Gaseous nitrogen emissions from caged laying hen manure.

Pratt, Emma Victoria (2006). Gaseous nitrogen emissions from caged laying hen manure. PhD thesis The Open University.

DOI: https://doi.org/10.21954/ou.ro.0000fe19

Abstract

A series of replicated, randomised block experiments were conducted to quantify the effect of temperature and egesta moisture content on the nitrogen losses during caged laying hen manure storage and to determine if the addition of a carbonaceous substrate to fresh caged laying hen egesta would reduce these losses.

During short-term storage (10-days), increasing temperature (15.3 - 25.4°C) and initial moisture content (722 - 796 g/kg) produced a linear increase (PcO.Ol) and a non-linear increase (PcO.OOl) in nitrogen loss from the manure, respectively. The interaction between these variables (P<0.05) produced a large increase in the rate of nitrogen loss from intermediate moisture samples, stored at the highest examined temperature. During long-term (18-weeks) manure storage, increasing temperatures produced a non-linear increase (P<0.05) in the rate of nitrogen loss.

The addition of carbohydrates (initially at 8 g/kg, for 7-days) to laying hen manure was examined to reduce nitrogenous losses during storage. This showed that straw had no effect on the loss of nitrogen; glucose additions increased the loss of nitrogen and starch additions tended (P>0.05) to increase bacterial numbers. The addition of sucrose or maltose to the manure increased bacterial numbers (P<0.05) and gaseous nitrogen losses were reduced (P<0.05). Addition of increasing levels of sucrose (0-50g/kg) gave a non-linear reduction in nitrogen loss (PcO.Ol). The lowest level of nitrogen loss was obtained with 35 g/kg of added sucrose.

The application of sucrose at this inclusion level and the storage of the amended manure over 12 weeks showed that nitrogen losses were reduced for up to the fourth week of storage and thereafter there was no difference in nitrogenous losses.