Evaluation of Wet-Feeding Wheat-Based Diets to Broiler Chickens

Nutrition Update
Volume 13 No.2, November 2002

Poultry researcher, Dr Tom Scott at Agriculture and Agri-Food Canada has investigated the use of wet-feeding broiler chicks wheat-based diets. Based on initial studies, Dr Scott indicated that wet feeding increased growth rate, but had a varied effect on feed conversion ratio when different sources of wheat were used. These studies indicate that broilers cannot eat enough dry diet to attain their genetic potential for growth.

The study was initiated to determine if variation in feed intake of dry sources of wheat-based diets could be related to differences in the time it takes for wheat-based diets to absorb water and be digested in the gut. Scott's theory is that, by adding water to the diet before feeding, the diet is then already hydrated and digestion can begin immediately. This faster rate of digestion enables the bird to eat more and grow faster.

The study tested wet and dry forms of three sources each of Hard Red Spring (HRS) and Durum wheat types. Each of the six wheat types was included at 80% of the diet and each diet was split and fed with or without a wheat enzyme. The 12 diets were then fed as is (dry) or with 1.2 parts water. The wet diets were prepared daily (preliminary studies showed that mould growth in the wet diets was not a negative factor). All diets were each fed to six cages of eight broilers from 0 to 21 d of age. The following table summarizes the effect of wheat source and wet and dry feeding.

The data indicate that feed intake of all dry wheat-based diets was limited and as a result the growth rate of the birds was limited. With water added to the diets before feeding there was an almost equal increase in feed intake and growth of the Durum wheat-based diets, therefore the FCR remained constant. However, when water was added to the HRS diets, feed intake increased (40%) disproportionally to the increase in body weight (15%). As a result FCR was markedly increased by feeding HRS diets in wet form. The AME of the wet HRS diets was also decreased. Scott is now trying to determine if this disproportional change in feed value of wet HRS is related to a loss in digestibility from added water or because the broiler is simply eating more and not expending energy to digest the feed. In effect, can the bird use different strategies to digest different diets, but still obtain the nutrients to maximize growth?

Other comments on the trial include the observations that wet fed wheat-based diets may not require a supplemental enzyme as the water activates enzymes in wheat. Dr. Scott also indicated that wet feeding reduced the bird's ability to scatter feed from the trough, reducing feed wastage. Although total water intake (that from feed and drinkers) increased with wet feeding, this was due to a higher feed intake as the ratio of water to feed consumed was constant for wet and dry diets. This manner of feeding may also have benefits for reducing early chick mortality as chicks would get water and feed from the same source. If you have questions about this research, you can contact Tom Scott at ScottTA@agr.gc.ca

Reprinted from an article submitted to the 2002 Directory of Research for Agriculture and Agri-Food Canada.

For more info:	Carlyle Bennett, M.Sc.
	Business Development Specialist - Poultry
	Livestock Knowledge Centre
	Manitoba Agriculture, Food and Rural Initiatives