This study was conducted to evaluate the effect of season on the superovulatory ovarian response and embryo recovery rate in Boer goat does. Twenty mature does (mean body weight of 55 kg) were synchronised for oestrus with the aid of CIDR devices for a period of 17 days and superovulated with pFSH (Folltropin®-Vetrepharm) during the natural breeding season (n = 9) and non-breeding season (n = 11). The superovulation treatment entailed a total dose of 200 mg pFSH/doe given i.m. in 7 dosages at 12 h intervals, starting 48 h prior to CIDR removal (the first dose being 50 mg and all others 25 mg). Does were observed for signs of oestrous behaviour 3 times daily at 8 h intervals following CIDR withdrawal with the aid of teaser bucks to determine the onset and duration of the induced oestrous period. Cervical inseminations with 0.1 ml fresh undiluted semen were performed 36 and 48 h following CIDR removal and the embryos surgically flushed 6 days following the second AI. Recovered structures (ova and embryos) were microscopically evaluated and classified according to their morphology. The total number of structures in terms of unfertilised ova, fertilised ova, degenerated embryos and transferable embryos from each doe flushed was recorded. All the donor does exhibited oestrus during the breeding and non-breeding season with the mean period to the onset of oestrus (24.9±4.8 h) being significantly (P < 0.05) earlier during the natural breeding season, compared to the non-breeding season (30.5±9.1 h). The duration of the induced oestrous period was also significantly (P < 0.05) longer during the natural breeding season (24.0±5.7 h) than the non-breeding season (18.2±3.7 h). The mean ovulation rate per donor, total number of structures and embryos recovered per donor did not differ between seasons. The mean number of unfertilised ova per doe was significantly (P < 0.05) higher during the non-breeding season (3.3±2.8), compared to the natural breeding season (0.9±2.4). The total number of degenerated embryos and transferable embryos however, did not differ between seasons. Season as such had an effect on the onset and duration of the induced oestrous period; however, it did not affect the oestrous response. Therefore, it would seem that superovulation in the Boer goats is warranted, irrespective of season.

Abstract The aim of this trial was to evaluate the effect of embryo cryopreservation techniques on the survivability of embryos and fertility following transfer to Boer goat does. The oestrous cycles of 27 mature recipients Boer goat does were synchronised using controlled internal drug release dispensers (CIDR’s) for 16 days. At CIDR removal, does were injected with 300 IU eCG. The recipient does were allocated to 3 groups (n = 9 per group), based on the technique of cryopreservation used for the embryos transferred. The in vivo produced embryos used were at blastocyst stage and surgically collected on day 6 following AI from Boer goat donors superovulated with pFSH. The first group received fresh embryos and served as the control, the second group of does received conventional slow frozen/thawed embryos and the third group received vitrified/thawed embryos. Two blastocysts were transferred per doe. A pregnancy rate of 85.7% (n = 6) was obtained following the transfer of fresh embryos and tended to be better than in does receiving slow frozen and vitrified embryos, (n = 4; 50.0% and n = 3; 37.5% does pregnant, respectively). The overall gestation period recorded for all does was 146.3 ± 3.0 d, with an overall litter size of 1.7 ± 0.5 being recorded. The kidding rate of the recipient does declined to 57.0% (4) and 25.0% (2) for fresh and conventional slow frozen groups, respectively. An embryo survival rate of 35.7% (n = 5) for fresh, 25.0% (n = 4) for conventional slow freezing and 31.3% (n = 5) for vitrification was recorded and was not affected by the number of CL’s present on the respective ovaries at the time of transfer. There was a tendency for more females to be born than males (ratio 1 : 2, male : female) but this could not be related to the cryopreservation technique. Although the pregnancy rate following the transfer of fresh embryos was satisfactory, the embryo survival rate following the transfer of either fresh or cryopreserved embryos tended to be less acceptable. More research is warranted with larger numbers of animals, directed at improving the survivability of embryos following fresh and cryopreserved goat embryo transfer.

