Jim Fernandes

Effect of arginine on the development of the pectoralis muscle and the diameter and the protein:deoxyribonucleic acid rate of its skeletal myofibers in broilers

This work aimed at evaluating the effects of the supplementation of starter diet with Arg on breast muscle development in broilers and the activation of satellite cells and the aggregation of myofibrillar protein. Male Cobb chicks (n = 990) were randomly assigned to 1 of 5 treatments in a complete random design. Measurements of 33 chicks per treatment were made in 6 repetitions. The treatments consisted of a basal diet with 1.390% digestible Arg (without supplementation) and 4 dietary levels of Arg (1.490, 1.590, 1.690, and 1.790%) with Arg:Lys ratios of 1.103, 1.183, 1.262, 1.341, and 1.421, respectively. Arginine supplementation was used only in the starter phase (1 to 21 d). Dietary supplementation with Arg had a positive effect (P < 0.05) on breast and breast fillet weight on d 7 and 21 and on myofiber diameter on d 14 and 21. However, no effect was observed (P > 0.05) on the protein:DNA ratio, which demonstrates that Arg does not interfere with the mitotic activity of the satellite cells. Independently from mechanism, Arg affected muscle growth in the starter phase positively. Dietary supplementation with Arg in the starter phase had no effect (P > 0.05) on the carcass yield of broilers on d 42. Diet supplementation with Arg at levels above the ones recommended for the starter phase may be necessary for improved muscle development in broilers.

Effects of organic mineral dietary supplementation on production performance and egg quality of white layers

This trial aimed at evaluating the effect of organic trace mineral supplementation of commercial layer diets on productive performance and egg quality. One-hundred-ninety-two Hy Line W36 white 69-w-old layers were distributed into a completely randomized design with three treatments, and eight replicates, with eight birds each. Treatments consisted of a basal diet supplemented with inorganic trace minerals (R1), and two others experimental diets containing 0.250 ppm (R2) and 0.500 ppm (R3) of an organic source of zinc, manganese, and selenium. Feed intake (g/bird/day), feed conversion ratio (kg/dozen egg and kg/kg egg), egg weight (g), egg production (%), thin and cracked eggshells (%), specific gravity (g/mL), Haugh Units, total egg solids (%), yolk yield, white and shell yields (%), eggshell thickness, and egg Se content were evaluated Tukeys test analyzed differences among means at 5% of probability using PROC GLM in SAS (2000). Although not significant as compared to the non-supplemented diet, improvements on relative cracked-plus-thin shells were observed with the use of organic mineral blend. The addition of the organic blend to the diet at 0.250 kg/ton resulted in (p<0.05) higher total egg solids. Also, as compared to eggs from control group, fresh and dried yolk yields were higher with the dietary inclusion of the organic mineral blend at 0.250 and 0.500 kg/ton.

Regeneration of the intestinal mucosa in Eimeria and E. Coli challenged broilers supplemented with amino acids

The aim of this study was to evaluate the regeneration of the intestinal mucosa in Eimeria and E. coli challenged broilers supplemented with glutamine, arginine, and threonine. Six hundred male broilers at one d of age from the Cobb strain were utilized. The design was completely randomized using a 2×3 factorial design (unchallenged and challenged and 3 diets). A commercial diet was used as a control and 2 other diets were formulated with glutamine (1.5 and 3% Aminogut®), arginine (1 and 2% L-Arginine), and threonine (1 and 2% L-threonine). The animals that consumed diets supplemented with amino acids presented better (P<0.05) feed conversion in the period from one to 42 d of age. The ability of cell proliferation and the villus:crypt ratio in response to enteric challenge were greater (P<0.05) for broilers that received diets supplemented with amino acids. High levels of amino acids in the experimental feeds reflected in greater protein levels in poultry house litter, and they did not interfere with ammonia production. The supplementation of diets with trophic amino acids can positively contribute to the regeneration and proliferation of the intestinal mucosa in broilers and to the maintenance of zootechnical performance when submitted to enteric challenges.

