Resumo em Inglês:

ABSTRACT This study was carried out to identify the effect of the egg shape index on the hatchability, performance, and carcass yield of Japanese quails (Coturnix coturnix Japonica ). Eggs were incubated in three groups, according to three different egg shape index (SI) values (Group SI-I: 70.00-73.85%, Group SI-II: 73.86-77.71% and Group SI-III: 77.72-81.57%). Unhatched eggs weight loss (HEWL) was correlated with the egg shape index groups (SI-I: 18.51%, SI-II: 13.34% and SI-III: 13.96%; p<0.01), but not with the initial unhatched egg weight (HIEW), hatched egg weight (HEW), or eggshell weight of unhatched eggs (HSW) (p>0.05). The live weight of female and male chicks hatched from SI-I, SI-II, and SI-III egg shape index groups were compared at weeks 4 (female/male: 249.12/237.77, 244.69/236.35, and 241.52/229.72 g, respectively) and 5 (female/male:304.89/272.42, 295.76/274.34, and 285.42/271.29 g, respectively), and the results showed that females were heavier than males (p<0.05; p<0.01; p<0.001, respectively).The effect of egg shape index on slaughter weight (p<0.05), left leg weight (p<0.05), liver weight (p<0.01) and liver rate (p<0.01) was significant. Females were heavier at slaughter than males in the egg shape index groups SI-I (p<0.05), SI-II (p<0.05), and SI-III (p>0.05) (female/male: 296.87/283.80, 287.95/278.00 and 283.86/278.10 g, respectively). Males presented higher carcass yield in SI-I (p>0.05), SI-II (p<0.01) and SI-III (p<0.05) (female/male: 74.40/75.92, 74.50/76.44 and 74.80/76.42%) groups than females. Egg shape index had no effect on initial egg weight (IEW), shell blunt end weight (SBW), chick weight, shank length, growth performance or carcass traits, but egg shape indexwas correlated with egg length, egg width, and hatchability of fertile eggs (p<0.05).

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the influence of the supplementation of vegetable oils rich in polyunsaturated fatty acids to the diet of Leghorn layers on yolk color and on yolk lipid oxidation of eggs stored at room temperature for 10 days. Sixty eggs laid by commercial white layers (Lohmann LSL) fed diets supplemented with different vegetable oils were used. Hens were fed one of the following treatment diets: conventional diet with no oil inclusion (T1); T1 diet with 2.5% linseed oil inclusion (T2); T1 diet with 2.5% canola oil (T3); T1 diet with 2.5% soybean oil (T4); T1 with 5.0% linseed oil (T5); T1 diet with 5.0% canola oil (T6); T1 diet with 5.0% soybean oil (T7); T1 diet with 2.5% linseed oil + 2.5% soybean oil (T8); T1 diet with 2.5% canola oil + 2.5% soybean oil (T9); and T1 diet with 2.5% linseed oil + 2.5% canola oil (T10). Eggs were evaluated as to yolk lipid peroxidation (TBARS values) and yolk color, as determined by colorimetry and subjective sensorial analysis. Data were submitted to analysis of variance and means were compared by the test of Tukey at 5% significance level. It was concluded that the inclusion of vegetable oils in commercial white layer diets does not significantly change egg yolk pigmentation, as colorimetrically evaluated. However, when subjectively assessed, the yolks of the eggs laid by hens fed diets supplemented with vegetable oils tend to be paler. The yolks of the eggs laid by layers fed diets containing sources of polyunsaturated fatty acids presented high lipid oxidation, particularly when compared with those derived from layers fed the diet with no oil supplementation.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate the possible effects of glutamine and broiler breeder age on the development of intestinal mucosa in broiler chicks during first week of age. For this purpose, 32 one-day-old broiler chicks were distributed according to a completely randomized experimental design in a 2 x 2 factorial arrangement. Treatments consisted of two broiler breeder ages (30 and 60 weeks) and two dietary glutamine supplementation levels (0% and 1%). The morphological development of intestinal mucosa, particularly villus height and crypt depth, was evaluated. The results showed that the supplementation with 1% of glutamine influenced the development of villus height in the duodenum (p=0.009), jejunum (p = 0.006), and ileum (p = 0.001), as well as crypt depth in the jejunum (p = 0.037) of 7-day-old broilers. These results suggest that the presence of glutamine influenced the development of intestinal mucosa during the first week of age, when these tissues are highly influenced by dietary components, especially by trophic agents. The results show that broiler breeder age (30 or 60 weeks) did not influence the evaluated parameters.

