1. Interaction effects of sexual preparation and diurnal period on reproductive capacity of boars

2. 5 Programme 3: Farmer Support and Development 5.1 Strategic Goals Goal 1 – Improvement of primary production and advancement in agro-processing Goal 2 – Economically suitable agricultural development Goal 4 – Improved stakeholders relations Goal 6 – Household food security Goal 7 – Farmer settlement support T. Teele 1 and D.O. Umesiobi 2# 1 Extension and Advisory Services, Department of Agriculture and Rural Development, P O Box 50, Parys, 9585 2 School of Agriculture and Environmental Sciences, Central University of Technology, Free State, Private Bag X20539, Bloemfontein, 9300, South Africa #Corresponding author: E-mail: umesiobi@cut.ac.zaumesiobi@cut.ac.za

3. Contents Introduction Motivation of the study Problem statement Project rationale Objectives Hypothesis Research design and methodology Statistical analysis Results and discussions Conclusions and recommendations References Acknowledgements

4. Introduction Successes in the pig production industry therefore depend mostly on the sexual drive of the boar and the ability to produce semen of a required quality with a large number of normal live sperm for optimum fertilization capacity of sows (Umesiobi et al., 2002; Umesiobi, 2007). Increasing use of assisted reproductive techniques in the pig has exposed a need for additional aids such as sexual preparation of boars, involving sexual restraint and false mounting, to help animal reproductive physiologists and breeders optimise the ejaculates obtained from boars Orgeur and Signoret (1984), Price (1987), Umesiobi and Iloeje (1999) and Umesiobi et al. (2004) observed that the male, if not stimulated to a high level of excitability, becomes somnolent and sluggish in sex drive and the ejaculatory reflex weakens

5. Motivation of the study Numerous studies (Umesiobi & Iloeje, 1999; Umesiobi et al., 2002; Umesiobi, 2006a, b; Umesiobi, 2008a, b, c) have been conducted to optimise the reproductive potential of artificial insemination (AI) pigs to equal or better that of natural mating, conception rate and litter size are less than optimal in most production systems (Umesiobi et al., 2004). Boars that obtain adequate sexual preparation exhibit a relatively rapid ejaculation rate, and are capable of inseminating a greater number of females per unit time than males with poorer sexual drive (Umesiobi, 2004) The interaction effect of sexual preparation and diurnal period on reproductive capacity of boars has not been determined

6. Problem statement Sexual preparation of boars has not received adequate attention from researchers Precise guidelines are not available Boars should be subjected to a few minutes of sexual restraint and false mounting before they are used for breeding Reproductive performance is most critical in boars with low sexual drive Larger number of boars are needed to sire offspring that grow faster and yield more meat

7. Project rationale Boar sexual drive is a critical feature of a breeding system in which a predetermined number of females are to be bred weekly. Sexual drive and semen viability should not be taken for granted, especially during the summer months. Boars are temperamental and individualistic. Some boars possess many desirable traits, and are aggressive and fertile; others are sterile or possess no sex drive. Although boars that lack a sex drive are self-eliminating, they cause additional problems because the other boars must be used more frequently to compensate for them.

8. Objectives The primary aim and objectives of the study The primary aim of this study was to determine the interaction effects of sexual preparation and diurnal period on reproductive capacity of boars In order to achieve this aim, the following objectives were achieved: A literature review was conducted to gain insight and perceptions on current views of the principles of the role of sexual preparation and diurnal periods on reproductive capacity of boars. The principles of the role of sexual preparation and diurnal periods were utilised to identify fundamental performance indicators by means of which the reproductive capacity of boars were evaluated.

9. Specific objectives and Hypothesis A field experiment was conducted to determine: the interactive effects of sexual preparation on reproductive capacity of boars, and the effects of diurnal periods on reproductive capacity of boars Hypothesis Sexual preparation and diurnal period has significant interaction effect on reproductive capacity of boars

10. Research design and methodology Twelve Large White boars (aged 2.0 years) and 36 sows of the same breed and age were randomly selected The experimental boars were trained to mount the artificial sow at 6 to 8 months of age The research protocols were conducted in 4.5 m x 4.5 m pig pens. Individual pens had a combination of concrete and solid steel rod flooring and were each equipped with a nipple waterer. The animals were limit-fed, at a rate of 2 kg/day