Abstract The aim of this trial was to evaluate the effect of embryo cryopreservation techniques on the survivability of embryos and fertility following transfer to Boer goat does. The oestrous cycles of 27 mature recipients Boer goat does were synchronised using controlled internal drug release dispensers (CIDR’s) for 16 days. At CIDR removal, does were injected with 300 IU eCG. The recipient does were allocated to 3 groups (n = 9 per group), based on the technique of cryopreservation used for the embryos transferred. The in vivo produced embryos used were at blastocyst stage and surgically collected on day 6 following AI from Boer goat donors superovulated with pFSH. The first group received fresh embryos and served as the control, the second group of does received conventional slow frozen/thawed embryos and the third group received vitrified/thawed embryos. Two blastocysts were transferred per doe. A pregnancy rate of 85.7% (n = 6) was obtained following the transfer of fresh embryos and tended to be better than in does receiving slow frozen and vitrified embryos, (n = 4; 50.0% and n = 3; 37.5% does pregnant, respectively). The overall gestation period recorded for all does was 146.3 ± 3.0 d, with an overall litter size of 1.7 ± 0.5 being recorded. The kidding rate of the recipient does declined to 57.0% (4) and 25.0% (2) for fresh and conventional slow frozen groups, respectively. An embryo survival rate of 35.7% (n = 5) for fresh, 25.0% (n = 4) for conventional slow freezing and 31.3% (n = 5) for vitrification was recorded and was not affected by the number of CL’s present on the respective ovaries at the time of transfer. There was a tendency for more females to be born than males (ratio 1 : 2, male : female) but this could not be related to the cryopreservation technique. Although the pregnancy rate following the transfer of fresh embryos was satisfactory, the embryo survival rate following the transfer of either fresh or cryopreserved embryos tended to be less acceptable. More research is warranted with larger numbers of animals, directed at improving the survivability of embryos following fresh and cryopreserved goat embryo transfer.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: In this study, the effects of energy content of the feedlot diet as well as the length of the production period were investigated for Boer goat slaughter kids. The kids were housed in individual pens on the Elsenburg experimental farm, Western Cape, South Africa. Boer goat castrate kids were weaned at approximately 18 weeks of age (weighing 22.2 ± 3.5 kg) and were randomly allocated to one of three trial diets that varied in energy content; namely a low, medium and high energy diet (11.3, 12.0 and 12.7 MJ ME/ kg feed respectively) which were supplied ad libitum. The goats were further randomly allocated to one of five slaughter groups that were slaughtered at five week intervals at a commercial abattoir. The first group of goats was slaughtered at the start of the trial in order to serve as a baseline reference. During the study the effects of dietary energy content, and time spent in the feedlot were investigated for the feedlot production and slaughter characteristics of Boer goat kids. Additionally the effect of the energy content of the feedlot diets on the sensory and chemical properties of goat meat were evaluated. During the production period individual feed intake and live weight gain were monitored on a weekly basis. It was observed that live weight of the goats increased throughout the production period. Quadratic functions were used to describe the change in average daily gain and dry matter intake of the goats during the feeding period. Goats that were fed the low and medium energy diets exhibited higher daily gains (P= 0.02) and dry matter intakes (P< 0.01) than goats on the high energy diets. Dietary energy content and age of the animal in the feedlot did not influence the feed conversion ratio to produce a unit of live weight. A linear function was used to model the growth of the goats during this production period. The goats were not able to reach the point of inflection on the growth curve. Therefore the sigmoidal growth curve could not be plotted which could have been modelled by a function similar to the Gompertz model. Dressing percentages of the carcasses varied throughout the production period for all the diets, with goats on the low energy diet having the lowest dressing percentage (45.8%; P= 0.04). The energy content of the trial diets had no effect on the yield of the offal components and