Study on acid-base metabolism in dairy cattle under field condition

Abstract

The acid-base status of dairy cattle is important for the production and general health of the animal. The acid-base level of the blood should be kept within a narrow range, which is in a healthy animal kept within the range with the help of buffers in the body. But when the acid or base load is too high, the buffer systems are not able to correct it and an alkalosis or acidosis develops in the blood. Ruminal acidosis is a condition most often seen in dairy cattle and feedlot cattle, the subacute ruminal acidosis the most common form in dairy cattle. The condition appears most often in dairy cattle due to carbohydrate overload in the rumen in early lactation, due to the drastic increase of concentrate feeding according to the drastic increase in milk production the first period after parturition in high yielding dairy cattle. The rumen microflora and papillae are not able to adapt to this change fast enough, causing volatile fatty acid and lactic acid to accumulate in the rumen, resulting in a low pH in the rumen. This low pH affects the fermentation in the rumen, and the feed efficiency will decrease. Along with the decreased feed efficiency, the low pH can cause injury to the mucous membrane of the rumen, and let the acids gets into the bloodstream causing a disturbance of the acid-base balance of the blood. Clinical signs seen in dairy cattle with subacute ruminal acisosis (SARA) are often diarrhoea, anorexia, decreased milk production and decreased fat content of the milk, the severity of the condition determines how serious the clinical signs seen are. The preventive measurements for this condition in dairy cattle is mainly the feeding regime especially in the last part of dry period and early lactation; its is important to give the microflora and papillae of the rumen time to adapt to rations richer in concentrate than earlier fed. Treatments for disorders of the acid-base balance, and then especially ruminal acidosis seen in dairy- and feedlot- cattle, are mainly to correct the dehydration, electrolyte balance, acid-base balance and to improve the feeding regime for the future. This is a disorder that can have great economic influence on a farm, so it is important to take the feeding regime on the farm serious.