Resumo em Inglês:

ABSTRACT The classical and the most commonly used approach for the prevention of coccidiosis in chickens is the incorporation of synthetic coccidiostats into their feed during the first weeks of their life. This approach has been challenged by consumers, objecting against residual antimicrobials and drug resistant microorganisms that may contaminate poultry products. Moreover, the coccidiostat application approach has been challenged in the last decade by the emerging regulations in the developed world, targeting the cessation of such a practice. The pressures from the consumers as well as from regulation agencies resulted in a great need for alternative methods to reduce, or completely replace the use of coccidiostats in modern chicken production. This replacement requires seeking for safer products that do not have any negative impact on the consumer's health. Such products are very much in demand, especially in organic poultry farming. The purpose of this review is to present approaches for the replacement of coccidiostat application in chickens through improvements in poultry house management, research in vaccine developments, and application of holistic natural products for the prevention of the economic losses resulting from coccidiosis.

Resumo em Inglês:

ABSTRACT Present study was conducted to investigate the effects of the dietary supplementation of coriander oil on broiler performance, blood characteristics, microbiota, and small intestine morphology measurements. A number of one-day-old broiler chickens (Ross 308) were allocated to five treatments, with four replicates according to a completely randomized design (CRD). Birds were offered either a corn-soybean meal basal diet (control), or the basal diet supplemented with 600 mg/kg of a flavophospholipol antibiotic, 100, 200, or 300 mg/kg coriander essential oil. At 42 days of age, two birds per replicate were selected for blood collection, slaughtered, and its intestinal microbiota and morphology were investigated. The results indicated that weight gain, feed intake, and feed conversion ratio significantly improved by the dietary inclusion of the coriander oil and antibiotic compared with the control treatment (p<0.01). Blood biochemistry parameters were not affected by dietary treatments (p>0.05). Birds fed the coriander oil and antibiotic diets had lower populations of Escherichia coli than control group in cecum (p<0.05). The dietary treatments influenced the morphology of small intestinal villi. Birds fed antibiotic and coriander essential oil presented higher villus height and crypt depth compared with those in the control treatment (p<0.01). Coriander essential oil supplementation significantly decreased epithelial thickness and the number of goblet cell of the small intestinal compared with the control treatment (p<0.0001). In conclusion, coriander oil was shown to be an efficient growth promoter. The intestinal health improvement obtained with coriander oil was associated with improvements in broiler growth performance.

Resumo em Inglês:

ABSTRACT This study was designed to assess the role of bacteriophage P22 in the adhesion, invasion, intracellular survival of, and cellular immune response to Salmonella Typhimurium in intestinal epithelial INT-407 and chicken macrophage-like HD11 cells. The ability of S. Typhimurium to adhere, invade, and survive to INT-407 and HD11cells was evaluated under Salmonella infection alone (control), phage treatment followed by Salmonella infection (PS), Salmonella infection followed by phage treatment (SP), and a combination treatment with Salmonella and phage (S+P). The number of S. Typhimurium associated on INT-407 cells was reduced from 4.2 to 2.7 log cfu/cm2 by phage treatment (SP). The number of intracellular S. Typhimurium within INT-407 cells was significantly reduced to below the detection limit (0.7 log cfu/cm2) compared with the control (3.4 log cfu/cm2). S. Typhimurium remained inside HD11 cells at 49% and 17% levels in the absence and presence of phages, respectively, at 24 h post-infection (hpi). The expression levels of IFN-g, IL-10, IL-1b, IL-6, IL-8, iNOS, and IL-12 increased in HD11 cells regardless the absence and presence of phages, while those of IL-16, TLR2-1, TLR3, and TLR7 were decreased at 0 and 24 hpi. This study sheds new light on our understanding of the role of phages in Salmonella adhesion, invasion, survival, and cellular immune responses.

