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This study determined the effects of short-term energy inputs on ghrelin secretion and possible links with changes in the follicle population or the ovulation rate. Oestrous cycle was synchronized in 16 Manchega sheep using progestagen sponges and cloprostenol. Half of the animals were treated from days 0 to 4 by the oral administration, twice daily, of 200 ml of a glucogenic mixture containing 70% of glycerol, 20% of 1,2-propanediol and 10% of water; the control group received 200 ml water. The mean (GS.E.M.) plasma glucose increased immediately after the first administration (3.9G0.3 vs 3.0G0.1 mmol/l in control group, P!0.05), remaining statistically different during the treatment. However, plasma ghrelin levels were similar in both groups. On the other hand, the results indicated that short-term energy inputs modify ovulation rate (1.9G0.1 vs 1.3G0.2 in control group, P!0.05) by increasing the number of follicles able to be selected to ovulate during the period of treatment (R4 mm in size; 5.9G0.6 vs 4.3G0.4 at day 2, P!0.05). After sponge withdrawal, the number of these follicles decreased throughout follicular phase (5.8G0.8 to 1.5G0.4, P!0.0005) while the number of large follicles increased (R6 mm in size; 0.8G0.4 to 2.0G0.3, P!0.05); this would indicate an active growth of preovulatory follicles that were not found in the control group. Thus, the increases of ovulation rate by high-energy inputs would be caused by an enhancement in the developmental competence of preovulatory follicles. Reproduction (2008) 136 65-72

A method has been developed for simultaneously determining alpha-tocopherol and cholesterol in fresh pig meat by HPLC. It allows a reduction in the number of analyses and brings savings in time and materials. The unsaponifiable fraction is extracted following the modified method of Liu et al. (Liu, Q.; Scheller, K. K.; Schaefer, D. M. Technical note: A simplified procedure for vitamin E determination in beef muscle. J. Anim. Sci. 1996, 74, 2406-2410). The modifications introduced are the use of nitrogen atmosphere during the extraction, the addition of an antioxidant in the organic extraction phase, and the use of alpha-tocopherol itself as an internal standard. There is then a chromatographic analysis which allows the separation of the two compounds in question. To identify and quantify, two different detectors are used in series: the first is a fluorescence detector (alpha-tocopherol), and the second is a light-scattering detector (cholesterol). The technique shows sufficient sensitivity to determine the normal levels of alpha-tocopherol and cholesterol in meat, with recovery percentages of 78% and 97%, respectively. The average amount of alpha-tocopherol and cholesterol in samples from pig Longissimus dorsi muscle analyzed using this method is 1.8 and 620 mg/kg of fresh meat, respectively.