Efeito do período de jejum na fase final de criação de frangos de corte machos sobre desempenho e mortalidade

The objective of this work was to evaluate effect of fasting period in the last growing phase on performance and mortality of male broilers. Two thousand one-day old male chicks were distributed in five randomized blocks according to a 4x2 factorial. (Four feeding programs (FP): ad libitum or one of three fasting schedules: 8-12, 12-16 and 8-16; and two strains (S): Ross or Hubbard-Peterson). Fifty birds were used per replicate. Birds were raised under identical feed and management conditions until day 42. During the experimental period (days 43-56), average temperature, relative humidity and temperature-humidity index (THI) recorded at day and at night were 29.4°C, 57.7 % and 78.1; and 22.0°C, 73.1% and 67.4, respectively. No SxP interaction was observed for all characteristics studied. At day 56, the Ross broilers showed higher mean weight (3104 g), weight gain, WG (3059 g), feed/ gain ratio, FC (2.22) and production factor, PF (213), than the Hubbard-Peterson birds (3011, 2967, 2.28 and 194, respectively). During the experimental period, the Ross broilers showed higher WG (831 g) and FC (3.40) than the Hubbard-Peterson ones (770 and 3.67, respectively). Birds submitted to the 8-12 h fast showed higher feed intake (2864 g) than those that fasted during the 8-16 period (2690). No effect of P on mortality was observed, either considering the overall period (days 1-56) or the experimental period (days 43-56). Fasting in the last phase of rearing not aided by other practices failed to decrease heat stress effects on performance and mortality of male broilers.

O Tempo de Corte com Discos Abrasivos Pode Ser Reduzido pelo Controle da Velocidade de Corte

This work presents an experimental study on the life of abrasive discs in cut-off type operations with two conditions of cutting speed. The cutting time is shown with a comparative analysis of the cutting speed.

Uso da restrição alimentar quantitativa para diminuir a mortalidade de frangos de corte machos

The effect of feed restriction (0, 10, 20, 30, 40 and 50%) from 8 until 14 days post-hatching on performance, total mortality incidence and sudden death syndrome (SDS) rate was studied in male broilers during winter and summer.Ad libitum fed broilers had a better performance, but a higher total mortality rate (13.00% in winter, 3.67% in summer) and SDS (3.67% in winter, 0.67% in summer). All restricted groups had a lower mortality level in winter than the control group with a non linear response influenced by feed restriction. Birds submitted to 40% feed restriction showed the lowest mortality incidence (2.67%) followed by groups submitted to 30% (4.67%), 50% (5.33%) and 10% and 20% (7.67%) feed restriction. Birds fed ad libitum had the highest SDS incidence (3.67%, against .33, 1.00, .67, 1.33 and 1.33% at 10, 20, 30, 40, 50% feed restriction, respectively), but differences were not significant. In summer, incidences of total mortality and due to SDS were low and not influenced by feed restriction, either during the restrictive period itself (8 to 14 days) or during the total period of raising (1 to 49 days). In both seasons, the feed restricted birds showed compensatory gain only until three weeks post-restriction period. At 49 days, body weight and weight-gain were lower in feed restricted birds, but feed :gain ratio rate was improved. This resulted in better productivity index in winter, but not in summer. The feed restriction at 30 to 40% for seven days during the second week may decrease mortality in male broilers raised in winter without lowering productivity if the restriction is followed by at least three weeks of full feeding.

Efeito da seleção quanto ao peso corporal nas características reprodutivas em linhagens de frangos de corte

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do Nível de Energia da Dieta e da Exposição Prévia ao Calor sobre a Respiração Mitocondrial do Músculo Cardíaco de Frangos de Corte

This work was conducted aiming to evaluate the effect of dietary energy level and the previous heat exposure on the respiratory activity of the mitochondria from the cardiac muscle of broiler chickens. It was used broiler chickens (Hubbard) from both sexes and fed with diet containing 2900 kcal ME/kg or 3200 kcal ME/kg. The birds were heat stressed (35°C/4h) in the 1 st, 21 st and 42 nd days of age. The respiratory activity of mitochondria from cardiac muscle was evaluated in a Gilson oxygraph, model 5/6, by using alpha-ceto-glutaric as substrate and the ADP (adenosine-di-phosphate) to stimulate the respiratory activity. There was not effect of dietary energy level and previous heat exposure on the respiratory activity of the mitochondria from cardiac muscle. However, the females presented higher respiratory activity than males. By reason of the low oxidative capability of the heart muscle fiber of the male broiler chickens, these could be more sensitive to cardiac disease than females.

Control preventivo dinamico de sistemas de energia electrica usando redespacho de generacion y corte de carga

A model for preventive control in electrical systems is presented, taking into account the dynamic aspects of the network. Among these aspects, the effects provoked by perturbations which cause oscillations in synchronous machine angles (transient stability), such as electric equipment outages and short circuits, are presented. The energy function is used to measure the stability of the system using a procedure defined as the security margin. The control actions employed are load shedding and generation reallocation. An application of the methodology to a system located in southern Brazil, which is composed of 10 synchronous machines, 45 busses, and 72 transmission lines. The results confirm the theoretical studies.

Salmonella em carcaças de frango congeladas

Hundred and fifty frozen broiler carcasses of four commercial brands, purchased at retail stores for Salmonella research, were examined: 43 of the carcasses referred to each of the brands A, B, D and 21 of brand C. Thirty-two percent of the samples were found positive; 11 serotypes were identified as S. Agona, S. Anatum, S. Enteritidis, S. Hadar, S. Havana, S. Mbandaka, S. Montevideo, S. Ouakam, S. Poona, S. Schwarzengrund and S.14, 5, 12:-. Antibiogram testing of the isolated strains showed 100% resistance to ampicilin, 75.0% to cefhalotin, 52.1% to cephoxitin, 22.9% to tobramicin, 6.2% to polimixin B and to tetracyclines, 4.2% to gentamicin, and 2.1% to netilmicin, to aztreonam and to amicacin. All strains showed total sensibility to chloramphenicol and to sulfazotrim.

Estudo da geometria do cavaco no corte com discos abrasivos

This paper shows a research about the study of the chip's geometry generated in the diving cut-off operation, under several cutting conditions. As a result it was possible to verify tint the cutting conditions and the type of the material being cut can directly affect the chip's geometry.

Efeito da restrição alimentar inicial e da temperatura ambiente sobre o desenvolvimento de vísceras e ganho compensatório em frangos de corte

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

Extra̧ão de Macro e Micronutrientes Pela Parte Aérea de Erva-Doce EM Fuņão de Calagem e Aduba̧ão com Esterco de Cama de Frango

A greenhouse experiment was conducted in the Soil Science Department of the Botucatu College of Agricultural Sciences (UNESP), Brazil, using a Dark Red Latosol in 25 L pots. The soil was limed to 50 and 70% of base saturation; and doses 0, 10, 20, 30 and 40 t ha-1 of chicken manure were applied, in December of 1999. The experimental design was completely randomized blocks with a factorial arrangement 5x2, 10 treatments and three replications. This work was carried to evaluate leaf number, height plants, fresh and dry weight by aerial part of sweet fennel, and macronutrients and micronutrients removal. The organic fertilization affected the accumulation of N, P, K, S, B and Mn; liming affected the nutrient uptake, except for the Ca, Mg, S and Fe; the interaction of factors affected K, Mg and Mn.