Resumo em Inglês:

ABSTRACT The aim of study was to determine the impact of a probiotic preparation containing live bacteria Bacillus cereus var. toyoi on the performance of turkeys in order to define the effective dose of the preparation and to evaluate its influence on poults' livability in the first month of life. Three hundred and sixty B.U.T. 9 male turkey were divided into three groups. The control group (I) was fed a diet with no probiotic additive, and groups II and III were given a probiotic product containing 0.2x109 and 1x109 B. toyoi CFU/kg of feed respectively. Body weight was recorded in weeks 1, 6, and 18. Livability, feed conversion ratio, and European Efficiency Factor (EEF) were estimated. In experiment II, the impact of a standardized probiotic dose on livability and performance parameters of B.U.T. 9 turkey poults were evaluated. Two groups were selected within each sex: control (C), feed without probiotic, and experimental (T), which feed contained the probiotic preparation. Mortality and body weight were registered. The better livability and performance of the turkeys fed probiotic justifies the use of bacteria Bacillus cereus var. toyoi to improve performance results and livability during the first weeks of the turkeys' life. The bacterium strain concentration of 1.0x109 CFU/kg of feed can be assumed as optimal.

Resumo em Inglês:

ABSTRACT Rearing environmental conditions are important for turkey production, because this bird is particularly sensitive to heat stress. This study aimed at measuring the wattle temperature response of turkeys of three different ages (61, 96, and 131 days old) exposed to different combinations of dry bulb temperature, relative humidity, and wind speed ranges, as an indication of their physiological responses. The experiment was conducted with 42 male birds housed in a controlled environment chamber and exposed to different combinations of two air speed (WS) ranges (WS1 = 0.3-0.6 ms-1, considered low, and WS2 = 1.2-1.6 ms-1, considered high), dry bulb temperature (DBT) between 22 and 34 °C, and relative humidity (RH) between 40 to 90 %. The statistical analysis showed that WS, DBT, and RH significantly influenced wattle temperature of 61-d-old turkeys, while only WS and DBT influenced this response when turkeys were 96 days old. Furthermore, DBT was highly correlated with both low and high WS. In 131-day-old turkeys, WT response was virtually the same at both wind speed ranges when high DBT was applied. Turkey wattle temperature was influenced by wind speed, and was dependent on both environmental dry bulb temperature and relative humidity, as well as bird age.

Resumo em Inglês:

ABSTRACT The aim of this study was to investigate the prevalence of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) strains and to identify the stx gene types in wild captive and companion birds. In total,657 E. coli isolates from 219 birds belonging to 38 different species were investigated for the presence of STEC and EPEC strains. It was shown that five birds (2.28%) carried strains positive for one or more of the virulence factors investigated. The results indicated that 1.8% (n=4) and 0.45% (n=1) of the birds carried STEC and EPEC strains, respectively. All STEC strains harbored the stx2f and eae genes and this finding reveals the role of other birds, in addition to pigeons, as reservoirs of STEC. The only EPEC strain in this study was isolated from a Myna. Based on our knowledge, this is the first report of Stx2f-producing STEC in Geese, Duck and Lesser kestrel. In conclusion, the results indicate a low frequency of STEC carriage in wild and companion birds, and point out the need of additionally screening for the presence of stx2f in all the eae-harboring strains from birds.

Resumo em Inglês:

ABSTRACT The incidence of the psittacine beak and feather disease virus (BFDV) was investigated in Brazilian native parrots with normal feathering arriving at rescue and triage centers for wild animals (CETAS, IBAMA) in the state of Minas Gerais, Brazil. BFDV DNA was investigated by previously described PCR technique for the partial amplification of BFDV ORF-1 in DNA extracts from blood, cloacal swab or liver of psittacines. Some birds provided more than one sample. Nine species of psittacines were sampled between January 2009 and October 2010. Blood (n=46) or cloacal swab (n=128) samples were obtained from psittacines immediately upon arrival at the triage centers. Liver samples were collected from necropsied birds dead on arrival (n=167). All swab samples were negative, except for one Ara ararauna individual (n=3) which blood presented the BFDV DNA. On the other hand, 11 liver samples were positive for BFDV DNA, with a prevalence of 7.8% in Amazona aestiva (n=140). No BFDV DNA was detected in the liver of Amazona amazonica (n=11), A. vinacea (n=5), A. rhodochorytha (n=4), Anodorhynchus hyacinthinus (n=3), Ara ararauna, (n=3), Aratinga leucophtalma (n=2), Guarouba guarouba (n=1) and Pionus maximiliani (n=1). In most cases, alopecia was not associated with BFDV detection in liver, and liver histopathology was inconclusive. Although all cloacal swab samples were negative, a few psittacines (n=19) that died at CETAS-Belo Horizonte were retested, and 21% were detected as positive in liver. A group of psittacines (n=16) was clinically evaluated, and despite showing feather dystrophy, all birds were negative in the cloacal swabs, except for one, which blood sample was positive (A. ararauna). The obtained sequences of the BFDV strains BH 215 and BH 732 were deposited in the GenBank (JQ649409 and JQ649410). A 98% similarity with strain sequences described in Australia, Japan, and New Zealand was observed. It is possible that these strains arrived in Brazil through the legal and illegal trade of parrots. However, it was not possible to associate BFDV infection with the geographical origin of birds and no local marker was detected. The rates of detection, although similar to other studies, indicate the tendency of a high incidence of the disease, possibly associated with stress, and high bird density and wide transmission in captivity conditions.

