Effects of feed on plasma leptin and ghrelin concentrations in crib-biting horses.

The research article discusses a study examining the relationship between two hormones, leptin and ghrelin, and crib-biting behaviour in horses. The results suggest that horses exhibiting crib-biting behaviour have lower levels of leptin.

Objective and Methodology

• The main aim of the study was to investigate if there is a link between plasma concentrations of ghrelin and leptin and crib-biting behaviour in horses. Crib-biting is a compulsive oral behaviour seen in some horses, but the reasons behind it are not well understood.
• The researchers collected plasma samples from a group of 15 horses that exhibited stereotypic crib-biting behaviour and another group of 15 matched control horses. Samples were obtained before and during their first feed of the day in their usual environment.

Observations and Findings

• Researchers found that the average leptin concentration in the blood was lower in horses that were observed crib-biting before and after they were fed, compared to horses that were not.
• The intensity of crib-biting in horses was also seen to correlate negatively with leptin levels, i.e., the more intense the crib-biting behaviour, the lower the leptin concentration.
• The study showed that crib-biting activity was significantly higher shortly after feeding than before or 30 minutes later. This suggests a possible relationship between feeding and the onset or exacerbation of crib-biting behaviour.

Ghrelin Concentrations

• Ghrelin is a hormone that stimulates hunger. The study showed that plasma ghrelin levels were significantly higher before feeding concentrate rather than before feeding hay or after feeding concentrate.
• However, unlike leptin, ghrelin concentrations did not differ between crib-biting and non-crib-biting horses, indicating there was no correlation between ghrelin levels and crib-biting behaviour.
• A significant negative correlation was noted between the body composition score (a measure of a horse’s body condition) and plasma ghrelin concentration, but the implications of this correlation on crib-biting behaviour are not clear from the abstract.

Conclusion and Implications

• The study suggests a possible link between leptin concentrations and crib-biting behaviour in horses. However, it does not establish cause-and-effect, and more research is needed to confirm the findings and explore potential physiological mechanisms.
• Understanding the factors influencing crib-biting behaviour can potentially aid in the development of effective treatment and prevention strategies.