Effect of dietary betaine supplementation on the performance, carcass yield, and intestinal morphometrics of broilers submitted to heat stress

The objective of this study was to evaluate the effect of betaine in methionine- and choline-reduced diets fed to broilers submitted to heat stress. In total, 1,408 male broilers were randomly distributed into eight treatments, according to 2 × 4 (environment x diet) factorial arrangement, with eight replicates of 2 birds each. Birds were reared environmental chambers under controlled temperature (25-26 °C) or cyclic heat-stressing temperature (25-31 °C). The following diets were tested: positive control (PC), formulated to meet broiler nutritional requirements; negative control (NC), with reduced DL-methionine and choline chloride levels; and with two supplementation levels of natural betaine to the negative control diet (NC+NB1 and NC+NB2). Live performance, carcass traits, and intestinal morphometrics were evaluated when broilers were 45 days of age. The results showed that all evaluated parameters were influenced by the interaction between environment and diet, except for breast meat drip loss. The breakdown of the interactions showed that birds fed the PC diet and reared in the controlled environment had greater breast drip loss than those submitted to the cyclic heat-stress environment. Birds submitted to cyclic heat stress and fed the PC diet presented the lowest feed intake. Feed conversion ratio was influenced only by diet. The FCR of broilers fed the NC+NB2 diet was intermediate relative to those fed the PC and NC diets. The addition of betaine in the diet, with 11.18% digestible methionine and 24.73% total choline reductions, did not affect broiler live performance, carcass yield, or intestinal morphometrics.

Effects of dietary clinoptilolite and calcium levels on uric acid and calcium blood concentrations and bone quality of commercial layers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Methane emissions and estimates of ruminal fermentation parameters in beef cattle fed different dietary concentrate levels

Using sorghum silage, the effect of roughage/concentrate ratios was evaluated on nutrient intake, digestibility, ruminal parameters and methane production by beef cattle. Three treatments (0, 30 and 60% of concentrate in DM of the diet) were distributed in three Latin squares, with nine animals and three periods. Dry matter intake increased as the grain concentration in diet increased; pH showed opposite behavior. Methane emissions were lower for animals fed the diet exclusively with sorghum silage as compared with those fed 30% of concentrate, but was similar to that of animals receiving 60% of concentrate. Losses of ingested gross energy as methane were reduced by 33% when grain concentration was increased in the diet. Concentrations of propionic and butyric acids were greater in diets with grain concentrate; acetic acid concentration was not affected. Concentrate in diet increases available energy for the metabolism, measured by lower losses of ingested gross energy as ruminal methane. © 2013 Sociedade Brasileira de Zootecnia.

A procedure to evaluate the efficiency of utilization of dietary amino acid for poultry

The aim of this study was to develop a procedure based on Gompertz function to determine the efficiency of utilization of amino acid. The procedure was applied to determine the efficiency of utilization of dietary lysine, methionine+cystine and threonine by growing pullets and based on the efficiencies were estimated the requirements for the growth phase of birds. The Gompertz function was fitted to the data of feed intake, body weight, feather-free body protein weight and feather protein weight of four strains of laying hens in the growth phase. The rates of consumption and daily protein deposition (PD) were calculated. The amino acid deposition was obtained by multiplying the PD by the amino acid concentration in feather protein and feather-free body protein. The results showed that the efficiency of utilization of amino acid decreased with maturity and, conversely, there was a proportional increase of the requirement per kg of weight gain. The procedure based on the Gompertz function to determine the efficiency of utilization of amino acid proved to be suitable to evaluate the efficiency of utilization of amino acid and can be a useful tool to diagnose the effectiveness of the nutritional management, aiding in decision-making on the nutritional management.

Effect of lipid sources with different fatty acid profiles on the intake, performance, and methane emissions of feedlot Nellore steers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of excessive energy intake and supplementation with chromium propionate on insulin resistance parameters in nonlactating dairy cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acerola (Malpighia emarginata DC.) juice intake protects against alterations to proteins involved in inflammatory and lipolysis pathways in the adipose tissue of obese mice fed a cafeteria diet

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Modelling of the nitrogen deposition and dietary lysine requirements of Redbro broilers

The aim of this study was to determine the coefficients of the Goettingen model for Redbro birds and estimate the digestible lysine requirements. To determine the model parameters, three nitrogen balance trials were performed in Periods I (14-28 days), II (42-56 days) and III (70-84 days), using 42 birds per trial. The birds were individually housed and subjected to six diets with increasing levels of nitrogen, with lysine as the limiting amino acid (deficient by 20% in relation to other amino acids). Dietary nitrogen concentrations were 8, 16, 24, 32, 40 and 48 g/kg. A control diet was added to confirm lysine as the first limiting amino acid. Nitrogen balance trials were divided into 5 days of adaptation and two periods of excreta collection, each one of 5 days. The response of the birds to a control diet confirmed that lysine was the first limiting amino acid. The adjustment of the exponential functions between nitrogen retention or excretion and nitrogen intake allowed estimation of parameters of the Goettingen model. The maximum potential for nitrogen retention was 3276, 2585 and 2603 mg/BWkg0.67.day, nitrogen maintenance requirement was 225, 135 and 122 mg/BWkg0.67.day and efficiency of nitrogen utilisation was 313 x 10(-6), 406 x 10(-6) and 415 x 10(-6) in the phases of 14-28, 42-56 and 70-84 days. The digestible lysine intake for Periods I, II and III, based on 60% of the maximum potential for nitrogen retention, was 711, 989 and 1272 mg/day (1.225%, 1.137% and 1.09% of lysine in the diet for a daily feed intake of 58, 87 and 117 g/day), respectively.