Resumo em Inglês:

ABSTRACT Beauveria bassiana is naturally found in broiler chicken houses, and has been shown to be active against the lesser mealworm, Alphitobius diaperinus. The effectiveness of soil application of B. bassiana in emulsifiable oil-type formulation (Unioeste 4 isolate) to control the lesser mealworm in commercial poultry house was evaluated. The fungus was applied to the dirt floor of poultry house at 4.2 × 109 conidia/m2 (treated aviary) and the insect population was assessed before and 96, 146 and 216 days after application (DAA). In the control aviary, no treatment was performed to control those insects. Molecular techniques were used to confirm the presence of the fungus in dead A. diaperinus. Significant treatment effects were observed, with 56% and 73% of insect population reduction on 96 and 146 DAA, respectively. However, on 216 DDA, insect population resumed to values close to those initially observed. In the control aviary, the population grew steadily, reaching almost 110% the initial population on 96 DAA, and close to 200% on 216 DDA. The results demonstrate the potential of the applied control strategy, even with a single application of the fungus; however, reapplications may be required after 3-6 months for more effective control.

Resumo em Inglês:

ABSTRACT Laying hens reared under tropical conditions are usually under heat stress. Propolis is known for its pharmaceutical properties, such as increasing cell tolerance to hyperthermia, because of its antioxidants effects. This study aimed at evaluating the influence of different dietary propolis inclusion levels on the performance, egg quality, and bird surface temperature of layers. In this experiment 120 55-wk-old Isa Brown(r) layers were distributed according to a completely randomized experimental design into four treatments (0, 1, 2 and 3% dietary propolis inclusion levels), with three replicates of ten birds each. Performance and egg quality parameters, and birds' surface temperature were evaluated. Egg production, egg mass, feed intake, and feed conversion ratio were influenced by the treatments. Bird surface temperature was not affected by propolis dietary inclusion. The egg yolk color changed with the treatment (p<0.05) when brightness and red and yellow concentration were considered. Evaluators noted a slight difference among treatments during the sensory analysis. The use of propolis in the hens' diet did not improve performance and worsened the eggs' quality.

Resumo em Inglês:

ABSTRACT The relationships between egg measurements [egg weight (EGWT), egg width (EGWD), egg shape index (EGSI), egg volume (EGV) and egg density (EGD)], and egg components [eggshell (SWT), yolk (YWT) and albumen (AWT)] were investigated in laying hens with 32, 45, and 59 weeks of age with an objective of managing multicollinearity (MC), using stepwise regression (SR) and ridge regression (RR) analyses. There were significant correlations among egg traits that led to MC problems in all eggs. Hen age influenced egg characteristics and the magnitude of the correlations among egg characteristics. Eggs produced at older age had significantly (p<0.01) higher EGWT, EGWD, EGV, YWT and AWT than those produced at younger age. The SR model alleviated MC problem in eggs produced at 32 weeks, with condition index greater than 30, and one predictor, EGWT had a model fit predicted egg components with R2 ranged from 60 to 99%. The SR model of eggs produced at 45 and 59 weeks indicated MC problem with variance inflation factors (VIF) values greater than 10, and 4 predictors; EGWT, EGWD, EGV and EGD had a model fit that significantly predicted egg components with R2 % ranged from 76 to 99 %. The RR analysis provided lower VIF values than 10 and eliminated the MC problem for eggs produced at any age group. It is concluded that the RR analysis provided an ideal solution for managing the MC problem and successfully predicting egg components of laying hens from egg measurements.

