Air velocity and exposure time to ventilation affect body surface and rectal temperature of broiler chickens

Increasing air movement over poultry by using fans (ventilation) has become an accepted means of reducing environmental heat stress over the last several years. The purpose of this study was to evaluate the effect of air velocity and exposure time to ventilation on body surface and rectal temperature of broiler chickens. Male broiler chickens aged 36-42 days were placed in individual wire cages and exposed to five different air velocities (5.7, 4.2, 3.1, 2.4, or 1.8 m/sec). Throughout the experiment head, back, leg, and rectal temperatures were monitored every 10 min during a 30-min period for each air velocity. The data showed that exposure time to the wind affected (P<.05) leg and body temperature, with a rapid reduction being observed during the first 10 min. There was a reduction in leg temperature with air velocity of 2 m/sec; however, air velocity lower than 4.5 m/sec was not effective in decreasing head and back temperature. The results suggest that air velocity of 2 m/sec, in air temperature of 29 degrees C, improves heat loss in the birds. The data also indicate that exposure time to ventilation seems to be a critical point in the maintenance of bird thermal homeostasis.

Estimates of genetic correlations between days to calving and reproductive and weight traits in Nelore cattle

Data comprising 53,181 calving records were analyzed to estimate the genetic correlation between days to calving (DC), and days to first calving (DFC), and the following traits: scrotal circumference (SC), age at first calving (AFC), and weight adjusted for 550 d of age (W550) in a Nelore herd. (Co)variance components were estimated using the REML method fitting bivariate animal models. The fixed effects considered for DC were contemporary group, month of last calving, and age at breeding season (linear and quadratic effects). Contemporary groups were composed by herd, year, season, and management group at birth; herd and management group at weaning; herd, season, and management group at mating; and sex of calf and mating type (multiple sires, single sire, or AI). In DFC analysis, the same fixed effects were considered excluding the month of last calving. For DC, a repeatability animal model was applied. Noncalvers were not considered in analyses because an attempt to include them, attributing a penalty, did not improve the identification of genetic differences between animals. Heritability estimates ranged from 0.04 to 0.06 for DC, from 0.06 to 0.13 for DFC, from 0.42 to 0.44 for SC, from 0.06 to 0.08 for AFC, and was 0.30 for W550. The genetic correlation estimated between DC and SC was low and negative (-0.10), between DC and AFC was high and positive (0.76), and between DC and W550 was almost null (0.07). Similar results were found for genetic correlation estimates between DFC and SC (-0.14), AFC (0.94), and W550 (-0.02). The genetic correlation estimates indicate that the use of DC in the selection of beef cattle may promote favorable correlated responses to age at first mating and, consequently, higher gains in sexual precocity can be expected.

Qualitative feed restriction for heavy swines: effect on digestibility and weight of organs of digestive tract, and environmental impact of feces

Foram utilizados 50 suínos machos castrados para avaliar o efeito da restrição alimentar qualitativa sobre a digestibilidade dos componentes dietéticos, os órgãos do trato digestório, a composição e a produção fecal. Foram utilizadas cinco dietas experimentais, com níveis de restrição qualitativa de 0, 5, 10, 15 e 20%. Houve redução linear (P<0,001) para todos os coeficientes de digestibilidade, com exceção da fibra em detergente ácido, que apresentou resposta quadrática (P<0,05). Os teores de sólidos totais (P<0,01) e voláteis (P<0,05), e minerais totais (P<0,001) nas fezes aumentaram com os níveis de restrição alimentar, enquanto os níveis de K (P<0,05), Cu (P<0,01) e de N, P, Na, Ca, Mg, Fe e Zn (P<0,001), apresentaram resposta quadrática. A excreção diária de fezes, sólidos totais e voláteis, minerais totais, N, P, K, Mn e Cu (P<0,001), Ca, Na, Mg e Fe (P<0,05) apresentaram aumento em função do nível da restrição alimentar qualitativa. A restrição qualitativa pode ser alternativa para destinação de resíduos da agroindústria, conferindo boas propriedades às fezes suínas, no que diz respeito à utilização para adubação de culturas.

