An investigation of red deer milk in New Zealand and the implications for future production : A dissertation submitted in partial fulfilment of the requirements for the Degree of Bachelor of Agricultural Science with Honours at Lincoln University

Abstract

The development of a deer milking industry in New Zealand to produce niche and gourmet products for growing markets has been explored. Studies are lacking on the characteristics of deer milk, including whether there are seasonal changes in its content and how it compares to other animal milks. This study aimed to characterise the fatty acid (FA) profile of red deer milk from hinds grazing lucerne at Aratiatia, Taupō, New Zealand. Milk samples were collected from 43 red deer hinds in March, with a second sample collected from 22 of the original hinds collected in April. These milk samples were analysed using FAME evaluation to determine the FA profiles of individual deer. The samples were compared between mid- and late-lactation, as well as a comparison being made to the FA profiles of dairy cows in New Zealand. Large variations in FA proportions were observed between deer and the proportion of dietarily desirable FAs such as conjugated linoleic acid (CLA) within the sampled population. This suggests that future selection for deer with desirable fatty acid profiles may be possible, but the practicality of doing this within an evolving industry may be challenging. All of the deer milk FA proportions measured differed significantly between mid- and late-lactation (all P < 0.05). The changes observed tended to be opposite to that typically seen for cows’ milk in New Zealand, and it is suggested that the changes may be due to increased fat content and changes in energy balance towards the end of lactation observed in cervid species. The skewed distribution of essential fatty acids suggested a ‘baseline physiological limit’. This may be due to the lesser extent of domestication of the species and the requirements of the neonate. When the deer FA profiles were compared to cows’ milk, many differences were observed. Deer milk had higher proportions of short-chain fatty acids SCFAs, lower proportions of long-chain fatty acids (LCFAs) and higher proportions of polyunsaturated fatty acids (PUFAs) relative to cows’ milk (P < 0.05). Deer milk also had higher proportions of the omega-3 FA group and reduced proportions of conjugated linoleic acid (CLA) compared to cows milk (P < 0.05). Using some of these findings to our advantage, deer milk could be marketed as a ‘healthy product’ containing higher levels of omega-3 relative to other animal milks. The differences observed between individual deer over the two stages of lactation may allow for further manipulation of the milk to obtain more desirable FA profiles, but at this stage of development of the industry, more focus may be placed on increasing production and developing markets. Further research is required to confirm some of these findings and could be directed towards further characterisation of deer milk FA profiles, including how feed and the stage of lactation affects the contents of deer milk.