Introduction:

feeding for sheep production in the tropics accounts from 48 to 90% of total production cost; additionally, the use of grains also makes producers dependent on the international market. Moderate weight gains in rams could be obtained with foliage from tropical trees; however, some plants such as Hibiscus Rosa-sinensis have compounds that could act as phytoestrogens, which could compromise its potential use as animal feed.

Method:

twelve Pelibuey rams, aged 24±3 months old, 45±6 kg live weight and a body condition score of 2.3±0.3 in a scale from 1 to 5, were assigned to one of two treatments for 45 days. T1 (n = 12), commercial feed (500 g d-1 by sheep) with 16% CP, and T2 (n = 12), 20% of H.rosa-sinensis (451 g DM kg MV ~ 1.6 kg d-1 per animal). Both treatments were supplemented with (Pennisetum purpureum x P. Typhoides var. CT-11S) grass. Parameters of semen quality were evaluated: ejaculate volume (Vol, mL) and concentration (EC, millions per mL) and eight individual motility parameters were used: curvilinear speed (VCL, μ/s), straight line velocity (VSL, μ/s), mean velocity (VAP, μ/s), linearity index (LIN, %), straightness index (STR, %), oscillation index (WOB, %), mean amplitude of lateral head displacement (ALH, u) and beat frequency to tail (BCF, Hz). Student s t test was used to determine differences between treatments for VOL and CE and VCL, VSL and VAP. A factor reduction, followed by a two-step clustering procedure of individual motility parameters allowed determining the structure of subpopulations by sperm motility. Analyses were performed using SPSS 15.0 software for I Windows.

Results:

no statistical differences (P>0.05, T1 vs T2, Mean±SD) were found in ejaculate volume (0.79±0.31 vs 0.81±0.32 ml), Sperm concentration / ml (4051±729.5 vs 4860±598.6 million/ml). For individual sperm motility, we found differences (P<0.01) for VCL (90.18 ± 39.16 vs 131.26 ± 63.16 μ/s), VSL (52.94 ± 36.72 vs 71.64 ± 54.44 μ/s), VAP (70.42 ± 36.23 vs 101.41 ± 59.87 μ/s), LIN (55.14 ± 27.02 vs 50.88 ± 26.64 %), STR (69.16 ± 24.93 vs 65.68 ± 24.52 %), WOB (75.94 ± 16.81 vs 73.47 ± 18.94 %), ALH (2.99 ± 1.26 vs 3.96 ± 1.74 μ) and BCF (7.33 ± 3.12 vs7.71 ± 3.25 Hz). The obtained subpopulations by two step procedure, indicate that the highest motility-derived indexes occur in animals fed with H. rosa-sinensis.

Conclusion:

inclusion of H. rosa-sinensis in feed for Pelibuey rams, did not alter the semen volume or concentration, but individual motility parameters (VCL, VSL and VAP) are different. The analysis of subpopulations highlighted differences in individual motility between treatments, thus showing the structure of motility in the ejaculated. Since no deleterious effect was observed in this trial, H. rosa-sinensis could be considered as an alternative to feed Pelibuey rams in the tropics.