Resumo em Inglês:

ABSTRACT In 2006, the International Organization for Standardization (ISO) published two standard protocols for the detection and enumeration of Campylobacter spp. in foods: the ISO 10272-2(direct method) and the ISO 10272-1 (enrichment method). The aim of this study was to compare the efficiency of these two methods in the detection of Campylobacter spp. and propose a modification in the enrichment method. Compared with the enrichment method, the direct method yielded a higher number of positive results for Campylobacter spp. and, consequently, presented higher sensitivity percentage. The isolation of Campylobacter spp. was more difficult when 10 mL of rinse was used in the enrichment method, which is currently recommended by the ISO protocol. Therefore, different rinse volumes were tested (2.5 and 5 mL). The most efficient recovery of Campylobacter spp. occurred when 2.5 mL of rinse were used in the enrichment method, most likely due to a lower number of microbial contaminants than that present in the 5 or 10 mL rinses. The proposed modification of the enrichment method will contribute to the food analysis by improving the detection of Campylobacter spp. in chicken carcass.

Resumo em Inglês:

ABSTRACT An experiment was conducted of the poultry facilities of La Salle Agricultural College in Xanxerê, SC, Brazil, to evaluate the effect of the administration of sodium bicarbonate, glucose and vitamin E to the drinking water during pre-slaughter feed withdrawal on carcass yield, organ relative weights (heart, liver, proventriculus, and gizzard), gizzard emptying, and meat quality of broiler chickens. The applied treatments were: water as control; 50g/L of glucose; 50g/L de glucose + 200mg/L of vitamin E; 75g/L of glucose; 75g/L + 200mg/L of vitamin E; 0.45% of sodium bicarbonate; 0.45% of sodium bicarbonate + 200mg/L of vitamin E; 0.55% of sodium bicarbonate; 0.55% of sodium bicarbonate + 200mg/L of vitamin E; 200mg/L de vitamin E. On the last day before slaughter, during the water diet period,500 birds were distributed in a completely randomized experimental design with ten treatments and ten replicates of five birds each. No difference in broiler carcass yield and organ relative weights was found. There were no significant changes in gizzard contents, in ultimate meat, cooking loss, shear force value, or in the meat color parameters L* (lightness), a* (redness) and b* (yellowness). It was concluded is that the addition of glucose, sodium bicarbonate, and vitamin E to the drinking water during pre-slaughter feed withdrawal period has no influence on carcass yield or on relative organ weight, neither on the emptying of the gizzard contents and the meat quality of broiler chickens.

Resumo em Inglês:

ABSTRACT The present study was carried out to investigate the influence of freezing-thawing cycles (0, 2, 4 and 6) on lipid oxidation and myowater contents and distribution. Nine replicates of chicken breast meat samples were used for each cycle. Lipid oxidation was determined by measuring peroxide value, and malondialdehyde (MDA) concentrations, which reflect thiobarbituric acid reactive substance (TBARS). Color was determined with a digital colorimeter. Muscle moisture contents were determined by drip loss and thawing loss, water holding capacity, and nuclear magnetic resonance (NMR). The results showed that, as the number of freeze-thaw cycles increased, meat redness decreased and MDA and peroxide values increased. Drip loss and thawing loss tended to decreasing as the number of freeze-thaw cycles increased. Water holding capacity also decreased as a function of increasing freeze-thaw cycles. NMR relaxometry profile showed freeze-thaw cycles change the water distribution of meat subjected to multiple freeze-thaw cycles. In conclusion, multiple freezing and thawing rate (6 cycles) increased lipid oxidation, decreased myowater, and impaired the color of chicken meat.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate the in vitro bioactivity of tea tree (Melaleuca alternifolia) essential oil against larvae and adult forms of lesser mealworms (Alphitobius diaperinus) and its influence on the soil fauna. Tests were performed in triplicate using pure tea tree oil (TTO; 1, 5, 10, 25, 50, and 100%), TTO nanoparticles (1, 3, and 7.5%), or terpinen-4-ol, the main compound of the tea tree oil, at the same concentrations of TTO. Larvae and adult mortality occurred at concentrations up to 10 and 50% of TTO, respectively. No larvicidal or insecticidal effect of TTO nanoparticles was observed. Terpinen-4-ol showed insecticidal and larvicidal effect at concentrations higher than 25%. The evaluation of TTO effect on soil organisms was performed by standard ecotoxicological tests (ISO) with the springtail species Folsomia candida. Only TTO was used for ecotoxicological tests in doses of 1, 5, 10, 25, 50, and 100 mg kg-1 of soil. TTO had no negative effects on F. candida survival or reproduction. Therefore, it was concluded that M. alternifolia oil may be a new alternative for control of the lesser mealworm.

