J. F. M. Menten

Efeito de genótipo e do sistema de criação sobre o desempenho de frangos tipo caipira

The present study evaluated the influence of genotype and rearing system on the performance of alternative lines of broiler chickens. Two experimental lines (Caipirinha and 7P) and two commercial lines (Label Rouge and Paraiso Pedres) were reared under intensive or semi-intensive (access to the pasture area after 21 d of age) in an experiment with eight treatments, four replicates and 35 birds per experimental unit. Corn-soybean meal based feed and water were offered ad libtum in the pen area only, and the chickens in the semi-intensive system had free access to the pasture area. The experiment was terminated when each pen reached 2300 g of average weight. Interaction line x system was detected for variable age at 2300 g (Age 2300) and average daily weight gain; the line Caipirinha on the semi-intensive had Age 2300 increased (79.2 d vs. 73.3 d), while there was no difference for Label Rouge (84.0 d vs. 83.0 d), 7P (62.0 d vs. 62.2 d) and Paraiso Pedres (60.8 d vs. 61.0 d). Feed intake (5688 g) and feed conversion (2.46) for the Label Rouge broilers were different from the others (feed intake from 4304 to 2996 g and feed conversion from 1.87 to 2.17), and rearing system affect these variables. Mortality was not affected by genetic lines or rearing system. The access to pasture in the semi-intensive system did not result in feed economy or improvement in the feed conversion, but resulted in reduction on the daily weight gain (as a consequence of daily feed intake) in the Caipirinha, probably because the birds stayed for a longer period of time in the pasture area.

Óleo de Soja, Óleo Ácido de Soja e Sebo Bovino Como Fontes de Gordura em Rações de Frangos de Corte

The objective of this research was to evaluate less expensive fat sources as alternatives to soybean oil in broiler diets. A total of 1,440 day-old male Ross chicks were raised to 42 days of age in a randomized block design of six treatments and six replicates, fed diets containing 4% supplemental fat from the sources: soybean oil (SOY4), beef tallow (TAL4), acidulated soapstock (SOAP4), mixtures 2%:2% (SOAP2/TAL2), (SOAP2/SOY2) and (SOY2/TAL2). Liveweight, weight gain, feed intake, feed:gain ratio and viability were analyzed using non-orthogonal contrasts: 1- SOY4 X (SOAP4 + TAL4 + SOAP2/TAL2); 2- SOY4 X (SOAP2/SOY2 + SOY2/TAL2); 3- SOAP2/SOY2 X SOY2/TAL2; 4- SOAP4 X SOAP2/SOY2; 5- SOAP4 X SOAP2/TAL2. Liveweight, weight gain and feed:gain of SOY4 were better (p .05) and soybean oil in the mixture equally improved the results of the alternative sources (contrast 3). The performance of birds fed SOAP4 was inferior to those fed SOAP2/SOY2 (p<.06) but was similar to those fed SOAP2/TAL2 . The abdominal fat did not differ among the treatments, but abdominal fats reflected the composition of the different fats. These results confirmed the superiority of soybean oil relative to the other fat sources fed to broiler and demonstrated that the quality of acidulated soapstock and beef tallow may be improved when used in 1:1 mixtures with soybean oil.

Mixture of formic and propionic acid as additives in broiler feeds

The presence of Salmonella species in feeds and ingredients is an important source of salmonella contamination for animals. Organic acid mixtures have shown to be an effective alternative to eliminate salmonellas in feeds and chickens. In the present study, the performance of male broiler chickens receiving levels (0, 0.25, 0.50, 1.0 and 2.0%) of a mixture of organic acids (OAs) (70% formic acid and 30% propionic acid) in the diet was evaluated from the age one to 42 days, in a completely randomized experimental design with five treatments and five replications of 40 birds each. Diets were based on corn, soybean meal and soybean oil. Body weight, weight gain and feed intake from the age one to 21 days were affected by the treatments; 2% OAs in the diet reduced body weight and weight gain. Feed intake increased with concentrations of 0.25 and 0.5% and was reduced with 2% of OAs. From the age one to 42 days, only feed intake was affected, showing a quadratic effect, increasing at the levels of 0.25 and 0.5% and decreasing at 2% of OAs. The mixture of OAs at doses which are effective for the control of salmonella did not affect chicken performance, and the inclusion of 1% OAs in the diet resulted in a performance similar to that of untreated birds.

