ABSTRACT It was investigated if pre-incubation ascorbic acid (AA) injection in fertile eggs incubated at high temperature impacts the performance, the yield of carcass and parts, and the intestine morphology of broilers reared under heat stress. Three thousand Cobb® fertile broiler eggs were randomly distributed according to weight into three incubations treatments (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 thermoneutral, cold, and hot house temperatures. Broilers reared under hot temperature presented lower feed intake and weight gain than the broilers of the different rearing temperatures. Egg incubation at 39.0 ºC and 39.0 ºC + AA reduced broiler viability. Carcass and cut yields were not influenced by incubation and rearing procedures. Duodenal goblet cell count was lower in broilers from eggs of the treatment 39ºC + AA than in broilers from the other incubation treatments and in broiler rearing in hot temperature. In the jejunum, the goblet cell counts were higher in broilers that were reared under hot than thermoneutral temperatures. The incubation treatment of 39 ºC+AA increased the goblet cell counts in the ileum of broilers reared under cold temperatures. Rearing temperature influenced the duodenal villi counts, which were lower under cold rearing conditions than in the two other rearing temperatures. The results showed that egg incubation at 39°C, independently of ascorbic acid injection, did not produce an effective epigenetic heat adaptation in broilers.

ABSTRACT Trade liberalization during the last decades has increased among nations as a result of decreased tariffs. However, during the same period, market agents have created new protection measures to replace such mechanisms in an attempt to promote the domestic economic stability of countries, while expanding and ensuring the trade between nations. Considering that Brazil is the second largest broiler producer and chicken-meat exporter worldwide, the present study proposed to analyze the main barriers imposed on Brazilian chicken meat imports by the ten major importing countries. This is a documentary research with primary and secondary data, of a descriptive-exploratory nature, under a qualitative approach. Semi-structured questionnaires including open- and close-ended questions were sent using Survey Monkey software to the Brazilian Association of Animal Protein. The study revealed that technical requirements are those most often imposed by the importing countries, indicating their concern about the safety, quality, and origin of the imported good. Commercial requirements do not constitute a problem for the growth of Brazilian chicken meat exports; however, the requirements made by some countries preclude the exports.

ABSTRACT Intensive broiler production requires large flock density, which compromises litter quality and increases the prevalence of footpad lesions. The present study aimed at comparing the incidence of footpad dermatitis of broilers reared in two different rearing environments. Data from two broiler houses were recorded during 42 d. Air temperature and relative humidity; litter moisture, pH, and temperature; footpad surface temperature; and the incidence of footpad lesions was investigated. Litter quality was analyzed in a 2 x 4 factorial arrangement, with two house types (dark house or open-sided house) and four rearing phases (21, 28, 35, and 42 d of growth), with four replicates per treatment using 12 replicates. Four replicates were used for analyzing the air environment data. For the footpad lesion identification, a randomly factorial scheme of recording the surface temperature was built (2 x 2) using two houses, and the broiler sex using 15 replicates in the grow-out stages. The measures of association (odds ratio and risk ratio) were calculated. The multi-criteria analysis (Analytic Hierarchy Process - AHP) was applied for estimating the house that provided less prevalence of lesions. The field data did not provide enough evidence for selection of a particular house with less incidence of footpad dermatitis. However, when applying the measures of association data, and corresponding literature data to the AHP, there was an indication that the dark-house provided broiler rearing condition that reduced the incidence of footpad lesions.

ABSTRACT Adequate environmental temperature control is essential for incubation efficiency. Layer breeder eggs (n=360) were weighed and distributed in a completely randomized experimental design with two treatments, consisting of two incubation temperatures (T1=37.5 °C, control; and T2=39.0 °C, hot), with two incubators per temperature, and 90 eggs per incubator, totaling 360 eggs. Hatchability, embryo mortality, and chick cloacal and body surface temperatures were not affected by incubation temperature. Eggs incubated at the hot temperature presented greater egg mass loss and higher eggshell conductance than those incubated at the control temperature. Layer chicks derived from eggs incubated at control temperature showed greater absolute weight, yolk-free egg mass, and heavier hearts than those from eggs submitted to heat stress during incubation. The control group presented lower base excess and ionized calcium blood levels. Incubating eggs at temperatures higher than those recommended compromises body and heart development of layer chicks and negatively affects blood ionized calcium availability, and therefore, bone mineralization during embryo development. Efficient temperature control during the incubation of fertile eggs is essential to obtain good quality layer chicks.

