# Characteristics of Large Antlers Reveal Key Features to Reach Full Genetic Potential

## TL;DR

This study explores how antler characteristics in red deer relate to genetic potential and investment, finding that weight is a better indicator than length.

## Contribution

The study identifies weight as the best estimate of antler investment and links burr size to genetic potential.

## Key findings

- Weight correlates more strongly with antler characteristics than length.
- Burr size reflects genetic potential but is not sufficient for large antlers.
- Antlers from the Latvian competition were 47% heavier than those from the UCLM farm.

## Abstract

Large antlers are important in red deer breeding and hunting, but they are also fighting structures in which males can invest heavily (up to 28% of their skeleton material, which is mobilized for its fast growth). Deer could grow fighting antlers that are larger and weaker, shorter and more robust, or their antlers could be on a scale of non-variable patterns. In addition to the genetic growth potential, food availability and health state or senescence of the male could affect how the different parts of the antler are sequentially grown. In this study, we examined how the different parts of the red deer antler correlate with each other and with variables that could estimate antler investment (weight or length) in a set of antlers from males fed a balanced diet from farms. Age influenced antler characteristics only if still-growing males were included (3 and 4 years). Weight is the best estimate of investment in antlers, as it showed a higher correlation than length with the rest of antler characteristics. Burr (the base of the antler where it connects to the head of the deer) seems to show the growth potential, as large antlers had large burrs, but the antler could be shorter or lighter than predicted, likely if other factors reduced the potential antler investment.

Antlers are costly bone structures that grow every year. Thus, in addition to the genetic potential, its full potential size depends on the physiological state and food availability. Our aim was to examine antler characteristics related to genetic potential (burr perimeter) with final antler investment (antler weight) and how they relate with antler structural characteristics: beam length, circumference at mid and upper parts of the beam, and length of first (brow) and midbeam (third) tines. We measured 206 antlers from the University of Castilla-La Mancha experimental farm (UCLM) and from 203 top size antlers from Latvian International Antler Competition (LIAC). The results show that UCLM and LIAC had antlers of similar length (4.6% difference), but LIAC had 47% heavier antlers. The body growth explained that correlations of antler measurements with age were higher in males of 3 or more years, but much weaker in fully grown males (5 years or older). Weight reflected investment in antlers, as it showed the greatest correlation with all measurements, but length had weaker correlations. A large burr cross-section seems to reflect genetic potential, because it is necessary but not sufficient to grow large antlers. The results could be a useful tool for deer breeders.