The growing restriction of antibiotic growth promoters (AGP) use in farming animals has raised a concern regarding the viability of the animal production system. In this new context, feed additives with proven positive impact on intestinal health may be used as strategy to avoid losses on performance. The aim of this study was to evaluate the effects of a protected blend of organic acids and essential oils [P(OA+EO)] on growth performance, nutrient digestibility, and intestinal health of broiler chickens. A total of 1,080 Cobb × Cobb 500 male broilers were randomly distributed in four treatments with 10 replicates (27 birds/each). Treatments were as follow: non-challenged control; challenged control; AGP (enramycin at 10 g/t); and P(OA+EO) at 300 g/t. All birds on challenged groups were challenged with Eimeria spp. at 1 day and with Clostridium perfringens at 11, 12, and 13 days. Body weight gain (BWG), feed intake and feed conversion ratio (FCR) were evaluated until 42 days. At 17 days, one bird per pen was orally gavaged with fluorescein isothiocyanate-dextran (FITC-d) and blood samples were collected for FITC-d detection to assess intestinal permeability. At 21 days, apparent ileal nutrient and energy (IDE) digestibility, intestinal macroscopic and histologic alterations (ISI) and, expression of mucin2 (MUC2), claudin1 (CLDN1), and occludin (OCLN) genes in the jejunum were evaluated. From 1 to 42 days, birds from the non-challenged and P(OA+EO) groups had greater (P < 0.001) BWG compared to challenged control and AGP groups. The challenged control group presented the worst FCR (P < 0.001). IDE was 106 kcal/kg greater when broilers were fed P(OA+EO) compared to the challenged control group. Broilers supplemented with P(OA+EO) had improved intestinal integrity with lower blood FITC-d concentration and ISI scores, and greater expression of MUC2, CLDN1, and OCLN genes compared to the challenged control group (P < 0.05). In conclusion, the P(OA+EO) and the AGP led to increased growth performance, nutrient digestibility and intestinal health of challenged broilers. A marked difference occurred in favor of the P(OA+EO), suggesting that this blend may be used to improve intestinal health and broiler growth performance in AGP free programs.

The effects of lutein and conjugated linoleic acid (CLA) on growth performance and immune response of broiler chickens were evaluated in the presence and absence of Salmonella lipopolysaccharide (LPS) immune challenge. Cobb chicks (360; 1 to 22 d of age) were used in a 3 × 2 factorial arrangement of CLA (0, 1, and 2%) and lutein (0 and 50 mg/kg) dietary levels. At d 8 and 15, birds were injected with BSA to assess IgY production. At d 20, birds were injected with LPS. Samples of liver, spleen, and duodenum were collected at 3 and 16 h post-LPS challenge for RT-qPCR analysis of RXRα, RXRγ, PPARα, PPARγ, TLR-4, IL-1β, IL-2, IL-10, and IL-12 gene expression. CLA decreased BW, BW gain (BWG), and G:F from d 1 to 20, but these effects were reversed when lutein was included in the 1% CLA diet (P < 0.001). The production of IgY anti-BSA increased following a 2% CLA supplementation (P < 0.01). LPS increased the liver:BW ratio at 3 h post-injection (P < 0.001) and decreased BWG at 3, 16, and 40 h (P < 0.001). Lutein decreased plasmatic nitric oxide levels (P < 0.01). LPS downregulated PPARα mRNA in the duodenum (P = 0.02) and liver (P = 0.04), and PPARγ (P = 0.01) and RXRα (P = 0.08) in the spleen; these effects were not reversed by CLA or lutein as initially hypothesized. Although LPS upregulated IL-1β (P = 0.02) and IL-12 (P = 0.07) expression, lutein downregulated these pro-inflammatory cytokines in the liver (P = 0.03 and P = 0.07, respectively). Lutein decreased splenic (P = 0.09) but increased hepatic (P = 0.06) TLR-4 mRNA. A dietary CLA supplementation of 2% increased hepatic RXRα (P = 0.10). In conclusion, CLA decreased broiler chicken growth performance, but lutein could prevent this negative effect (depending on CLA dose). Lutein had an anti-inflammatory effect, and a 2% CLA supplementation improved the humoral immune response.

