The effect of hemi-orchidectomy on reproductive traits of boars

Large White boars (n = 120) were assigned to hemi-orchidectomy at 60, 100, 140 or 300 days of age or as intact controls throughout the 450 day observation period to evaluate the effects of unilateral testicular hypertrophy on libido (reaction time - RT), ejaculation rate (EJACS) and sperm quality in hemi-orchidectomised males. Hemi-orchidectomy of the experimental males involved the surgical removal of the left testis. Sperm viability tests were performed from aliquots of fresh semen following libido and sexual capacity tests. Hemi-orchidectomy of boars at days 60, 100, 140 and 300 of age caused the weight of the remaining testis to hypertrophise by 15.1%, 124.4%, 346% and 483.2%, respectively, as compared to the uncastrated control at 450 days. All the measurements were taken at the end of the study period (day 450). Total daily sperm production per testis (TDSP) increased to 154%, 160.8, 184.3% and 247%, respectively, with this increase being dramatic (247%) in the 300 day old boars. At day 450 compensatory testicular hypertrophy in boars hemi-orchidectomised at day 300 resulted in the highest number of mounts (15.6 ± 0.8 per 30 min), ejaculation rates (9.7 ± 0.9 per 30 min), total sperm count (94.1 ± 4.7 x 109), sperm motility (90.3 ± 1.7%) and normal acrosome morphology (92.2 ± 2.3%), with the shortest RT (2.2 ± 0.5 min). Mounting frequency, RT, EJACS, total sperm, sperm motility and normal acrosome morphology were correlated with testis weight, TDSP, seminiferous tubular diameter, tubular length, tubular mass and total Leydig cell mass. Results suggest that hemi-orchidectomy induces compensatory testicular hypertrophy, leading to significant improvement in the reproductive output of boars. These responses became more pronounced the older the boars were when orchidectomised. South African Journal of Animal Science Vol. 36(3) 2006: 181-18

Validation of the polysemen admixture on viability and acrosomal morphology of boar spermatozoa

Semen were collected using artificial vagina (AV), from 5 large white boars aged 2-2.5 years twice a week for 16 weeks in each of the two seasons, early rainy (ER) and late rainy (LR) seasons, to determine the effects of multiple semen pool admixture on the viability and acrosomal morphology. The semen qualities studied were sperm motility, live sperm and sperm concentration, while the acrosomal parameters includes normal apical ridge (NAR), damaged apical ridge (DAR), missing apical ridge (MAR) and loose apical ridge (LAC). There were no significant (P>0.05) seasonal effects. Three-boar semen admixture gave the highest percentage NAR, motility, live sperm concentration and least DAR and LAC, although these were not significantly (P>0.05) different from the 2-boar semen admixture. The result of this study suggests that 3-boar semen admixture is most suitable for use in artificial insemination program

Agricultural business diversification and its implications on the sustainability of pig-farming SMMEs in the Central Free State of South Africa

Published ArticlePig-farming SMMEs in the Central Free State of South Africa resort to diversification as a business development strategy, with the aim of prevailing through or sustaining pressures over a number of dynamic risks. However, the frequency of liquidations among these enterprises substantiates the statement that sustainable performance is less than satisfactory. This article aims to illustrate theoretical debates on the nature and consequences of diversification as well as to provide an empirical insight into a five-years-result of diversification attempts. Based on a questionnaire survey of 144 participants comprising 71 diversified and 73 specialised pig-farming SMMEs, results show that there is no significant association between diversification and sustainable performance among pig-farming SMMEs in the Central Free State of South Africa. Hence, the study identified entrepreneurial idiosyncrasies to be largely responsible for results shown in each of the variables studied, such as sales growth, gross profit, and return on investment. All three performance indicators were critical variables, indicating performance sustainability of the study population. With respect to the risk nature of diversification decisions, it is recommended that to maximize the probability of success, a careful examination of all critical factors motivating the option is required

Effects of season and diurnal period on the body physiology of Nigerian sheep breeds

