Theses and Dissertations

Issuing Body

Mississippi State University


Nicodemus, Molly

Committee Member

Rude, Brian J.

Committee Member

Mochal-King, Cate Ann

Committee Member

Christainsen, David L.

Committee Member

Liao, Shenfa

Date of Degree


Document Type

Dissertation - Open Access


Animal and Dairy Science

Degree Name

Doctor of Philosophy (Ph.D)


College of Agriculture and Life Sciences


Department of Animal and Dairy Sciences


Fat supplementation is a common practice to increase caloric intake in the performance horse. The effects of fat on fiber digestibility is unknown. Understanding of digestibility in the equine digestive tract is limited by sampling technique. While cecal and ileal cannulations have previously been utilized to determine equine nutrient digestibility and gastrointestinal physiology, the current research has been limited to singular portions of the equine digestive tract. The objectives of this dissertation were to determine the effects of dietary fat supplementation on nutrient digestibility and blood insulin, glucose, and fatty acid concentrations using dual cannulated ponies. The first step to this objective was establishment of a dual cannulated pony herd for research. This study resulted in a post-operation survival rate of 63%. Five of the dual cannulated ponies were fed hay and pelleted alfalfa and supplemented with vegetable oil at 0, 5, 10, or 15 % of total diet. Ileal, cecal, fecal, and blood samples were taken with blood samples analyzed for glucose, insulin and fatty acids. There was a treatment by time effect (P < 0.1) for apparent ileal and cecal fat digestibility and apparent cecal digestibility of crude protein. Apparent total tract digestibility of NDF, ADF and fat was affected by time (P < 0.1). Adding fat increased (P < 0.1) apparent total tract digestibility of fat. At 0 h post feeding apparent total tract digestibility of protein was greatest (P < 0.1) compared to other time periods. Plasma concentration of insulin increased (P < 0.1) over time. Ponies consuming 0 % fat diet had increased C14:0 compared to 5, 10, and 15 % diet. Adding fat at 5, 10, and 15 % of the diet increased C18:2 n-6 when the ponies were fed 0 % fat. Further research using a dual cannulated equine research herd is needed to more completely understand digestibility of other components of the equine diet.