Performance of broilers fed with highly digestible ingredient in the prestarter and starter raising periods

O objetivo deste trabalho foi avaliar o efeito de dieta, com inclusão de um núcleo energético-proteico (NEP) de alta digestibilidade, no desempenho produtivo e características de carcaça de frangos de corte. O NEP constituiu-se de composto de óleo degomado de soja, milho pré-gelatinizado, soja biprocessada, mananoligossacarídeos e peptídeos. O total de 864 pintainhos machos, da linhagem AgRoss 508, com um dia de idade, foram pesados individualmente e distribuídos em blocos ao acaso. Os tratamentos consistiram de suplementos com diferentes teores de NEP, com oito repetições com 27 aves cada: T1, controle, 0% de NEP; T2, 7% de NEP (1-7 dias) e 3,5% de NEP (8-21 dias); T3, 14% de NEP (1-7 dias) e 7% de NEP (8-21 dias); e T4, 21% de NEP (1-7 dias) e 10,5% de NEP (8-21 dias). Aos 21 dias de idade, o peso corporal, ganho de peso, consumo médio de ração, conversão alimentar e rendimento de carcaça e cortes não foram afetados significativamente pelos tratamentos experimentais. A utilização de NEP na dieta de frangos de corte não altera o desempenho das aves e não interfere nas variáveis de características de carcaça.The objective of this work was to evaluate the effect of the diet, with the inclusion of an energetic-protein nucleus (EPN) composed of highly digestible ingredients, on the productive performance and carcass traits of broiler chicks. The nucleus was composed by degummed soybean oil, pre-gelatinized corn, twice-processed soybean, mannanoligosaccharides and peptides. The total of 864 male AgRoss 508 broiler, with one day of age, were weighed individually and distributed in a randomized block design. Treatments consisted of: T1, control, 0% EPN; T2, 7% EPN (1-7 days) and 3.5% EPN (8-21 days); T3, 14% EPN (1-7 days) and 7% EPN (8-21 days); and T4, 21% EPN (1-7 days) and 10.5% EPN (8-21 days of age). At 21 days of age, body weight, weight gain, average feed intake, feed conversion and carcass and cut-ups yield were not significantly affected by treatments. The EPN inclusion in the diets did not influence the performance, carcass traits and cut-ups of broilers

Genetic and phenotypic parameters for productive traits in white egg layer stocks

Utilizaram-se 2.054 fêmeas Leghorn da linhagem CC e 1.514 da linhagem DD do CNPSA-EMBRAPA, para estimar herdabilidades (h2) e correlações genéticas (rg) e fenotípicas (rp) do peso médio do ovo (PMO), taxa de postura de 23 a 40 semanas de idade (TP) e massa de ovos (MO) de 35 a 40 semanas de idade. Os efeitos de incubação (I), reprodutor (R) aninhado em linhagem (L) e fêmea aninhada em R e L influenciaram significativamente todas as características estudadas. As médias estimadas, referentes a PMO, TP e MO, foram, respectivamente, 56,4 g; 83,3% e 2.122 g referentes a CC e 56,0 g; 82,3% e 2.107 g referentes a DD. As estimativas de h2 e rg indicam que diferentes estratégias de seleção deveriam ser utilizadas nas duas linhagens, para melhorar a taxa de postura, devendo ser aplicada seleção individual em CC e seleção familiar em DD. Em ambas as linhagens deverá ser considerada a seleção também referente a PMO, para evitar redução no tamanho dos ovos.Information on 2054 CC and 1514 DD White Leghorn layer chicken lines from the CNPSA-EMBRAPA, in Concórdia, SC, Brazil, were used to estimate heritability (h2) and genetic (rp) and phenotypic correlations (rp) for average egg weight (PMO), egg production rate from 23 to 40 weeks of age (TP), and egg mass from 35 to 40 weeks of age (MO). Incubation (I), sire (R) within line (L) and female within R whithin L significantly affected all traits. Least square means for PMO, TP and MO were, respectively, 56.4 g; 83.3% and 2.122 g for CC and 56.0 g; 82.3% and 2.107 for DD. The estimates of h and rg indicate that individual selection applied in line CC and family selection applied in line DD would improve TP the most. In both lines, however, selection for PMO is necessary in order to avoid reducing the size of the eggs

