Maitê de Moraes Vieira

Fatty-acid composition of free-choice starter broiler diets.

Two experiments were carried out to evaluate the inclusion of vegetable oils with different fatty acid content in starter and pre-starter broiler diets. In Experiment I 480 1- to 9-day-old male Ross 308 broilers were fed diets containing corn oil (CO), acid corn oil (ACO), linseed oil (LO) or coconut fat (CoF). Chicks were distributed according to a factorial 2x2x2arrangement (2 free fatty acids - FFA ) x (2 n6:n3 ratios) x (2 medium-chain fatty acids levels - AGMC). Performance responses and dry matter (DMM), crude protein (CPM), and crude fat (CFM) metabolizability were evaluated. In Experiment II, 480 1- to 20-day-old male Ross 308 broilers were offered the free choice of 2 different diets: with no fat addition, or with 10% addition of the following fat sources: CO, LO, CoF, soybean soapstock (SBS), acid soybean oil (ASO), or acid cottonseed oil (ACtO). Performance responses and diet selection were evaluated. In experiment I, there were no significant effects of the diets on performance, DMM, or CPM; however, the inclusion of FFA depressed CFM. In experiment II, there was a marked preference of birds of the diets with fat inclusion, leading to the selection of diets with more than 3100 kcal/kg ME in the period of 1 to 20 days, independently of fat source. The broilers selected the high fat and energy diets since the first days of age, which resulted in better bird performance.

Effect of vitamin E levels on the cell-mediated immunity of broilers vaccinated against coccidiosis

Studies on the relationships between animal nutrition and immunity have sought reliable methodologies to measure responses. Cellmediated immune response is similarly studied in humans. The cutaneous basophil hypersensitivity test (CBH) is one of the methods to measure that response and consists in the infiltration of inflammatory cells, particularly of lymphocytes and basophils, as result of the application of substances capable of inducing cell proliferation in determined sites, such as wings, wattle, and interdigital space in birds. CBH is considered a simple and fast method and can be applied in birds of different ages. In immunocompetence studies with poultry, phytohemagglutinin-P (PHA-P) is a commonly used substance, despite the variability of the response related to the method of application (intradermal injection) and the antigens used. In the present experiment, PHA-P was used to observe the cell-mediated immune response of 216 chicks fed three dietary levels of vitamin E from 1 to 36 days of age. All birds were immunologically challenged by vaccination against coccidiosis at three days of age and against Newcastle Disease (NCD) at 14 and 30 days of age. At 36 days of age, birds were submitted to the CBH test according to the methodology of Corrier & DeLoach (1990). Birds fed 65mg/kg of vitamin E presented lasting cell reaction (p £0.08), which indicates that this vitamin E level improved cell immune response of birds due to its antioxidant and immunomodulating properties. The use of this vitamin E level can be considered by nutritionists under practical conditions, aiming to improve broiler immunity.

Nutrient balance of layers fed diets with different calcium levels and the inclusion of phytase and/or sodium butyrate

In this study, Hisex Brown layers in lay were evaluated between 40 and 44 weeks of age to evaluate the inclusion of bacterial phytase (Ph) and sodium butyrate (SB) to diets containing different calcium levels (CaL). Performance, average egg weight and eggshell percentage, in addition to nutrient metabolizability and Ca and P balance were evaluated for 28 days. Birds were distributed according to a completely randomized experimental design with a 3x2x2 factorial arrangement, with three calcium levels (2.8, 3.3, 3.8%); the addition or not of phytase (500PhU/kg) and the addition or not of sodium butyrate (20mEq/kg), composing 12 treatments with eight replicates of one bird each. There was no additive effect of phytase or SB on the evaluated responses. Feed intake and feed conversion ratio were influenced by CaL, with the best performance obtained with 3.3% dietary Ca. Ca balance was positively affected by dietary Ca, and P balance by the addition of phytase. Ca dietary concentration, estimated to obtain Ca body balance, was 3.41%, corresponding to an apparent retention of 59.9% of Ca intake.

Determination of apparent metabolizable energy of crude glycerin in broilers chickens.

The objective of the experiment was to determine the Apparent Metabolizable Energy corrected for nitrogen (AMEn) of a glycerin product derived from biodiesel production for broilers. A number of 35 male Ross 308 broilers, with 35 days of age was fed ad libitum diets containing 0, 5, 10, 15, or 20% glycerin. AMEn was determined using total excreta collection, with four days of adaptation and three days of collection. Increasing glycerin intakes resulted in increased water excretion. Glycerin AMEn varied as a function of dietary inclusion levels, and a cubic equation was identified by regression analysis. Maximum AMEn level- 4890 kcal/kg DM- was obtained with 15% glycerin inclusion. However, this level caused excessive water excretion, making its use unpractical.