Influência do sistema de criação sobre o desempenho, a condição fisiológica e o comportamento de linhagens de frangos para corte

The objectives of this research were to evaluate the influence of rearing systems (intensive or semi-intensive) on the performance (body weight and feed efficiency), chicken physiological condition under heat stress (rectal temperature, respiratory frequency and hematocrit) and behavioural parameters (frequency in the pasture areas) of broilers lines. To evaluate broilers performance and physiological condition on the ages of 45, 55, 65 and 75 days one experiment was carried out in boxes with 4,5 m2 of inside area and 35 m2 of outside area were 35 broilers were reared in each box. Another experiment was carried out to evaluate the frequency of broilers it the pasture areas from 35 to 75 days of age. One of the evaluated lines did not show adaptation to the semi-intensive rearing system. Significant differences were found in broilers performance and physiological conditions in both systems. In the semi-intensive rearing system the rectal temperature, respiratory frequency, hematocrit and feed efficiency were smaller and body weight larger than in the intensive rearing system. It was concluded that the semi-intensive rearing system provided conditions that increased broilers welfare and positively influenced the physiological conditions and performance of the broilers.

Extratos vegetais em dietas para frangos de corte

ABSTRACT - The trial was carried out to evaluate different blends of plants extracts in broilers diets. It was used 1,350broilers distributed in a randomized block design with six replicates and five diets, one without additive and the four others,each containing one of the following additives: 10 ppm of avilamycin; 200 ppm of a product containing essential oils ofcarnation, thyme, cinnamon and microencapsulated capsicum; 100 ppm of a product containing essential oils of syntheticcinnamaldehyde and carvacrol and capsicum oleoresin microencapsulated; 500 ppm of a commercial product containingeucalypt oil, essential oil of Chinese cinnamon, leaves of Chilene boldo and seeds of fenu-Greek at the initial phase and1200 ppm in the grower and finisher phases. Performance parameters were evaluated at 21 and 42 days of age and the carcasscharacteristics at 44 days of age. From 27 to 30 days of age, it was carried out the metabolism trial trough total excretacollection method and metabolizable energy and the crude protein digestibility of the diets were determined. The diets withplant extract blends had no significant effect on the performance when compared to diet without additives or diet withavilamycin. The lack of challenge in the experimental facilities and the use of diets with high digestibility ingredientsmight have contributed to broilers express all their potential making undetectable the improvement made by the inclusionof any of these additivies. Diets with plant extract blends promote performance similar to those obtained with dietscontaining avilamycin.Key Words: additives, carcass characteristics, metabolic assay, performance

Diferentes fontes de proteína na dieta pré-inicial de frangos de corte

ABSTRACT - The purpose of this study was to determine the N-corrected apparent metabolizable energy (EMAn) of alternativeprotein ingredients, for newly hatched chicks, and to evaluate the effects of the utilization of these ingredients in the first week broilerfeed, on the performance and gastrointestinal tract (TGI) development. In the metabolism trial, 288 male chicks from 4 to 7 day s wereallotted to a completely randomized design with six treatments (a reference diet and five diets with inclusion of the test ingr edients) andfour replicates of 12 birds. The ingredients evaluated were: isolated soy protein (IS), dried whole eggs (OP), blood plasma (PS ), corngluten meal (GM) and dried sugar cane yeast (LS). To evaluate the performance and TGI, 624 birds were allocated in brooder batt erieswith six treatments and four replicates of 26 birds. The treatments were: 1 - corn and soybean meal diet, 2 - corn and soybean meal diet+ IS, 3 - corn and soybean meal diet + OP, 4 - corn and soybean meal diet + PS, 5 - corn and soybean meal diet + GM and 6 - cor n andsoybean meal diet + LS. The birds received the treatments only from 1 to 7 days. Birds were sampled at 1, 4 and 7 days of age i n orderto evaluate the TGI organs. The EMAn of the ingredients determined for chicks in the first week were 2,110; 5,095; 3,831; 3,374 and2,037 kcal/kg (as-fed basis) for IS, OP, PS, GM and LS, respectively. In general, the performance of the birds from 1 to 7 days was affectedby the different treatments, but this effect was not maintained up to 21 days. The different protein sources affected the TGI d evelopment,but these effects did not explain broiler performance.Key Words: broilers, gastrointestinal tract, metabolizable energy, newly hatched chick diets, performance, protein

