Comparison of electrocardiogram parameters during two methods of euthanasia in white leghorn hens.

This study's objective was to evaluate if electrocardiogram (ECG) parameters differ depending on euthanasia method, and if welfare implications result. Sixteen mature laying hens previously outfitted with subcutaneous wireless telemetry and housed in conventional cages or aviaries were used. Manual cervical dislocation (CD) and 30% CO2 displacement were chosen. Continuous ECG data collection began 5 min prior to the procedure to establish a baseline, then continued during and following euthanasia until complete cessation of cardiac activity. Insensibility and euthanasia were determined by an experienced handler to be loss of posture and the end of neuromuscular convulsions with no noticeable breathing. The attending veterinarian monitored and confirmed successful euthanasia via auscultation of the heart. Veterinary confirmation occurred within 5 min for all hens, thus a 5-min sampling period was used. Samples of ten successive QRS complexes per hen per minute were used to calculate average QRS complex amplitude and heart rate. Data were analyzed using the Glimmix Procedure in SAS 9.4, and reported as deviations from baseline. Housing was not a significant factor (p > 0.05). Heart rate showed a significant effect for method (p = 0.0232), time (p < 0.0001), and method*time interaction (p = 0.0001). Compared to baseline, heart rate for CD was 238 bpm higher at minute 1 (p < 0.0001) and 106 bpm higher at minute 2 (p = 0.0027) compared to CO2. While there was no significant effect of method on QRS amplitude (p = 0.6220), there was a time effect (p = 0.0266). Cervical dislocation as a method of euthanasia may induce a greater stress response in laying hens compared to CO2 displacement.

Evaluating the effect of cooking and gastrointestinal digestion in modulating the bio-accessibility of different bioactive compounds of eggs.

Eggs' nutritional value has been enhanced by enriching hen's diet with bioactive compounds, but factors influencing bio-accessibility are unspecified. This study investigated the effect of hen breed, diet enrichment, and cooking methods in modulating the egg compounds' bio-accessibility after gastrointestinal (GI) digestion. White Leghorn (WLH) and Rhode Island Red (RIR) hens were fed a corn-soybean-based diet enriched with flaxseed and carotenoids; eggs were collected, cooked, and subjected to simulated GI digestion. The results showed that egg proteins were equally digestible with no change in the degree of hydrolysis (DH). The linolenic fatty acid in enriched-cooked samples remained bio-accessible after GI digestion. The lutein bio-accessibility in enriched eggs decreased after GI digestion except in RIR fried sample. Eggs from WLH and RIR achieved similar peptide content after GI digestion. These results elucidate the bio-accessibility of different bioactive compounds in cooked eggs and the use of eggs as potential functional foods.

Effect of xylanase on the performance of laying hens fed a low energy corn and soybean diet.

This study was conducted to determine the effect of high- and low-activity xylanase in a corn and soybean diet on the performance of laying hens. There were 2 phases each with 4 treatment diets: positive control (PC), negative control (NC) with lower metabolizable energy (ME) and nutrient density, and 2 different xylanases supplemented to the NC diet. Phase 1 was 23-43 wk of age and phase 2 was 43-58 wk, for a total duration of 35 wk. The NC diet had a lower ME in phase 2 than phase 1. There were 72 cages with 3 Bovan White Leghorns each. Egg production (EP) was recorded daily, feed intake (FI) weekly, and average egg weights (EW) biweekly. Egg production and FI were calculated using biweekly periods, also used to determine egg mass (EM) and feed conversion (FC) with biweekly EW. BW was recorded and analyzed for weeks 0, 10, 20, and 35 of the study. Egg production did not differ among treatment groups (phase 1: P = 0.47; phase 2: P = 0.54). In phase 1, EW and EM were significantly lower in the NC diet with enzyme B, compared to both the PC and NC diets (P = 0.019; P = 0.01). The PC diet yielded higher EW than all other treatments in phase 2 (P = 0.036), but no differences in EM were present (P = 0.12). Baseline BW was not different (P = 0.63), but hens fed the PC diet had higher BW in subsequent measurements (P ≤ 0.05). Hens fed the PC diet had lower FI than all other treatment groups in both phases (P = 0.0001), and had an improved FC than the 2 enzyme groups in phase 1 (P = 0.0001) and all other treatment groups in phase 2 (P = 0.0001). The enzymes did not improve the performance of the birds.

Short-term effects of lower oil dried distillers grains with solubles in laying hen rations.

Extraction of oil from dried distillers grains has become a common practice among US ethanol producers. The valuable oil has been diverted to markets other than poultry feed, leaving new dried distillers grains with solubles (DDGS) products higher in fiber and purportedly lower in ME. This study compared 3 DDGS products with 10.3, 7.3, or 5.2% ether extract, respectively, with a corn-soy control ration in young Bovan laying hens for a feeding period from 20 to 33 wk of age. The DDGS was fed at the rate of 20% of the ration. Lower oil content of DDGS had no effect on short-term egg production parameters: feed intake, egg production, egg weight or mass, and hen weight gain. The diets containing lower fat DDGS (5.2%) did have reduced AME and kilocalories per day intake for laying hens. For each percent reduction in oil from a normal DDGS sample (10.3%) to medium oil (7.3%) DDGS, AME decreased 42.3 kcal/kg of diet. However, total kilocalories per day intake did sustain good egg production during this short trial.