Effects of Leucaena leucocephala on semen quality
The effects of Leucaena leucocephala on semen quality, fertility and reproductive
performance of dihydroxy pyridone-adapted South African Nguni goats
A. A. AKINGBADE a1 c1, I. V. NSAHLAI a2 and C. D. MORRIS a3
a1 Department of Animal Production and Health, Ladoke Akintola University of Technology,
Ogbomoso, Nigeria
a2 Discipline of Animal and Poultry Science, University of Natal, Pietermaritzburg, South
Africa
a3 Range and Forage Institute, Agricultural Research Council, Pietermaritzburg, South Africa
Abstract
The effects of feeding Leucaena leucocephala on semen quality and fertility were examined
using four dihydroxy pyridone (DHP)-adapted (21.0, 26.5, 27.0 and 31.0 kg) and four
DHP-unadapted (28.0, 31.0, 40.0 and 44.0 kg) South African indigenous Nguni bucks
(mature male goats). The DHP-adapted bucks were assigned to air-dried Leucaena
leucocephala forage (LL; Leucaena group) while the unadapted ones were maintained on a
cereal-based concentrate diet (C; concentrate group) containing 122 g crude protein
(CP)/kg over an 84-day period. Buck semen samples were collected on days 0 and 77 of
the study. On the last day of the study (day 84), bucks in the Leucaena group were divided
into two equal subgroups; a subgroup was assigned to Leucaena leucocephala-grass pasture
(LGP) with ten does (mature female goats) while the second subgroup was assigned to
natural pasture (NP) with nine does. Similarly, the two concentrate subgroups were
separately assigned to mate nine and ten does on LGP and NP plots, respectively. The
proportions of normal semen on both groups were not significantly different. However,
semen quality on LL treatment increased significantly (P = 0.004) between days 0 and 77
and probably explains the significant (P<0.01) difference between the fertility rates of
bucks on both treatments. There was no evidence that feeding LL was detrimental to
semen quality and fertility of bucks and to conception among females mated by the bucks
fed the forage; perhaps due to the fact that the bucks had adapted to DHP as a result of
the DHP-degrading rumen bacteria (Synergistes jonesii) that were transferred to them by the
does. Synergistes jonesii is known to be capable of detoxifying mimosine and its toxic
metabolites to innocuous compounds.