Resumo em Inglês:

ABSTRACT The poultry market has changed due to a higher consumer interest on products with differentiated organoleptic characteristics, making of free-range broiler production a promising activity. This experiment was conducted to determine the digestible lysine requirements of Redbro Cou Nu male and female chickens during the starter phase (one to 21 days of age). Six hundred and thirty Redbro Cou Nu broilers were distributed into 30 pens (21 chickens/pen) according to a randomized complete design in a 5 x 2 factorial arrangement, consisting of five levels of digestible lysine and two sexes, with three replicates (pens) per treatments. Diets with increasing digestible lysine levels (8.1, 9.5, 10.9, 12.3 and 13.7 g of digestible lysine per kg of diet) were offered ad libitum. The following performance traits were evaluated at the end of the experiment (d 21): feed intake, lysine intake, body weight gain, and feed conversion ratio. No interaction between dietary lysine level and sex was observed for the evaluated traits. The effect of sex was only detected on body weight gain, while effects of dietary lysine level were only detected on the feed intake. Males presented higher body weight gain than females. Lysine intake and body weight gain increased, and feed conversion ratio decreased as the level of dietary lysine increased. The best feed conversion ratio was obtained when birds were fed 12.95 g of digestible lysine per kg of diet.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the use of natural and alternative sources of methionine and choline which can be allowed to use in organic livestock systems to feed broilers produced in Brazil. Seven hundred and twenty one-d-old male Cobb broilers were randomly allocated to four treatments with six replicates of 24 birds each. The treatments consisted in substituting the commonly used DL-methionine 99% by a vegetable source of methionine and cholinechloride 60% by alternative source of choline in the form of phosphatidylcholine. The following treatments were evaluated: I) feed with DL-methionine 99% and choline chloride 60%, II) feed with an vegetable methionine source and choline chloride 60%, III) feed with DL-methionine 99% and choline as phosphatidylcholine, and IV) feed with vegetable methionine source and choline as phosphatidylcholine. Daily weight gain, body weight, feed intake, feed conversion ratio, and mortality were evaluated for the periods of 1 to 21 and 1 to 42 days of age. During both periods, broilers fed the vegetable methionine source presented lower daily gain and lower body weight. When only choline chloride was substituted by the alternative choline source, broiler performance was not different compared with that of the control group. The group fed the diet with substitution of both DL-methionine 99% and choline chloride 60% by natural sources presented lower daily weight gain, final body weight, and feed intake. Further research on alternative nutrient sources are required for the development of the organic production chain.

Resumo em Inglês:

ABSTRACT Insulin-like growth factor binding protein-2 (IGFBP-2) regulates a broad spectrum of biological activities involved in growth, development, and differentiation. This study aimed at comparing polymorphisms in intron2 of the IGFBP-2 gene among four chicken breeds and at analyzing the associations between its genotypes and body weight in Jinghai Yellow chicken by using PCR-SSCP technique. For primer P2, three genotypes (AA, AB and BB) were observed in the four chicken breeds. Gene sequencing revealed one insertion/deletion (the inserted/deleted TC after position 552bp) in the intron 2 of IGFBP-2 gene. For primer P5, three genotypes were identified in Jinghai Yellow chickens, and named CC, CD and DD. Gene sequencing revealed two SNPs (C1107G, C1130T) and one inserted/deleted GCCAGGT after 1115bp in the intron 2 of IGFBP-2 gene. The results of the linear model analysis showed that Jinghai Yellow chickens with AA genotype had significantly heavier body weight, at hatch and 12 weeks of age, than those of the AB genotype (p<0.05). The A allele had a positive effect on body weight. We speculate that mutations in intron 2 could be used as genetic markers for body weight in Jinghai Yellow chicken. This study provides valuable information for the protection of genetic resources and for breeding of Jinghai Yellow chicken.