No Abstract

Boar effects and their relations to fertility and litter size in sows

Twenty Large White boars and 60 sows were used in two experiments for this study. In experiment 1, 20 sows were assigned per group to each of three treatments, twice daily for a 30-min period during a 4-wk  observation, involving: (1) NBE, a control in which sows were not exposed to boars during oestrus detection; (2) FBE, in which sows were exposed to fence-line boars during oestrus detection and (3) PBE, in which sows received physical contact with the boar during oestrus detection. In experiment 2, semen were collected at 24- or 96-h intervals from each boar and used (3.5 x 109 sperm/100 mL/sow) to artificially inseminate three oestrus-synchronised sows, 24 h after the onset of oestrus, for four weeks. Boar exposure for 4 d before oestrus induction (PG600) increased the proportion of sows expressing oestrus within 7 d by 44% with 88.3 ± 5.5% farrowing rate in the PBE group with the shortest interval from PG600 to oestrus (3.5 ± 0.2 d), number of returns to oestrus (0.01 ± 0.02) and farrowing-farrowing interval (136 ± 0.01 d). On average, 45.8 ± 2.5% of the control NBE group of the sows showed spontaneous oestrus compared to 56.3 ± 1.9 vs. 88.5 ± 0.7% of FBE and PBE groups, respectively. Ejaculates collected on the 96-h intervals had larger volumes (288 ± 9.3 vs. 124.9 ± 5.7 mL), sperm motility (87.1 ± 3.3 vs. 55.2 ± 0.9%) and type of movement (8.7 ± 0.5 vs. 3.0 ± 0.1), live sperm (78.3 ± 9.6 vs. 57.9 ± 12.6.), sperm/mL (132.6 ± 8.1 vs. 90. 4 ± 12.1 x10<sup>6</sup>), total  sperm/ejaculate (83.2 ± 7.7 vs. 52.5 ± 4.6 x109) and normal acrosome (92.5 ± 18.4 vs. 55.5 ± 15.6%) than ejaculates collected on the 24-h intervals. Semen collected at 96-h had gave higher non-return rate (93.5 ± 2.9 vs. 76.8 ± 5.2 %), farrowing rate (85.5 ± 14.3 vs. 56.8 ± 9.1%,), litter size (12 ± 0.03 vs. 8 ± 0.02) and live piglets were 30% higher compared with those from sows inseminated with semen collected at 24-h intervals, respectively. Results suggest that direct exposure of boars to sows prior to semen collection enhances oestrus expressions and farrowing rates. Secondly, ejaculating boars at 96-h intervals enhances semen quality and quantity leading to significant improvement in the fertility and litter size of artificially inseminated sows.Keywords: Boar exposure, ejaculation frequency, semen viability, fertility, litter siz

The effect of vitamin E supplementation on the libido and reproductive capacity of Large White boars

In this study the effect of dietary supplementation of vitamin E on libido, servicing capacity (SC), sperm quality and serum α-tocopherol of Large White boars was evaluated. Twenty four boars were divided into three groups of eight boars each. Groups were randomly allocated to treatment groups, i.e. 0, 40 or 70 IU of dl-α-tocopheryl acetate/kg of diet. Libido was defined as the time from intromission to ejaculation being recorded as the reaction time (RT) in minutes. Serving capacity (SC) was measured by number of mounts, combats, head-kicks, anogenital sniffs during a 30 min test period. Semen was collected by the use of an artificial vagina following the SC test, and afterwards analyzed for quantitative and qualitative parameters. The 70 IU supplementation of dietary vitamin E per kg diet to pigs resulted in the highest number of mounts, combats, head-kicks and anogenital sniffs with the shortest RT in comparison to the 40 and 0 IU vitamin E supplementation. The 70 IU vitamin E boar group produced semen with the highest semen volume, sperm cell motility, progressive movement, acrosomal normal apical ridge (NAR), percentage live sperm, sperm concentration per mL semen volume and total number of sperm per ejaculate and improved serum α-tocopherol concentrations (5.1 ± 0.5 μg/mL). Results suggest that supplementing 70 IU per kg α-tocopheryl acetate in boar diets appears to be most beneficial in optimizing libido and reproductive capacity in breeding boars.Keywords: Boars, dl-α-tocopheryl acetate, reaction time, servicing capacity, sperm viabilit

Evaluation of potato hash silage from two bacterial inoculants and their effects on the growth performance of grower pigs

Potato hash was mixed with wheat bran at 7:3 ratio, treated with  homofermentative LAB inoculant (BMF, bonsilage forte),  heterofermentative lactic acid bacteria (LAB) (LFLB, Lalsil Fresh LB) and without LAB inoculant and ensiled in 210 L drums for 90 days. After 90 days of ensiling, concentrates that contained 40% potato hash silage (PHS) were formulated and the treatment groups were control (no silage), untreated PHS, BMF treated PHS and LFLB treated PHS. The diets were fed to 64 growing pigs (60 days old and 30.4 ± 2.3 kg body mass). The pigs were allocated in a complete randomized block design with four  treatments, and each treatment consisted of eight boars and eight sows. Pigs were fed ad libitum, feed intake was measured daily while body masses were recorded at the start and weekly throughout the experimental period. The dry matter intake (DMI) was higher in the control diet (1062 g/kg) than in the untreated PHS diets (933 g/kg), BMF treated PHS (873 g/kg) and LFLB treated PHS (919 g/kg) diets, respectively. Pigs in the control group had higher final body weight (60.77 kg), average daily gain (ADG) (551 g/d) and better feed conversion rate (FCR) (4.92 g/g) at the end of the trial compared to those in other treatment groups. It can be concluded that potato hash silage produced with or without LAB inoculants had the same effect on the growth performance of growing pigs. However, further work is needed to evaluate the effects of higher dietary inclusion levels (>40 %) of ensiled potato hash on pig growth and reproductive performance.Keywords: Potato hash, grower pigs, LAB inoculation, growth performanc