Applicability of teeth examination as a tool for age estimation in a semi-arid cattle production environment in Namibia.

ABSTRACT

Regression analysis was used to evaluate teeth examination as a tool for estimating age in beef and dairy cattle at Neudamm farm, Namibia, in 2018. There was a significant difference in age (months) between the overall mean actual age (M=60, SD=4.57) and the mean estimated age (M=57, SD=4.52 months) in beef cattle; t(74) = 3.61, p<0.001. There was no significant difference between the overall mean estimated age and the mean actual age (M=42.5, SD=5.18) and (M=41.3, SD=5.21 months) in dairy cattle; t(30) = 1.45, p=0.16. There was a very strong positive relationship between the overall teeth examination-estimated age and actual age in beef cattle [r (74) = 0.98, p<0.001]. There was a very strong positive relationship between the overall teeth examination-estimated age and actual age in dairy cattle [r (30) = 0.99, p<0.001]. A very strong positive relationship was also evident between the teeth examination-estimated age and actual age in beef cattle aged 45 months and below [r (37) = 0.93, p<0.001]. There was a very strong positive relationship between the teeth examination-estimated and actual age in dairy cattle aged 45 months and below [r (20) = 0.97, p<0.001]. There was a very strong positive relationship between the teeth examination-estimated age and actual age in beef cattle aged over 45 months [r (35) = 0.93, p<0.001]. There was a very strong positive relationship between the teeth examination-estimated age and actual age in dairy cattle aged over 45 months [r (8) = 0.97, p<0.001]. It was therefore concluded that under the given conditions of the study and the range of ages and the breeds under study, age estimation through teeth examination is reliably applicable for aging cattle in general. Age estimation through teeth examination was found to be more accurate in dairy than in beef cattle.