiotics and/or prebiotics have shown promise as they help promote the colonization of beneficial bacteria in the GI tract of the host, increase feed efficiency, increase egg production, and provide protection against pathogenic bacteria. In this feeding trial, Leghorn HyLine W36 hens were fed diets supplemented with either 0.05% IMW50(prebiotic), 0.05% CALSPORIN (probiotic), 0.05% IMW50 and 0.05% CALSPORIN, or a control diet with no prebiotic or probiotic additive. The birds were maintained on this diet from 1 day to 66 weeks of age, over which time feed intake and egg production was measured. From 37 to 65 weeks of age, every 3-5 weeks, egg quality was evaluated through specific gravity, egg weight, albumen height, and eggshell breaking force measurements. At 6, 16, 32, and 64 weeks of age, the microbiota population in the ileal digesta was evaluated using T-RFLP analysis methods. Then at 64 weeks of age, splenic IFN-γ, IL-6, IL-10, and IL-12 expression was measured by RT-qPCR. Unexpectedly, fluctuations in feed disappearance were observed, potentially linked to factors such as changes in diet type, temperature variations, feed wastage, or a technical error. Birds on CALSPORIN-containing diets showed resilience and maintained egg production during a decline in feed disappearance, suggesting enhanced capabilities in digesting larger particle sizes. However, there were trade-offs, as egg quality parameters slightly decreased in supplemented diets. CALSPORIN alone showed a promising effect on survival probability. Microbial diversity in the ileum increased with CALSPORIN, but the IMW50 alone led dysbiosis, possibly impacting infection resistance. Additionally, the combined supplementation of IMW50 and CALSPORIN may have introduced a disruption in immunological homeostasis.

Molting is a natural occurrence in the Avian species that can include a period of fasting. Animal rights groups view the longepted standard industry practice as inhumane. Based on influences from these groups and the recommendation of its scientific committee, United Egg Producers (UEP) requires members of its Animal Care Certified Program use a noneed withdrawal molting program, even though the morphological and physiological effects of this method have not been studied in depth and the existing literature provides contradictory results. Research regarding how to induce a noneed withdrawal molt has been performed using feed that is nutrient deficient or contains an additive to cease egg production. Studies have shown subsequent egg production to be comparable to hens molted using feed withdrawal. This study was designed to determine the morphological and physiological changes that occur in a noneed withdrawal molt. Two hundred hens divided into 40 groups of 3 birds each were molted in a staggered pattern so that the morphological and physiological effects of noneed withdrawal molt could be measured with identical environmental and housing variables. Data was divided into 5 sections including Control (n=5), Start (n=7), Mid-Molt (n-7), Near End (n=7), and Over (n=15). Internal organs were examined and measured. Corticosterone levels were measured to determine if noneed withdrawal molting causes less stress to hens. Pertinent blood parameters including cholesterol, glucose, O2, CO2, hemoglobin, and hematocrit were also measured. Results indicate internal organ weight changes due to noneed withdrawal molt were as expected. Decreases in the oviduct length, ovary weight, follicle weight, and follicle number indicate regression of the reproductive tract. No differences (P<0.05) were observed in corticosterone levels, suggesting that a noneed withdrawal molt does not increase stress in laying hens.