ABSTRACT This experiment was conducted to evaluate the welfare and production performance of broilers reared under different stocking densities. A total of 1242 one-day-old Cobb500 broiler males were distributed randomly among four treatments with nine replicates each. The treatments consisted of different broiler stocking densities (10.41; 11.45; 12.50 and 13.54 birds/m²). The parameters evaluated were regadring production performance (body weight, body weight gain, feed intake, feed conversion ratio, uniformity, and carcass yield), animal welfare (cortisol, lactate, total protein, albumin, glucose, triglycerides, cholesterol, uric acid seric, and hemogram), and litter quality (temperature, humidity, and volatilized ammonia concentration). The broilers reared at 12.5 birds/m2 presented the best feed conversion ratio at 42 days of age. Neither the carcass traits nor the stress parameters studied were influenced by the stocking densities. It was concluded that the stocking density of 12.50 birds/m² results in the best feed conversion ratio among the studied treatments for the production cycle of 42 days. 124 onedayold one day old Cobb Cobb50 each 10.41 1041 10 41 (10.41 11.45 1145 11 45 1250 12 50 1354 13 54 13.5 birds/m². birdsm² birdsm . birds m² m birds/m²) gain intake uniformity yield, yield , yield) cortisol, cortisol (cortisol lactate protein albumin glucose triglycerides cholesterol seric hemogram, hemogram hemogram) temperature, temperature (temperature humidity concentration. concentration concentration) 125 5 12. birdsm2 m2 birds/m 4 age Cobb5 10.4 104 1 (10.4 11.4 114 135 13. 10. (10. 11. (10 (1 (

ABSTRACT Post-hatch delayed placement damages the physical and physiological development of broiler chicks. This study was designed to find adequate levels of betaine inclusion in pre-hatching and pre-starter feed, in order to minimize the negative effects of post-hatch delayed placement on broiler chicks. Newly-hatched chicks were allotted in a completely randomized design, with five treatments, five replicates of ten birds each. Five dietetic levels of betaine (control, 0.070, 0.130, 0.200 and 0.260%) were used in the pre-starter ration, offered to the chicks in the transporting box and during the pre-starter phase. Performance, yolk sac retraction, plasma glucose concentration, weight and histomorphometry of the small intestine were evaluated, after 24 hours of feed access and at 7 days of age. A metabolic trial was performed from seven to ten days of age. Betaine supplementation linearly influenced the chick’s ileum crypt depth after 24 hours in the transportation box. There was a quadratic effect, with an increase in feed intake up to 0.152% betaine supplementation. There was an improvement in the quality of the jejunum with betaine supplementation above 0.1%. The metabolizable coefficient of the ether extract was improved until reaching 0.163% of betaine supplementation. Betaine supplementation around 0.150% increases feed intake, the use of ether extract and interferes with the intestinal villi of chicks at seven days of age.

ABSTRACT The objective of this study was to evaluate the performance and carcass yield of broilers submitted to heat stress during different rearing stages. A total of 840 one-day-old CobbAvian48TM male broilers were housed in an experimental house equipped with conventional ventilation system and foggers. Birds were distributed according to a completely randomized design into four treatments, with six replicates of 35 birds each. The treatments consisted of: T1 (control) - birds reared under natural temperature and relative humidity conditions from 1 to 42 days of age; T2 - birds submitted to heat stress (HS) from 16 to 21 days of age; T3 - birds submitted to HS from 22 to 42 days of age; and T4 - birds submitted to HS from 16 to 42 days of age. Birds were submitted to heat stress daily for one hour (12:00-13:00h).On day 42, performance data were determined. Six birds per replicate were selected and sacrificed to obtain carcass, parts, and giblet weights and yields. Performance parameters were not influenced by the treatments. Broilers submitted to 1-h cyclic heat between 16 and 42 days of age presented lower deboned breast weight compared with those maintained in natural temperature and relative humidity conditions. It was concluded that the performance of broilers submitted to short cyclic heat periods is not impaired.

ABSTRACT Two experiments were conducted to evaluate the effect of broiler breeder age and incubator type on hatching parameters, hatch window, embryo diagnosis results, and hatchling physical quality. The treatments consisted of a combination of three broiler breeder ages (29, 35 and 59 weeks of age) and two incubator types (single stage, SS; or and multiple stage, MS). A completely randomized design in a 3x2 factorial arrangement was applied. In Experiment I, 1,896 eggs were used and 360 eggs in Experiment II. There was an interaction between breeder age and incubator type only for hatchling physical quality score. Independently of incubator type, hatchability rate, late embryo mortality, and egg contamination were higher in the eggs laid by older breeders (59-wk-old). Early mortality (0-4 days) was higher in the embryos from young breeders (29-wk-old). A shorter hatch window birth was obtained in the SS incubator, resulting in higher hatchling body weight relative to egg weight, and better hatchling physical quality score. Both types of incubators provide good conditions for embryo development; however, the physical quality of chicks derived from eggs from intermediate-aged breeders (35-wk-old) is better when eggs are incubated in SS incubators.

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.

