Suplementação mineral no manejo reprodutivo

Abstract

The effect of mineral supplementation on pregnancy rate after synchronization with progestagen and fixed time artificial insemination (FTAI) was evaluated in no pregnant or barren Australian Merino sheep (n = 260) in autumn / winter 2010. Ewes were selected based on their body condition score. Average body condition score was 2.7 (range 1-5) with an average weight of 30.0 kg at TAI. All females were synchronized on a random day of the estrous cycle. The day they received an intravaginal pessary containing 60 mg of medroxyprogesterone acetate (MAP; Progespon®, Intervet) and mineral supplement was considered day zero (DO). After 12 days (D12) 250 IU of eCG (Novormon ®, Syntex, Argentina) were given intramuscular and the progesterone pessary was removed. After 55 to 60 hours (D14) fixed time insemination was performed. Ewes were distributed randomly into four groups (G). Ewes (n = 65) of G1 received 0.375 g anhydrous sodium selenite + 20.0 g anhydrous sodium glycerophosphate (Mineral supplement 1), and 15 g calcium lactobionate + 30 g of magnesium lactobionate + 8.0 g of zinc lactobionate (mineral supplement 2), subcutaneous. The ones from group 2 (G2) received Suplement 1, Group 3 (n = 65) was treated with Supplement 2. Ewes that received a single application of 0.9% saline solution (n=65) subcutaneous, without mineral supplementation constituted the control group (G4). Pregnancy diagnosis was performed by rectal ultrasonography 30 days after TAI resulting in 66.6%, 44.6%, 39.3% and 46.6% pregnancy rate in group 1, 2, 3 and control group, respectively. Mineral supplementation with magnesium, calcium, zinc (Mineral supplement 1) and selenium (mineral supplement 2) resulted in a higher rate of pregnancies (P <0.05), suggesting that these minerals may increase sheep production.