PSVII-26 The effect of consuming red clover pasture and beneficial fatty acid supplements on ram lamb seminiferous tubule microscopic features

Abstract Fatty acids and phytoestrogens have been linked to short- and long-term alterations of reproductive performance in sheep. Red clover (RC) contains phytoestrogens, which have been linked to reduced reproductive performance in sheep. However, rams fed RC have increased omega-3 polyunsaturated fatty acids (n-3 PUFAs) and conjugated linoleic acid (CLA). These beneficial fatty acids may improve reproductive performance in rams. Fish oils (FO) contain significant amounts of n-3 PUFA and these improve reproductive performance. This study aimed to determine the effects of RC pasture and beneficial fatty acid supplementation on ram lamb seminiferous tubule histology. Crossbred ram lambs (n =32; 2 to 3 mo of age) were randomly divided into four groups (n = 8 per group) and balanced by body weight (BW) and dam parity. Two groups grazed tall fescue (TF)/RC, and two grazed TF pasture for 10 wk. These groups were then further randomly subdivided to receive a fat supplement [soybean oil (SBO; n = 8), SBO + CLA (n = 8), or FO (n = 8)] or no fat supplementation (CON; n = 8) during a 5-wk finishing diet. Then rams were slaughtered, and their testes were collected, fixed, and processed for histology. Testes cross sections were viewed under light microscopy and photos were taken for image analysis. Seminiferous tubule diameter, luminal diameter, cell count, and the average cell nuclear area: tubule area were determined using Image-Pro 10 software (Media Cybernetics). No significant differences were noted in tubular diameter or luminal diameter between any treatment groups. Those on TF had significantly greater cell counts (371.3 ± 39.6 vs. 305.9 ± 44.2; P < 0.05) than rams on TF/RC pasture. Soybean oil produced a significantly lower ratio than SBO + CLA (0.000324 ± 0.000190 vs. 0.000408 ± 0.000300, P < 0.05) but a greater cell count (498.2 ± 36.2) than CON, SBO + CLA, or FO (289.7 ± 52.9 vs. 282.2 ± 50.3 vs. 284.3 ± 50.9; P < 0.001). No statistical difference was noted in ratios between the two pastures. Rams on TF/RC, with no supplementation had the least cell counts (227.2 ± 58.2) of all treatment groups, with significantly fewer counts than TF/RC + SBO rams (412.4 ± 62.0 P < 0.05) and TF + SBO rams (583.9 ± 37.3; P < 0.001); the latter had the greatest cell count of all treatment groups. Results suggest that RC and oil supplementation impact cell count, and oil supplementation impacts ratios but neither factor had an impact on tubule or luminal diameter.