Uraemia in the mare: effects of seasonal variations, of energy level of the diet and individual differences.

The research study focuses on the variations in uraemia levels in heavy breed mares and the factors that influence it such as seasonal changes, dietary energy levels, and individual differences.

Research Context and Methodology

• The study commenced by focusing on 35 mares during an entire grazing season. The purpose was to observe the mean uraemia, which is a condition characterized by high levels of urea and other nitrogenous waste compounds in the blood denoting potential kidney issues.
• The mares were subjected to different types of grass and their uraemia levels were carefully monitored.
• The second phase of the study included 15 mares fed with isonitrogenous diets, diets containing equal amounts of nitrogen, based on hay or straw. These mares also received concentrates at two different levels.
• The intention here was to discern the impact of diet on uraemia and any variations pre-and post-foaling.
• The study also conducted tests on two separate herds of 7 and 5 mares respectively, who were sampled 9 times throughout a year, to investigate the individual effect on uraemia.

Studied Findings

• It was observed that uraemia varied between 48.5 and 67.5 mg/100 ml plasma depending on the season and type of grass. First-cycle pasture grass resulted in the highest uraemia levels.
• Uraemia levels were found to be lower when mares were fed winter diets, with readings ranging between 28.6 to 36.0 mg/100 ml.
• Mares that were fed isonitrogenous diets and low concentrate levels saw higher uraemia levels (35.6 to 44.0 mg/100 ml plasma), as compared to those fed with higher concentrate level diets (25.8 to 33.3 mg/100 ml).
• The physiological stage of the mares seemed to have a very slight impact on uraemia.
• Individual differences among the mares significantly affected uraemia levels. This variation remained unexplained by age differences.

Conclusions

• This study adds valuable information to the understanding of uraemia in mares. It signified that factors such as seasonal variations, the energy content of the diet, and individual differences significantly contribute to uraemia variations beyond just the nitrogen concentration of the diet.