Influence of environmental temperature, dietary energy level and sex on performance and carcass characteristics of pigs

Pigs are quite sensitive to high environmental temperatures and the thermoregulation mechanisms represent great expenses in energy for heating loss, reducing animal well-being and production performance, and altering carcass quality. The aim of this study was to assess the effects of sex and dietary energy level in growing-finishing pigs submitted to characteristic seasonal variation of temperature in subtropical humid climate, and to propose a mathematical model to predict growth performance and carcass characteristics. Twenty-eight crossbred growing-finishing pigs were randomly allotted to twelve treatments, in a 2x2x3 factorial trial (2 sex; 2 environmental conditions, and 3 energy levels). Heat stress condition (climatic chamber) showed temperatures of 31 oC at 7:00 and 22 oC at 17:00 (maximum of 33 °C) and thermal comfort condition (stall) showed temperatures of 18 °C at 7:00 and 24 °C (maximum of 27 °C). Pigs were fed ad libitum with diets containing 12.2 (low), 13.6 (medium) and 15.0 (high) MJ ME/ kg DM. Voluntary feed intake, daily weight gain, and final body weight were higher (P<0.01) at thermal comfort condition and were influenced by sex (P<0.01) in growing pigs. Feed to gain ratio decreased as the energy level increased (P<0.01), with values of 2.67, 2.59, and 2.32 (12.2, 13.6, and 15.0 MJ ME/kg DM, respectively). There was energy level and sex interaction only for daily weight gain. Regarding finishing pigs, environmental conditions also showed effects (P<0.01) on voluntary feed intake, daily weight gain, and final body weight. Performance of pigs was better at thermal comfort condition. Feed to gain ratio values were 3.55, 3.42, and 2.95 for low, medium, and high energy level, respectively. Interactions between energy level and sex were observed for voluntary feed intake, daily weight gain, and final body weight (P<0.05). Carcass yield and quality were affected by environmental condition and dietary energy level. Both hot and cold carcass weight increased as energy of ration increased. Cold carcass weight increased by 1.142 kg/MJ EM whereas backfat thickness was up to 252 mm/MJ EM. Longissimus thoracis muscle thickness was around 16 mm smaller in pigs under heat stress, but lean content was 2.68% higher in those animals. Regression equations were proposed to predict the performance values in the different situations studied.

In vitro evaluation of the effect of dietary acids and toothbrushing on human root dentin permeability

OBJECTIVES: The purpose of this in vitro study was to quantify the alterations in human root dentin permeability after exposure to dietary acids and to evaluate the effect of toothbrushing after acid application. METHOD AND MATERIALS: Extracted human third molars had their crowns sectioned above the CEJ, pulp tissue removed, and cervical root dentin exposed using a high-speed bur (approximately 1 mm in depth of substance loss). From each root fragment, one specimen was prepared. A total of 25 specimens were used and distributed randomly into five groups. The specimens were attached to a hydraulic pressure apparatus to evaluate the alterations of root dentin permeability after exposure to different acids. Dentin permeability was measured after the following sequential steps: (1) treatment with EDTA for 3 minutes to obtain the maximum permeability; (2) root planing to create a smear layer; (3) exposure to different acidic substances for 5 minutes (vinegar, cola drink, lemon juice, white wine, and orange juice); and (4) brushing for 3 minutes. RESULTS: All acidic substances increased dentin permeability after root planing. Lemon juice produced higher values for permeability when compared to the other substances (P = .009); moreover, orange juice showed similar results (P < .02) except when compared to vinegar (P = .12). Brushing right after acid exposure significantly reduced dentin permeability except in the vinegar group (P = .07). CONCLUSION: Under the experimental conditions, dietary acids increased root dentin permeability, and immediate brushing reduced permeability levels.