Resumo em Inglês:

ABSTRACT The experiment was conducted to evaluate the feed intake, body weight gain, total energy (kJ), protein (g) intake, energy and protein efficiency ratio (EER, PER), net energy, and metabolic body weight, on two commercial broiler chickens (Arian and Ross 308 strains). Four treatmentsincluded diets formulated based onAMEn(kJ/g) Total Amino Acid (TAA) (T1), AMEn(kJ/g) Digestible Amino Acid (T2), TMEn (kJ/g) Total Amino Acid (T3), and TMEn (kJ/g) Digestible Amino Acid (DAA) (T4) for commercial broilers chickens. The findings of the study indicated that AMEn or TMEn treatments yielded improved utilization of net energy in 42 days, but did not affect the efficiency of dietary AMEn and TMEn for net energy, diet energy and protein efficiency ratio (EER, PER) in broilers. Findings indicated that NE is a better predictor of poultry feeds than AMEn or TMEn. This is attributed to the fact that AMEn had a significant effect on NE and efficiency of AMEn or TMEn and HI (Heat Increment) for NE value. Finally, NE is the final objective of energy evaluation of feed and feedstuffs for poultry nutrition.

Resumo em Inglês:

ABSTRACT This study aimed at investigating the effects of three incubation temperatures during the hatching period on egg weight loss, hatchability, chick weight at hatching and length of the incubation period of red-legged partridge (Alectoris rufa) under artificial incubation. One hundred and fifty eggs obtained from a red-legged partridge game farm were randomly allocated to three batches of 50 eggs each. Eggs were incubated at 37.8ºC during the first 20 days, and subsequently at 37.0, 37.4 or 37.8ºC until hatching. Fertility was 74.7% and a good hatching performance was obtained, characterized by 85.7% hatchability, 9.1% egg weight loss after 20 days of incubation, 13.8±0.1 g chick weight at hatching, and 23.2±0.1 days incubation length. Hatchability, egg weight loss after 20 days of incubation, and length of the incubation period were not affected by incubation temperature during the hatching period. However, hatching synchrony improved when the incubation temperature was increased from 37.0 to 37.8°C (p<0.05). Thus, hatching distribution became very leptokurtic and very positively skewed with the increase in incubation temperature during the hatching phase. In conclusion, higher hatching synchrony can be achieved in A. rufa when setting temperatures within the range 37.0 to 37.8ºC to incubate eggs during the hatching period. Consequently, incubation temperature management during the hatching phase may have a direct impact on hatching synchrony and hatchling management.

Resumo em Inglês:

Abstract Campylobacteriosis is a worldwide foodborne zoonosis disease caused by Campylobacter jejuni. This microorganism is considered a commensal bacterium in chicken hosts. C. jejuni produces epithelial cell modifications and induces a cytokine gene transcription innate immunity repertoire. In the present study, we describe the invasiveness, morphological cellular modifications, and transcript level expressions of innate immune cytokines from C. jejuni-inoculated chicken ileum explants. C. jejuni was internalized by epithelial ileum cells at 15 minutes postinoculation (p.i.) and was detected intracellularly for 4hs (p.i.). Inoculated explants displayed significant increases in cell height. C. jejuni induced a significant elevation of Transforming Growth Factor Beta 3 (TGF-b3) and Interleukin-1b (IL-1b) transcripts. In conclusion, C. jejuni is internalized in explanted epithelial ileum cells, produces morphological cell modifications, and induces gene transcription of both anti-inflammatory and pro-inflammatory cytokines.

Resumo em Inglês:

Abstract The objective of the present study was to evaluate the effect of the dietary detoxified castor seed cake (DCC) inclusion on broiler performance and carcass traits. Two hundred and fifty Cobb-500(r) broilers were distributed according to a completely randomized experimental design consisting of five treatments (dietary inclusion of 0.0, 2.5, 5.0, 7.5, and 10.0% DCC) with five replicates of 10 birds each (five males and five females). Feed intake (FI), body weight gain (WG), and feed conversion ratio (FCR) were evaluated from one to 40 days of age. Carcass yield and the yields of the breast, leg (drumstick+thighs), and wings were determined when broilers were 40 days old. Live performance parameters were influenced by DCC dietary inclusion, and levels 2.00, 1.38, and 1.25% DCC impaired FI, WG, and FCR, respectively. Carcass and parts yields were not affected by dietary DCC inclusion. It was concluded that the addition of DCC levels up to 1.25% to broiler diets does not impair live performance or carcass traits.

