Conceptions Rates using Brahman Bull Semen Frozen in Milk Based Extender Containing Egg Yolk or Soybean Lipids:

Transcription

1 Coceptios Rates usig Brahma Bull Seme Froze i Milk Based Exteder Cotaiig Egg Yolk or Soybea Lipids: Field study i tropical coditios R. Gozález 1,2, M. Rosales 3 F. Perea 3, J. Velarde 2, E. Soto 1,2, R. Palomares 1, H. Herádez 1 ad A.T. Palasz 4 1 Facultad de Ciecias Veteriarias,, Uiversidad del Zulia,, Veezuela, 2 Veezolaa de Isemiació Artificial y Trasplate de Embrioes,, C.A. (Viateca), 3 Departameto de Ciecias Agrarias.. Uiversidad de los Ades, Veezuela, 4 Departameto de Reproducció Aimal. INIA, Madrid, Spai

2 Itroductio For years egg yolk have bee used i the cryopreservatio of seme e from domestic ad wild species as a effective compoet of cryopreservatio rvatio media. However, the potetial trasmissio of Salmoella species,, the Newcastle Disease virus ad the presece cryoprotective atagoists that ihibit respiratio of spermatozoa ad reduce their motility provides a strog argumet for the elimiatio of egg yolk from seme cryopreservatio procedures. It is assumed that the protective actio of egg yolk to be due to small multilamellar vesicle of low desity lipoproteis (LDL) that ca be produced by cetrifugatio of egg yolk. Low desity lipoproteis make up about two-thirds thirds of the total solids of chicke egg yolk ad are preset i i the soluble fractio of egg yolk. Phospholipids play a essetial l role i the stability of the LDL structure. Chemical compariso of chicke egg yolk compositio ad bull sperm membrae idicates that the commo compoet preset i high cocetratio i both the chicke egg yolk ad the bull sperm membraes mbraes is phospholipid - phosphatidyl cholie.

3 Objectives To examie the efficacy of double cetrifuged chicke egg yolk i Brahma bull seme exteder. To examie whether phosphatidyl cholie of soybea-origi origi ca substitute for the egg yolk i Brahma bull seme exteder.

4 Eviromet ad aimals Evirometal coditios Seme was collected ad AI was performed durig the dry seaso betwee December ad April i a tropical forest eviromet. The mea temperature for the regio was betwee C, with mea raifall of mm/year ad the relative humidity of 60-70%. Aimals 3 pure breed Brahma bulls 174 cross breed Brahma cows

5 Seme exteders Basic exteder solutio was prepared i 1% milk cotaiig 10 mg ml - 1 of fructose ad was supplemeted by: Exteder 1* - (cotrol), 8% of whole egg yolk Exteder 2* - 8% of rectified egg yolk Exteder 3* mg ml - 1 of lipids of soybea-origi origi cotaiig 10% of phosphatidyl cholie *1000 IU of peicilli, 1mg ml -1 streptomyci ad 150µg ml -1 licomyci were added to each exteder? Glycerol was added to each exteder i 2 steps i 15 miute itervals to a fial glycerol cocetratio of 7%.

6 Materials ad Methods Seme collectio, freezig ad thawig Seme was collected by meas of artificial vagia. Ejaculates with at least 60% motility were diluted i 2-steps 2 as follows: Step 1, each ejaculate was split at 3 eve parts ad diluted at 26 0 C with each of the exteders cotaiig o glycerol. Step 2, 14% of glycerol was added i 15 miute itervals to a fial glycerol cocetratio of 7%.? Seme was aspirated ito 0.5mL plastic straws (20 x 10 6 sperm/per straw).? Seme was froze 7 cm above liquid itroge (LN 2 ) for 8 mi, ad the pluged ito LN 2. Straws were thawed i a water bath at 37 0 C for 30s.

7 Experimet I Total of 157 cows were isemiated with seme collected from 3 differet Brahma bulls A, B ad C ad froze i 3 differet exteders supplemeted with: whole egg yolk (cotrol) Exteder 1 rectified egg yolk Exteder 2 lipids of soybea-origi origi Exteder 3 Bull A & Exteder 1 (cotrol) =19, Exteder 2, =20, Exteder 3, =22 Bull B & Exteder 1 (cotrol) =20, Exteder 2, =20, Exteder 3 =20 Bull C & Exteder 1 (cotrol), =20, Exteder 2, =15,Exteder 3, =24 Pregacy rates were determied by palpatio 45 Days after AI.

8 Experimet II Total of 117 cows were isemiated with seme collected from bull B ad froze i 3 tested Exteders: Exteder 1 (cotrol) = 37 Exteder 2 = 48 Exteder 3 = 39? Post-thaw thaw seme viability were determied by pregacy rates 45 Days after AI.

9 Results Experimet I Table 1. Coceptio rates of cross breed Brahma cows isemiated with 3 differet Brahma bulls seme froze i milk-glycerol based exteders supplemeted with 2 differet preparatios of egg yolk or soybea lipids. Bull A B Whole egg Yolk (34.5) This is mistake 9 (45.0) Exteder supplemet Rectified egg Yolk (50.0) 12 (40.0) Soybea lipids (50.0) 12 (48.0) C 27 8 (29.6) (50.0) (54.2)

10 Experimet II Table 2. Pregacy rates of cross breed Brahma cows isemiated with oe Brahma bull seme froze i milk-glycerol based exteders supplemeted with 2 differet preparatios of egg yolk or soybea lipids. Exteder supplemet Whole egg yolk Rectified egg yolk Soybea lipids 37 (24.3) a 48 (41.6) b 39 (46.1) b ab- percetages betwee colums with values ot i commo differ (P< 005)

11 Coclusios Results suggest that rectified egg yolk by meas of double cetrifugatio improved efficacy of Brahma bull seme exteder. Lipids of soybea origi cotaiig 10% of phosphatidyl cholie ca successfully replace egg yolk i Brahma bull seme exteder ad are equally effective as rectified egg.