F. R. F. Jaenisch

Condições térmicas ambientais e desempenho de aves criadas em aviários com e sem o uso de forro

This experiment was carried out in a completely randomized experimental design, factorial arrangement 2x2, to evaluate the effect of period of year and type polyethylene liming on thermal and humidity of aviaries and performance of broiler. Four aviaries were divided in four boxes to house 200 chickens each. The recorded performance traits were body weight, weight gain feed intake, feed:weght gain ratio and mortality from hatch to 42 days of age. Better thermal conditions and higher chicken performance were observed in the polyethylene liming aviaries.

Comparison of the effect of different methods of molt: Production and welfare evaluation

The purpose of this study was to evaluate alternative molting protocols assessing hen welfare and performance during and after molt. Hyline W-36 pullets were housed at 15 wk of age, and their egg production was obtained during this first cycle. When birds were 80 wk, the following molting treatments were applied: a conventional molt consisting of 10 d of fasting followed by cracked corn for 8 d and a pullet developer diet for 10 d; and 4 alternative molting programs: a soy hulls-based diet (12% CP, 1,455 kcal/kg of ME, and 1.38% Ca) offered for 14 d followed by cracked corn for 4 d and a pullet developer diet for 10 d; and the other 3 molt regimens consisted of feeding soy hulls for 4, 8, or 12 d followed by 10, 6, or 2 d, respectively, of a soy hulls-based diet and 4 d of cracked corn plus 10 d of a pullet developer diet. A nonmolted group of birds was fed a laying hen diet during the experimental period. Hen-day egg number was recorded daily for 56 wk (through 80-136 wk of age). The nonmolted hens showed lower hen-day production and fewer intact eggs and a higher number of cracked and shell-less eggs compared with those of the molted hens (P < 0.0001). A significant treatment by age effect (P < 0.0001) was observed for the variables of high-density lipoproteins and triglycerides. Control hens showed the lowest high-density lipoprotein concentration and the highest triglyceride levels at 84 wk of age when compared with all treatments. The lack of difference in heterophil-to-lymphocyte ratio during molt suggests little influence of molting protocols on this variable. Regardless of the treatments, molting was deleterious to bone quality. A high mobilization of Ca through bone resorption for eggshell formation could explain the results obtained. Behavioral patterns coincided with a decline in frustration activities and an increase in alertness as molt proceeded until 83 wk of age. Alternative molting diets consisting of soybean hulls were successful in providing acceptable postmolt egg production performance.

Efeito da restrição alimentar qualitativa no desempenho, na incidência de distúrbios metabólicos e no rendimento de carcaça em frangos de corte

This experiment was conducted to evaluate the performance, control of the of metabolic diseases incidence, and carcass yield of male broiler chickens allotted to a feed restriction from 8-14 days of age. The nutrient restriction was achieved by feeding a starter diet (21,5% CP and 3050 ME, kcal/kg) with 25 or 50% soybean hulls. The treatment of restriction involved the feeding of these diets either on continuously or intercalated form (with the non-diluted starter diet). After the restriction period, the birds returned to the regular starter diet up to 21 days of age. In the following period, from 22 to 35 days of age, the birds were fed a growing diet (21% CP - 3200 ME, kcal/kg) and from 36 to 42 days, a finishing diet (19% CP - 3200 ME, kcal/kg). After they have been submitted to the feed restriction, the birds showed lower body weights as compared to the control treatment for all ages. The diet dilution did not influence the incidence of ascites or sudden death syndromes. There were no differences on carcass breast or thigh yield. Abdominal fat content presented no consistent differences among treatment. The treatments with diet dilution of 50% of soybean hulls resulted on inferior gross margin. The nutritional strategy to reduce the losses by metabolic diseases and the abdominal carcass fat content was accomplished by losses on the performance of the birds.

Evaluation of litter material and ventilation systems in poultry production: I. overall performance

The objective of the present work was to evaluate the performance, mortality and the incidence of lesion on the foot-pad of broilers and litter enterobacteriaceae load in two ventilation systems and two litter materials. The experiment was carried out in four 12 m × 10 m broiler houses, internally divided in 4 pens, with 200 birds/pen for four consecutive flocks, each one with 42 days of duration and interval of 15 days of downtime between flocks. It was evaluated two ventilation systems (stationary and oscillating fans), and two litter materials (soybean straw and rice husks). Performance variables studied were body weight, weight gain, feed conversion ratio and mortality of birds at 21, 35, and 42 days of age. Flock mortality was daily recorded, and total mortality was used for analysis. Evaluation of lesions by using foot-pad macroscopic examination was performed in all birds at final weighing. It was also performed quantitative examinations of litter enterobacteria. Statistical analyses were performed by using the mixed model theory for repeated measures and logistical regression. Rice husks litter promoted the best performance of birds at all studied ages. Results did not permit to recommend a ventilation system inasmuch as both had similar performances. Soy straw litter causes a high incidence of foot-pad lesions. Enterobacteria occurrence is lower in reused litter.

Histopatologia em pulmões e corações de frangos suplementados com oxigênio durante a fase de incubação

Histopathological analysis of broiler chicken lungs and hearts were made to determine the effect of 2% oxygen supplementation during the hatchery period on the first and the 40th days of ages. The histopathological description response of the heart and lung indicated that oxygen supplementation during egg incubation, carried out in this work, resulted in less severe changes in chick’s organs and reduction of the mortality rates.

