Andrea Machado Leal Ribeiro

Utilização da Energia de Dietas para Frangos de Corte Formuladas com Óleo Ácido de Soja

Acidulated soapstock, a by-product from the vegetable oil industry has been widely used in poultry nutrition. It is produced by the acid treatment of the residue left after refining vegetable oils. Several concerns exist on the use of this product, such as: adulteration, peroxidation, impurity, and uncertain energetic value. The current experiment focused on the use of the acidulated soapstock in broiler feeds compared with soybean oil. Feeds formulated with 4 and 8% added acidulated soapstock or soybean oil or their mixture in the ratios of 2 : 2 and 4 : 4 % were given to 7 day-old broiler chicks to 42 days of age placed in heated batteries. Birds receiving the diets with acidulated soapstock plus soybean oil had lower body weight at the end of the experiment when compared with birds on the treatments exclusively prepared with acidulated soapstock or soybean oil. This response was independent of the level of oil inclusion. Birds on the lower inclusion level consumed more feed, regardless of the oil source and showed poorer feed conversions, but did not show reduction in body weight when compared to the higher level of inclusion. Acidulated soapstock demonstrated an excellent potential as an energy supplement to be used in broiler feeds and had its energetic value determined as 8.114 kcal EMAn/kg DM, 5% below the value determined for soybean oil.

Effects of corn particle size and physical form of the diet on the gastrointestinal structures of broiler chickens

The objective of this experiment was to investigate the effects of different particle sizes, expressed as Geometric Mean Diameter (GMD) of corn (0.336mm, 0.585mm, 0.856mm and 1.12mm) of mash and pelleted broiler chicken diets on the weight of the gizzard, duodenum and jejunum+ileum; on the pH of the gizzard and small intestine and on the characteristics of the duodenal mucous layer (number and height of villi and crypt depth) in 42-day-old broilers. The physical form and the particle size of the diet had no significant effect on gizzard and intestine pH (p > 0.05). A greater gizzard weight was seen in the birds receiving pelleted diet and particle size of 0.336mm (p < 0.008). However, for the particle sizes of 0.856 and 1.12 mm, a greater weight was found in birds that received mash diet (p < 0.039 and p < 0.006, respectively). Also, gizzard weight was greater with increasing corn GMD independent of the physical form of the diet. In the mash diet, the increase in particle size promoted a quadratic response in the weight of duodenum and jejunum + ileum. The pelleted diet promoted a greater number of villi per transverse duodenum cut (p < 0.007) and greater crypt depth (p < 0.05). As the particle size increased, there was a linear increase of villus height and crypt depth in the duodenum, irrespective of the physical form of the diet.

Effects of prebiotics and probiotics on the colonization and immune response of broiler chickens challenged with Salmonella Enteritidis

The present study aimed at evaluating the effect of the prebiotic Bio Mos™ (2 kg/ton up to 10 days; 1 kg/ton from 10 to 21 days; and 0.5 kg/ ton from 21 days to slaughter), of the probiotic Lac XCL 5x™ (by spraymixing), of a combination of the two supplements (prebiotic + probiotic), and of one growth promoter antimicrobial agent (Avilamycin at 15 ppm). Birds were orally challenged with inoculated Salmonella Enteritidis (SE) 10 6 CFU at 3 days of age. Four hundred and eighty male Ross chicks were used. The experiment lasted 28 days, and the analyses were conducted at 15 and 28 days of age. Cecum and liver bacterial colonization of production of anti-SE antibiodies, intestinal micrometry and bird performance were assessed. Neither the prebiotic, nor the probiotic influenced performance or production of anti-SE antibodies in SE-challenged birds. Intestinal micrometry and bird mortality were not influenced by prebiotic or probiotic supplementation, or by the antimicrobial agent. The use of an antimicrobial agent produced higher SE CFUs in cecum bacterial counts, while prebiotic and probiotic yielded lower counts. The combination prebiotic+probiotic did not produce significantly different results from the individual use of the additives.

Efeito da Energia, Relação Energia: Proteína e Fase de Crescimento Sobre o Desempenho e Composição de Carcaça de Frangos de Corte

Two experiments (EXP) were carried out to investigate the effects of crude protein (CP) levels reduction in high-energy (H) (3.200kcal ME/kg) and low-energy (L) (2.900kcal ME/kg) diets, on the performance and carcass composition of male broiler chickens. The CP levels were decreased to meet the following energy: protein (E:PB) ratios: 139, 146, 153 and 160 (kcal/%) for starter diets (EXP 1) and 160, 167, 174 and 181 (kcal/%) for grower diets (EXP 2), in both energy levels, keeping MET + CIS and LYS levels at the same concentration. All birds received a same diet before (EXP 2) or after (EXP 1) feeding the experimental diets. Feeding H diets resulted in better performance, but also in higher carcass fat deposition. In EXP 1, birds fed with L diets during the starter period had similar body weight gain (BWG), in the total period (1 to 42 days), than those H diets, however with better caloric conversion (kcal/kg) (CC). Also, the best CC was obtained with E:PB of 139. Lower BWG, sometimes occurred with lower levels of dietary CP, but in all experiments the CC was decreased with wider E:PB ration. In both EXP, protein utilization was improved with higher levels of dietary energy and with lower levels of dietary CP.

