Hoof renewal time from birth of Thoroughbred foals

Abstract

Abstract:Introduction: Thoroughbred foals are born with fully developed hooves and stand within minutes of birth. A ring in the hoof horn occurs at birth and grows down the hoof wall, separating the fetal hoof (distal) and foal hoof (proximal). Birth rings in hoof horn have been noted in other species and used to estimate age. Hoof wall renewal in all ages of horse has been poorly reported. Furthermore horn growth and complete hoof capsule renewal has not been measured in Thoroughbred foals. Partial hoof wall avulsions are relatively common. The objective was to measure the time taken for the fetal hoof of newborn foals to grow to the bearing border and be replaced by hoof grown since birth.Method: Thoroughbred foals (N=150) on four Newmarket stud farms were studied during June to September. The age of the foal and the day that routine hoof trimming removed the remnants of the fetal hoof of the front hooves was recorded. Foals that were on restricted exercise, ill or where the remnants of the fetal hoof still remained after trimming were excluded from the data. 45 foals fulfilled the criteria. The data were tabulated in Excel, analysed in Minitab and assessed for normality (AndersonDarling). Results:The mean age at which the fetal hoof was removed with routine trimming was 145±15 days (95% confidence interval, 141.77-147.16), range 120-165 days.Conclusions: Thoroughbred foals replaced the fetal hoof half the time given for mature horses (270-365 days). Knowing the time of hoof renewal will allow accurate predictions of healing to be made in cases of partial hoof wall avulsion and other hoof lesions and may assist in determining the age of foals.Declarations: Approval was given by the University of Central Lancashire Animal Projects Committee. There were no sources of funding and no competing Interests.

Morphometric changes in the hoof capsule of Criollo foals from birth to weaning

“…Average growth rate of the hoof was higher in the foals' first four months (4.69±0.08, 5.21±0.08, 5.60±0.05, and 6.01±0.10cm in months 1 to 4, respectively), which was in accordance with that reported in Thoroughbred foals by CURTIS et al (2014). In addition, changes in toe length can be described as: toe length = 4.8060987 + 0.2875192 × month -0.0524012 (month -3.74569)2, R²=0.54, P≤0.01.…”

“…In adult horses, the hoof wall of thoracic limbs increases by 0.63cm and that of pelvic limbs by 0.72cm (GLADE & SALZMAN, 1985), within the 270-365 d required to complete its growth down to the weight-bearing margin (KAINER, 2006). Recent studies investigated hoof formation during pregnancy (FRANCIOLLI et al, 2011) and evaluated the time necessary for the fetal hoof to grow down from the coronary band to the distal margin (CURTIS et al, 2014). However, no studies conducted so far have investigated the biometrics of natural hoof growth from birth to weaning.…”

Science in brief: Highlights from the biomechanics and physiotherapy abstracts at the International Conference on Equine Exercise Physiology

“…With regard to growth, hoof renewal in Thoroughbred foals was found to occur at twice the speed given for mature horses . In addition, external characteristics, including the hoof–pastern axis and hoof angle, which are commonly used to assess dorsopalmar conformation in adult horses, cannot be used in foals .…”

Quantitative Analysis and Development of the Fore Feet of Arabian Foals from Birth to 1 Year of Age

“…12 A recent study reported faster hoof wall growth in young foals compared with adult horses. 13 Considering the normal physiological changes in growing foals, the likelihood of additional hoof wall growth is feasible. Our results indicate significantly thicker hoof walls at the distal aspect; yet, identification of the causal mechanism has yet to be investigated.…”