Print version ISSN 1405-3195
BULBARELA-GARCIA, Gerónimo et al. Effect of L-arginine and fish oil on the reproductive performance of hair sheep synchronization with a progestagen. Agrociencia [online]. 2009, vol.43, n.4, pp. 371-377. ISSN 1405-3195.
L-arginine is a substrate of the enzyme nitric oxide synthase for production of nitric oxide (NO), which has an influence in reproductive physiology, while fish oil inhibits the production of NO. Therefore, an study was performed about the effects of a supplement (for 3 d) of L-arginine (A) (for 3 d) and fish oil (AC) on the onset of estrus (E), percentage of estrus (PE), ovulatory rate (TO), percentage gestation (PG) and prolificity (PR) in hair sheep ewes treated (12 d) with 40 mg of fluorogestone acetate (AFG) using an impregnated polyurethane sponge inserted into the vagina. The treatments were the following: P=progesterone oil alone (n=7); AFG+eCG=40 mg fluorogestone acetate (12 d) + 400 IU equine chorionic gonadotropin (eCG; n=8); AFG+A=AFG+300mg kg-1 A (n=10); AFG+AC=AFG+ 6 % AC (n=11); AFG+A+AC (n=8). E was different (p<0.05) in ewes treated with AFG+eCG with 33.20±3.9 h. PE was not different among ewes treated with AFT + eCG, AFG+A and AFG+AC, but it was different (p<0.05) from that of those treated with AFG+A+AC and those treated with P alone. TO among ewes was different (p<0.05) for AFG+A (1.70±0.13), AFG+A+AC (1.80±0.13), AFG+AC (1.60±0.16) corpora lutea per ewe vs AFG+ECG (1.50±0.19) and P (1.40±0.25). PG was different (p<0.05) en AFG+eCG 100% (8/8) and AFG+AC 90.9 % (10/11) vs AFG+A 70.0 % (7/10) and AFG+A+AC 87.5 % (7/8) and P 28.6 % (2/7). PR was different (p<0.05): the largest number of lambs per ewe was obtained with AFG+A (1.7±0.18) and the smallest number with AFG+A+AC (1.1±0.14). There was no difference in PR among the ewes treated with P (1.5±0.50), AFG+eCG (1.4±0.18) and AFG+AC (1.4±0.16). The ewes treated with AFG+A and AFG+AC showed reproductive characteristics similar to those treated with AFG+ eCG and better characteristics than those treated with P alone. There was a negative interaction in PR with the supplement A+AC. A apparently influences the reproductive behavior of hair sheep ewes.
Keywords : Fish oil; fluorogestone acetate; L-arginine; prolificity; ovulatory rate.