Resumo em Inglês:

Abstract An experiment was conducted to investigate the effects of hydroalcoholic extract of Withania coagulans (WC) fruit and 1.25-dihydroxycholecalciferol (1.25-(OH)2 D3) on bone mineralization, mechanical and histological properties of male broiler chickens at 21 and 42 d of age. A total of six hundred male day-old Ross 308 broiler chickens were randomly distributed according to a completely randomized experimental design in a 2×3×2 factorial arrangement with 12 treatments of five replicates of 10 birds each. Treatments consisted of two basal diets (positive control with adequate Ca level and negative control with 30% less Ca), three levels of WC (0, 100, or 200 mg/kg diet), and two levels of 1.25-(OH)2 D3 (0 or 0.5 µg/kg diet). Birds were housed in floor pens. The diets were fed ad libitum from one to 42 days of age. On day 21 and 42, one bird per replicate was sacrificed and its tibiae were removed. Both Ca and P retention increased when dietary Ca level was reduced (p<0.001). The addition of 200 mg WC/kg to positive control diet increased Ca retention (p<0.01). Except for tibia diameter, no significant main effects of experimental treatments were observed on tibia physical characteristics or on bone mineralization. The diet with 30% Ca reduction decreased tibia diameter at 42 days of age (p<0.05). The dietary addition of 1.25-(OH)2 D3 increased tibia fracture energy, width of tibia mineralized zone, and serum Ca at 42 days of age (p<0.05). At 21 days of age, supplementation of 100 mg WC/kg increased cortical thickness (p<0.05). At 42 days of age, supplementation of 100 mg WC/kg increased tibia shear force (p<0.05) and fracture energy (p<0.01). The results of this experiment showed that supplementation of 100 mg/kg hydroalcoholic extract of WC fruit increased tibia cortical thickness, shear force, and fracture energy.

Resumo em Inglês:

Abstract Newcastle Disease (ND) has been identified as a major constraint to local poultry production with its impact being felt more in rural poultry production which forms about 80% of Ghana poultry population. However documented evidence on ND virus activity in rural poultry in Ghana is still lacking. Hence, this study was conducted to evaluate the level of circulating antibodies against ND using the Haemagglutination Inhibition (HI) technique. Sera collected from unvaccinated 292 chickens and 153 guinea fowls randomly selected from households and a live bird market in Kumasi and its environs were evaluated for Newcastle disease virus antibodies. Results showed 81.8 % (239/292) of local chickens and 24.2 % (37/153) of guinea fowls tested positive for ND antibodies. Comparison was made between the seroprevalence of ND antibodies in household and live bird market as well as between sexes. Significantly higher prevalence rate (p<0.05) was observed with chickens sampled from households compared to those from the live bird market. Higher ranges of titers were also observed in chickens from households than those from live bird markets. The presence of ND antibodies in these unvaccinated local chickens and guinea fowls indicated the presence of the virus amongst the rural poultry population, hence aneed for improvement in vaccine campaignand delivery against ND for rural poultry especially with the use of thermostable and improved oral or feed-based vaccine delivery systems.

Resumo em Inglês:

Abstract Dexamethasone (DEX) is a corticoid hormone that is experimentally used to mimic the effects of increased levels of endogenous corticosterone observed during the stress response. Currently, stress is considered one of the major predisposing factors for diseases in the poultry industry. The aim of this study was to analyze the effects of DEX and/or of a 20-fold coccidial vaccine dose on leukocyte phenotypes in the spleen and cecal tonsils of chickens. Twenty specific-pathogen-free (SPF) Leghorn chickens were divided into four groups: a non-treated group (NT), a DEX-treated group (Dex), a vaccinated group (V) and a DEX-treated+vaccinated group (Dex+V). On experimental day (ED) 42, each bird in the vaccinated groups received a anti-coccidial vaccine. DEX was injected in the birds of the Dex and Dex+V groups (0.9 mg/kg) onED42 and ED45. The immunophenotyping was performed by flow cytometry analysis of splenocytes and cecal tonsils cells onED48. DEX treatment per se was unable to change CD4+CD8+, CD4+CD8+ and CD4-CD8+ populations with TCRgd or CD28 in the spleen, or macrophages and T lymphocytes in the cecal tonsils. V group birds presented higher numbers of splenic macrophages compared with those measured in the Dex+V group. The number of CD4+CD25+ cells in the spleen of birds of the V group was higher than those measured in the other experimental groups. Our data suggest that CD4+CD25+ cells and macrophages might be influenced by DEX treatment in spleen, but not in the cecal tonsils of chickens inoculated with Eimeria.

