Intake and Digestibility of Silage by Pregnant Sows and Effects of Silage Treatment with Maxgrass Additive

Abstract

Grass silage provides an alternative feed for extensively kept sows, but previous experiments have indicated very variable intake and utilisation, dependant on silage quality. ‘Maxgrass’ silage additive (BP Nutrition) is a blend of compounds including ammonium hexamethanoate, ammonium hexapropanoate and octanoic acid. It is designed to modify fermentation, so that the resulting silage retains a higher proportion of water soluble carbohydrates. This should improve the nutritive value for pigs.The experiment comprised two parts: an intake/growth study and a separate digestibility study. The same two experimental silages, either treated with Maxgrass or an untreated control, were offered to groups of pregnant sows in a randomised block experimental design in each experiment. Second cut, mainly perennial ryegrass herbage was cut by mower conditioner and direct ensiled. Alternate loads were left untreated or treated with Maxgrass at a mean rate of 6.04 litres/tonne.