Non-ruminants Full-length research article Growth performance and intestinal health of broilers fed a standard or low-protein diet with the addition of a protease ABSTRACT-We evaluated the effects of a protease supplementation on the growth performance and intestinal health of broilers. Cobb chicks (392; 1-42 d) were divided into four treatments (seven replicates of 14 birds each). There were two feed formulations: a standard diet (SD) and a low crude protein and digestible amino acids diet (Low CP&AA). The two diets were either supplemented (+P) or not (−P) with a protease (Jefo Protease; 1.25 g kg −1). Performance was evaluated by feeding phases (1-7, 8-21, 21-35, and 35-42 d). On day 28, ileum samples were analyzed by a morphometric index for histological alterations (I See Inside Scoring System-ISI). Broilers fed the Low CP&AA had a poor feed conversion ratio (FCR); however, the addition of the protease to the Low CP&AA positively affected FCR and body weight gain and promoted a performance similar to the group fed SD−P. Birds fed diets supplemented with the protease presented the best ISI morphological index, mainly as a result of the low number of alterations regarding the lamina propria, epithelial thickness, and enterocyte proliferation. It is possible to conclude that the enzyme improves feed conversion and lamina propria, epithelial thickness, and proliferation of enterocytes index of broiler chickens when added to a standard diet or with a low crude protein and digestible amino acids diet.

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Two experiments were conducted to compare the immunocompetence of Cobb high performance and rustic Label Rouge broilers and the influence of reduced growth rates subsequent to feed restriction on the IgY anti-bovine serum albumin (BSA) response. In the first experiment (EXP), 360 broilers were assigned to 36 cages from 1 to 42 days of age. A completely randomized design was applied in a 3 × 2 factorial arrangement, with 3 groups (Label Rouge, Cobb ad libitum, and Cobb Restricted Intake), and 2 levels of energy (3,100 and 2,800 kcal/kg); there were 6 replicates per treatment. In the second EXP, 384 Cobb 500 male broilers were randomly assigned to the following feed restriction programs from day 8 to 16: Control, fed ad libitum; Quantitative (80% of the control amount); By Time (fed for 8 h/d), and Qualitative (80% limiting nutrients) restriction. Blood samples were collected on days 35 and 42 (EXP 1) and weekly from day 7 to 42 (EXP 2) for IgY anti-BSA quantification. In EXP 1, the production of IgY anti-BSA was lower in the Cobb groups (P < 0.0001) than in the Label Rouge group, and higher in the Cobb Restricted Intake group (P < 0.0001) compared with the same genetic strain fed ad libitum. Birds fed the low energy diet presented lower (P ≤ 0.06) IgY anti-BSA, independent of genetics. In EXP 2, no difference (P > 0.05) was observed 1 wk after the first BSA inoculation. However, at day 28, birds in all feed restriction programs had higher (P < 0.05) IgY anti-BSA than the Control group fed ad libitum. At day 35, the greatest residual effect of IgY anti-BSA was observed in the Quantitative restriction group. No differences (P > 0.05) were observed between groups after 42 d. The 3 early feed restriction programs had beneficial effects on the humoral immune response. Overall, Quantitative restriction promoted a longer lasting IgY anti-BSA response. Lower growth rate, due to feed restriction or genetic potential, improves humoral immunity in broiler chickens.

Non-ruminants Short communication Increased urinary losses in piglets fed diets containing high levels of glycerin ABSTRACT-This study evaluated the nutritional value of glycerin added to diets of weaned piglets and its effects on animal performance and urinary losses. Weaned piglets were individually housed in metabolic cages and fed diets in which a basal diet containing lactose (Gly0) was replaced by 50 (Gly50), 100 (Gly100), or 150 g kg −1 (Gly150) of glycerin; or a diet in which 100 g kg −1 of the lactose in the basal diet was replaced by glycerin (Gly100Lac0). Diets were offered for two periods of 12 days (phase I and phase II). Performance, nutrient digestibility, nitrogen retention (NR), and urinary production were measured. Digestible (DE) and metabolizable energy (ME) of glycerin were calculated using substitution method and compared to iso-nutritional diets formulated with or without glycerin. No significant differences on average daily gain, average daily feed intake, and feed conversion ratio were found. Glycerin inclusion caused a linear increase in urinary production. Piglets fed Gly100Lac0 diet had higher urinary production, compared with piglets fed Gly0. Glycerin had no significant effects on total tract apparent digestibility (TTAD) coefficients of dry matter (DM), crude protein, and gross energy (GE). Also, no significant effects were found in total tract apparent metabolizability (TTAM) coefficient of GE, NR coefficient, DE, ME, and fecal GE losses. Urinary production and GE in urine increased linearly and quadratically, respectively, with increased levels of glycerin in diets. The Gly100Lac0 diet resulted in lower DM TTAD and GE TTAM and higher GE losses in urine and feces compared with Gly0. The nutritional value of glycerin allows its inclusion at up to 100 g kg −1 in diets of weaned piglets without impairing animal performance and metabolism. Also, glycerin can replace 100 g kg −1 of lactose without impairing performance.