Dietary, anthropometric, and biochemical determinants of plasma high-density lipoprotein-cholesterol in free-living adults

The level of high-density lipoprotein is thought to be critical in inhibiting lesion formation as well as reducing the lipid load of preexisting atherosclerotic lesions. With the aim of determining the main determinants of plasma HDL-cholesterol (HDL-c) in free-living adults, 997 individuals (52.3 10 years, 67 females) were selected for a descriptive cross-sectional study. The used data corresponded to the baseline obtained from participants clinically selected for a lifestyle modification program. Covariables of clinical, anthropometry, food intake, aerobic fitness, and plasma biochemistry were analyzed against plasma HDL-c either as continuous or categorized variables. After adjustments for age, gender, and BMI the excess of abdominal fat along with high carbohydrate-energy intake and altered plasma triglycerides were the stronger predictors of reduced plasma HDL-c. In conclusion lifestyle interventions aiming to normalize abdominal fatness and plasma triglycerides are recommended to restore normal levels of HDL-c in these free-living adults. Copyright © 2011 Erick Prado de Oliveira et al.

Differences in dietary pattern between obese and eutrophic children

Background: Excessive consumption of energy is a decisive factor of obesity, but a simple quantitative assessment of consumption between obese and eutrophic individuals not always explains the problem, raising questions about the importance of the qualitative aspects of food. Therefore, the purpose of this study was to evaluate the differences in nutrient composition and meal patterns between eutrophic and obese schoolchildren. Methods. The diet of 83 children (42 obese and 41 eutrophic), aged between 7 and 11 years of age, was assessed by two non-consecutive dietary recalls. After the software analysis of macro and micronutrients composition, the different types and amount of legumes, fruits and vegetables were analyzed to verify the dietary patterns. Results: No differences were verified in energy consumption between the groups (eutrophic = 1934.2 672.7 kcal, obese = 1835.8 621.2 kcal). In general, children showed consumption within the recommended ranges of carbohydrates, lipids and proteins. The average consumption of fiber was higher in the eutrophic group (20.7 g) when compared to the obese group (14.8 g). The dietary fiber was strongly correlated with the number of servings of beans (r = 0.77), when compared to fruits (r = 0.44) and leafy vegetables (r = 0.13). It was also observed that the higher the consumption of fiber and beans, the lower the proportion of dietary fat (r = -0.22) in the diet. Generally, there was a low consumption of fiber (20.7 g = eutrophic group/14.8 g = obese group), beans (1.1 portions in the eutrophic and obese groups), fruits (0.7 portions eutrophic group and 0.6 obese group) and vegetables (1.3 eutrophic group and 1.1 obese group). Conclusions: It is concluded that the obesity was more related to a dietary pattern of low intake of dietary fiber than excessive energy consumption and macronutrients imbalance. © 2011 de Oliveira et al; licensee BioMed Central Ltd.

Dietary intake and blood lipid profile in overweight and obese schoolchildren

Abstract. Background: The high blood lipid levels and obesity are one of the main risk factors for cardiovascular diseases, and the atherosclerotic process begins in childhood. Some environmental factors are supposed to be involved in this relationship, such as dietary factors. This study aimed to investigate the relationship between dietary intake and blood lipids levels in overweight and obese schoolchildren. Methods. This is a cross-sectional study with 147 overweight and obese schoolchildren in Botucatu city, Brazil. The anthropometric measurements (body weight, height, body mass index, waist circumference and skinfolds), pubertal staging evaluation and biochemical tests were taken in all children. Three 24h-recall were applied in order to estimate the dietary intake and its relationship with blood lipid levels. The Student t test and multiple linear regression analysis were used for statistical analysis. Statistical significance was assessed at the level of 0.05. The data were processed in SAS software (version 9.1.3; SAS Institute). Results: At this study, 63% of children were obese (body mass index higher than 95§ssup§th§esup§ percentile) and 80% showed high body fat percentage. The percentage of children with abnormal total cholesterol and triglycerides was 12% and 10%, respectively, and 28% presented at least one abnormal lipid levels. The average values of anthropometric measurements were higher in children with elevated lipid levels. Total cholesterol levels were positively related to full-fat dairy products and triglycerides levels to saturated fat percentage. Conclusions: Saturated fat was positively associated with elevated lipid levels in overweight and obese schoolchildren. These results reinforce the importance of healthy dietary habits since childhood in order to reduce the risks of cardiovascular diseases in adulthood. © 2012 Rinaldi et al.; licensee BioMed Central Ltd.