retail cuts of the carcass. Generally it was observed that the yields of the hindquarter and neck cuts decreased whilst that of the forequarter increased with the age of the goats at slaughter. The degree of carcass fatness increased with time spent in the feedlot, with the majority of fat being deposited in the abdominal cavity, rather than in the subcutaneous fat depot. Dietary energy content was expected to influence the levels of intramuscular fat, which in turn would affect the eating quality of the meat. However, the levels of energy in the diets fed to goats did not influence the tenderness, juiciness or the aroma and flavour profiles of the goat meat as observed during descriptive sensory analysis of the meat by a trained panel. Chemical analysis of the cooked meat samples also showed that the levels of intramuscular fat did not vary between the samples, resulting in the lack of differences detected between treatments in the sensory evaluation. / AFRIKAANSE OPSOMMING: In hierdie studie is die effek van die energie-inhoud van die voerkraal dieet, tesame met die lengte van die produksie tydperk, vir Boerbok lammers ondersoek. Die lammers is in individuele kampies gehuisves op die Elsenburg proefplaas, Wes- Kaap, Suid-Afrika. Die gekastreerde Boerbok lammers is gespeen op ’n ouderdom van ongeveer 18 weke (gewig van 22.2 ± 3.5 kg) en is ewekansig toegewys aan een van die drie proefdiëte waarvan die energie-inhoud gewissel het; naamlik 'n lae, medium en hoë-energie dieet (11.3, 12.0 en 12.7 MJ ME / kg voer onderskeidelik) wat ad libitum verskaf is. Die bokke is verder lukraak toegewys aan een van vyf slag groepe, wat met vyf weke tussenposes by ’n kommersiële abattoir geslag is. Die eerste groep bokke is aan die begin van die proef geslag om sodoende as basislyn verwysing te dien. Tydens die studie is die effek van die verskil in energie-inhoud van die dieet en die tyd wat in die voerkraal gespandeer is, op die voerkraal produksie en slag eienskappe van die Boerbok lammers ondersoek. Daarbenewens is die effek van die verskil in energie-inhoud van die voerkraal dieet op die sensoriese en chemiese eienskappe van bokvleis geëvalueer. Tydens die produksie periode is individuele voerinname en liggaamsgewig toename op ’n weeklikse basis gemonitor. Dit is waargeneem dat die liggaamsgewig van die bokke tydens die hele produksie tydperk toegeneem het. Kwadratiese funksies is gebruik om die verandering in die gemiddelde daaglikse toename tydens die voerperiode, sowel as die droëmateriaal inname van die bokke te beskryf. Bokke wat die lae en medium-energie diëte gevoer is, het hoër daaglikse toenames (P = 0.02) en droë materiaal inname (P< 0.01) as bokke op die hoë-energie dieet getoon. Die voeromset verhouding benodig om ’n eenheid lewendige gewig te produseer is nie beïnvloed deur die energie-inhoud van die dieet, of die ouderdom van die bokke in die voerkraal nie. ’n Lineêre funksie is toegepas om die groei van die bokke gedurende die produksie tydperk te modelleer. Die groei van die bokke kon nie die infleksiepunt van die groeikurwe bereik nie. Dus kon die sigmoïdale groeikurwe nie getrek word nie, wat deur ’n funksie soortgelyk aan die Gompertz model gemodelleer kon word. Uitslag persentasies van die karkasse het l regdeur die produksie tydperk varieër vir al die diëte; bokke op die lae-energie dieet het die laagste uitslagpersentasie gehad (45.8%; P = 0.04). Die energie-inhoud van die proefdiëte het geen effek op die opbrengs van die afval komponente en handelsnitte van die karkasse gehad nie. Oorhoofs is dit waargeneem dat die opbrengs van die agterkwart en neksnitte afgeneem het, terwyl dié van die voorkwart toegeneem het met slag ouderdom. Die vetheidsgraad van die karkas het toegeneem met tyd spandeer in die voerkraal, met die meerderheid van die vet gedeponeer in die buikholte, eerder as in die onderhuidse vetlaag. Daar is verwag dat die energie-inhoud van die dieet die vlakke van binnespierse vet sal beïnvloed, wat op sy beurt ‘n effek op die eetkwaliteit van die vleis sal hê.. Teenstrydig met verwagtinge het die vlakke van energie in die dieet van die bokke geen invloed gehad op die sagtheid, sappigheid of die aroma en geur profiele van bokvleis nie, soos waargeneem deur middel van beskrywende sintuiglike analise van die vleis deur 'n opgeleide paneele. Chemiese ontleding van die gaar vleismonsters het ook geen verskillein die vlakke van binnespierse vet tussen die verskillende monsters getoon nie, wat gelei het tot daar geen verskille tussen die behandelings in die sensoriese evaluasie waargeneem is nie.