Resumo em Inglês:

ABSTRACT This study evaluated the effects of dietary non-phytate phosphorus (NPP) and 1a-hydroxycholecalciferol (1a-OH-D3) on the growth performance, bone mineralization, and carcass traits of 1- to 21-day-old broiler chickens. On the day of hatch, 600 male Ross 308 chicks were weighed and randomly assigned to 12 treatments, with five cages of 10 birds each. A 6 × 2 factorial arrangement was applied, consisting of 0.20%, 0.25%, 0.30%, 0.35%, 0.40%, or 0.45% NPP and 0 or 5 μg/kg of 1a-OH-D3. The basal diet contained 0.52% calcium (Ca) and was not supplemented with vitamin D3. Dietary NPP levels significantly affected growth performance and tibia mineralization (except width) of broilers; by contrast, meat yield and organ relative weight were not influenced by NPP. The inclusion of 1a-OH-D3 improved growth performance, tibia mineralization, and carcass and breast yield, whereas it decreased the relative weights of the liver, heart, and kidney. A significant interaction between NPP and 1a-OH-D3 was observed for body weight gain (BWG), feed efficiency (FE), mortality, serum Ca and P levels, tibia breaking-strength, ash weight, and Ca content, as well as breast yield and heart relative weight. These results suggest that broilers fed with 5 μg of 1a-OH-D3 per kg of diet obtain optimal growth performance and tibia mineralization when dietary NPP level was 0.30% and the analyzed Ca to NPP ratio was 1.97.

Resumo em Inglês:

ABSTRACT Light is an important factor in the management of laying poultry. The ideal lamp spectrum that provides the best welfare conditions still needs to be determined. Wavelength and light intensity influence poultry behavior and their welfare. This study evaluated the influence of four lamps types with different light spectra on the behavior of seventy 52-week laying hens. Incandescent, fluorescent, and sodium and mercury vapor lamps were set in a different poultry house each and supplied similar light intensities. Layer behavior was video-recorded three times weekly using video cameras installed on the ceiling. The effects of different wavelengths emitted by the light sources on layer behavior were evaluated by the Kruskal-Wallis median test. Results indicated that incandescent and sodium vapor lamps increased the occurrence of nesting, and of active behaviors, such as floor-scratching and pecking.

Resumo em Inglês:

ABSTRACT Two trials were performed to determine apparent metabolizable energy (AME) and AME corrected for zero nitrogen balance (AMEn) values and coefficients of apparent metabolizability of nitrogen (CAMN) and of ether extract (CAMEE) of slow- and fast-growing broilers (Isa label and Cobb, respectively) fed four different diets between 10 to 17 days or 28 to 35 days of age. The method of total excreta collection was applied. The tested feedstuffs were corn, whole corn germ (WCG), sorghum, and soybean meal (SBM). A randomized block experimental design was applied, with two treatments (breeds) and four replicates of ten animals each in the first trial, and four replicates of six animals each in the second trial. No differences in CAMN values were observed between the breeds; however, Isa Label birds presented higher CAMEE for all tested feedstuffs. The AME and AMEn values obtained in Isa Label chickens fed the corn diet were 5.75 and 3.44% higher relative tothe Cobb birds, respectively. Breed did not influence AME and AMEn values of the other tested feedstuffs. Independently of breed, age influenced the AME and AMEn values of WCG, sorghum and SBM, suggesting that birds become utilize feed more efficiently as they age.

Resumo em Inglês:

ABSTRACT The aim of this study was to design a new mechanical nesting system based on scientific works on the behavior of laying hens, and to compare its performance with that of a hand-operated Dutch nest. The equipment was assessed in two poultry houses; in the first one, the eggs were collected manually, whereas in the second one, the newly designed mechanical nest was used for the collection. A total of 7,800 hens and 800 males were housed in each poultry house, and the percentages of eggs produced, nest dirty eggs, floor eggs, and cracked and discarded eggs were determined between weeks 25 and 52. The percentage of eggs with microcracks, infertility, embryo mortality, bacterial contamination, fungal contamination, chicks with stunting syndrome and hatching from both types of nest was assessed in the hatchery on a fortnightly basis. The mechanical nest designed herein proved to be a good alternative to the hand-operated Dutch nest, but it still has to be improved in order to have the same performance, especially with regard to reduction in the incidence of floor eggs.

