The objectives of this twelve-week feeding trial were to determine the  effects  of  dietary  Saccharomyces  cerevisiae  and/or  zinc  oxide  on  epididymal  sperm  characteristics,  testicular  morphometric  traits,  and  growth parameters of bucks. 16 (New Zealand White) bucks 16-wk-old, weighing 2.8kg were randomly allotted to one of 4 treatment groups. Each  treatment  was  replicated  four  times,  with  1  buck  per  replicate,  in a completely randomized design (CRD). Each treatment group was randomly  assigned  to  one  of  the  four  commercial  experimental  diets  designated  thus:  TA  =  control  diet  with  no  additives,  TB =  0.12g/kg  Saccharomyces cerevisiae, TC = 150mg/kg zinc oxide and TD = 0.12g/kg Saccharomyces cerevisiae +150 mg/kg zinc oxide. Although treatment had  no  effect  (p>0.05)  on  final  body  weight,  average  daily  weight  gain  and  feed  conversion  ratio,  epididymal  sperm  characteristics  and  testicular morphometric traits differed significantly (p<0.05). Bucks on TB(Saccharomyces cerevisiae-based diet) had improved (p<0.05) sperm concentration,  motility  and  live  sperm,  tubule  diameter,  epididymal  volume, volume fraction of duct, and total duct volume, but decreased testicular  volume.  Bucks  fed  TA  (control  diet)  had  improved  volume  fraction  of  tubule  but  recorded  the  highest  incidence  of  head  and  tail  sperm  abnormality.  Though,  TC(zinc  oxide-based  diet)  enhanced  (p<0.05)  seminal  vesicle  volume,  sperm  pH  was  better  among  bucks  fed  TD  (Saccharomyces  cerevisiae  +  zinc  oxide-based  diet).  It  can  be  concluded that dietary inclusion of Saccharomyces cerevisiae at 0.12g/kg  of  feed  improved  epididymal  sperm  characteristics  and  testicular  morphometric traits of rabbit bucks. 

(10) (PDF) Epididymal Sperm Characteristics, Testicular Morphometric Traits and Growth Parameters of Rabbit Bucks Fed Dietary Saccharomyces cerevisiae and/or Zinc Oxide.