title: The non-significant effect of feeding level, growth rate and age on libido of young Afrikaner bulls.
abstract: Afrikaner bulls (n = 30) between 9,5 and 15 months old, were allocated to 2 dietary treatments fed ad libitum. Diet 1 consisted of 70% concentrate and 30% Eragrostis curvula hay (11,4 MJ ME kg-1 DM) and Diet 2 of 40% concentrate and 60% E. curvula hay (9,3 MJ ME kg-1 DM). Five libido tests were conducted per bull between the ages of 16 and 28 months. Bulls were pre-stimulated for 10 min by close contact with previously synchronised oestrous heifers. Three bulls were then simultaneously allowed a period of 15 min with 6 heifers. Manifestations of libido were indexed as follows: 1. smelling heifer and definite signs of interest; 2. attempt to mount without erection; 3. mount with erection but no intromission; 4. successful service. Libido values fluctuated highly both within and between bulls. Libido did not improve over the 16 to 28-month age period nor with experience as successive tests were conducted. Bulls on Diet 1 grew significantly faster during the first 7,5 months of the trial, but demonstrated non-significantly higher libido scores. It was concluded that maturation over the 16 to 28-month age period, learning experience and level of feeding had no effect on libido.
authors.affiliation: Department of Livestock Science, Faculty of Agriculture, University of Pretoria, Republic of South Africa.
authors.forename: C
authors.initials: C
authors.lastname: Maree
authors.forename: N H
authors.initials: NH
authors.lastname: Casey
authors.forename: I E
authors.initials: IE
authors.lastname: Jacobi
mesh_terms: D000367:Age Factors; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000254:growth & development / Q000502:physiology*; D007989:Libido; D008297:Male