Monoammonium phosphate (MAP) brings phosphorus to rumen microflora
Ruminants need phosphorus for their bones structure and cells function, but compare to monogastric animals, their also need phosphorus for rumen microflora that has a higher P requirement than animal needs for maintenance (Meschy, 2010).
The total need of phosphorus for ruminal bacteria is, partly, satisfied by the availability dietary phosphorus and the salivary recycling.
Therefore, Durand et Kawashima (1980) emphasized that phosphorus water solubility is important to ensure a good productivity rumen.
Monoammonium phosphate (MAP) provides a high phosphorus content (26%) and a high water-soluble phosphorus (>90%).
In vitro trials showed a high and fast solubilization of phosphorus from monoammonium phosphate in the rumen juice. The result is a directly P intake for ruminal microorganisms.
In case of Subacute Ruminal Acidosis (SARA), P salivary recycling decreases resulting in a drop of available phosphorus for rumen bacteria and therefore, a decline of cellulolytic activity (Durand et al., 1989 ; ; Goselink et al. 2015).
Therefore, thanks to its high water-soluble phosphorus, Monoammonium phosphate (MAP) allows to maintain the bacterial activity (especially cellulolytic bacteria).
Monoammonium phosphate (MAP) brings nitrogen to ruminant.
Once ingested, the nitrogenous components of dairy diet can take two different pathway according to their degradability: the dietary protein nitrogen with 2 different fractions and the non-protein nitrogen (NPN). NPN fraction provides a direct source of nitrogen for microbial protein synthesis.
Indeed, ruminal bacteria are the only one able to use this NPN fraction. Urea is the predominate source of non-protein nitrogen, but others NPN sources exist as monoammonium phosphate (MAP) which provides 11% N.
By providing synchronously 26% of P highly available and 11% of soluble nitrogen (N), Monoammonium phosphate (MAP) stimulates ruminal activity.
How to use monoammonium phosphate (MAP) in ruminants?
Monoammonium phosphate (MAP) is distributed to 30-70 g/cow/day. MAP is used on dairy cows and can be used for beef cattle as well. As it does not contain calcium, monoammonium phosphate is suitable for dry cows (close-up period). The objective is to provide a synchronized supply of P and N for rumen microorganisms, to optimize the ruminal fermentations and thus, the performances of the animals.