Increases in ovulation rate in lupin-fed ewes are initiated by increases in protein digested post-ruminally.
Parous Merino ewes were maintained outdoors in feedlots during the beginning of the spontaneous breeding season and fed a maintenance ration of wheaten hay. For 14 days, ewes in each of 4 groups (N = 40/group) were given supplements of lupin grain or formaldehyde-treated casein and/or wheat starch. These were calculated to supply equivalent amounts of protein post-ruminally and/or digestible energy. Supplementation with lupin grain significantly increased ovulation rate by 37% by increasing the proportion of ewes with two ovulations. Similar increases in ovulation rate were achieved by increasing the supply of digestible protein post-ruminally in the casein and casein + starch-supplement groups. Increasing the intake of digestible energy separately in the starch-supplement group did not increase ovulation rate. It is concluded that increases in ovulation rate in ewes fed a lupin supplement are the result of significant increases in the amount of protein digested post-ruminally.
Nottle
M B
MB
Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, Glen Osmond, South Australia.
Hynd
P I
PI
Seamark
R F
RF
Setchell
B P
BP
D000818:Animals; D004044:Dietary Proteins / Q000378:metabolism*; D004063:Digestion; D002149:Energy Intake; D007887:Fabaceae; D005260:Female; D010060:Ovulation; D010946:Plants, Medicinal; D012417:Rumen; D012756:Sheep / Q000502:physiology*
D004044:Dietary Proteins