Increase of gastric area and weight gain in rats submitted to the ingestion of gasified water

OBJETIVO: em virtude do aumento progressivo da utilização de bebidas gaseificadas e do ganho de peso na população brasileira, e sabendo-se que os refrigerantes têm no gás carbônico um fator em comum, planejou-se um estudo experimental em ratos para investigar os efeitos da água gaseificada na ingestão hídrica e alimentar, ganho de peso, área gástrica, glicemia, hematócrito e hemoglobina. MÉTODOS: Foram constituídos 4 grupos de 12 ratos acompanhados por 36 dias. Ao Grupo-1 foi oferecido 35 g/dia de ração ad libitum e 20 ml de água não gaseificada em 4 períodos diários, ao Grupo-2 foi oferecido 35 g/dia de ração ad libitum e 20 ml de água gaseificada em 4 períodos diários, ao Grupo-3 foi oferecido 10 g/dia de ração ad libitum e 20 ml de água não gaseificada em 4 períodos diários e ao Grupo-4 foi oferecido 10 g/dia de ração ad libitum e 20 ml de água gaseificada em 4 períodos diários. RESULTADOS: Os resultados identificaram que os animais que foram submetidos ao tratamento com água gaseificada (Grupo-2 e Grupo-4), apresentaram um maior volume de ingestão hídrica e aumento significativo da área gástrica (p<0,001), no Grupo-2 a ingestão alimentar assim como o ganho de peso foi significativo (p<0,01), os dados de glicemia, hematócrito e hemoglobina não tiveram alterações significativas entre os grupos estudados. CONCLUSÃO: Nas condições em que foi realizado este experimento, concluímos que a água gaseificada favoreceu a ingestão hídrica e alimentar, o ganho de peso e o aumento da área gástrica.

Isotopic traceability in body tissues and in different breeding periods of broilers

Rastrearam-se a inclusão de farinha de vísceras de aves (FV) em dietas de frangos por ocasião de eventual substituição de dieta contendo FV por dieta estritamente vegetal, e vice-versa, por isótopos estáveis de carbono e de nitrogênio. Foram distribuídos aleatoriamente 192 pintos de um dia de idade, em 12 tratamentos com quatro repetições de quatro aves. Os tratamentos constituíam-se de dieta de vegetais (VG) passando para dietas contendo FV, após certa idade, ou o inverso, em que as aves começaram se alimentando de dieta FV e depois passaram para dieta VG. Aos 42 dias de idade, foram coletadas amostras de músculo peitoral (Pectoralis major), quilha e tíbia, para determinação das razões isotópicas (13C/12C e 15N/14N). A técnica dos isótopos estáveis somente não foi capaz de rastrear a utilização de FV na alimentação de frangos de corte, quando esse ingrediente fez parte da dieta das aves apenas nos primeiros sete, 14 ou 21 dias de idade. Entretanto, há a possibilidade da aplicação dessa técnica em aves mais jovens, amostradas antes de eventual mudança de dieta, pois elas podem ter a assinatura isotópica da alimentação estabilizada em torno de duas semanas de idade.

Desempenho e medidas biométricas de caprinos de diferentes grupos raciais

Objetivou-se avaliar o desempenho de cabritos de três grupos raciais. Foram considerados nas avaliações o peso, o ganho de peso, as medidas biométricas, a conversão alimentar e o custo de produção relativo à alimentação. Utilizaram-se 41 cabritos, machos e fêmeas, de três grupos raciais (A - Alpino; ½ BA - ½ Boer + ½ Alpino; e ¾ BA - ¾ Boer + ¼ Alpino), avaliados aos 60, 90 e 120 dias em sistema de confinamento. As médias foram comparadas por análise de variância utilizando-se o teste Tukey. O desempenho não diferiu entre os grupos raciais. O escore corporal foi maior nos animais ¾ BA, o que pode representar vantagem econômica ao produtor se esses animais forem comercializados vivos. Com o avanço da idade, houve aumento do comprimento corporal, da altura anterior, da altura posterior, do perímetro torácico, do perímetro da perna, da largura da garupa e da largura do peito. Os machos foram superiores às fêmeas quanto às medidas biométricas e quanto ao peso ao nascimento, aos 60 e aos 90 dias. Os machos Alpinos foram mais pesados aos 120 dias e apresentaram, ainda, maior ganho de peso no intervalo dos 30 aos 60 dias. O menor custo de produção relativo à alimentação por quilograma de cabrito produzido foi observado aos 90 dias de idade.