Immune response of broilers fed conventional and alternative diets containing multi-enzyme complex

The present study aimed at evaluating the effect of adding a commercial multi-enzyme complex to conventional and alternative broiler diets on the immune response and occurrence of lesions in the intestinal mucosa. In total, 900 male broiler chicks were distributed according to a completely randomized design, with six treatments of six replicates each. Two control diets were formulated: one with conventional feedstuffs (T1), based on corn and soybean meal, and one with alternative feedstuffs (T4), containing corn, millet, and soybean, canola and sunflower meals. Based on these diets, other four were prepared with reduced metabolizable energy, digestible amino acids, calcium and available phosphorus levels and the addition (T3 and T6) or not (T2 and T5) of a multi-enzyme complex. Broilers fed diets based on conventional feedstuffs had higher levels of defense cells compared with those fed diets that included millet with canola and sunflower meals. On the other hand, the use of enzymes in conventional or alternative diets decreased the number of these cells in the ileal mucosa.

Effects of methionine source, arginine: lysine ratio and sodium chloride level in the diets of grower broilers reared under high-temperature conditions

The objective of this study was to evaluate the influence of methionine sources (DL-methionine 99% powder (DLM) or methionine hydroxy analog liquid 88% (HMTBA)), arginine:lysine (Arg:Lys) ratio and sodium chloride (NaCl) content in the diet of broilers on their performance, carcass yield, serum biochemistry, duodenal mucosal morphology, and immune response. Birds were kept under high temperature conditions during the grower phase and were inoculated or not with an antigen. The use of HMTBA promoted better live performance and carcass yield than the use of DLM. Diets with 1.05 Arg:Lys ratio resulted in better live performance, higher carcass and breast meat yields, longer villi, shallower crypts, and stronger immune response when broilers were challenged than the 1.40 ratio. The dietary supplementation of 6.0 g NaCl/kg promoted better growth performance and carcass weight than 2.0 g NaCl/kg. There was no influence of the different methionine sources or NaCl concentrations on any evaluated intestinal morphology parameter or immune response, nor of any interactions between these sources of variation.

Effects of Guanidionoacetic Acid and Arginine Supplementation to Vegetable Diets Fed to Broiler Chickens Subjected to Heat Stress before Slaughter

The objective of this study was to evaluate the supplementation of guanidinoacetic acid (GAA) and L-arginine (L-Arg) as creatine precursors to vegetable diets on the carcass yield and meat quality of broilers subjected to two days of heat stress before slaughter. A total of 1260 broiler chicks were distributed according to a completely randomized design into four treatments with nine replicates of 35 birds each. The treatments consisted of: T1 – vegetable diet based on corn and soybean meal (control diet); T2 – control diet with the inclusion of meat meal (3%); T3 – control diet supplemented with GAA (0.08%); and T4 – control diet supplemented with L-Arg (0.8%). The birds were submitted to heat stress for two days before slaughter (from 42 to 44 days of age). The birds fed the diets supplemented with GAA or L-Arg presented heavier carcasses (p<0.0035), higher breast yield (p=0.0685), and lower of abdominal fat deposition (p=0.0508) than those fed the control diet and the control diet with meat meal. The cooking loss of the breast fillets of broilers fed the control diet supplemented with meat meal, GAA or L-Arg was lower (p<0.0068) compared with those fed the control diet. Thawing and pressure-driven breast fillet weight losses, and pH, luminosity, redness (a*value), and yellowness (b* value) values were not influenced by the treatments. When GAA is less expensive than commercially-available Arg, the dietary supplementation of GAA is more advantageous, based on the meat yield improvements observed in the present study.

Using processed feeds for laying quails (Coturnix coturnix japonica)

The aim of this experiment was to determine the productive performance and egg quality of Japanese quails fed different types of processed rations (mash, extruded, or pelleted). One hundred and fortyfour 18-w-old quails (Coturnix coturnix japonica) were housed in galvanized wire cages and fed a 21.50% CP and 2850 kcal ME/kg basal feed supplied in mash, extruded, or pelleted form. Experimental data were analyzed by ANOVA as a complete randomized design, with three treatments (ration forms) and six replicates of eight quails each. When necessary, means were compared by Tukeys test at 5% significance. Quails fed pelleted feed presented higher egg production, feed intake, and egg mass weight as compared to mash- and extruded-diet-fed birds. Under the conditions of the present experiment, it was possible to conclude that the feed physical form did not affect egg quality, except for pelleted diets, which promoted good production performance and high egg mass. However, the use of feed pelleting should be economically analyzed considering the final cost of egg production.