Performance and carcass quality in comercial lines of broilers

Frangos de corte das linhagens comerciais Arbor Acres (AA), Pilch (PL), Cobb (CB) e Hubbard (HB) foram avaliados para comparar características de desempenho e carcaça. O experimento constou de 3 grupos: machos (M), fêmeas (F) e misto (M+F). As características avaliadas foram: consumo de ração (CR), ganho de peso (GP), conversão alimentar (CA) e viabilidade (VB) até 49 dias. Foi utilizado um grupo de 20 aves por parcela como unidade experimental. Aos 50 dias de idade, retiraram-se ao acaso uma ave de cada parcela M e F e um macho e uma fêmea da parcela MF, para avaliação do rendimento de carcaça (RC), porcentagem de gordura abdominal em relação ao peso vivo (PGA) e ao peso da carcaça eviscerada (PCE). Diferenças significativas de CA, (P < 0,05) foram observadas entre linhagens, tendo a linhagem PL apresentado o melhor resultado. Quanto às características de carcaça, a linhagem CB apresentou menor PC e a AA menor RC, em relação às demais. O efeito do grupo foi significativo (P < 0,05) sobre todas as características avaliadas, com exceção da VB. As fêmeas apresentaram menores PV, PC e RC, e maiores PGA e PCE que os machos. Correlações fenotípicas significativas foram observadas entre PV e PC (r=0,98); PCE e RC (r=0,52); PV e RC (r=0,35). Resultados semelhantes foram encontrados, quando se levou a linhagem em consideração, com exceção da HB, na qual a correlação entre PV e RC não foi importante.Four commercial lines of broilers (AA, PL, CB and HB) were evaluated in order to compare their performance, and carcass yield and composition. The experiment was divided into three groups: males (M), females (F) and mixed (M+F). Feed intake (CR), body weight (PC), feed conversion (CA) and viability (VB) up to 49 days were measured using a pen as the experi-mental unit. At 50 days of age, one bird was removed at random from each pen in the M and F groups and one male and one female from each pen in the M + F groups, in order to evaluate car-cass yield (RC), percentage of abdominal fat relative to live weight (PGA) and to eviscerated car-cass weight (PCE). Significant differences (P < 0.05) were observed between lines in relation to CA, with best results for line PL. In relation to carcass traits, CB birds showed the lowest PC and AA birds the lowest RC. The effect of groups was significant (P < 0.05) for all traits except for VB. Females presented lower PV, PC and RC and higher PGA and PCE than males. Significant phenotypic correlations were observed between PV and PC (r = 0.98), PCE and RC (r = 0.52) and PV and RC (r = 0.35). Similar results were observed when the line was taken into conside-ration, except for HB birds, for which the correlation between PV and RC was not important

Exact result for the Green's function of a two-dimensional interacting electron gas with spin-orbit interaction in a perpendicular magnetic field

An exact property is established for the Green's function of a uniform two-dimensional interacting electron gas in a perpendicular magnetic field with spin-orbit interaction. It is shown that the spin-diagonal Green's function is exactly diagonal in the Landau level index even in the presence of electron-electron interactions. For the Green's function with different spin indexes, only that with adjacent Landau level indexes is non-zero. This exact result should be helpful in calculating the Green's function approximately

Avaliação de materiais alternativos em substituição à maravalha como cama de aviário Alternative material to replace wood shavings as broiler litter

Com o objetivo de testar materiais alternativos para cama de aviário na criação de frangos de corte, foram alojados seis lotes consecutivos, cada um contendo 5.600 aves, apenas fêmeas, distribuídas em 35 boxes. Os tratamentos consistiram de sete tipos de material para cama (maravalha; casca de arroz; sabugo de milho triturado; capim-cameron picado; palhada de soja picada; resto da cultura do milho picado; e serragem), cada um com cinco repetições. Avaliaram-se nas aves o peso corporal médio e o consumo médio de ração e, nas camas, os teores de N, Ca, P e pH. Observaram-se ainda a presença de salmonela, a contagem de oocistos de eimeria na cama e o escore de lesões no intestino das aves ao abate. A utilização dos materiais alternativos avaliados como cama de aviário, por seis lotes consecutivos, como alternativas à maravalha não prejudicou o desempenho de frangos de corte. Esses materiais, após o descarte, por apresentarem valor em minerais superior ao da maravalha, podem ser utilizados na adubação de culturas.<br>Aiming to evaluate alternative materials to be used as broiler litter reutilization, six consecutive lots of 5,600 female broilers were allocated to 35 pens. The treatments consisted of seven types of litter materials: wood shavings, rice husk, ground corncob, chopped camerongrass, chopped soybean straw, chopped corn stalk and sawdust, each one with five replications. In the birds, it was evaluated the average body weight, feed consumption and in the litter, it was evaluated the contents of N, Ca, P and pH. The presence of salmoella, the eimeria oocists counting in the litter, and the gut birds lesions score at slaughter were also observed. The use of alternative materials evaluated as litter, per six concecutive lots, as a alternative for wood shavings did no prejudice the performance of broilers. These materials, by presenting mineral values higher than wood shavings, after discarding, could be used as culture fertilizers

Performance, carcass characteristics and litter moisture in broilers housed at two densities

The effect of stocking density in broiler chickens (11.08 and 13.20 birds m-2), between 5 and 45 days of age, was assessed with regard to performance, cut yield, litter moisture and frequency of pododermatitis injuries. Further, 476 one-day chicks Cobb 500(r) were distributed in a completely randomized design at two densities (birds m-&#178;), with seven replications per treatment in 14 experimental units. Birds housed at a lower density (11.08) increased feed intake (p < 0.05), without any effect on weight gain and feed conversion. Retail yields were not influenced (p > 0.05) by treatments. In the case of higher density (3.20) the litter showed higher moisture content (p < 0.05) at 28 and 35 days of age. There was a higher occurrence of pododermatitis in birds housed at a density of 13.20 birds m-2. Results show that increased housing density from 11.08 to 13.20 birds m-2 does not affect growth performance, carcass yield and cuts. However, a housing density of 13.20 birds m-2 increased litter moisture and provided a higher occurrence of grade I pododermatitis