Survival rate, body size and food abundance in pure and mixed blowfly cultures

The influence of food abundance, larval density and interspecific interactions on the survival and body size of Chrysomya albiceps, Chrysomya megacephala and Cochliomyia macellaria was investigated in pure and mixed cultures, to determine the impact of competition and/or facultative predation on native and introduced blowfly species in South America. In mixed cultures there was complete elimination of C. megacephala and C. macellaria. Chrysomya albiceps exhibited higher survival in mixed compared to pure cultures, suggesting that predation offers more advantages than competition for food. Body size of C. albiceps was significantly affected by food scarcity in pure cultures. However, tibia size in males of all species suffered no significant variation as a function of food scarcity. The implications of these results for population dynamics of introduced and native blowfly species are discussed.

Fecundity, body size and population dynamics of Chrysomya albiceps (Wiedemann, 1819) (Diptera: Calliphoridae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytochemistry of fat body trophocytes and ovaries of workers and queens of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae: Meliponini) during vitellogenesis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Performance of body fat and body mass index cutoffs in elevated blood pressure screening among male children and adolescents

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Body sway and sensory motor coupling adaptation in children: Effects of distance manipulation

The purpose of this investigation was to examine coupling between visual information and body sway in children and young adults at various distances from a moving room front wall. Sixty children (from 4 to 14 years old) and 10 young adults stood upright inside a moving room that was oscillated at .2 and .5 Hz, at distances of .25, .5, 1, and 1.5 m from a front wall. Visual information induced body sway in all participants in all conditions. Young children swayed more than older participants, whether the moving room was oscillated or not. Coupling between visual information and body sway became stronger and the room movement influence became weaker with age. Up to the age of 10, coupling strength between visual information and body sway and the room movement influence were distance dependent. Postural control development appears to be dependent on how children reweight the contribution of varying sensory cues available in environment in order to control body sway. (C) 2007 Wiley Periodicals, Inc.

Diversity and evolution of macrohabitat use, body size and morphology in a monophyletic group of Neotropical pitvipers (Bothrops)

The Neotropical pitviper genus Bothrops comprises about 40 species, which occur in all main ecosystems of cis-Andean South America. We explored the relationships of body size and form (tail length and stoutness) with macrohabitat use in 20 forms of Bothrops. Sen-ii-arboreal habits appeared only in forest forms. Semi-arboreals are significantly more slender and have longer tails than terrestrials; body size is not significantly different between terrestrials and semi-arboreals. Within Bothrops, independent contrasts for macrohabitat use were significantly correlated with contrasts of tail size (positively) and stoutness (negatively); thus, the more arboreal the species, the longer its tail and the more slender its body. Contrasts of adult body size seems to remain constant over the lower range of macrohabitat use, but to decrease in species of Bothrops which are more arboreal. Reconstructions of character states indicate that: (1) the ancestor of Bothrops was a small, stout, terrestrial species; (2) semi-arboreal habits appeared one to three times in the genus; (3) a decrease in stoutness and an increase in tail length occurred along with an increase in arboreality in some clades. Although macrohabitat use seems to be important in determining body form in Bothrops, our results also indicate that tail size, stoutness and body size may also be affected by selective agents other than macrohabitat use. The selective agents responsible for the shifts in macrohabitat use in Bothrops are still uncertain, although they may have included prey availability and/or predation pressure. The plasticity of macrohabitat use, morphology and body size described in this study may have been key features that facilitated the highly successful ecological diversification of Bothrops in South America.

Atomic Bose-Einstein condensation with three-body interactions and collective excitations

The stability of a Bose-Einstein condensed state of trapped ultra-cold atoms is investigated under the assumption of an attractive two-body and a repulsive three-body interaction. The Ginzburg-Pitaevskii-Gross (GPG) nonlinear Schrodinger equation is extended to include an effective potential dependent on the square of the density and solved numerically for the s-wave. The lowest collective mode excitations are determined and their dependences on the number of atoms and on the strength of the three-body force are studied. The addition of three-body dynamics can allow the number of condensed atoms to increase considerably, even when the strength of the three-body force is very small compared with the strength of the two-body force. We study in detail the first-order liquid-gas phase transition for the condensed state, which can happen in a critical range of the effective three-body force parameter.