Federal University of Agriculture, Abeokuta (FUNAAB)
Doi
Abstract
Udder traits of extensively managed 229 West African Dwarf (WAD) goats and 143 three West African Dwarf (WAD) sheep in Southwestern Nigeria were evaluated and factors affecting them were determined. Traits evaluated were udder and teat morphometrics including udder length (UL), udder width (UW), udder circumference (UC), distance between teats (DT), teat length (TL), teat width (TW) and teat circumference (TC). Udder and teat shapes and teat placement were also evaluated. In WAD goats, the average UL, UW, UC and DT were significantly (p<0.05) influenced by age, parity and physiological status (pregnancy and lactation status) but age alone significantly (p<0.05) influenced TL, TW and TC. In sheep, age, pregnancy and lactation status significantly (p<0.05) influenced TL and UC respectively. In both species, all udder and teat dimensions increased with age and parity while largest and smallest udder and teat dimensions were observed for lactating and non-lactating (dry) animals respectively. The average UL, UW, UC, DT, TL, TW and TC of WAD goats were 12.44 ± 0.15 cm, 8.81 ± 0.11 cm, 26.81 ± 0.32 cm, 8.27 ± 0.09 cm, 2.40 ± 0.02 cm, 1.22 ± 0.02 cm and 3.11 ± 0.03 cm respectively. The average UL, UW, UC, DT, TL, TW and TC of WAD sheep were 11.30 ± 0.15 cm, 8.78 ± 0.13 cm, 26.21 ± 0.36 cm, 9.02 ± 0.12 cm, 2.10 ± 0.02 cm, 1.19 ± 0.02 cm and 3.06 ± 0.03 cm respectively. It is evident that WAD goats had larger udder size than WAD sheep, thus, indicating greater milk production potentials. Udder shapes found in WAD goats and sheep were bowl, cylindrical and funnel with the latter not found in sheep. Bottle, cylindrical and funnel shaped teats were found in both species while vertical and oblique teat placements were recorded in both species. In both goats and sheep, bowl shaped udder was the most predominant with 57.20% and 83.92% occurrence respectively. Cylindrical shaped teat was most prevalent in both species with 64.43% and 83.91% occurrence respectively. Oblique (tilted) teat placement was the most frequent in both species with 77.73% and 95.10% occurrence respectively in goats. High positive significant (p<0.05) phenotypic correlations were found between UL and UW (r = 0.68), UL and UC (r = 0.62), UL and DT (r = 0.42), UW and UC (r = 0.73), UW and DT (r = 0.59), UC and DT (r = 0.53). In sheep, high positive significant (p<0.05) phenotypic correlations were also found between UL and UW (r = 0.74), UL and UC (r = 0.65), UL and DT (r = 0.53), UW and UC (r = 0.72), UW and DT (r = 0.65), UC and DT (r = 0.54). In essence, this could be a basis for selecting udder traits of WAD goats and sheep as an indirect response in multiple traits selection programme especially for milk production .  