Evaluation of litter material and ventilation systems on poultry production: II. thermal comfort

The objective of this study was to evaluate environmental thermal conditions in broiler houses with two different ventilation systems and two different litter materials. The experiment was carried out in four 12 m × 10 m broiler houses, internally divided in 4 boxes/poultry house, with 200 birds/pen for four consecutive flocks, each one with a duration of 42 days with 15 days of downtime between flocks. Treatments tested were two ventilation systems (stationary or oscillating fans), and two types of litter materials (soybean straw or rice husks). It was collected in the center of each pen and in the external enviroment, dry and wet bulb temperatures, black globe temperature, and air velocity. These data were collected at 3-hour intervals from 8:00 a.m. to 6:00 p.m. at the fourth, fifth and sixth week age of the bird. Based on the data collected at each time, wet and globe temperature index (WBGT) and radiant heat load (RHL) were determined. Litter temperature reaings were also performed by using an infrared thermometer. Effects of flock, ventilation, week, hour and the interactions among factors on the studied variables were evaluated in the analysis of the internal thermal environment by using the theory of mixed models for repeated measures. Ventilation provided by stationary and oscilating fans had equal behavior and it did not affect the studied variable. However, both ventilation systems are sufficient to soften internal thermal conditions in the broiler house in relation to the external environment. Relative humidity of the air is higher when rice husks is used as litter material.

Impact of treatments for recycled broiler litter on the viability and infectivity of microorganisms

The microbiological risk of recycled litter depends on the efficacy of the management system applied to inactivate residual microorganisms and preserve the health of the successive broiler flock. This study aimed to assess the viability and infectivity of the Newcastle Disease Virus (NDV), Infectious Bursal Disease Virus (IBDV) and Salmonella Heidelberg in recycled litter exposed to different treatments. The litter was contaminated with microorganisms and submitted to the treatments (T): T1: shallow fermentation; T2: quicklime (calcium oxide); T3: shallow fermentation followed by addition of quicklime; T4: no treatment. Sentinel chicks housed on the treated litter showed that T1 and T3 inactivated residual IBDV. Analysis of the litter subjected to T1 also showed reduced levels of total enterobacteria. T2 was not able to reduce the microorganisms assessed and its association with T1 (T3) failed to enhance the effect of the treatment. NDV did not survive in the broiler litter, regardless of the treatment applied, and it was also not detected in the sentinel chicks. S. Heidelberg remained viable in the litter submitted to all studied treatments, being isolated from the sentinel chicks of all the experimental groups. The antimicrobial activity of T1 and T3 was associated to higher ammonia contents in the broiler litter. The results indicate that the shallow fermentation treatment is efficient for controlling residual IBDV and total enterobacteria in the recycled litter.

Primeira análise filogenética de Avipoxvirus (APV) no Brasil

This study represents the first phylogenetic analysis of avian poxvirus recovered from turkeys in Brazil. The clinical disorders related to fowlpox herein described occurred in a turkey housing system. The birds displaying characteristic pox lesions which were observed on the neck, eyelids and beak of the turkeys. Four affected turkeys were randomly chosen, euthanized and necropsied. Tissues samples were submitted for histopathological analysis and total DNA was further extracted, amplified by conventional PCR, sequenced and phylogenetically analyzed. Avian poxviruses specific PCR was performed based on P4b core protein gene sequence. The histological analysis revealed dermal inflammatory process, granulation tissue, hyperplasia of epithelial cells and inclusion bodies. The P4b gene was detected in all samples. Sequencing revealed a 100% nucleotide and amino acid sequence identity among the samples, and the sequences were deposited in GenBank®. The four Avian poxviruses fragments sequenced in this study clustered along the A1 clade of avipoxviruses, and were classified as Avipoxvirus (APV). Additional studies, such as virus isolation, PCR and sequencing includinga large number of specimens from the Brazilian turkey production must be conducted due to the hazardous risk that poxvirus infections may cause to the Brazilian poultry production scenario, given that Brazils turkey production attracts attention due to its economic importance worldwide. Our findings point to the need to identify the prevalence of APV in Brazilian turkey production, to perform risk assessment studies and continued surveillance of APV infections in both wild and commercial avian species.

Evaluation of the Welfare of Broiler Chickens Reared in Different Heating Systems

In the present study, the evaluation of the welfare of broiler chickens reared in four different heating systems was assessed. The experiment was conducted in four aviaries with dimensions of 12 x 10m and 1000 birds each, at Embrapa Swine and Poultry Farm facilities, during four consecutive rearing cycles of 42 days. The heating systems evaluated were: a bio-fuel heater, a gas heater (GLP), a vegetable coal brick heater and a firewood heater. To assesses birds’ welfare the following variables were obtained: heterophil/lymphocyte ratio (H/L), fluctuating asymmetry, foot pad assessment and gait score assessed by four gait scoring levels, 1- Regular (walk up 10 steps without limp or unbalance), 2- Impairment 1: walk up 10 steps and limping or unbalanced, 3 – Impairment 2: walk up four steps, limping or unbalanced gait 4 - remains still. All evaluations were performed when birds were 42 days-old. The birds had no foot pad lesions. Results from the fluctuating asymmetry test showed that birds were in a state of welfare. There’s no effect of the heating treatments on gait score results. Between 95 to 97% of birds presented high level of welfare considering the locomotion stage exhibited during the experimental period. For the hematological evaluation, results showed that the number of heterophils increased and of lymphocytes decreased, thus changing the H/L ratio. This situation was consistent with the conditions of blood collection after routine management of birds, considered stressful. In conclusion, regardless the heating system applied, birds remained in good welfare conditions.