Evaluation of Incubation Yield, Vaccine Response, and Performance of Broilers Submitted to In-Ovo Vaccination at Different Embryonic Ages

The aim of this study was to evaluate the effects of in-ovo vaccination on different incubation days of broiler embryos derived from young and old breeders on incubation indexes, vaccine response, and broiler performance. A number of 20,160 fertile eggs was distributed according to a completely randomized design in a 4 x 2 factorial arrangement (in-ovo vaccination on 16, 17, 18, or 19 days of incubation, and breeders of 31 or 52 weeks of age), totaling eight treatments with 15 replicates of 168 eggs each. Vaccination procedures and vaccines (strains and doses) were those routinely applied in commercial hatcheries. After hatch, 960 male chicks were housed and distributed according to the same experimental design previously applied in the hatchery. There were hatching losses (p<0.05) when eggs were vaccinated before 18 days of incubation. Greater Mareks disease antibody titers were obtained when the in-ovo vaccination was performed on day 19 of incubation, regardless breeder age. Embryonic age at vaccination did not compromise broiler performance in the field, and the flexibility of embryonic age for in-ovo vaccination can reduces incubation costs.

Efecto de la suplementación de vitamina K3 sobre el comportamiento productivo y calidad ósea de pollos de engorde

SUMMARY Vitamin K is involved in blood clotting process and plays an important role in bone formation. Thus, this study aimed to evaluate the supplementation of different levels of vitamin K 3 on growth performance and bone parameters of broiler chickens. For this purpose, 1,500 broiler chickens were distributed in a completely randomized experimental design. The treatments consisted of a control diet containing 1.6 mg of vitamin K 3 /kg of diet and 5 levels of vitamin K 3 (11.6 mg/kg; 21.6 mg/kg; 41.6 mg/kg, 61.6 mg/kg and 81.6 mg/kg), with 5 replicates and 50 chickens per experimental unit. At 7, 21, and 40 days of age, growth performance (body weight, body weight gain, feed intake and feed:gain ratio) and bone parameters (bone length and diameter, Seedor index and bone strength) were evaluated. The increase in vitamin K 3 levels improved the feed intake, body weight and body weight gain in the pre-initial phase. At 40 days old, all performance parameters were similar among the different levels of vitamin K 3 . At 21 and 40 days of age, bone parameters were impaired as dietary levels of vitamin K 3 increased. The results suggest that the recommended level of vitamin K 3 in broiler chicken diets is 1.6 mg/kg of diet.

Performance, abdominal fat deposition and bone characteristics of broilers fed diets containing different lipid sources

Two experiments were carried out to evaluate the performance, abdominal fat yield, and bone parameters of broiler chickens fed diets containing different lipid feedstuffs as energy source. During the starter phase (1 to 21 days) of Experiment 1, a completely randomized design with four treatments with eight replicates of 49 birds each one was applied. Broilers were fed starter diets formulated with different lipid sources: soybean oil (SO), cottonseed oil (CO), poultry offal oil (PO), and beef tallow (BT). During the finisher phase (21 to 42 days) of Experiment 1, each initial treatment was divided in two experimental groups: one fed the same fat ingredient as the previous period, and the other fed SO as energy source. Thus, during this period, a completely randomized design with seven treatments, four replicates, and 43 broilers per experimental unit was tested. During the starter phase (1 to 21 days) of Experiment 2, all broilers were fed with the same soybean oil-supplemented diet. The experimental groups were divided during the finisher phase (21 to 42 d) in a completely randomized design with five treatments groups with six replicates of 30 birds each. During this period, treatments consisted of diets formulated with SO, rapeseed oil (RO), sunflower oils (SFO), PO, or BT as lipid sources. No effects (P>0.05) of the treatments on any of the studied parameters were observed in either experiment. Results suggest that there is no influence of animal or vegetable dietary lipid sources on performance, abdominal fat deposition, or tibia density and strength in broilers.