Field Study of Dairy Cows with Reduced Appetite in Early Lactation: Clinical Examinations, Blood and Rumen Fluid Analyses

A Steen

doi:10.1186/1751-0147-42-219

Abstract

The study included 125 cows with reduced appetite and with clinical signs interpreted by the owner as indicating bovine ketosis 6 to 75 days postpartum. Almost all of the cows were given concentrates 2 to 3 times daily. With a practitioners view to treatment and prophylaxis the cows were divided into 5 diagnostic groups on the basis of thorough clinical examination, milk ketotest, decreased protozoal activity and concentrations, increased methylene blue reduction time, and increased liver parameters: ketosis (n = 32), indigestion (n = 26), combined ketosis and indigestion (n = 29), liver disease combined with ketosis, indigestion, or both (n = 15), and no specific diagnosis (n = 17). Three cows with traumatic reticuloperitonitis and 3 with abomasal displacement were not grouped. Nonparametric methods were used when groups were compared. Aspartate aminotransferase, glutamate dehydrogenase, gamma-glutamyl transferase and total bilirubin were elevated in the group with liver disease. Free fatty acids were significantly elevated in cows with ketosis, compared with cows with indigestion. Activity and concentrations of large and small protozoas were reduced, and methylene blue reduction time was increased in cows with indigestion. The rumen fluid pH was the same for groups of cows with and without indigestion. Prolonged reduced appetite before examination could have led to misclassification. Without careful interpretation of the milk ketotest, many cases with additional diagnoses would have been reported as primary ketosis. Thorough clinical examination together with feasible rumen fluid examination and economically reasonable blood biochemistry did not uncover the reason(s) for reduced appetite in 14% of the cows. More powerful diagnostic methods are needed.

Highlights

Reduced appetite in dairy cows in early lactation is one of the clinical signs of bovine ketosis and indigestion caused by simple indigestion or subacute ruminal acidosis (Radostits et al 2000)
On the basis of clinical examination, rumen fluid examination, and clinical biochemistry the material was divided into 5 diagnostic groups: ketosis (K), indigestion (I), combined ketosis and indigestion (K+I), liver disease in addition to ketosis, indigestion, or both (L), and a group with reduced appetite but none of the above diagnoses (N)
The methylene blue reduction time is an indirect measure of the redox potential and bacterial activity of rumen fluid (Dirksen 1969)

Summary

Introduction

Reduced appetite in dairy cows in early lactation is one of the clinical signs of bovine ketosis and indigestion caused by simple indigestion or subacute ruminal acidosis (Radostits et al 2000). After indigestion was defined as a separate diagnosis in the Norwegian Disease Recording System in 1989, the number of reported cases of bovine ketosis decreased, the incidence is still high. Several investigations indicate that the figures from the health card statistics may be inaccurate (Cote et al 1969, Øverby et al 1974, Simensen et al 1990). Terms like “doubtful”, “false”, physiologic, spontaneous, alimentary, type I and II, and secondary ketosis have been used. In many thoroughly examined ketosis patients various concurrent diseases can be found (Cote et al 1969, Dale 1978, Dirksen 1992), i.e. secondary ketosis is more frequent than usually thought.

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Conclusion