Changes

SARA can impact production parameters. Milk yield is lowered, although on farms where subacute rumenal acidosis is an ongoing, chronic problem, this may not be recognised. Milk butterfat levels are also reduced, which may be due to two factors. Firstly, milk fat is produced from acetate and butyrate, which in turn are produced from fibre in the diet. Dietary fibre is often reduced in SARA

SARA can impact production parameters. Milk yield is lowered, although on farms where subacute rumenal acidosis is an ongoing, chronic problem, this may not be recognised. Milk butterfat levels are also reduced, which may be due to two factors. Firstly, milk fat is produced from acetate and butyrate, which in turn are produced from fibre in the diet. Dietary fibre is often reduced in SARA

and so butterfat levels are, in turn, decreased. Alternatively, the changes in the rumen environment in subacute rumenal acidosis could interfere with the biohydrogenation of fatty acids, and milk fat could be reduced in this way.

and so butterfat levels are, in turn, decreased. Alternatively, the changes in the rumen environment in subacute rumenal acidosis could interfere with the biohydrogenation of fatty acids, and milk fat could be reduced in this way. Reproductive performance is also poor; bulling behaviour and the duration of oestrus are negatively affected, and subobtimal nutrition reduces conception rates.

The incidence of a number of diseases is increased by concurrent subacute rumenal acidosis. For example, cases clinical acetonaemia and left displacement of the abomasum occur more frequently with herds where SARA is an issue. Loose faeces gives contamination of the environment and the udder, and in combination with the detrimental effects of SARA on the immune system, this can give a rise in levels of environmental mastitis.

The incidence of a number of diseases is increased by concurrent subacute rumenal acidosis. For example, cases clinical acetonaemia and left displacement of the abomasum occur more frequently with herds where SARA is an issue. Loose faeces gives contamination of the environment and the udder, and in combination with the detrimental effects of SARA on the immune system, this can give a rise in levels of environmental mastitis. Subacute rumenal acidosis also predisposis to coriosis (the bovine equivalent of laminitis), so affect herds may have a high prevalence of foot lameness, with solar abscesses and ulcers frequently seen. Knowledge of the mechanism for induction of coriosis by SARA is limited.

 

* Laminitis. SARA predisposes to laminitis (Nordlund

2000). Affected herds may have a high prevalence of foot

lameness. However, there is a time lag between the period

of nutritional insult and the resultant lameness. While the

exact mechanism by which SARA predisposes animals to

 

 

* Poor reproductive performance. This is a reflection

===Laboratory Tests===

===Laboratory Tests===