Resumo em Inglês:

ABSTRACT The aim of the study was to evaluate the effectiveness of preventive-detox preparation (P-dP) based on humic and aluminosilicate substances in the diet of laying hens (3% daily dose) previously intoxicated with methylmercury chloride (CH3ClHg, 5 mg Hg/kg feed mixture) for six weeks. Mercury content in the whole eggs of the group intoxicated with CH3ClHg increased compared to the control group: 488-fold after 1 wk, 622-fold after 2 wks, and 853-fold after 6 wks of intoxication. The use of P-dP in the group previously intoxicated with CH3ClHg reduced he mercury content of whole eggs by 18.4%, on average, whereas the average was 29.9% two weeks after the discontinuation of CH3ClHg and P-dP supply. Maximum Hg content in the whole egg was observed in group III (299.7 g), whereas the highest mercury level was obtained in the egg albumen.

Resumo em Inglês:

ABSTRACT In this study, an intelligent method was implemented for the detection and classification of chickens by infected Clostridium perfringens type A based on their vocalization. To this aim, the birds were first divided into two groups that were placed in separate cages with 15 chickens each. Chickens were inoculated with Clostridium perfringens type A on day 14. In order to ensure the absence of secondary diseases and their probable effect on bird vocalization, vaccines for common diseases were administered. During 30 days of the experiment, chicken vocalization was recorded every morning at 8 a.m. using a microphone and a data collection card under equal and controlled conditions. Sound signals were investigated in time domains, and 23 features were selected. Using Fisher Discriminate Analysis (FDA), five of the most important and effective features were chosen. Neural Network Pattern Recognition (NNPR) structure with one hidden layer was applied to detect signals and classifying healthy and unhealthy chickens. Firstly, this neural network was trained with 34 samples, after which eight samples were tested for accuracy. Classification accuracy was 66.6 and 100% for days 16 and 22; i.e., two and eight days after the disease, respectively. The results of this study demonstrated the usefulness and effectiveness of intelligent methods for diagnosing diseases in chickens.

Resumo em Inglês:

ABSTRACT Salmonella enterica is a large group of Gram-negative bacteria responsible for a number of foodborne infections associated with the consumption of contaminated poultry products. The hygienic status of raw chicken meat marketed at Ibague, Tolima, Colombia, is currently unknown. To address this issue, a cross-sectional study was conducted to estimate the prevalence of Salmonella spp., in raw chicken marketed at different outlets in this city. Salmonella spp. was isolated by standard microbiological methods, followed by biochemical, serological, and molecular confirmation. Additionally, risk factors associated with the presence of the bacteria were identified. The prevalence of Salmonella in raw chicken was 17.41% (47/270), and 14 different serotypes were found, out of which S. Paratyphi B (36.17%), S. Hvittingfoss (19.15%) and S. Muenster (10.64%) were the most prevalent and represented 65.95% of all serotypes. Amplification of 284 bp of the invA gene was achieved by PCR in a number of randomly selected isolates. Raw chicken as the only type of meat sold at stores (odds ratio: 2,157, p<0.05), and stainless steel as a contact surface of chicken meat (odds ratio: 13,29, p<0.05), were found to be potential risk factors for the presence of Salmonella in chicken meat. This work serves as a reference about the current status of Salmonella in chicken meat marketed in Ibague, Tolima, Colombia, and indicates the need to establish appropriate control and contingency measures to minimize the presence of the bacteria in raw chicken to prevent its transmission to humans.

Resumo em Inglês:

ABSTRACT The purpose of this study was to evaluate the effect of green monochromatic light emitting diodes (LED) or white fluorescent lamps on the growth performance of broilers reared in open houses. Two hundred broilers (Ross 308) were sexed and divided into four treatments, according to sex and supplemental light source: T1, males under green LED; T2, males under fluorescent lamps; T3, females under green LED; and T4, females under fluorescent lamps, totaling 50 birds per treatment with five replicates each (n=10). Broilers of both sexes received natural light during the day and supplemental lighting (fluorescent or LED) during the night, according to age. Individual body weight, mortality, and feed intake were recorded weekly per replicate. Feed conversion ratio and the European Efficiency Index (EEI) were calculated. Data were analyzed by a two-way ANOVA. The results indicated differences (p< 0.05) in female body weight in week 6, (2202.31 ± 32.93g green LED vs 2191.08 ± 62.13g fluorescent lamp), but no differences in daily weight gain, feed conversion ratio, or mortality were detected. However, the use of green LED promoted higher EEI in males in weeks 5, 6, and 7, and in females in week 5 (p < 0.05). Green monochromatic LED may be used for supplemental lighting of male broilers reared in open houses with natural light. Its use for female broilers is recommended if the birds are marketed up to 5 weeks of age.

