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5.3 Characteristics Of Export Diets

Pellets. The pellets currently used on ships for sheep and cattle are small (10mm diameter) and durable, designed for use in modern automated feeding systems. The components have normally undergone considerable grinding, making small particles that make up the pellet. Processes of heat, steam and pressure gelatinise the starch matrix of the grain, binding the finely ground components together.

When pellets become a large proportion of the diet, chewing, ruminating and saliva production may be reduced hence rumen buffering may be reduced. Lactic acid may be produced rapidly from the gelatinised starch and particulate grain of the pellets. Under these circumstances, the acid buffering capacity of the rumen may be overwhelmed, ruminal pH may drop, and fermentation may slow or even cease. Nitrogen recycling will be reduced and deleterious changes to the rumen mucosa (rumenitis, parakeratosis) may develop.

Hay and chaff. Hay and chaff may be loaded on board, mainly for feeding sick animals in hospital pens. The quantities are usually relatively small because hay and chaff are difficult to load, store and feed out compared to pellets. However, it is recommended that sufficient hay and chaff be loaded on to ships to supplement the pellet diet of ruminants with at least 0.5% body weight per day of good quality long stem cereal hay or coarsely chopped chaff. The longer fibre particles, by helping to maintain rumen fermentation, may reduce the incidence of some of the important nutrition-related diseases of ruminants seen in the export process such as acidosis, bloat, persistent inappetence and salmonellosis. There may be significant economic and animal welfare benefits if the provision of hay or chaff reduces the number of sick animals, drug usage and the need for hospital pens; as well as improving weight gains, body condition scores, and general health of animals.