11. Research design and methodology SEXUAL PREPARATION AND BOAR SELECTION Prior to sexual preparation, the boars were randomly recruited and trained for two weeks two ejaculates were collected in 12 hour interval 0, (0R) 5 (5R) and 10 (10R) sexual restraint (sexual preparation) tests Libido was recorded as the reaction time (RT) (in minutes) 30 minutes reaction time at 8:30 and 14:30 hours (diurnal period) Semen was collected by the use of a gloved hand device following sexual stimulation

12. Research design and methodology SEMEN COLLECTION AND EVALUATION Semen was collected immediately after 0MR, 5MR and 10MR of sexual preparation at 8h30 and 14h30 diurnal periods, Twelve mature Large White boars were used to collect semen over receptive sows on oestrus. Semen was collected by artificial vagina (AV) and immediately strained through cheese-cloth to remove the gelatinous portion.

13. Artificial vagina device connected to a graduated semen bottle for easy semen evaluation

14. Research design and methodology SEMEN COLLECTION AND EVALUATION The sperm-rich fraction was considered to be that portion of the ejaculate that was distinctly milky in appearance as opposed to the watery pre and post-sperm fractions. Semen volumes in ml were recorded after collection. Semen characteristics were analysed at the Agriculture Laboratory of the Central University of Technology, Free State, while other characteristics were analysed at the Veterinary Laboratory, National Veterinary Division of the Department of Agriculture, Bloemfontein. Motility was analysed under microscope while SpermCueR hemacytometer was utilised for the determination of sperm concentration. Progressive sperm motility (%) was estimated from 0 to 100 using a light microscope (Umesiobi, 2004; Umesiobi et al., 2004).

15. Research design and methodology SEMEN COLLECTION AND EVALUATION The percentage of live sperm cells was determined by vital staining with eosinnegrosin stain. The acrosomal morphology was assessed by mixing a high grade Indian ink with semen on a slide and the mixture then drawn out to make a thin smear. The smear was read using a light microscope at x400 magnification. Semen from each experimental group was then collected and sperm cells from each boar were used (3 x 109 sperm/80 ml/sow) to artificially inseminate 3 oestrus-synchronised sows (twice), 12 and 24 hours after the onset of oestrus (Umesiobi and Iloeje, 1999; Strzezek et al., 2000).

16. Statistical analysis Data were analysed using the general linear model procedure of SAS (2002 SAS, Version 9.1). The statistical model included sexual restraint classification of boars (0, 5 and 10R) and individual boars (breeding boar) within treatment groups. As libido test data for mounts, reaction time and ejaculations were discrete, these were analysed using the Wilcoxon signed rank test, and presented as least-square means ( s.e.).

17. Results Semen viability parameters 0 MR5 MR10 MR 08h3014h3008h3014h3008h3014h30 Semen volume (ml)113.35 ± 13.64 a 103.23 ± 6.15 a 116.67 ± 8.82 a 123.33 ± 5.23 ab 117.50 ± 10.7 b 120.81 ± 9.16 c Motility (%)69.16 ± 3.74 a 63.31 ± 3.8 a 66.71 ± 2.47 a 72.5 ± 4.42 b 60.83 ± 2.39 bc 70 ± 2.58 c Semen concentration per ml (x10 6 ) 655 ± 10.45 a 680.4 ± 35.36 a 702.8 ± 57.14 a 762.29 ± 39.1 b 736.5 ± 58.53 c 670.5 ± 40 b Semen conc. per ejaculate (x10 9 ) 112.81 ± 2.66 a 107.83 ± 3.47 a 113 ± 2.77 a 112.93 ± 1.76 a 108.85 ± 3.34 b 109.55 ± 3.37 c Live sperm (%)61.67 ± 3.57 a 66.17 ± 2.89 a 64.17 ± 3.27 b 67.5 ± 2.14b c 60.83 ± 3.26 b 70.83 ± 3.52 c Normal sperm (%)60 ± 2.24 a 60.83 ± 2.71 a 63.33 ± 5.1 a 56.67 ± 2.79 b 66.6 ± 5.11 c 62.5 ± 2.81 d Acrosome morphology: Normal apical ridge (%) 56.5 ± 3.09 a 68.5 ± 7.82 a 56.16 ± 4.33 a 61.2 ± 4.61 b 65.67 ± 4.4 bc 74.33 ± 3.46 c Damage apical ridge (%) 31.83 ± 12.85 a 16.67 ± 5.26 a 21.83 ± 5.54 a 25.5 ± 5.9 ab 18.17 ± 6.7 b 7.66 ± 4 c Missing apical ridge (%) 8 ± 1.88 a 8.65 ± 2.75 a 15.33 ± 3.22 b 6.16 ± 7.11 a 7.5 ± 1.28 ab 6.48 ± 2.73 c

