Lupins and energy-yielding nutrients in ewes. II. Responses in ovulation rate in ewes to increased availability of glucose, acetate and amino acids.
An experiment, using a total of 320 Merino ewes, over two successive breeding seasons was conducted to investigate the separate effects of energy-yielding and protein-yielding nutrients on ovulation rate in sheep. The available energy-yielding or protein-yielding nutrients in the blood of sheep fed a maintenance pelleted ration were increased by either intravenous infusions of metabolites (acetate, glucose or acetate + glucose), feeding lupin grain, modification of the pattern of rumen fermentation to increase propionate production using the ionophore, lasalocid, or by feeding of ruminally undegradable protein (formaldehyde-treated casein). All treatments were given for 9 days prior to and including expected time of ovulation. Ovulation rates were measured by laparoscopy. In the first season (the 1984 experiment) when the effects of lupin grain, glucose + acetate and formaldehyde-treated casein were compared, ovulation rates were increased significantly in the group fed lupin (29%, P less than 0.001) and the group infused with glucose + acetate (24%, P less than 0.01). There was an apparent (17%) but statistically non-significant increase in the group fed casein. In comparisons between lupin grain, glucose, acetate, glucose + acetate, formaldehyde-treated casein and lasalocid in the 1985 experiment there were similar significant increases in ovulation rates in the groups fed lupin, and those infused with glucose or glucose + acetate (approximately 25%, P less than 0.001). The increase in the group infused with acetate was lower at 14% (P less than 0.05) and the increases of 7% in the groups fed casein or lasalocid were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)
Teleni
E
E
Department of Agriculture, South Perth, Australia.
Rowe
J B
JB
Croker
K P
KP
Murray
P J
PJ
King
W R
WR
D000085:Acetates / Q000008:administration & dosage / Q000494:pharmacology*; D000596:Amino Acids / Q000008:administration & dosage / Q000494:pharmacology*; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002364:Caseins / Q000494:pharmacology; D004044:Dietary Proteins / Q000494:pharmacology; D002523:Edible Grain; D004734:Energy Metabolism; D004971:Estrus / Q000187:drug effects; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous; D010060:Ovulation / Q000187:drug effects*; D012756:Sheep
D000085:Acetates; D000596:Amino Acids; D002364:Caseins; D004044:Dietary Proteins; D005947:Glucose