Pre and Peri-pubertal Feeding of Melengesterol Acetate (MGA) Alters Testis Characteristics in Bulls

Bulls were fed 1 mg/head/day of MGA from 5.5 to 6.5 months ; 6.5 to 9; or fed a control diet. Body weight, scrotal circumference, combined testis weight, testis composition, and testosterone concentration were measured. Feeding MGA prior to puberty increased scrotal circumference and decreased testosterone concentration at 12 months compared to controls. Thus, feeding MGA prior to puberty can alter testis characteristics in bulls

Progestin Concentrations Alter Follicle Characteristics and May Affect Quality of Oocytes (Eggs)

Cows were treated with two progestin concentrations to develop ovulatory follicles exposed to different hormone environments. Cows were assigned to Control Group receiving a CIDR for 7 days (4-6 ng/ml of progestin), or to MGA-14 Group receiving 5mg/head/day of MGA for 14 days (\u3c 1 ng of progestin). Our hypothesis was that the MGA-14 treatment would develop larger, persistent follicles with less granulosa cells per follicle volume and may have altered gene expression profiles in oocytes and granulosa cells. Cows in the MGA-14 treatment had larger follicles and less granulosa cells per volume than controls, suggesting that their development mimicked persistent follicles and may be of poorer quality