Dietary, anthropometric, and biochemical determinants of uric acid in free-living adults

Background: High plasma uric acid (UA) is a prerequisite for gout and is also associated with the metabolic syndrome and its components and consequently risk factors for cardiovascular diseases. Hence, the management of UA serum concentrations would be essential for the treatment and/or prevention of human diseases and, to that end, it is necessary to know what the main factors that control the uricemia increase. The aim of this study was to evaluate the main factors associated with higher uricemia values analyzing diet, body composition and biochemical markers. Methods. 415 both gender individuals aged 21 to 82 years who participated in a lifestyle modification project were studied. Anthropometric evaluation consisted of weight and height measurements with later BMI estimation. Waist circumference was also measured. The muscle mass (Muscle Mass Index - MMI) and fat percentage were measured by bioimpedance. Dietary intake was estimated by 24-hour recalls with later quantification of the servings on the Brazilian food pyramid and the Healthy Eating Index. Uric acid, glucose, triglycerides (TG), total cholesterol, urea, creatinine, gamma-GT, albumin and calcium and HDL-c were quantified in serum by the dry-chemistry method. LDL-c was estimated by the Friedewald equation and ultrasensitive C-reactive protein (CRP) by the immunochemiluminiscence method. Statistical analysis was performed by the SAS software package, version 9.1. Linear regression (odds ratio) was performed with a 95% confidence interval (CI) in order to observe the odds ratio for presenting UA above the last quartile (♂UA > 6.5 mg/dL and ♀ UA > 5 mg/dL). The level of significance adopted was lower than 5%. Results: Individuals with BMI ≥ 25 kg/m§ssup§2§esup§ OR = 2.28(1.13-4.6) and lower MMI OR = 13.4 (5.21-34.56) showed greater chances of high UA levels even after all adjustments (gender, age, CRP, gamma-gt, LDL, creatinine, urea, albumin, HDL-c, TG, arterial hypertension and glucose). As regards biochemical markers, higher triglycerides OR = 2.76 (1.55-4.90), US-CRP OR = 2.77 (1.07-7.21) and urea OR = 2.53 (1.19-5.41) were associated with greater chances of high UA (adjusted for gender, age, BMI, waist circumference, MMI, glomerular filtration rate, and MS). No association was found between diet and UA. Conclusions: The main factors associated with UA increase were altered BMI (overweight and obesity), muscle hypotrophy (MMI), higher levels of urea, triglycerides, and CRP. No dietary components were found among uricemia predictors. © 2013 de Oliveira et al.; licensee BioMed Central Ltd.

Effect of dietary sodium restriction on body water, blood pressure, and inflammation in hemodialysis patients: a prospective randomized controlled study

Purpose: Accumulating evidence suggests an association between body volume overload and inflammation in chronic kidney diseases. The purpose of this study was to evaluate the effect of dietary sodium reduction in body fluid volume, blood pressure (BP), and inflammatory state in hemodialysis (HD) patients. Methods: In this prospective controlled study, adult patients on HD for at least 90 days and those with C-reactive protein (CRP) levels ≥0.7 mg/dl were randomly allocated into two groups: group A, which included 21 patients treated with 2 g of sodium restriction on their habitual diet; and group B, which included 18 controls. Clinical, inflammatory, biochemical, hematological, and nutritional markers were assessed at baseline and after 8 and 16 weeks. Results: Baseline characteristics were not significantly different between the groups. Group A showed a significant reduction in serum concentrations of CRP, tumor necrosis factor-α, and interleukin-6 during the study period, while BP and extracellular water (ECW) did not change. In group B, there were no changes in serum concentrations of inflammatory markers, BP, and ECW. Conclusions: Dietary sodium restriction is associated with the attenuation of the inflammatory state, without changes in BP and ECW, suggesting inhibition of a salt-induced inflammatory response. © 2013 Springer Science+Business Media Dordrecht.

