Cc. Pomares et al., LUPIN AND COWPEA SUPPLEMENTS FOR GROWTH, WOOL PRODUCTION, AND REPRODUCTION IN RAMS, Australian journal of experimental agriculture, 35(4), 1995, pp. 447-452
Lupins and cowpeas were fed at 0.0, 0.5, 1.0, and 2.0% liveweight (LW)
to groups of 6 or 7 South Australian Merino rams for 11 weeks as supp
lements to a maintenance diet of grass hay. Productive and reproductiv
e parameters were examined. Supplementation at all levels of either gr
ain increased (P<0.001) LW, condition score, backfat thickness, and wo
ol growth, with rams showing similar responses when given cowpeas and
lupins. The weights of the pancreas of rams decreased (P<0.01) as the
levels of supplementation increased. Semen characteristics (volume, co
ncentration, motility, etc.) and response to freezing did not differ b
etween the diets. Feeding either legume increased (P<0.001) testicular
size, lupins giving a slightly greater response than cowpeas. Sperm p
roduction per g testicular tissue was not significantly altered. Incre
asing levels of either supplement increased (P<0.001) the weights of t
he seminal vesicles, more (P<0.01) so with lupins. The same effects oc
curred with the weight of epididymides except for rams fed cowpeas at
the highest level. Histologically, the testes revealed an increase (P<
0.001) in the number of round spermatogenic cell nuclei and the cross-
sectional diameter of stage 8 tubules in rams after legume grain suppl
ementation at 2.0% LW compared with controls. The response was higher
in lupin-fed rams (P<0.05). Plasma luteinising hormone (LH) and follic
le stimulating hormone (FSH) were measured in rams fed at maintenance
or with lupins or cowpeas at 2.0% LW. Rams responded equally to all le
gumes. Concentrations of LH in peripheral blood increased (P<0.001) by
140% and FSH concentrations were elevated (P<0.01) 4-fold. Cowpeas, a
tropical grain legume similar in nutrient composition to lupins, have
similar potential when used as a supplement to improve productive and
reproductive capabilities of Merino rams.