Resumo em Inglês:

ABSTRACT One-day old chicks were randomly distributed into acute heat stress (AHS) or persistent heat stress (PHS) groups. Each group was further divided into control (CK), and three AHS ages (1, 2,or 3 weeks of age) experimental subgroups. The chicks in AHS subgroups were submitted to acute heat stress (40oC for two hours between 12:00 and 14:00 hours during the weekend) and the effects of heat stress on several daily behaviors were observed. At 8 days of age, the chicks of PHS subgroups were submitted to heat stress (40oC daily). The heat treatment ceased during the weekends and the effects on the behavior were observed three times daily for three consecutive days. The results showed that, compared with the CK group, the duration and frequency of drinking and lying-down behaviors of the AHS birds increased, whereas the duration of feeding and standing significantly decreased (p<0.01). The time spent walking by PHS birds was significantly longer than that of the CK groups (p<0.01), and drinking was also significantly longer than that of the CK group and was significantly different when birds were three weeks old (p=0.05). When heat stress lasted for two and three weeks in PHS group, the duration of lying down was longer compared with the CK group; however, this behavior was significantly shorter than the CK group when birds were three weeks old (p<0.05). These results indicate that heat stress significantly affects the daily behavior of broilers, including feeding, drinking, lying, standing, and walking.

Resumo em Inglês:

ABSTRACT The objective of this study was to determine the effects of different zilpaterol hydrochloride (ZH) levels and feeding methods on the growth performance and carcass traits of Japanese quails. In this trial, 224 male quails with 34 days of age were distributed into seven treatments. A factorial arrangement with three ZH levels (0.2, 0.225, and 0.25 mg zilpaterol/kg of live weight−1) × two feeding methods (ZH supplementation daily or every two days) plus a control treatment (no ZH supplementation) was applied. The weight gain of birds fed ZH every two days was significantly higher than those fed ZH daily during the period of 41-47 days (p=0.03). During the period of 34-40 days, ZH-supplemented birds presented higher weight gain (p<0.001) and better feed conversion ratio (p=0.005) compared with the control group. Moisture, protein, ash, and cholesterol levels of the combination of breast and leg were not affected (p≥0.10) by zilpaterol supplementation. Leg muscle fat and protein contents of control birds were higher and lower compared with ZH-supplemented birds, respectively (p=0.002 and p=0.05). In conclusion, ZH supplementation in the diet of male Japanese quail improved growth performance during the finishing period (34-40d), and the most economical level of ZH is 0.2 (mg/kg of LW−1 d−1), when supplemented every two days.

Resumo em Inglês:

ABSTRACT The objective of this study was to investigate the influence of two cleaning and disinfection programs on broiler performance and on the microbiological status of the facilities. This trial was an observational study of comparative character. Two experiments were conducted, with 960 birds each. Both experiments were carried out in a positive-pressure broiler house. Broilers were distributed in pens equipped with a bell drinker and a tube feeder each. In the first experiment, new wood shavings were used as litter material, and in the second, reused wood shavings were used. Two treatments with16 replicates of 30 birds each were evaluated. The regular treatment consisted of dry and wet organic matter removal, followed by washing. The European treatment consisted of dry organic matter removal, humidification, washing with water under high pressure, detergent application, rinsing, and application of two combined disinfectants: glutaraldehyde 250g/L + formaldehyde 185g/L; p-chlor-m-cresol 210 g/L. Biosecurity measures were adopted during daily management tasks to prevent cross contamination between treatments. The effectiveness of the treatments was evaluated by microbiological analysis performed before and after treatment applications, as well as by broiler performance results. Live performance results were similar between both treatments when broilers were reared on new litter. When reused word-shavings were used as litter material, the European treatment promoted better broiler performance. The European treatment was more effective than the regular treatment in reducing total microbial counts in the facilities when reused wood shavings were used as litter material, and positively influenced broiler performance.