Feeding different levels of vitamin E and selenium has no effect on serum immunoglobulin Y (IgY) production by layers vaccinated against Escherichia coli and avian encephalomyelitis virus

The effects of vitamin E and selenium (Se) supplementation on the immunity of hens vaccinated against a mixture of six swine-pathogenic Escherichia coli (EC) and avian encephalomyelitis virus (AEV) were studied. Antibody production (AbP) was evaluated in ninety 49 to 57-weekold H&N Nick Chick hens fed diets containing 14IU Vitamin E kg-1 (basal diet), 27, 59, 111, or 111IU vitamin E kg-1 + 0.56ppm Se supplementation. At 51 wks of age, half of the hens were vaccinated against EC, and all birds were vaccinated against AEV. At 53-weeks of age, the birds received a second dose of EC vaccine. Blood samples were collected weekly and serum was analyzed by ELISA for antiEC IgY and was expressed as optical density (OD). Vaccinated hens had higher serum OD than the non-vaccinated hens (P≤0.05). Vaccinated hens fed 27 and 59IU of vitamin E/kg had a higher (P<0.05) serum OD than hens fed 111IU + Se. Neither EC nor AEV seem to be appropriate models for the study of the influence of micronutrients on immune responsiveness of older hens.

Efficacy of hyperimmunized hen egg yolks in the control of diarrhea in newly weaned piglets

The effect of a hyperimmunized (GLOBIGEN®) hen egg yolk–based product was evaluated for the control of diarrhea caused by enterotoxigenic Escherichia coli (ETEC) F4 and F18 in newly weaned piglets. The negative control (NC) animals were not challenged and received 40 ppm of colistin as a growth promoter, 2300 ppm of zinc, and 150 ppm copper. The other three treatments were all challenged with ETEC F4 and F18: 0.2% GLOBIGEN®, 4% dry porcine plasma (DPP), and a positive control (PC). Animals on GLOBIGEN® does not differ from NC (p > 0.05) in weight gain. They also had better feed efficiency than DPP (p < 0.05). Animals in GLOBIGEN® did not present diarrhea as was seen in DPP and PC. GLOBIGEN® also showed reduced F4 and F18 (p < 0.05) excretion compared to PC. The results of this study suggest that GLOBIGEN® acts efficiently in diarrhea control, being a viable alternative to the use of antibiotics in newly weaned piglets.

Respostas fisiológicas e de desempenho de leitões suplementados com B-glucanos e desafiados imunologicamente

ABSTRACT This study was done to evaluate immunological responses and performance of weaning piglets receiving diets with different levels of β -glucans. Thirty males from a commercial line with 34 days of age and 10.9±0,6kg initial weight were housed in individual metabolic cages during 14 days. The treatments only differed in β -glucans levels: 35; 70; 140 and 280g/T. On the 14 th day, half of the pigs were inoculated with 2.7mg LPS (lipopolysaccharide)/mL of solution (PBS)/pig and the other half received 1mL PBS/pig. Rectal temperature (RT), respiratory frequency (RF), biochemical profile and animal behavior (120 and 390 minutes after LPS inoculation) were evaluated. As the experiment was conducted, performance was not affected by β -glucans. An RT increase was observed due to LPS and time of temperature measurement. LPS- injected animals receiving 280g/T of β -glucans had the same RT as the LPS- non injected group. Clinical signs were near the expectation for acute inflammation. LPS-injected presented

Inclusão de ácidos graxos de cadeia curta em diferentes níveis de cálcio na dieta de frangos de corte

Ninety six Cobb male broilers from 21 to 31 days of age were fed including short chain fatty acids (SCFA) and different level of calcium. Calcium (Ca), phosphorus (P), balance, dry, organic and mineral matter metabolizability, crude energy and crude protein metabolizability, tibia ash percentage and animal performance were measured. Experimental diets were assigned in a 5x4 factorial arrangement (without acids, formic acid, acetic acid, propionic acid and butyric acid) x (0.40, 0.59, 0.78 and 0.97% of Ca) in a randomized completely design. Increasing Ca levels affected positively and in a quadratic form Ca and P balance and the best levels were estimated at 0,87% and 0,75% of Ca dietary, respectively and affected linearly dry, organic matter metabolizability and tibia ash percentage. However, the efficiency of Ca retention was decreased quadratically with the increase of Ca level. The SCFA did not show detectable effects on the studied responses, and no interaction with dietary levels of Ca used. The estimated Ca requirement considering calcium balance was 0.87%.

Reproductive success or failure in four breed groups of beef bulls

The objective of this study was to determine the main causes of failure in bull breeding using a soundness evaluation in Rio Grande do Sul State/Brazil. We evaluated 19,836 bulls from 15 different breeds with ages ranging from two to eight years. The failures of bulls in each step were analyzed by logistic regression. The binary logistic regression was applied because the response variable had only two responses: Success (1) and Failure (0). Older bulls are more likely to be rejected than are younger bulls, regardless of their genetic group. Depending on the step of the assessment, one or another group is rejected. All steps of bull breeding soundness evaluation (BBSE) are important, with special attention to the failures of the behavioral evaluation (libido and physical ability). A BBSE performed before the breeding season reduces the risk of sub-fertile bulls in the herd.