Resumo em Inglês:

Abstract This study investigated the effects of the addition of different antioxidants to broiler diets on their live performance, liver antioxidant composition and concentrations, immune response, and meat and skin color. A total of 945 three-day-old Ross 308 broiler chicks of both genders were randomly allocated to one of nine dietary treatments (n=105), with three replicates 35 chicks per pen, as follows: T1: control (commercially available corn-and soybean-based broiler diet); T2: selenium (control+0.5 mg/kg Sel-PlexTMSe yeast); T3: vitamin E (control+200 mg/kg Kavimix-E-50 a-tocopherol acetate); T4: lutein (control+100 mg/kg 5% Lutein Beads XB); T5: lycopene (control+100 mg/kg 5% Lyco Beads XB);T6: canthaxanthin (control+25 mg/kg 10% Carophyll(r)Red);T7: apo-ester (control+25 mg/kg 10% Carophyll(r)Yellow); T8: lutein+zeaxanthin (control+25 mg/kg Xamacol(r)); and T9: b-carotene (control+100 mg/kg 10% Rovimix(r)). Feed (starter, grower, developer and finisher phases) and water were provided ad libitum for 42 days. Body weights, feed intake, feed conversion values and plasma carotene concentrations were recorded weekly, and liver antioxidant concentrations were recorded at the end of the experiment. Newcastle disease (LaSota) vaccination was performed on day 22. HI titers were measured on days 14, 21, 35 and 42 to determine the effects of the antioxidants on the immune system. The addition of selenium, vitamin E, and carotenoid supplements to the commercial broiler diet significantly increased antioxidant accumulation in the liver and the plasma. All antioxidants assessed significantly improved the immune response. Selenium and vitamin E supplementation also significantly improved total carotenoid concentrations in the plasma. The carotenoids enhanced skin and meat color. None of the supplements tested influenced growth (p>0.05).

Resumo em Inglês:

Abstract Conventional bacteriology techniques and quantitative polymerase-chain reaction (qPCR) were applied to the eggshell, albumen, and yolk of washed and unwashed commercial white and brown eggs, to detect Salmonella spp. Pooled samples of eggshells, albumen, and yolk of white and brown eggs were collected at the poultry house and at the egg-storage room. Salmonella spp. was detected by conventional bacteriology in 5.4% (21/387) of analyzed samples and in 16% (68/387) by qPCR. In the 114 unwashed white eggs samples of eggshell, albumen and yolk, the bacterium was identified in 2.6% of the eggs (3/114) by conventional bacteriology and in 13.2% (15/114) by qPCR. In the 90 samples of washed eggs, 6.7% (6/90) were contaminated as detected by conventional bacteriology and 10.0% (9/90) by qPCR. In the 81 samples of unwashed brown eggs, Salmonella spp. was detected in 6.1% of the eggs (5/81) by conventional bacteriology and 27.2% (22/81) by qPCR. In the 102 samples of brown washed eggs, 6.9% (7/102) where positive by conventional bacteriology and 35.3% (16/102) by qPCR. All samples detected as positive by conventional bacteriology were also positive by qPCR. Salmonella Agona represented 18.2% (4/22) of identified serovars, Salmonella enterica subs. enterica O: 4.5 18.2% (4/22), Salmonella Schwarzengrund 18.2% (4/22), Salmonella Cerro 13.6% (3/22), Salmonella Anatum 13.6% (3/22), Salmonella Enteritidis 9.1% (2/22), Salmonella Johannesburg 4.5% (1/22), and Salmonella Corvallis 4.5% (1/22). The qPCR method provided better detection of Salmonella spp. in commercial eggs than conventional bacteriology. The conventional egg washing and disinfection procedures are not efficient to eliminate Salmonella.

