Lactic yeast for stallion´s sperm quality.

Trial#67: Evaluation of the effects of the supplementation of the diet with livelactic yeast (Kluyveromyces B0399) on stallion´s sperm quality.

 P.G. Rassu (1), A. Cannas (1), R. Cherchi (2), S. Delogu (2), G. Enne (1);
1_Department of Science of Zootechny, University of Sassari (Italy)
2_Sardinian Institute for the promotion of horses, Ozieri (SS) (Italy), Faculty of Veterinary Medicine, University of Udine (Italy)

INTRODUCTION

The use of probiotics in horse nutrition is not widespread: however, some studies have shown that digestibility of NDF (Hill and Gustell, 1998) and nitrogen retention (Glade and Riesik, 1986) are improved by the utilisation of yeast cultures. No information about the effects of live lactic yeast supplementation on sperm quality has been found in literature.

The aim of this study is to evaluate the effects of the supplementation of the diet with live lactic yeast (such is Kluyveromyces fragilis B0399) on stallions' sperm quality.

MATERIAL AND METHODS

Twelve stallions of anglo-araba-sarda breed were housed in individual boxes and fed a basal diet of oat hay ( about kg 8.0), oat grain (kg 2.8) and commercial pellets (kg 2.0). After 15 day preliminary period (P) they were divided into two groups: group C (control), fed the basel diet; group T (treated), fed the basel diet plus 20 g/head/d of Turval 6 Horse probiotic containing live lactic yeast (gen Kluyveromyces B0399), for 90-day experimental period (S). In P,S, and in two-month post-experimental period (PS), during which yeast was suspended, sperm samples were collected for 2 consecutive days each month, from 3 stallions per group, chosen on the basis of thei suitability to artificial vagina collection.
Sperm analysis was carried out on samples collecte in the second day, being the first a "day og drain"; gel-free volume, spermatozoa concentration, live and abnormal spermatozoa were determined.
Sperm quality were then subjected to the ANCOVA analysis, using their values in the P period as covariate.
 

RESULTS AND DISCUSSION

The chemical composition of the diet changed slightly during the trial (CP 7.4-9.7%; EE 1.7-2.4%; NDF 54.2-57.1%; ADF 36.3-40.5%; NFE 24.8-28.9%; Ash 6.0-7.8%; AIA 1.6-3.1%), mainly due to the variation in hay quality. Daily DMI (about 11.0 kg) was sufficient to meet maintenance requirements of horses, since body weight was almost constant during the trial in both groups: kg 575-573 (initial and final weight for group C and kg 574- 575 (initial and final body weight for goup T).

Being the trial carried out between December and May, seasonal effects, suche as photoperiod, have probably influenced sperm characteristics.

During P and S period, group C semen was quite better for almost all parameters (Table 1).

During the PS period, group T (treated) showes better sperm quality, especially for live spermatozoa percentage (83% vs 65%; P<0.05); this could be explained by the fact that nutritional effect are not immediat because of the tme required by spermatogenesis ( McKinnos A.O. and Voss, 1993).

CONCLUSIONS

The interesting results of live lactic yeast supplementation obtained on stallions sperm characteristics suggest further studies with doses of live lactic yeast than 20 g/head/day and for a period longer than 90 days used in this experiment.

ACKNOWLEDGEMENTS

The authors are grateful to Turval Laboratories s.r.l., Mr. R.Rubattu, A.Mazza. A.Fenu and A.Bartulu for collaboration. Research funded by CNR Prof. Enne.

Table 1- Sperm quality (average data)    

Fig 1 - Variation(%) of live spermatozoa of treated group(T) vs control group(C). 

Fig 1 - Variation (%) of live spermatozoa of treated group (T) vs control group (C). 

Object: TRIAL N.67. (summary of text)
Evaluation of the effects of the supplementation of the diet with live lactic yeast (Kluyveromyces B0399) on stallion's sperm quality. ( summary ).
S.P.G. Rassu ¹, A. Cannas¹, R. Cherchi², S. Delogu², G. Enne¹,
¹Departimento di Scienze Zootecniche, Unversity of Sassari (Italy)
² Institute d'Incremento Ippico della Sardegna, Ozieri (SS) (Italy)