18. Results and discussions Sexual restraint of 10 min (10R) at 8:30 hours (diurnal period) resulted in the highest number of mounts, ejaculation rate and shortest reaction time Volume, motile spermatozoa, semen concentration per ml improved at 10R 08:30 Semen concentration per ejaculate (x10 9 ), live sperm and normal sperm were significantly improved with 5R at 14:30 and 10R at 08:30 and 14:30, respectively, with highest values recorded with 10R at 08:30 hours

19. Conclusions and recommendations This study suggest that boars sexually stimulated at 5 minutes during the afternoon hours (5MR14h30) significantly improved boars some of the semen characteristics However, boars sexually prepared at 10MR8h30 in the early hours persistently produce optimum sperm viability, with improved reproductive capacity 10 min of sexual restraint of boars conducted during the morning hours were most suitable for semen collection and use in AI services

20. References Flowers, W. L. 1997. Management of boars for efficient semen production. J. Reprod. Fertil. Suppl. 52:67–78. McDonald, J.H. 2008. Handbook of Biological Statistics. Baltimore, Maryland: Sparky House Publishing, pp. 1-28. Morrow, M. E. W., 2005. Semen extension: A comparison of methods. Swine News 28(8): 35-39. Price, E. O. 1987. Male sexual behaviour. Vet. Clinics of North America: Food Animal Practice 3: 405-422. Umesiobi, D. O. 2000. Effect of egg yolk, coconut water and fresh raphia palmwine extenders on the viability of boar sperm during storage at 50C. J. Agric. Rural Dev. 1(1) : 98 - 106. Umesiobi, D. O. 2006a. The effect of hemi-orchidectomy on reproductive traits ofboars. South African Journal of Animal Science 36(3): 181-188. Umesiobi, D. O. 2006b. Effect of oral administration of Clomiphene citrate on sperm viability and fertility of boar semen. J. Appl. Anim. Res. 30: 167- 170.

21. References Umesiobi, D. O. 2007. Measures of libido and their relation to testicular hypertrophy and fertilizing competence in boars. Journal of Animal Science 85(Suppl. 1): 815. Umesiobi, D. O. 2008a. Measures of servicing capacity of boars and their effects on subsequent fertility in artificially inseminated gilts. Journal of Applied Animal Research 34: 9-12. Umesiobi, D. O. 2008b.. Supplemental Vitamin E: A requirement for optimizing fecundity rates and litter size in sows. The Philippine Agricultural Scientist 91 (2): 187-194. Umesiobi, D. O. 2008c. Effects of sexual stimulation of boars on the fertility and fecundity rates in sows. The Philippine Agricultural Scientist 91 (1): 379-385. Umesiobi, D. O. and Iloeje, M. U. 1999. Effect of sexual teasing and diurnal period of semen collection on reaction time and semen characteristics of Large White boars. J. Sustain. Agric. and Environ. 1(2) 231 - 235. Umesiobi, D. O., Iloeje, M. U. and Berepubo, N. A. 2002. Artificial insemination in sows using Guelph and two local semen extenders. Nig. J. Anim. Prod. 29(1): 121 - 126. Umesiobi, D. O., Kalu, U., Ogundu, U., Iloeje, M. U., Anyanwu, D. C., McDowell, L. R. 2004. Fertility studies on two methods of libido maintenance in West African Dwarf rams. J. Anim. Vet. Advances 3(2), 81-84. Strze ż ek, J., Fraser, L., Demianowicz, W., Kordan, W., Wysocki, P., Hollody, D. 2000. Effect of depletion tests (DT) on the composition of boar semen. Theriogenology. 54(6): 949-963.

22. Acknowledgement Prof. D O Umesiobi Department of Agriculture and Rural development, Free State (DARD) Department of Agriculture, Fisheries and Forestry (DAFF) Central University of Technology, Free State (CUT, FS) National Research Foundation (NRF) Grootvlei Prison Farm, Piggery unit