Effect of dietary energy concentration on performance parameters and egg quality of white leghorn laying hens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Meta-analysis of the response of broilers to the digestible lysine intake

Pós-graduação em Zootecnia - FCAV

Exercise and oxidative stress: p,otential effects of antioxidant dietary strategies in sports

Free radicals are produced during aerobic cellular metabolism and have key roles as regulatory mediators in signaling processes. Oxidative stress reflects an imbalance between production of reactive oxygen species and an adequate antioxidant defense. This adverse condition may lead to cellular and tissue damage of components, and is involved in different physiopathological states, including aging, exercise, inflammatory, cardiovascular and neurodegenerative diseases, and cancer. In particular, the relationship between exercise and oxidative stress is extremely complex, depending on the mode, intensity, and duration of exercise. Regular moderate training appears beneficial for oxidative stress and health. Conversely, acute exercise leads to increased oxidative stress, although this same stimulus is necessary to allow an up-regulation in endogenous antioxidant defenses (hormesis). Supporting endogenous defenses with additional oral antioxidant supplementation may represent a suitable noninvasive tool for preventing or reducing oxidative stress during training. However, excess of exogenous antioxidants may have detrimental effects on health and performance. Whole foods, rather than capsules, contain antioxidants in natural ratios and proportions, which may act in synergy to optimize the antioxidant effect. Thus, an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain an optimal antioxidant status. Antioxidant supplementation may be warranted in particular conditions, when athletes are exposed to high oxidative stress or fail to meet dietary antioxidant requirements. Aim of this review is to discuss the evidence on the relationship between exercise and oxidative stress, and the potential effects of dietary strategies in athletes. The differences between diet and exogenous supplementation as well as available tools to estimate effectiveness of antioxidant intake are also reported. Finally, we advocate the need to adopt an individualized diet for each athlete performing a specific sport or in a specific period of training, clinically supervised with inclusion of blood analysis and physiological tests, in a comprehensive nutritional assessment. (C) 2015 Elsevier Inc. All rights reserved.

Dietary fiber as fat substitute in emulsified and cooked meat model system

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The optimal lysine and threonine intake for Cobb broiler breeder hens using Reading model

This study aimed to determine the optimal intake of lysine and threonine for broiler breeder hens. Two experiments were conducted to evaluate the responses of birds to digestible lysine (Lys) and threonine (Thr). Eight treatments were assessed in both experiments, with six replicates of eight birds in the Lys experiment and ten birds in the Thr experiment. The dietary levels of Lys and Thr were obtained by a dilution technique. The experimental period was ten weeks for each amino acid studied, which included six weeks of adaptation and four weeks of data collection. The amino acid intake, egg mass and body weight were adjusted using a Reading model. Based on the model coefficients, the cost of the synthetic amino acids sources and the price of fertile eggs determined the intake of each amino acid to maximize. The minimum intake of Lys and Thr reduced egg production by 40 and 30%, respectively, the weight of the eggs decreased by 12 and 9% with the same intake of Lys and Thr, respectively. The models generated by predicting Lys and Thr intake were as follows: Lys=11 x E+31 x W and Thr=9.5 x E+32 x W, where E=egg mass, g/bird per day, and W=body weight, kg/bird. Based on the models, 3 kg birds with an egg mass production of 50 g/day require 643 mg/bird per day of Lys and 569 mg/bird per day of Thr. The optimum economic intake was calculated at 954 and 834 mg/bird per day for Lys and Thr, respectively, reflecting a dietary concentration of 0.636% Lys and 0.556% Thr for a feed intake of 150 g/bird per day. (C) 2015 Elsevier B.V. All rights reserved.

The response to dietary threonine in laying-type pullets during growth

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Strategic use of dietary electrolyte balance and ratio for broiler chickens

The literature reports dealing with the dietary electrolyte ratio (K+Cl)/ Na are rare, although the concept has been proposed by Mongin in 1981. Thus, its application appears to be limited as a nutritional strategy in feed formulation, which usually meets only the minimum nutritional recommendations in Na, K and Cl. The objective of this study was to evaluate the performance of broilers submitted to different dietary electrolyte balances (DEB) Na+K-Cl and dietary electrolyte ratio (DER) from 1 to 21 d of age. A total of 1575 male 1-d old broiler chicks were randomly assigned to 5 treatments with 9 replicates of 35 chicks each. The treatments consisted of diets with 5 relation of electrolytes, arising from combinations DEB/DER 150/3, 250/2, 250/3, 250/4 and 350/3, with use of NaCl, NaHCO3, KCl, K2SO4 and CaCl2. All diets were corn-soybean meal based and formulated to meet or exceed the NRC (1994) requirements. Chicks had ad libitum access to feed and water in floor pens with wood shavings as litter. Body weight, feed intake and feed conversion ratio were measured at 21 d of age. It was found that only the feed conversion was significantly affected (P = 0.0142) by the combinations of relation of electrolytes (DEB and DER). The supplementation levels in DEB and DER were made to fit the data into a surface analysis to allow increasing levels of DEB (150–350 mEq/kg) and narrow and broad ratio of DER (2–4). For the canonical analysis of response surface was obtained the stationary point for body weight (DEB = 255.77 mEq/kg, and DER = 2.73:1) the value was 942.02 g; for feed intake (DEB = 251.69 mEq / kg and DER = 3.51:1), the value was 1200.02 g; and for feed conversion (DEB = 254.62 mEq/kg and DER = 3.06:1) the value was 1.35. The results of this experiment indicated that the best performance was obtained with combinations of relation of electrolytes for DEB between 251 and 255 mEq/kg and DER between 2.73:1 and 3.5:1.