Estresse térmico durante o pré-abate em frangos de corte

The chicken meat chain in Brazil is an important sector of agribusiness, accounting for the third largest worlds production and first place in exports. To meet this demand, it is essential to minimize management problems, which cause the appearance of physiological problems. The intensive genetic selection used to obtain faster growth rates for broilers contributed for the current improved strains to become very susceptible to heat stress. When the environment temperature rises above the thermoneutrality zone, the bird is submitted to a stress condition, which can generate acute hyperthermia, respiratory alkalosis, electrolyte imbalance, reduction in food consumption, lower growth rate, increased mortality rate and even negative effects on meat quality due to the incidence of pale meat and dark in other cases, interfering in properties such as industrial yield, water holding capacity, color and tenderness. The results of the evaluation of quality parameters observed in literature showed that the heat stress, chronic or acute, suffered by broiler chickens, generates negative consequences on the functional properties of meat. Further studies with this research line should be conducted, mainly in Brazil, for being a tropical country with high temperatures in the summer in order to understand, prevent and overcome the extent or intensity of this stress, avoiding problems and damages to the meat chain.

Variabilidade espacial da comunidade bacteriana intestinal de suínos suplementados com antibióticos ou extratos herbais

This trial was conducted to evaluate the effect of antimicrobial supplementation (association of 50 ppm of colistin, 50 ppm of zinc bacitracin and 50 ppm of olaquindox) or herbal extract (based on thyme, clove and oregano at levels of 0, 700, 1,400 and 2,100 ppm) on Bacteria population of duodenum, jejunum, ileum and cecum of swine at 56 days old. Denaturing gradient technique in polyacrylamide gel electrophoresis (DGGE) of amplicons from 16S rDNA V3 region was used. The number of detected amplicons changed according to intestinal segment analyzed and supplementation with growth promoter. Antibiotic and herbal extract decreased diarrhea incidence. Performance of animals supplemented with increasing levels of herbal extract and antibiotic was similar. The highest level (2,100 ppm) of herbal extract showed greater values of weight gain. It was possible to determine relations among the number of amplicons observed in the four segments of intestinal tract, growth promoter, daily weight gain and diarrhea incidence. The structure of Bacteria population of the intestinal tract of swine showed higher similarity, due to the sampling site than the growth promoter.

Uso de plasma suíno desidratado por Spray-Dryer na dieta de leitões desmamados precocemente

The objective of this work was to evaluate the spray-dried porcine plasma (SDPP) in the diet of 21 day-weaned pig. One hundred and twenty piglets averaging 5.75 kg of initial weight were used to test the inclusion levels of 0, 2.5, 5.0, and 7.5% of porcine plasma on phase 1 (from 0 to 14 days) and its effects on phase 2 (from 15 to 28 days). Except for the piglets in the control diet, all other animals were fed a starter diet with 2.5% of SDPP and 2.5% of spray-dried red blood cell (SDBC) during 15 to 28-day-post weaning period. The diets were formulated to contain in the phases 1 and 2, respectively, 1.4 and 1.2% of lysine, .54 and .42% of methionine, and 15 and 8% of lactose. A randomized block design with five replications and six animals per experimental unit was used. Average daily feed intake increased linearly in the phases 1 and 2, with the increasing level of SDPP. For overall period (from 0 to 28 days), there was linear response of average daily feed intake to the SDPP levels in the phase 1.The SDPP stimulated higher daily feed intake during the two weeks after weaning. This effect was maintained during the second phase (15 to 28 days post weaning), when a combination of 2.5% SDPP and 2.5% SDBC was used.

Foundation and perspectives of the use of plant extracts as performance enhancers in broilers

Feed is responsible for about 70% of broilers production costs, leading to an increasing number of studies on alternative dietary products that benefit bird performance and lower production costs. Since the 1950s, antimicrobial additives are the most frequently used performance enhancers in animal production and their positive results are observed even in high-challenge conditions. Since the 1990s, due to the ban of the use of some antibiotics as growth promoters and the growing trend of the public to consume natural products, plant extracts have been researched as alternatives to antibiotic growth promoters. The first study that evaluated the antibacterial activities of plant extracts was carried out in 1881; however, they started to be used as flavor enhancers only during the next decades. With the emergence of antibiotics in the 1950s, the use of plant extracts as antimicrobial agents almost disappeared. There are several studies in literature assessing the use of plant extracts, individually or in combination, as antimicrobials, antioxidants, or digestibility enhancers in animal feeds. Research results on the factors affecting their action, such as plant variety, harvest time, processing, extraction, as well as the technology employed to manufacture the commercial product and dietary inclusion levels show controversial results, warranting the need of further research and standardization for the effective use of plant extracts as performance enhancers, when added to animal feeds. This article aims at presenting plant extracts as alternatives to antibiotics, explaining their main modes of action as performance enhancers in broiler production.