Resumo em Inglês:

Abstract This study evaluated the effects of the dietary inclusion of an enzyme blend and a direct-fed microbials in broiler diets on litter production and quality. In total, 900 Cobb 500(r) broiler chicks were distributed according to a completely randomized design into 4 treatments and 9 replicates of 25 birds each. Broilers were reared from 1 to 42 days of age. The treatments consisted of the following diets: NC: negative control; DFM: NC + 500 ppm of direct-fed microbials product (DFM), containing Bacillus subtilis and Bacillus licheniformis; ENZ: diet formulated with an enzyme blend (20 ppm phytase, 200 ppm protease and 200 ppm of xylanase); DFM+E: ENZ + DFM. Birds and litter were weighed at the start and end of the rearing period, for litter production and waste ratio (Rw) determination. Litter samples were analyzed for dry matter (DM) content, total and thermotolerant coliform counts, nutrient composition (nitrogen (N), phosphorous (P) and potassium (K)), and fiber fraction (neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin). The dietary inclusion of the evaluated additivesdid not influence litter production or Rw; however, ADF (%), NDF (kg and kg/kg DM litter), and total and thermotolerant coliform counts were reduced, and N content increased in the litter. The diets containing enzymes (ENZ and DFM+E) reduced litter P content. The addition of exogenous enzymes and their combination with a DFM based on Bacillus spp .Did not affect waste production, and reduced litter microbial load, and the contents of P and insoluble fiber in the litter.

Resumo em Inglês:

Abstract Scientific literature on broiler chicken welfare in Brazilian industrial systems is scarce. This study aimed at assessing broiler chicken welfare on industrial farms in the State of Rio Grande do Sul, Southern Brazil, using the Welfare Quality(r) assessment protocol for poultry, to provide directly applicable scientific information. Results are presented as criteria scores ranging from 0 to 100, with higher scores indicating better welfare; and percentages of prevalence. The scores classified as excellent (above 80) were absence of prolonged thirst, absence of prolonged hunger, litter quality, breast blister and touch test. Enhanced scores (between 55 and 80) were comfort around resting, plumage cleanliness and dust sheet test. Acceptable scores (between 20 and 55) were thermal comfort, stocking density, absence of injuries, footpad dermatitis and hock burn; and unacceptable scores (below 20) were lameness and qualitative behavioral assessment. The median percentage of mortality and culled birds were 5.2% and 0.6%, respectively. This study provides useful information to select priorities of action on assessed farms and may contribute for setting up legal standards and guiding decisions related to animal welfare issues in Brazil.

Resumo em Inglês:

Abstract This study evaluated the performance, carcass yield and quality, and physiological stress indicators of broilers of three genetic strains reared at three housing densities for 29 days. A total of 828 day-old male chicks, with average initial weight of 40.0± 2.0g were used. Three genetic strains (Cobb 500, Ross 808, and Ross 508, with 276 birds each) and three housing densities (17, 19, and 21 broilers/m²) were tested. A completely randomized experimental design in a 3 x 3 factorial arrangement, with four replicates of 23 birds each, was applied. The following responses were evaluated: performance parameters (average weekly body weight, average daily gain, feed intake, feed conversion ratio), physiological stress indicators (blood glucose levels, blood cell counts), and carcass yield and quality (dermatosis, bruising, dermatitis, and femoral degeneration scores). Average weekly body weight (BW) and daily weight gain (DWG) were not influenced by rearing density (p≥0.05), but Cobb 500 broilers were the heaviest during the analyzed period. In the second week, Ross 508 birds showed better feed conversion ratio (FCR) when housed at the density of 17 broilers/m² (p≤0.001), whereas the best FCR of Ross 808 and Cobb 500 broilers was obtained at 21 broilers/m² (p≤0.001). Carcass yield was not influenced by the treatments (p≥0.05). Physiological stress indicators were not affected by the treatments, and remained within normal ranges (p≥0.05). Dermatosis scores (scratches) increased (p≤0.05) when housing density increased from 17 to 19 broilers /m².

Resumo em Inglês:

Abstract This experiment was conducted to evaluate the effect of in-ovo ascorbic acid (AA) injection on the bone development of broilers submitted to heat stress during incubation and rearing. One thousand (1,000) Cobb(r)fertile broiler eggs were randomly distributed according to the weight into five incubators, with 200 eggs per incubator. The incubation treatments were: eggs not injected with AA and incubated at 37.5°C; eggs not injected with AA and incubated at 39°C; and eggs injected with 6 µg AA/100 µL water prior to incubation and incubated at 39ºC. The hatched birds were reared at three different house temperatures: cold, thermoneutral, or and hot. The high incubation temperature negatively influenced broilers' bone characteristics. The femur of the birds hatched from eggs incubated at 39°C and injected with AA presented lower shaft mineral density, lower maximum force and lower elongation at maximum force. Their tibia presented reduced mineral density at the proximal and distal epiphysis. In-ovo AA injection of eggs incubated at high temperature did not minimize the negative effects of high rearing temperature on the performance andbone development of broiler chickens reared until 42 days of age.

Resumo em Inglês:

Abstract The Brazilian poultry industry is an outstanding national and international agribusiness sector. Among the Brazilian states, São Paulo is the largest producer of commercial eggs and the fourth largest producer and exporter of chicken meat. Alternatively, semi-intensive and/or organic poultry production have also obtained a significant share of the domestic market as a result of consumer demand. Helminths affect the performance of the birds, causing significant direct or indirect losses. The objective of the present study was to identify the main helminth species present in chickens reared in 17 municipalities of the state of São Paulo. In total, 359 adult birds were investigated. The birds were reared in different housing systems and were obtained from 69 farms in the selected regions. The birds were submitted to procedures for the detection and identification of helminth parasites, following international standards. The evaluation of the small intestine employed the Mello-Campos method (Mello & Campos, 1974), which allows better recovery of cestode scolices attached to the intestinal mucosa. Stereomicroscopy was used to evaluate the collected materials, and light microscopy was used to identify the species based on their morphological characteristics. The following helminth species were diagnosed in chickens reared in 17 municipalities of the state of São Paulo: nematodes (Ascaridia galli, Capillaria sp., Cheilospirura hamulosa, Heterakis gallinarum, Oxyspirura mansoni, and Strongyloides sp.), cestodes (Amoebotaenia cuneata, Choanotaenia infundibulum, Hymenolepis sp., Raillietina cesticillus, Raillietina echinobothrida, and Raillietina tetragona), and trematodes (Zygocotyle lunata and Postharmostomum commutatum).

Resumo em Inglês:

Abstract In this study, the live performance and costs of broiler production was examined and cost analysis were assessed in the Balıkesir, Bolu and Sakarya Provinces, which are the most important broiler-producing regions of Turkey. Annual (years 2012-2013) production data of 125 broiler farms were analyzed. Farms were scaled according to the irrearing capacities as small (1-10,000 broilers), medium (10,001-30,000) and large (30,001 and above). Cost and performance differences among farm scales and research centers were tested by one-way analysis of variance. Average live weight (LW), livability (LA), slaughter age (SA), feed conversion ratio (FCR), and production efficiency factor (PEF) values were calculated as 2.436 ± 0.006 kg; 93.502 ± 0.133%; 42.293 ± 0.079 days; 1.805 ± 0.004 kg; 298.802 ± 1.298, respectively. Feed and chicks accounted for 80.3% of the total cost per kg live weight (TLWC). There were no statistical differences among farm scales and provinces in terms of technical indicators and production performance (p>0.05). Farm size affected the TLWC (p<0.05). The results showed that broiler production in Turkey achieved similar performance levels as the main global broiler-producing countries; however, the cost of producing 1 kg live weight is 13%-60%more expensive in Turkey.

Resumo em Inglês:

Abstract The present study aimed at evaluating the effect of two strains of probiotics (Bacillus subtilis PB6 and Bacillus Cereus var. toyoi) on selected indicators of the antioxidant status and immune responses of broilers before and after challenge with Salmonella enterica subsp. Typhimurium (S. typhimurium). Birds were distributed into the following five treatments: negative control (CTL−); negative control+S. typhimurium (CTL+); antibiotic+S. typhimurium, (AB); Toyocerin(r)+S. typhimurium (TOYO); and CloSTATTM+ S. typhimurium (CLOS). Birds in all treatments, except for CTL−, were orally challenged with 3 x109 CFUS. typhimurium at 16 days of age. The results showed that total antioxidant capacity (TAC), superoxide dismutase activity (SOD), and hydrogen peroxide (H2O2) values were similar among all groups. The antibody titers against S. typhimurium and Newcastle disease (ND) were not affected by the treatments (p>0.05). However, S. typhimurium and ND titers were influenced by the interaction between week and treatment (p<0.01, p<0.05, respectively) and by week (p<0.001, p<0.001, respectively). In conclusion, S. typhimurium challenge had an impact on anti-Salmonella and NC titers. Both probiotics did not affect the broilers' antioxidant capacity.

Resumo em Inglês:

Abstract This experiment was conducted to study the effects of arginine supplementation on organ development, egg quality, blood parameters, and immune status of laying hens. A total of 360 25-week-old brown Leghorn laying hens were randomly divided into three groups with six replicates of 20 birds each and fed diets supplemented with 0, 8.5, or 17 mg of L-arginine/kg for 42 days. Results showed that the weight of proventriculus and duodenum in the treatment supplemented with 17 mg/kg L-arginine was heavier than that of 0 mg L-arginine/kg treatment (p<0.05). The weight of oviduct in the treatments supplemented with 17 mg/kg L-arginine was smaller than that of 0 and 8.5 mg L-arginine/kg treatment (p<0.05), and the small yellow follicle amount in the treatment supplemented with 17 mg/kg L-arginine was less than that of 0 mg L-arginine/kg treatment (p<0.05), while its yolk color was deeper than that of 0 mg L-arginine/kg treatment (p<0.05), and the IgY content showed the same tendency. Total cholesterol and triglyceride levels in the treatment supplemented with 8.5 mg/kg L-arginine were lower than that of 0 mg L-arginine/kg treatment (p<0.05). The concentration of IL-2 in the treatment supplemented with 17 mg/kg L-arginine were more than that of 0 mg L-arginine/kg treatment (p<0.05). The findings of this study show that 17 mg/kg L-arginine supplementation has beneficial effects onlayers' immune status and yolk IgY content, as well as on proventriculus and duodenum weight while no adverse effects were observed on laying performance, egg quality, or blood parameters.

Resumo em Inglês:

Abstract In order to investigate the expression levels of nerve growth factor (NGF) and its receptors (TrkA and p75) in prehierarchical follicles and oviducts of hens, five 130-day-old laying hens were examined by immunohistochemistry and RT-PCR analysis. NGF and its receptors were expressed in theca cells and granulosa cells of prehierarchical follicles, and they were also expressed in the epithelial cells of oviducts. The expression of the genes NGF, TrkA and p75 were significantly different in prehierarchical follicles (p<0.05 or p<0.01), and NGF and TrkA gene expression was significantly different in different parts of oviduct (p<0.05 or p<0.01). The expression of NGF and p75 mRNA levels was highest in large white follicle (LWF), as well as the expression of TrkA in small yellow follicle (SYF). In the oviduct, the expression of NGF was the highest in infundibulum, and lowest in isthmus. These results suggest that NGF may play an important role in the regulation of hen reproduction.

Resumo em Inglês:

Abstract This study aimed at evaluating the levels of moisture, protein, water to protein ratio, and water absorption during chilling of chicken giblets (heart, liver, and gizzard) to set legal limits of water absorption during this process. The survey was conducted in the southern Brazil, the largest broiler-producing region of this country. Giblets (heart, liver, and gizzard) were collected fresh from the processing line after evisceration and at the exit of the chiller after the immersion process from two processing plants. One of the plants (PP1) processes small chickens (1,100g live weight) and PP2 processes chickens with 2,800g live weight. In total, 448 samples were collected. Laboratory tests were performed in duplicate for each parameter measured. The results show that moisture levels of fresh giblets were higher in the gizzard, followed by the liver and the heart, whereas in chilled giblets, the gizzard still maintained the highest moisture level, but was followed by the heart and then the liver. Both in fresh and chilled samples, the liver presented the highest protein content, followed by the gizzard and the heart. Water to protein ratios were higher in chilled than in fresh samples, and was highest in the heart, followed by the gizzard and the liver. After immersion in the chiller, the heart presented the highest water absorption rate (6.59%), which was significantly higher compared with those of the liver (4.16%) and the gizzard (4.51%). Considering that the water absorption rates obtained both in fresh and chilled chicken giblets were below 8.00%, the following upper limits of water absorption are suggested for chicken giblet processing in Brazil: 7.0% for the heart, and 5.0% for the gizzard and the liver.

Resumo em Inglês:

Abstract The present report aims at describing the occurrence of Marek's Disease (MD) in a free range poultry farm based on macroscopic and microscopic lesions. For this purpose, seven free-range chickens were evaluated by gross and microscopic examination. Tumor lesions were observed in the liver and ovary, in addition of enlarged kidney and spleen, skin thickening and whitish lesions in streak form in the breast muscle. Fragments of the affected organs were collected and placed in 10% formalin for processing by the usual histopathology techniques, and stained with hematoxylin-eosin. Under microscopic evaluation, we observed pleomorphic populations of neoplastic lymphoreticular cells with pyknotic nuclei in the same organs, all compatible with MD. The macroscopic and microscopic lesions presented in this study were consistent with MD, meaning that the MD virus is present in the rearing environment of the studied chicken farm.