Egg Industry - October 2009

possibility is that mature hens with intact intestinal flora resist colonization. It is evident that hens housed on wire slats or in cages which inhibit coprophagy are generally refactory to Campylobacter infection since the organism cannot persist in a dry environment and requires moist fecal material in which to survive. The logical extension of this study would be to evaluate the shedding of SE in hens receiving successive doses of live attenuated SE vaccine as pullets compared to controls.

Article 228 - Room Environment Influence on Eggshell Bacterial Levels of Non-Washed and Washed Eggs from Caged and Caged-Free Laying Hens

There is renewed interest in the EU regarding the washing of eggs which is a standard U.S. practice. Eggs were collected from hens housed either on wire slats or from litter pens and were assayed for aerobic bacteria and coliforms. Non-washed eggs produced by hens on litter had higher numbers of bacteria and coliforms compared to eggs produced

on slats. Washing significantly reduced total plate count by 1. 6 log10 cfu/mL. Washing significantly reduced coliform counts by 0.5 log10 cfu/mL. Housing hens in cages with manure removal belts resulted in the lowest total plate counts for both non-washed and washed eggs compared to housing in a room with cages, slats or shavings. Since all commercial eggs are washed in accordance with USDA directives specifying temperature, chlorine level and pH of sanitizer, shell contamination in U.S. eggs should be low. It is noted that eggs produced on currently available on-belt manure drying systems are generally free of dust, resulting in cleaner eggs than those derived from high-rise houses.

Molting

Although producers conforming to UEP Guidelines now initiate molt using diets of low energy and salt content, there are still aspects of molting which are worthy of scientific evaluation including welfare and dietary formulation.

Article 242P – Molting Hens Using

Soy Hulls: 1. Physiological Response

A study conducted in Brazil considered the physiological stress of hens subjected to either feed removal or alternative molting programs. The response of hens was determined by assaying blood plasma, cholesterol, glucose, triglycerides, high and low density lipoproteins at 79 through 92 weeks of age using Hy-Line W-36 hens with induction of molt at 80 weeks of age (most molting in the U.S. commences at 65 weeks). The control comprised 10 days of fasting followed by cracked corn for 8 days and a pullet developer for 10 days. This regimen corresponds closely to previous U.S. practice. Alternative molting diets consisted of soy hulls for 4 to 12 days followed by low energy diets comprising soy hulls for 8 or 12 days, in turn followed by 10, 6, or 2 days of a low energy diet containing soy hulls and then 4 days of cracked corn and 10 days of pullet developer. Molted hens showed lower triglyceride levels than control birds regardless of molting diet. No differences were observed among treatments with respect