Effects of methionine and arginine dietary levels on the immunity of broiler chickens submitted to immunological stimuli

The present study aimed at assessing the effects of methionine and arginine on the immune response of broiler chickens submitted to immunological stimuli. Three methionine concentrations (0.31, 0.51, and 0.66% from 1 to 21 days of age; 0.29, 0.49, and 0.64% from 22 to 42 days of age) and 2 arginine concentrations (1.33 and 1.83%; 1.14 and 1.64% for the same life periods) were tested. Birds were divided into two groups for immunological stimuli (3x2x2 arrangement). Vaccines against Marek’s disease, fowl pox, infectious bronchitis, Freund’s Complete Adjuvant, Sheep red blood cells (SRBC), and avian tuberculin were administered to one group as immunological stimuli; the other group did not receive any stimulus. The experiment was carried out with 432 one-day-old male Ross broilers, distributed into 12 treatments with 6 replicates of 6 birds each. Performance data were weekly collected. Anti-SRBC antibodies were collected by hemagglutination test and cell immune response (CIR) was measured by tubercularization reaction in one wattle 24 hours after administration of the second tuberculin injection at 42 days of age. The weight difference between the two wattles of each bird (one injected with tuberculin and the other not) was the measure of CIR. Arginine levels did not influence either bird performance or immune response. Methionine concentrations higher or lower than usually adopted in broiler production (0.51 and 0.49%) equally failed to influence the birds’ immune humoral response, but the best CIR was observed at the intermediate methionine level. Vaccines administered on the first day of age impaired bird performance up to the 21 st day of age.

Suplementação de vitaminas e minerais orgânicos e sua ação sobre a imunocompetência de frangos de corte submetidos a estresse por calor

The objective of this experiment was to evaluate the effect of diet supplementation with vitamins C and E and organic minerals Zn and Se on immunological parameters of broilers from 1 to 35 days, kept on cyclic heat stress (25 to 32°C) and to evaluate the usefulness of bovine serum albumin (BSA) inoculation to determine humoral immunity. A total of 272 Ross broilers were used to evaluate four types of vitamin-mineral supplementation (VMS): D1- control diet with 60 and 30 IU of vit E for starter and growing diet, respectively, zero vit C, 80 ppm of inorganic Zn, 0.3 ppm of inorganic Se; D2 - control diet + 100 UI vit E and 300 ppm vit C/kg; D3 - control diet + 40 ppm Zn and 0.3 ppm Se/kg, both from organic sources; D4 - control diet and levels of VMS used in D2 and D3), and two environments: thermoneutral (TNA) and cyclic heat stress (CHS) from 14 days of age. Six and five birds per type of supplementation in CHS and TNA, respectively, were inoculated with BSA at 12 and 24 days. Birds serum at 35 days-old was analyzed by ELISA. Supplementation with vitamins and minerals did not influence antibody production of broilers challenged with BSA. Heat stress improved antibody anti-BSA production regardless of the diet. Inoculation with BSA did not influenced broiler performance and was a good strategy to evaluate humoral immunity of broilers, since the birds responded to the challenge improved antibody production and increased bursal size, despite the higher individual variation.

Influence of sulfur amino acid levels in diets of broiler chickens submitted to immune stress

Several changes in amino acid levels occur during an infection. As a rule, glycine, taurine and serine levels diminish considerably, while cysteine levels increase. Such changes may be attributed to the intense consumption of sulfur amino acids (SAA- methionine+cysteine) during infectious challenge. Methionine plays an important role in humoral and cellular immune responses. It has been suggested that such effect is exerted by intracellular glutathione and cysteine levels. Four-hundred thirty-two day-old Ross male broiler chickens were fed (from 1 to 42 days of age) three SAA levels in the diet (0.72, 0.82, and 0.92% from 1 to 21 days of age; 0.65, 0.75, and 0.85% from 22 to 42 days of age) and submitted to two immunological stimulus series. Vaccines against Marek’s disease, Fowlpox, Infectious Bronchitis and Infectious Bursal disease, Freund’s Complete Adjuvant, and avian tuberculin were used as immunological stimuli. The experiment comprised 6 treatments, with 6 replications using 12 birds per replicate. Performance data were collected weekly. Gumboro antibodies were measured by ELISA, and the cellular immune response by the tuberculin test. SAA levels tested did not influence immune response. Nevertheless, the vaccines applied on the 1 st day impaired chick performance up to the 21 days of age. The SAA levels generally adopted in poultry husbandry may not be enough to assure weight gain, especially when birds are raised if a lowchallenge infectious environment.

