Metabolic and luteal sequelae to heightened dietary fat intake in undernourished, anestrous beef XXXX induced to ovulate.

@entity4208 @entity1733 @entity291 @entity1176
Two experiments were conducted to evaluate the effects of dietary fat supplementation and a synthetic progestogen on metabolic hormone patterns and(or) in vitro and in vivo characteristics of induced corpora lutea (CL) in undernourished, post-partum beef @entity291 . Metabolizable energy intake was restricted in all @entity291 in both experiments before calving to achieve a body condition (BC) score of 4 (thin), with @entity291 fed to maintain BW and condition after calving. In Exp. 1, 16 @entity291 were fed isocaloric and isonitrogenous diets after calving with either no added fat (NL, n = 8) or added fat ( @entity1733 , n = 8; .374 kg of fat/500 kg BW). In Exp. 2, 32 pluriparous @entity291 that had reached targeted body condition were divided randomly at calving into a 2 x 2 factorial treatment arrangement: 1) @entity1733 -no implant; @entity1733 -CON, 2) @entity1733 -norgestomet implant d 14 to 21; @entity1733 -NORG, 3) NL-CON and, 4) NL-NORG. Forty-eight-hour @entity291 removal on d 21 and @entity1176 on d 23 were used to induce CL. The @entity1733 diet increased (P < .03) serum growth hormone (GH) concentrations, changed the puerperal pattern of serum insulin from cubic (P < .05) to linear (P < .05), and increased (P < .01) the in vitro production of @entity4208 by luteal tissue (Exp. 1). In Exp. 2, both @entity1733 diets and NORG treatments ( @entity1733 -NORG, @entity1733 -CON, NL NORG) tended to promote an increased (P < .09) frequency of luteal activity after @entity1176 , but only @entity1733 -CON and NL-NORG enhanced (P < .04) luteal lifespan.(ABSTRACT TRUNCATED AT 250 WORDS)
