Values of Metabolizable Energy and Metabolization of Nutrients for Slow- and Fast-growing Birds at Different Ages

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

Effect of Incubator Type and Broiler Breeder Age on Hatchability and Chick Quality

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

Effect of different electrolyte balances in broiler diets

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

Detection of Salmonella spp. by Conventional Bacteriology and by Quantitative Polymerase-Chain Reaction in Commercial Egg Structures

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

Digestible Threonine Levels in the Starter Diet of Broilers Derived from Breeders of Different Ages

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