533 Int. J. Morphol., 28(2):533-536, 2010. Morphometric Investigations on the Horns of Uda Rams in Nigeria: Implications in Veterinary Clinical Practice Investigaciones Morfométricas de los Cuernos de los Carneros Uda en Nigeria: Implicancias en la Práctica Clínica Veterinaria Olukole, S. G. OLUKOLE, S. G. Morphometric investigations on the horns of Uda rams in Nigeria: implications in veterinary clinical practice. Int. J. Morphol., 28(2):533-536, 2010. SUMMARY: Morphometric studies were carried out on the horns of 60 Uda rams. The mean values for the relative horn weight, weights of the right and left horns were 0.67%, 219.5g and 208g respectively. The mean values for the lengths of the right and left horns and the horn base circumference were 25.6cm, 27.4cm and 17.4cm respectively. There were significant differences (p< 0.05) between the lengths of the right and left horns; and between the weights of the right and left horns. There were also strong positive correlations between the body weight of the animals and the length of the horns. A graph of the length of the right horn against the body weight of the animals with a significant deviation from zero at 95% confidence intervals yielded a slope value of 0.4535, being an index that can be used to estimate the approximate body weight of a ram once the length of the right horn is known. This index, the first of its kind in literature, is therefore named the body weight-horn length (BWHL) index. The results obtained in this study will serve as valuable tools in weight estimation in animal management and drug administration in Veterinary clinical practice. It also provides a baseline data on the horns of Uda rams and a template for comparative regional anatomy of the horns of ruminants. KEY WORDS: Uda rams; Relative horn weight; Horn length. INTRODUCTION The population of sheep in sub-Saharan Africa is estimated at 127 million (Winrock International, 1992) and that of the humid tropics at over 20 million with about 80% of these in Nigeria (Charray et al., 1992; Gatenby, 2002; Olopade et al., 2005). Uda rams, also known as Northern Nigerian Fulani or Bororo are found in Northern Nigeria, Southern Niger, Central Chad, Northern Cameroon and Western Sudan. They are meat breeds of rams with distinctive markings, the front half of the body is usually black or brown and the back is often white. A horn is a pointed projection of the skin on the heads of various mammals, consisting of keratin and other proteins surrounding a core of living bone. Animals have a variety of uses for horns, these include: intraspecific display and combat (Lull, 1933; Sampson et al., 1997), defense against predators (Hatcher et al., 1907), thermoregulation and as aids in knocking down vegetation (Farke, 2004). In Nigeria, ram fight is fast becoming a major feature during the Id-el Kabir celebrations, hence its potential as a nascent tourist attraction. Few studies on the horn of animals have been documented: horn growth in Cantabrian chamois, Rupicapra pyrenaica parva (Pérez-Barbería et al., 1996), horn growth and population quality in Dall sheep (Bunnel, 1978), horn growth in mountain goats, Oreamnos americanus (Côté et al., 1998). However, not much research has been carried out on sheep in Nigeria (Olopade et al.). There is a dearth of information on the morphometry of the horns of domestic animals as anatomical studies on horns are poorly reported. This study aimed at investigating the gross anatomical dimensions of the horn of Uda rams with particular reference to their linear measurements and weights thereby providing baseline data on the subject area. Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Ibadan, Nigeria.