Two experiments (EXP 1 and EXP 2) were conducted to compare soybean oil (SO) and semi-refined rice oil (RBO) added to broilers diets. In EXP 1, 400 male Ross x Ross 308 broilers were reared in battery cages, and their performance was evaluated. A metabolism assay was performed. In EXP 2, 1344 broilers from the same strain were reared in floor pens with rice husks litter. In addition to performance, carcass yield and meat oxidative stability were evaluated. In both EXP, birds were distributed in a 2x4 factorial arrangement, with two types of oils (SO or RBO) and four oil inclusion levels (1%, 2.5%, 4%, or 5.5%). Two periods were considered: starter (1 to 21 days of age) and grower (22 to 42 days). In both EXP, oil type had no influence on starter performance. Although treatments promoted similar in weight gain (WG) and feed intake (FI), grower birds fed RBO had better feed conversion (FCR) in EXP 2, but not in EXP1. In both trials, increasing dietary oil levels negatively influenced FI and positively FCR. Weight gain was similar among all treatments in EXP 1, whereas in EXP 2, WG was higher when 4 and 5.5% oil was included in the feed. RBO presented 94% fat metabolizability, and crude energy and metabolizable energy levels of 9.260 and 8.714 kcal/kg, respectively. Carcass yield was not influenced by oil type; however, oil inclusion level negatively affected breast yield. The experimental treatments had no effect on meat oxidative stability. RBO can be used as an alternative to soybean oil in broilers diets

-An experiment was conducted to define a protocol to determine metabolizable nutrient and energy values of diets. The metabolizability (M) was calculated of the dry matter (DM); crude protein (CP); gross energy (GE) and AME n of a single diet. Eighty-one 21-day old (d) male birds were used. The tested methodologies were: Cr 2 O 3 (0.5%) as an indicator (partial collection) or Fe 2 O 3 (1%) as a marker; fasting (0, 4, 6 and 8 h) prior to excreta collection and at the end of the feeding period on the last day of collection (total collection). The excreta collection periods were also tested (3 and 5 days).Twenty 31-day old male broilers from the same group of birds were used to assess the effect of fasting on digestive organ weight. At the end of fasting the digestive organs were removed and weighed. Metabolism coefficients and energy were not different between 3 and 5 days of total collection. CPM was lower for marker utilization and 3 days excreta collection compared to the total collection. Eight hours fasting resulted in significantly lower CPM compared to the other periods or the no fasting. With the methodology of partial collection with 5 days of collection, the lowest values were observed for all the responses, compared to the 3 day collection period. The use of the total collection methodology produced the highest DMM and CPM compared to partial collection. No influence of fasting was observed on the digestive organ sizes, indicating that until 8 hours of fasting no changes were observed in either relative or absolute organ weight. However, the relative jejunum weight of birds submitted to 4 hours fasting was higher than that of birds under no fasting. Total collection, during a 3 day period, without fasting and marker use, is the best methodology for ingredient and feed evaluation of growing birds.Key Words: chromic oxide, excreta collection, fasting, ferric oxide, metabolizable energy organ size Estudo de variações metodológicas na determinação do metabolismo aparente de nutrientes em frangos de corte RESUMO -Realizou-se um ensaio com frangos de corte para a definição de um protocolo de determinação da metabolizabilidade dos nutrientes e da energia da dieta. Foram estimados os coeficientes de metabolizabilidade de matéria seca (MS), proteína bruta (PB), energia bruta (EB) e a energia metabolizável aparente corrigida para nitrogênio (EMA n )de uma mesma dieta, utilizando-se 81 aves, de 21 dias de idade. As metodologias testadas foram as seguintes: utilização de 0,5% de Cr 2 O 3 como indicador (coleta parcial) ou 1% de Fe 2 O 3 como marcador e aplicação ou não de jejum (0, 4, 6 e 8 horas)pré-início de coleta e após a última refeição, no último dia de coleta (coletas totais). Períodos de coleta de três ou cinco dias também foram testados. Retiradas do mesmo grupo original, 20 aves de 31 dias de idade foram usadas para avaliar o efeito do jejum sobre o tamanho dos órgãos digestivos. Após o jejum, os órgãos foram retirados e pesados. Os coeficientes de metabolizabilidade e a EMA n determinados pelo m...