A study on the effect of environmental temperature with relation to feed intake, mineral mobilization and respective incorporation into the egg yolk of Lohmann Brown egg layer chickens given purified lignin at the Neudamm farm in Namibia.

Abstract

It is of knowledge that the usage of antibiotics leads to development of antibiotic-resistance by pathogenic bacteria which pose a major threat to both animal and human health. Bio-stimulators can replace the use of antibiotics as growth promoters and exert positive influence on metabolic processes. Between June and July, 2013 a study was conducted on the effect of purified lignin on egg layer chickens. The objective of this study was to assess the effect of purified lignin on Lohmann Brown egg layer chickens under Namibian environmental conditions. The feed additive made of purified lignin, containing humic acid, pH 8.5-10, and 14% humidity which is soluble in water was used in this experiment. Lignin at concentrations of 60mg kg-1, 50mg kg-1 and 40mg kg-1 diluted in water were used to feed 1446 chickens (482 each experimental group), while 489 served as the control group), for 17 days with 10 days interval at 18◦C and 23% humidity. Feed intake was evaluated; eggs from both groups were harvested, sorted and graded in different categories daily. Egg content from both groups and the presence of microorganisms in the gastro-intestinal gut were assessed. Results revealed that experimental chickens had low feed intake (4.3kgs less) and produced more eggs graded as extra-jumbo and jumbo, with less egg fats and oil content (g/100g) - 17.4 for experimental group; 19.4 control group). No gastro-intestinal microbial organisms were found. Purified Lignin is suggested to improve digestibility and feed conversion. The use of 50mg kg led to reduced feed intake in the experimental group despite low temperature while increasing the mobilisation of Fe, (mg/kg) - 17.7; 13.7; Se mg/kg -0.68 and 0.89; protein into egg yolk (g/100g) - 19.1; 17.1. Evidently, lignin can be used in the poultry industry as a feed additive and bio-stimulator to increase Iron (Fe) uptake which in return increases the level of haemoglobin and Selenium (Se) which serves as an antioxidant, while concurrently reducing microbial meat contamination and replace the use of antibiotics as feed additive.