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The experimental treatments were two, a control diet (CT) and a high fibre diet (HFD), the latter containing 500 g/kg of unmolassed sugar beet pulp. The daily supply of NE was the same in both treatments, 23,4 MJ of NE. A total of 45 Large White x Landrace crossbred gilts were used. During the second oestrus cycle, ten gilts for each treatment were fitted surgically with a cannula in the jugular vein. The experimental diets were fed to the animals from the first detection of oestrus in the third oestrous cycle and up until either to the day 19 of the same cycle, moment in which 12 animals per treatment were slaughtered, or until insemination at the following oestrus. After insemination the gilts present in each treatment received the same diet until day 27-29 of gestation, when they were slaughtered.
Data recorded included body weight and backfat thickness, plasma concentrations of LH, progesterone, and oestradiol during the whole experimental period, oocyte maturity was determined on day 19 of the oestral cycle, and the embryo survival was studied on day 27-29 of gestation.
Results showed that feeding the HFD resulted in lower oestradiol concentration (P < 0,01) on days 17 and 18, concomitantantly with an increase (P = 0,016) in the LH pulses on day 18 compared to the CT fed gilts. Moreover, more oocytes in metaphase II were recovered from gilts receiving the HFD on day 19 of the oestrus cycle, and the percentage of embryo survival was also higher in these gilts on day 27-29 of gestation (73 vs 91%, P = 0,021).
This study shows the fact that a modification in the dietary composition can determine a better preovulatory environment, thereby enhancing the embryo survival in the first month of gestation.
EM Ferguson, J Slevin, MG Hunter, SA Edwards, y CJ Ashworth. 2007, Reproduction Research. Vol 133: 433-439.