Desempenho e composição corporal de frangos de corte alimentados com diferentes níveis de proteína e de aminoácidos ou com livre escolha das dietas

An experiment was carried out to evaluate the effect of diets with different protein levels and energy:protein ratio and amino acids on the performance and body composition of broilers (300 males and 300 females from 1 to 49 days of age), as well as the effect of these factors on the nutrients utilization efficiency. Three isoenergy experimental diets (D) were used (3000 and 3150kcal ME/kg for starter and growing phase, respectively) varying the levels of crude protein (CP) and the first 4 essential amino acids (AA) (lysine, methionine+cysteine, threonine and tryptophan): D1, control, with 22%CP; D2: 24%CP and 20% more AA than D1 (HighCP+20%AA) and D3, 20% CP and 12% less AA than D1 (LowCP-12%AA). On the growing phase the CP were 20, 22 and 18% for D1, D2 and D3, respectively, keeping the same AA proportion. A fourth diet was defined by free-choice between diets D2 and D3. Birds were alloted in a completely randomized design, in a 2 x 4 factorial (sex x diets) scheme and 5 replications of 15 birds each per treatment. Comparative slaughter technique was used for body fat and protein gain. Birds fed LowCP-12%AA diets showed reduced feed conversion, gain and body protein gain, but better protein intake-to-gain ratio. Broilers fed HighCP+20%AA diets had worse protein intake-to-gain ratio, but similar weight gain, cuts or carcass weight to control or free-choice birds. Fat and protein gain were similar among those 3 treatments. Free-choice birds showed the same performance and body composition of the control broilers. LowCP-12%AA diet was worse for broilers in starter phase than in growing phase. Male broilers were more efficient than females using nutrients, specially in the growing phase.

Effects of the reduction of dietary heat increment on the performance, carcass yield, and diet digestibility of broilers submitted to heat stress

This experiment aimed at verifying the effect of different diets and thermal environments on the performance, carcass yield, and diet digestibility of 21 to 42-day-old broilers. A total number of 288 21-dayold male Ross broilers were distributed in a 2 x 2 + 2 factorial arrangement, with six replicates, including the following factors: two environments (TNE – thermoneutral: 21-25°C and 73% RH; CHS – cyclic heat stress: 25-32°C and 65%RH), and two diets (control: 2.4% soybean oil and 19.5% protein; summer: 4.0% soybean oil and 18.5% protein). In TNE, two additional treatments were included with feed restriction of birds fed both the control and summer diets (pair-feeding), thereby maintaining the same feed intake level for both types of diet. Diet did not influence performance, dry matter and protein digestibilities, or carcass and part yields. TNE birds had better performance (p<0.001) as compared to CHS birds, but FCR was not different. CHS birds had lower breast yield (p<0.0001), and higher thigh yield (p<0.02) than TNE birds. In the pair-feeding treatments, environment did not influence performance, but dry matter digestibility was significantly lower in CHS (p<0.03), whereas protein digestibility was not affected. The difference in feed intake was the main responsible factor for the variation in the performance of heat-stressed birds.

Species distribution and antimicrobial susceptibility of enterococci isolated from broilers infected experimentally with Eimeria spp and fed with diets containing different supplements

Resistant bacteria in animal can be spread to environment and to humans. Poultry feed and infections caused by Eimeria spp. are important factors in determining the intestinal microbial communities. The aim of this study was to verify the prevalence of species and antimicrobial susceptibility of Enterococcus isolated from broilers fed with different supplements and infected experimentally with Eimeria spp. Broilers were divided in eight groups, fed with diets supplemented with a combination of antimicrobial, ionophore-coccidiostatics, probiotic, essential oil. At 14 days old all birds, except the control, received a solution containing oocysts of Eimeria spp. Samples of cloacal swabs from broilers were collected. A total of 240 Enterococcus sp. strains were isolated, confirmed genus by PCR, classified as species, tested for antimicrobial susceptibility and screened by PCR for the presence of tet(L), tet(M) and erm(B) genes. The overall distribution of species isolated from fecal samples was E. faecalis (40%), followed by E. casseliflavus/E. gallinarum (10.8%), E. mundtii (10.8%), E. faecium (10.8%), E. columbae (5.8%) and E. gallinarum (4.2%). Changes in the composition or frequency of Enterococcus species were observed in all dietary supplementation. Antimicrobial susceptibility tests showed resistance phenotypes a range of antibiotics, especially used in humans such as, streptomycin, penicillin, rifampicin and vancomycin. There was no correlation between different supplementation for broilers and antimicrobial resistance and the presence of tet(M), tet(L) and erm(B) genes. Dietary supplementation had effect on the Enterococcus sp. colonization, but did not have significant effect on the phenotype and genotype of antimicrobial resistance in enterococci.