ABSTRACT The aim of this study was to evaluate the effect of digestible threonine supplementation in the starter diet on the performance, intestinal parameters, and nutrient metabolism of broilers derived from breeders of different ages. In total, 480 one-day-old Cobb chicks, derived from 38-or 49-week-oldbreeders, were housed in experimental battery cages until 21 days of age and fed four different threonine levels (800, 900, 1,000, or 1,100 mg/kg) in the starter feed. A completely randomized experimental design in a 2x4 factorial arrangement (breeder age x threonine levels) was applied, totaling eight treatments with five replicates of 12 birds each. Broilers from older breeders fed 800 mg digestible threonine/kg of diet presented higher weight gain, with a positive linear effect. There was also an interaction between breeder age and threonine levels for the weight gain of 21-d-old broilers supplemented at maximum level of 1,003 mg Thr/kg diet during the starter phase. There was no effect of breeder age or threonine levels on nutrient metabolism during the period of 17-21 days. There was no influence of breeder age or threonine levels in the starter diet on intestinal morphometric measurements, absorption area, or percentage of goblet cells.

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.

This experiment aimed at evaluating the influence of the supplementation of digestible lysine and digestible arginine at different ratios in the diet fed to layers between 24 to 44 weeks of age on egg quality. In total,320 Lohmann LSL laying hens were allotted according to a completely randomized design in a 2 x 4factorial arrangement, consisting of two digestible lysine levels (700 or 900 mg/kg of diet) and four digestible arginine levels (700, 800, 900,or 1000 mg/kg of diet). Diets contained, therefore, digestible Lys:Arg ratios of 100, 114, 128, and 142 when the diet contained 700 mg digestible lysine per kg of diet, and 78, 89, 100, and 111 when 900 mg digestible lysine per kg was supplemented. The data obtained with digestible arginine levels were fitted to polynomial regression equations, and with digestible lysine, the F test (5% probability) was used to compare the means. The following variables were evaluated: egg weight; internal egg quality (yolk percentage and index, albumen percentage, Haugh units), eggshell quality (specific gravity andeggshell percentage); and whole egg, albumen, and yolk solids content. Digestible lysine and arginine interaction did not affect egg quality. Increasing levels of digestible lysine and arginine reduced eggshell quality and albumen solids, respectively. The levels of these amino acids suggested to improveegg quality are 700 mg digestible lysine and 700 mg digestible arginine/kg of feed at a Dig Lys: Dig Arg ratio of 100.

The aim of this study was to evaluate the performance, tibial density and mineral content, Na, K ,and Cl serum levels, and dry matter content of the litter of broilers fed diets with different levels of dietary electrolyte balances. Two experiments were carried out: during the starter phase (7 to 21 days of age, 960 broilers) and during the growe phase (22 to 38 days of age, 816 broilers). In both experiments, a completely randomized design with four treatments based on dietary electrolyte balance values (200, 240, 280 and 320 mEq/kg of diet) with four replicates was applied. Birds and diets were weighed when birds were seven, 14 and 21 days of age in the first experiment, and 22 and 38 days of age in the second experiment in order to determine weight gain, feed intake and feed conversion. Final body weight, weight gain, feed intake and feed conversion and mortality rate were evaluated. On days 21 and 38, the left tibia of two birds per replicate was collected to determine bone density and the serum was used for Na and K analysis. Litter dry matter content was also determined on days 21 and 38 . There was no effect of dietary electrolyte balance values on broilers performance between 7 and 14, 7 and 21, or 22 and 38 days of age, tibial bone density and mineral content, or on Na, K and Cl serum levels. Litter dry matter was linearly reduced as dietary electrolyte balance value increased. Diets with 200 mEq/kg may be recommended for broilers from 7 to 38 days of age with no negative influence on the evaluated parameters.

Três ensaios biológicos foram realizados com o objetivo de determinar o conteúdo de energia metabolizável e do coeficientes de digestibilidade do extrato etéreo da soja integral processada por diferentes métodos (extrusão e tostagem) e do farelo de soja reconstituído com óleo. No primeiro e segundo ensaios, foram utilizadas a metodologia tradicional de coleta total de excretas, utilizando pintos no primeiro ensaio e galos no segundo. No terceiro ensaio, empregou-se a metodologia de alimentação forçada (Sibbald, 1976) com galos adultos. De acordo com os resultados obtidos, as sojas testadas apresentaram composições bromatológicas semelhantes. Os processamentos usados para a soja integral conferiram diferenças na digestibilidade dos nutrientes da soja e os coeficientes de digestibilidade do extrato etéreo obtidos para a soja extrusada e para o farelo de soja com adição de óleo foram superiores aos obtidos para soja tostada pelo vapor. Os valores de energia metabolizável obtidos para a soja extrusada foram superiores aos encontrados para a soja tostada pelo vapor e para o farelo de soja com adição de óleo, que foram semelhantes entre si.

Three-assay birds were conducted to evaluate the contents of metabolizable energy and ether extract digestibility of processed full-fat soybeans by extrusion, by toast and of the soybean meal plus oil. Two assays were carried out by using the traditional total excreta collection by chicks and by rooster, and the other assay was developed by using the force-feeding adult rooster method (Sibbald, 1976). The results showed that the feed composition of the soybean-tested were similar. The different processing caused differences on digestibility of the nutrients of the soybeans tested and the value of coefficients of the nutrients in extruded soybean and soybean meal plus oil were higher than that heated soybean. The value of metabolizable energy was superior in extruded soybean.