Research Note: Preliminary assessment of the impact of dietary yeast products on egg production and cecal microbial profiles of laying hens

ABSTRACT: The objective of the current study was to conduct an initial comparison of commercial yeast products in layer hen diets on egg production parameters and the corresponding impact on the cecal microbiota. A short-term feeding study was conducted with 35 laying hens receiving either a control, or 1 of 4 different yeast fermentation products, Immunowall, Hilyses (both from ICC, São Paulo, Brazil), Citristim (ADM, Decatur, IL), and Maxi-Gen Plus (CBS Bio Platforms, Calgary, Canada) with 7 hens per treatment from 40 to 46 wk of age. At the end of the trial, hens were euthanized, the ceca removed and prepared for denatured gradient gel electrophoresis (DGGE) microbial compositional analyses. Although initial shell weight and shell thickness were similar among the treatment groups, hens fed Hilyses had lower shell weight and thickness at the end of the experiment. The most predominant DGGE bands with the strongest intensity were identified as Lactobacillus species and excised double bands were identified as Bacillus, Clostridium, or Lachnospiraceae. In this short-term feeding trial, the commercial yeast products tested had little effect on egg production and shell quality, and only moderately impacted the composition of mature layer hen cecal microbiota

A protected complex of biofactors and antioxidants improved growth performance and modulated the immunometabolic phenotype of broiler chickens undergoing early life stress

ABSTRACT: We evaluated the supplementation of a protected complex of biofactors and antioxidants [P(BF+AOx)] on growth performance, antioxidant activity, expression of immune-related genes, and immunometabolic phenotype of broilers submitted to early life stressors. The treatments were a nutritionally complete basal diet supplemented or not with P(BF+AOx) (Jefo Nutrition Inc., Saint-Hyacinthe, QC, Canada) from 1 to 14 d of age. 720 one-day old male Ross 308 chickens were placed into pens of 30 birds (12 replicates/treatment). Birds were double-vaccinated against infectious bronchitis (IB; MILDVAC-Ma5T) at the hatchery and submitted, on d 3, to an acute reduction on environmental temperature (from 32° C to 20°C) for 48 h. Feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) were calculated weekly. On d 7 and 15, samples were collected for expression of immune-related genes and kinome array analysis, and serum to evaluate the antioxidant status. Data were analyzed by ANOVA using SAS (SAS 9.4). From d 1 to 21 and d 1 to 28, the dietary supplementation of P(BF+AOx) significantly increased BWG (P < 0.05) by 3.6 and 3.8%, respectively, and improved FCR (P < 0.05) by 1.2 and 1.8%, respectively. From d 1 to 35, dietary supplementation enhanced BWG (P = 0.03) by 4%. Serum glutathione reductase activity on d 15 was higher in birds fed diets supplemented with P(BF+AOx) compared to the control diet-fed birds (P = 0.04). Dietary supplementation reduced the expression of IL-1β (P = 0.03) in the lungs on d 7. On d 15, dietary supplementation increased the expression of IL-6 (P = 0.02) and IL-10 (P = 0.03) in the liver. It was observed that, via decreased phosphorylation, catalase was activated in the jejunum and liver, and the phosphorylation of immunoregulatory or proinflammatory proteins was decreased. Other important cellular signaling pathways were also changed in the liver and jejunum due to the supplementation. The supplementation of P(BF+AOx) improves growth performance by promoting a general anti-inflammatory and antioxidant response in chickens undergoing early life stress

Relationship between bicarbonate retention and bone characteristics in broiler chickens

Determination of the bicarbonate retention factor (BRF) is an important step during development of the indicator amino acid oxidation technique for use in a new model. A series of 4-h oxidation experiments were performed to determine the BRF of broilers aged 7, 14, 21, 28, 35, and 42 d using 4 birds per age group. A priming dose of 1.2 mu Ci of (NaHCO3)-C-14, followed by eight half-hourly doses of 1 mu Ci of (NaHCO3)-C-14 were given orally to each of 4 birds per age. The percentage of 14 C dose expired by the bird at a steady state was measured. These birds, as well as 12 additional birds matched for age and BW, were killed, and femur bone mineral density was measured by quantitative computed tomography to determine the relationship between bone development and bicarbonate retention at each age. There was a correlation (r = 0.50; P < 0.05) between total cross-sectional femur bone mineral density and bicarbonate retention at each age. A prediction equation (Y = 6.95 x 10(-2) X - 3.51 x 10(5)X(2) + 27.58; P < 0.0001, R-2 = 0.79) where Y = bicarbonate retention and X = BW was generated to predict Y as a function of X. Bicarbonate retention values peaked at 28 d, during the stage of the most rapid bone deposition and the highest growth rate. A constant BRF was found from 1,900 to 2,700 g of BW of 35.15 +/- 1.095% (mean SEM). This retention factor will allow the accurate correction of oxidation of C-14-labeled substrates in broilers of different ages and BW in future indicator amino acid oxidation studies