MSCAGR (Animal Science) / Department of Animal science / The quality of cryopreserved Boer goat semen may be influenced by the source and concentration of energy supplements in the extender. The aim of the study was to improve the protocols for cryopreservation of Boer goat spermatozoa using different disaccharides concentrations as supplements in tris- egg yolk extender. Two experiments were carried out to investigate the effect of (a) addition of three disaccharides (maltose, sucrose and trehalose) and (b) disaccharides combination (maltose and trehalose) at different concentrations using tris-egg yolk extender. For experiment 1: the study was replicated six times and was conducted in a 3 x 2 x 2 factorial arrangement with three different sugars (sugars: maltose, sucrose and trehalose), two sugar concentrations (0.12g and 0.22g) and two evaluation times (0 hours before cryopreservation and 120 hours after cryopreservation). For experiment 2: the study was replicated six times and was conducted in a 2 x 2 factorial arrangement with two sugar concentrations (0.12g and 0.22g) and two evaluation times (0 hours before cryopreservation and 120 hours after cryopreservation). Semen ejaculates were collected at 7.00-9.00 am from three Boer goats twice per week. After collection, the semen samples were pooled and diluted with tris-egg yolk extender at the ratio of 1:7 (semen to extender). Sperm quality (progressive motility, non- progressive motility, kinetic motions, viability (live/dead) and morphology) were analyzed using computer aided sperm analyzer (CASA). For experiment 1: sucrose 0.12g had higher progressive motility (PM %) when compared to maltose, and trehalose at 0h but reduced after cryopreservation. Sucrose 0.12 showed high percentage of kinetic motions (straightness and average path velocity) when compared to other sugars at 0 hours. More morphological defects M (CH) were revealed by maltose 0.12 at 0 hours. Sugar type (ST) and evaluation time (ET) showed no significant difference (P>0.05) in progressive motility (PM %), sperm kinetic motion, sperm viability and morphology. For experiment 2: mixed/combined 0.12g (maltose and trehalose) revealed more progressive motility (PM %) at 0h and reduced after cryopreservation. Table 6 and 9: of experiment 1 and 2 showed an interaction caused by sugar concentration level and evaluation time (L X ET) on the percentage of cut head M (CH%) and coiled M(C%) morphological abnormalities. In conclusion addition of maltose 0.12g to the extender showed almost similar results with that of trehalose at 0h and 120h. Therefore addition of maltose and trehalose to the extender might improve the quality of Boer goat spermatozoa prior and post cryopreservation. / NRF

A genetic study of four commercial goat breeds in South Africa was performed using microsatellite markers. The commercial breeds included the Boer goat, Savanna, Kalahari Red and the Angora goat. Indigenous goat populations from Delftzijl and Groblersdal were also included in this study. Seventeen microsatellite markers were tested to determine the genetic variation. Genetic variation within the breeds were relatively high with heterozygosity values ranging from 57% for the Boer goat, 68% for the Kalahari Red, 69% for the Savanna goats and 70% for the Angora goats. First values indicated that the Savanna and Boer goat are genetically the closest (0.114), while the Kalahari Red and Boer goat are the least related (0.237). Phenotypic measurements included height, length, depth, heart girth, pelvic length and width for a phenotypic description. Significant differences were observed in the phenotypic measurements among all the breeds. The genetic and phenotypic differences indicate that these goats can be distinguished as different breeds. Results of this study contribute genotypic information of the commercial goats in South Africa. Copyright / Dissertation (MSc)--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted