Analysis of the Composition of Milk in the first Three Lactations in Ayrshire Cattle Across Four Decades

Neil R Mcewan,Roxanne B Knight

doi:10.1515/opag-2018-0026

Abstract

Abstract Using historic lactation records for Ayrshire cattle, we report a gradual increase in the production of milk, butter fat and protein levels across four decades. This was generally at the extent of attaining a level of increase per decade which was similar to the increase seen between animals during their first and second lactations in the previous decade. However these increases were achieved without significantly affecting the percentage of butter fat or protein throughout the time examined, and also without changing the heifer: second lactation ratios

Highlights

Much of modern milk production is dominated by the Holstein breed of cattle, there are still several other breeds around the world which are maintained as dairy cows
In all four decades studied, the mean yield of a heifer during her first lactation was approximately the 90% of the yield achieved during the second lactation, which in turn was around 95% of the milk yield achieved as a third lactation cow
More recently many breeders of Ayrshire cattle have used red and white Holstein sires in an effort to increase the size of the animals and the amount of milk they produce, while still maintaining the characteristic red/brown and white colour of animals in the breed, meaning that comparisons between animals from the closed gene pool of earlier years was not possible

Summary

Introduction

Much of modern milk production is dominated by the Holstein breed of cattle, there are still several other breeds around the world which are maintained as dairy cows. The relative abundance of these other breeds has declined over the last 60-70 years as the Holstein has become the predominant dairy breed (Capper et al 2009), each of these breeds still has an organisation (breed society) which was founded to promote the breed, as well as to maintain pedigree and production records associated with animals within the breed. Records held by these societies have been used to assist dairy farmers with decision making in the context of selecting factors such as which animals to retain as replacement stock within a herd, as well as which animals to consider buying at auction from other breeders as means of trying to enhance their own herd. Depending on the year(s) during which records were made, some records contain details of milk protein quantities, somatic cell counts within the milk, or classification score based on the conformation of the animal

Methods

Results

Conclusion