This study explores the impact of zinc supplementation to improve the quality of cooled equine semen, addressing a crucial aspect of genetic preservation in horses. The findings showed that adding various concentrations of zinc to the sperm does not significantly enhance sperm quality during cold storage and concentrations exceeding 3 mM had detrimental effects. These findings challenge the common belief of the protective role of zinc in sperm preservation, contributing valuable insights for the equine breeding industry.

This article belongs to the Collection Equine Science Part II.

There has been noticeable consolidation within the New Zealand Thoroughbred industry in the past 30 years. This is thought to be the result of the reducing focus on domestic market and increasing focus on export market. This study described the breeding population changes (domestic and export sector), commercial career, management and reproductive workload of New Zealand stallions between 2005 and 2015 in relation to the influence of the breeding focus and economic drivers.

This article belongs to the collection Equine Science Part II.

The New Zealand Thoroughbred breeding industry optimises return by producing early born foals and appealing to the export market. The foal’s parent and sibling performance history can influence sales return. These commercial pressures condense and displace the commercial breeding season from natural breeding season, and influence sire and mare selection. This study describes the influence of the commercial and biological constraints on the breeding management of the mare, structure of breeding herd, and the recruitment and replacement of breeding stock.

This article belongs to the collection Equine Science Part II.

Vitamin K (VK) has received considerably less attention over the past 50 years than other fat-soluble vitamins. Intakes of VK beyond that required for normal blood coagulation were believed to confer no additional benefits, and were therefore rarely investigated. Over the past decade, evidence has mounted for its intrinsic and essential roles in other functions within the body. In this review, we assess the current state of knowledge of VK as it pertains to metabolism and nutrition, particularly in the horse.

This article belongs to the collection Equine Science Part II.

Jumps racing in the southern hemisphere is unique and poorly described. This study aimed to describe the career profile and pattern of racing for jumps-racing horses in New Zealand by using industry race data. All jumps-racing horses in New Zealand had a primary career in flat racing, before repurposing in a jumps-racing career for a further 2 years, increasing specialisation as the horse aged. This strategy results in a decrease in wastage from the racing industry.

This article belongs to the Collection Equine Science Part II.

In comparison to other livestock, the respective role and perception of the horse in society differs dependent on the production system or use; for some, a horse is a pest, a production animal or a pet. This review examines how these perspectives alter the identification of equine-welfare issues and the primary issues associated with pasture-based equine production.

This article belongs to the collection Equine Science Part II.

Overseer® is the primary software tool used to estimate farm-level nutrient cycle and management for regulatory purposes in New Zealand. The model compares feed demand among different livestock by using ‘revised stock units’ (RSUs). The current RSU does not consider allometric scaling of metabolism to liveweight or the differences in digestive physiology and nutrient metabolism between ruminants and monogastric hindgut fermenters (horses). This paper investigates the implication of the current RSU values on feed-demand and N-intake estimations for equine stock classes.

This article belongs to the collection Equine Science Part II.