ABSTRACT Long storage periods may increase embryo mortality. The objective of this study was to evaluate the effects of storage period on the weight loss, eggshell surface temperature, hatchability, and embryonic mortality of Japanese quail eggs. Two hundred fertile eggs were collected from a flock of 30-week-old Japanese quails (Coturnix coturnix japonica). The eggs were collected for 10 consecutive days after lay, and immediately incubated. A completely randomized experimental design with 10 treatments, corresponding to the number of days eggs were stored between egg collection and setting, with 20 replicates each, was applied. Egg weight loss increased with storage period duration, starting on day 6 (2.1%, on average) and reached 3.26%, on average, in eggs stored for 10 days. The highest hatchability (p>0.05) was obtained in eggs stored for two days, which also lost the least weight (1.20%). Storage period did not influence eggshell surface temperature (p>0.05) during incubation, but higher temperatures (p<0.05) were measured on days 10 and 15 of incubation compared with day 5. Eggs stored for ten days presented the highest weight loss, and therefore, a storage period of up to five days is recommended to maintain the quality of incubated Japanese quail eggs. Furthermore, egg surface temperature increases during the second half of the incubation period as a result of increasing embryonic metabolic rate.

ABSTRACT Time of exposure and light intensity rearing house may affect the performance and egg quality of laying quails. This research aimed at evaluating the live performance, egg quality, biometry of the reproductive system, and the gastrointestinal tract of Japanese quails (Coturnix coturnix japonica) exposed to artificial light-emitting diodes (LED) of different colors in comparison with fluorescent lamps. A total of 240 Japanese quails were distributed in completely randomized experimental design with four treatments (fluorescent lamp, and green, red, or blue LED lamps) with six replicates of 10 birds each. Average egg weight and eggshell thickness were different (p<0.05) when LED bulbs were compared with fluorescent lamps. The egg weight of the birds exposed to the red LED was similar to those under a fluorescent lamp (p>0.05). The oviduct of 64-d-old hens exposed to green LED lighting was shorter (p<0.05) than those exposed to the fluorescent lamp. Red LED can be used to replace the fluorescent lamps, as they promote the same live performance, egg quality, and morphological development of the reproductive tract of laying Japanese quails.

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.

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.

ABSTRACTVitamin D is added to broiler diets to supply its physiological requirement for bone formation. The fast growth rate of modern broilers is often associated with poor bone formation. Increasing vitamin D supplementation levels and the use of more available sources have applied to try to prevent leg problems, to increase carcass yield, and to improve the performance of broilers. The present study evaluated three vitamin D supplementation levels (1) 3,500 IU (control); (2) control + 1,954 IU of 25-hydroxycholecalciferol; and (3) control + 3,500 IU of vitamin D in broiler diets supplied up to 21 days of age. The objective was to investigate if the vitamin D levels above the recommendations could reduce leg problems in broilers. In this experiment, a total of 1,296 one-day-old male and female Cobb(r) 500 broilers were used. A 2 x 3 factorial arrangement was applied, consisting of two sexes and three vitamin D levels. No difference was found between the levels of vitamin D (p > 0.05), the performance of males or females, the gait score, the valgus and varus incidence, the tibial dyschondroplasia incidence, the occurance of femoral degeneration, the bone colorimetric, and the carcass yield. Parts yield differences were found (p > 0.05), except for liver and intestine yields. We concluded that the lowest tested vitamin D level (3,500 IU per kilogram of feed) added to the diet was the best choice in terms of cost/benefit to help minimizing leg problems in broilers.

ABSTRACTThe pre-slaughter period is considered critical in broiler production. Several factors contribute to increase the birds' stress, such as handling, harvesting, and transportation, negatively affecting their welfare. This study aimed at evaluating the addition of lemon grass (Cymbopogon citratusStapf) to the drinking water of broilers during the pre-slaughter period on their behavior, blood cortisol, and surface temperature. The study was carried out at the experimental farm of the Federal University of Grande Dourados (UFGD), Dourados, MS, Brazil. In total, 2594 broilers were distributed according to a completely randomized experimental design, in a 3x2x2 factorial arrangement, with four replicates per treatment. Treatments consisted of three different lemon grass levels (Cymbopogon citratus Stapf) used in the form of an infusion (0, 0.1, and 5 g per L of water), sex (male or female), and genetic strain (Ross(r) 308 or Cobb(r) 500). The infusion was offered when birds were 42 days old. On that day, blood was collected for blood cortisol level determination, broiler surface temperature was recorded, and an ethogram was applied to register broiler behavior. Blood cortisol level and broiler surface temperature were not affected by treatments (p>0.05). The behavior of beak opening was different between the genetic strains (p<0.05), being more frequent in Ross(r) 308 broilers. Lemon grass water content did not affect broilers' surface temperature when consumed during the pre-slaughter period.

Dose-dependent positive effects on hatchability and hatchling weight have been attributed to ascorbic acid (AA) when eggs were submitted or not to intermittent heat stress during incubation. Fertile breeder (Cobb(r)) eggs were used to determine if the pre-incubation injection of AA in ovo affects the incubation and hatchling quality of egg incubated under thermoneutral or intermittent heat stress conditions. Eggs were not injected or injected with 0, 2,4, or 6% AA/100µL water and incubated at continuous thermoneutral (37.5ºC) or hot (39.0ºC) temperature. Eggshell temperature (EST) increased in the second half of the incubation period in all experimental groups. The EST of non-injected eggs and of those injected with water was higher when incubated at 39°C than at 37.5°C, but EST was not different among eggs injected with AA. Egg mass loss and eggshell conductance were higher in the eggs incubated at 39°C than at 37.5°C.Hatchability was lower in the eggs injected with AA. Liver and yolk sac weights were higher, whereas heart and liver weights were lower in hatchlings from eggs incubated at 39°C; however, hatchling weight was not affected by incubation temperature. The results showed that AA doses affected egg conductive heat loss and hatchability, and that they did not minimize the effects of high incubation temperature on liver and heart development.

This study aimed at evaluating diets containing different fiber sources and two crude protein levels on the performance, egg quality, and nitrogen metabolism of commercial layers. In total, 392 48-wk-old Isa Brown layers were distributed according to a completely randomized experimental design in a 3x2+1 (control) factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. Treatments consisted of three fiber feedstuffs (cottonseed hulls, soybean hulls, and rice hulls) and two dietary crude protein levels (12% and 16%). Cottonseed hulls associated with the high crude protein level (16%) resulted in the worst feed conversion ratio per dozen eggs. Diets with 16% crude protein resulted in the highest feed intake, egg production, egg weight, egg mass values, and improved feed conversion ratio (kg eggs/kg feed). The dietary inclusion of soybean hulls determined low yolk pigmentation, and of rice hulls, low egg specific gravity. The 16% crude protein diet with rice hulls promoted the best feed conversion ratio. Hens fed the reference diet presented higher egg mass and better feed conversion ratio per kg eggs and per dozen eggs. Hens fed the diets with low crude protein level (12%) had reduced nitrogen excretion, but presented worse egg production.

An experiment was carried out to evaluate the performance, egg quality and morphometry of the reproductive tract, liver, pancreas and tongue of laying hens submitted to different molting methods. Two hundred and eighty eight 72-week-old Isa brown layers were distributed according to a completely randomized design with six treatments (molting methods) and six replicates of eight birds each. Layers were fed diets containing 3000 ppm zinc oxide, 60 ppm or 120 ppm nicarbazin, 30 ppm or 60 ppm salinomycin, or were submitted to feed fasting. Data were submitted to analysis of variance and means were compared by the test of Tukey at 5% probability level. Molting methods alternative to feed fasting were effective to induce molting in layer and provided good performance results in the second laying cycle.

The objective of the present experiment was to compare the performance, egg quality and organ morphometrics of commercial layers submitted to alternative forced molting methods using dietary fibers. The experimental period included the phases of molting, rest, and second laying cycle (six periods of 28 days each). In the trial, 320 commercial Isa Brown layers with 72 weeks of age were distributed, according to a completely randomized experimental design into five treatments with eight replicates of eight birds each, totaling 40 experimental units. Molting was induced by feeding diets with the inclusion of alfalfa or soybean husks at 80% and 60% or feed fasting. Treatments were applied for 14 days. Performance and egg quality parameters were evaluated for the second laying cycle and organ morphometrics (liver, gizzard, proventriculus, reproductive apparatus) in two different slaughter dates. The obtained data were submitted to analysis of variance using the General Linear Model (GLM) procedure of SAS statistical package (SAS Institute, 2002). Alternative molting methods promoted similar performance and egg quality results after molting were similar to those obtained by the conventional fasting method. Feeding fiber produced the expected effects in terms of organ weight regression and recovery and may be used to induce molting in commercial layers.

An experiment was conducted to evaluate the biometrics of organs (ovary, oviduct, liver, proventriculus and gizzard) of laying hens submitted to different forced-molting methods of molt and maintained at three different temperature. Organs were evaluated after molting and resting period. Six hundred birds were distributed according to a completely randomized experimental design in a 5x3 factorial arrangement (forced-molting methods x environmental temperatures) into 15 treatments with 5 replicates of 8 birds each. The molting methods applied were the dietary inclusion of 90%, 70%, 50% of alfalfa, 2,800 ppm zinc oxide, or total feed restriction. Birds were kept at ±20 ºC, ±27 ºC, or ±35 ºC. Data were submitted to analysis of variance and means were compared by orthogonal and polynomial contrasts. The traditional forced-molting method (feed fasting) resulted in adequate performance. However, as the aim of the present study was to find an alternative method to feed fasting, the highest dietary alfafa inclusion level (90%) was shown to be efficient compared with other methods, particularly when hens were kept at high temperature. Therefore, this alternative forced-molting may be applied, especially when bird welfare is taken into consideration.