Protective effect of mannan oligosaccharides against early colonization by Salmonella Enteritidis in chicks is improved by higher dietary threonine levels

Aims: To evaluate mannan oligosaccharide (MOS) and threonine effects on performance, small intestine morphology and Salmonella spp. counts in Salmonella Enteritidis-challenged birds. Methods and Results: One-day-old chicks (1d) were distributed into five treatments: nonchallenged animals fed basal diet (RB-0), animals fed basal diet and infected with Salmonella Enteritidis (RB-I), animals fed high level of threonine and infected (HT-I), birds fed basal diet with MOS and infected (MOS-I), birds fed high level of threonine and MOS and infected (HT+MOS-I). Birds were inoculated at 2d with Salmonella Enteritidis, except RB-0 birds. Chicks fed higher dietary threonine and MOS showed performance similar to RB-0 and intestinal morphology recovery at 8 dpi. Salmonella counts and the number of Salmonella-positive animals were lower in HT+MOS-I compared with other challenged groups. Conclusion: Mannan oligosaccharides and threonine act synergistically, resulting in improved intestinal environment and recovery after Salmonella inoculation. Significance and Impact of the Study: Nutritional approaches may be useful to prevent Salmonella infection in the first week and putative carcass contamination at slaughter. This is the first report on the possible synergistic effect of mannan oligosaccharides and threonine, and further studies should be performed including performance, microbiota evaluation, composition of intestinal mucins and immune assessment. © 2012 The Society for Applied Microbiology.

Mannanoligosaccharide (mos) and β-glucan (β-glu) in dietary supplementation for Nile tilapia juveniles dept in cages

This experiment was conducted at an aquicolous enterprise with the objective of evaluating the use of MOS and β-GLU as dietary supplements in an experimental lot in order to follow the zootechnical performance, establishing a relationship with the hematological parameters, the morphological alterations of the intestine, and the enzymatic activity (protease, lipase and amylase), and the water quality of 3,000 tilapia juveniles kept in cages (Wt = 24 ± 0.26g). Nine cages (6.0 m3) were used, with three treatments and three replications. 1: commercial feed without supplementation (control); 2: 0.1% per ton of MOS; 3: 0.03% per ton of purified β-GLU. The feed contained 36% of crude protein (CP) incorporated into the premix MOS and purified β-GLU (BIORIGIN®). The tilapia that had received the diet supplemented with β-GLU in a period of 90 days showed a favorable condition of the immune system, increase in the absorption surface of the front part of the intestine and consequently, growth in the activity of the digestive enzymes, denoting higher efficiency in the use of the nutrients in juveniles, providing satisfactory zootechnical performance in comparison with the other diets. This product may be used as a dietary supplement for this species when kept in cages.

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.

Effects of dietary clinoptilolite and calcium levels on the performance and egg quality of commercial layers

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

Dietary fiber inclusion as an alternative to Feed Fasting to induce molting in Commercial Layers

The objective of the present experiment was to compare the performance, egg quality and organ morphometrics of commercial layers submitted to alternative forced molting methods using dietary fibers. The experimental period included the phases of molting, rest, and second laying cycle (six periods of 28 days each). In the trial, 320 commercial Isa Brown layers with 72 weeks of age were distributed, according to a completely randomized experimental design into five treatments with eight replicates of eight birds each, totaling 40 experimental units. Molting was induced by feeding diets with the inclusion of alfalfa or soybean husks at 80% and 60% or feed fasting. Treatments were applied for 14 days. Performance and egg quality parameters were evaluated for the second laying cycle and organ morphometrics (liver, gizzard, proventriculus, reproductive apparatus) in two different slaughter dates. The obtained data were submitted to analysis of variance using the General Linear Model (GLM) procedure of SAS statistical package (SAS Institute, 2002). Alternative molting methods promoted similar performance and egg quality results after molting were similar to those obtained by the conventional fasting method. Feeding fiber produced the expected effects in terms of organ weight regression and recovery and may be used to induce molting in commercial layers.