Thesis (MTech. degree in Agriculture.)--Tshwane University of Technology, 2011. / There is limited information on semen characterisation and fertility rate of unimproved indigenous goat following cryopreservation. The aim of the study was to characterise semen, evaluate raw and frozen-thawed semen and test the fertility rate of frozen-thawed semen.

No Abstract provided. Please read Chapter 5: "Conclusions and recommendations" / Dissertation (MInst Agrar (Animal Production Management))--University of Pretoria, 2006. / Animal and Wildlife Sciences / unrestricted

M. Tech. Agriculture / South African unimproved indigenous goats are disease tolerant, able to survive on harsh conditions such as extreme temperatures and poor vegetation. It is therefore, important to include this breed in breeding objectives during this time of climate change and when animals are resistant to antibiotics. However, these goats are under threat of extinction and very little information on their reproductive status is recognized. In order to improve or maintain South African unimproved indigenous goats, basic science concerning male fertility, semen quality and production should be investigated to conserve genetic materials for future breeding. Conflicting results have been reported concerning the effect of semen collection techniques on buck sperm quality. Longevity of sperm following semen collection is a major limitation to use fresh semen for artificial insemination in rural communities where majority of South African unimproved indigenous bucks are kept. Extenders such as Tris, egg yolk and cow skimmed milk have been used to prolong the survivability of buck sperm in other countries, but contradictory results have been reported concerning which extender is more suitable for buck semen. Egg yolk based extenders have been used mostly in buck semen compared to Tris or cow skimmed milk based extenders. The purpose of the study was to compare semen collection techniques on South African unimproved indigenous goat semen, and the utilization of indigenous chicken egg yolk for preserving South African indigenous buck semen.

Thesis (MA. Agricultural Management (Animal Production)) -- University of Limpopo, 2014 / Body measurements have been used in animals to estimate body weight especially in rural areas where scales are not readily available. The study was conducted in Sekhukhune District of the Limpopo province, South Africa where the goats between the ages of 20 and 30 months were used. Body weight and four morphological traits were taken on each goat in the morning before they were released for grazing in a total of 613 indigenous goats of both sexes (62 male and 551 female). Body weight was measured in kilogram (kg) using a balance scale, hip height and shoulder height measurement (cm) were done using a graduated measuring stick and the body length and heart girth were measured in centimetre (cm) using a tape rule. Means, standard deviations (SD) and coefficients of variation (CV) of body weight and morphological traits were calculated. Pair wise correlations among body weight and morphological traits were also determined and range from 0.81-0.91 for male and 0.72-0.89 for female goats, respectively and were significant (P<0.01). The direct effect of heart girth on body weight was the strongest in both sexes (path coefficient of 0.58 and 0.62 in males and females, respectively). Body length (males) and body length and hip height (females) also positively (P<0.05) influenced body weight. The direct effects of other linear type traits on body weight in both sexes were non-significant as revealed by t-test. These traits were indirectly realized mostly via heart girth. Thus, they were removed from the final regression equations to obtain much more simplified prediction models. The optimum multiple regression equation for male goats included heart girth and body length, In female goats, however, the v variables included in the final prediction model were heart girth, body length and shoulder height. The forecast indices obtained in this study could aid in weight estimation, selection and breeding programmes.

Thesis (MA. Agricultural Management (Animal Production)) -- University of Limpopo, 2014. / Body measurements have been used in animals to estimate body weight especially in rural areas where scales are not readily available. The study was conducted in Sekhukhune District of the Limpopo province, South Africa where the goats between the ages of 20 and 30 months were used. Body weight and four morphological traits were taken on each goat in the morning before they were released for grazing in a total of 613 indigenous goats of both sexes (62 male and 551 female). Body weight was measured in kilogram (kg) using a balance scale, hip height and shoulder height measurement (cm) were done using a graduated measuring stick and the body length and heart girth were measured in centimetre (cm) using a tape rule. Means, standard deviations (SD) and coefficients of variation (CV) of body weight and morphological traits were calculated. Pair wise correlations among body weight and morphological traits were also determined and range from 0.81-0.91 for male and 0.72-0.89 for female goats, respectively and were significant (P<0.01). The direct effect of heart girth on body weight was the strongest in both sexes (path coefficient of 0.58 and 0.62 in males and females, respectively). Body length (males) and body length and hip height (females) also positively (P<0.05) influenced body weight. The direct effects of other linear type traits on body weight in both sexes were non-significant as revealed by t-test. These traits were indirectly realized mostly via heart girth. Thus, they were removed from the final regression equations to obtain much more simplified prediction models. The optimum multiple regression equation for male goats included heart girth and body length, In female goats, however, the v variables included in the final prediction model were heart girth, body length and shoulder height. The forecast indices obtained in this study could aid in weight estimation, selection and breeding programmes

A total of 1076 sera from breeding goats were randomly collected from 24 different farms and tested with CHEKIT®-ELISA (Dr. Bommeli AG-IDEXX, Switzerland) for antibodies against Chlamydophila abortus. The farms were divided into two categories of 12 farms each, depending on their level of observed abortions over the previous 12 months: those with insignificant (<5 %) levels of abortions and those with significant (≥5 %) levels of abortions. The farmers were also interviewed on their level of awareness about chlamydophilosis and whether or not they were doing regular preventive vaccination against the disease. The study determined the seroprevalence levels of 25% at farm level and 8 % at individual animal level (at 95% confidence level). A total of 6 out of 24 farms had at least one positive breeding animal. Only 5 out of the 24 (20.8%) farmers interviewed were aware of chlamydophilosis and its zoonotic dangers. None of the 24 farmers interviewed practised any vaccination against chlamydophilosis. There was a significantly higher number of seropositive animals from farms with significant levels of abortions compared to those animals from farms with insignificant levels of abortions (P=0.0000). The study underscored the need for more farmer awareness and training on chlamydophilosis and its zoonotic dangers. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2007. / Veterinary Tropical Diseases / MSc / unrestricted

Thesis (PhD (Animal Sciences))--University of Stellenbosch, 2005. / Milk production records of all grade and registered Saanen dairy goats from the Milk Recording and Performance Testing Scheme of the Animal Improvement Institute of the Agricultural Research Council of South Africa and pedigree information of these animals from SA Studbook were analyzed to obtain specific genetic parameters. Records of goats with lactations exceeding 60 days in milk were used. A sufficient number of records only became available from 1985 onwards. Reproduction records were determined from milk recording data. The number of milk production records for the British Alpine and Toggenburg breeds was too small to warrant a genetic evaluation. In total, 3190 lactation records of 1413 Saanen does were available for the initial analysis. First and second parity records, 1190 and 775 records, respectively, were subjected to a separate genetic analysis. Milk production records (2319) of one commercial herd providing more than 70% of all the records in the national herd, were also subjected to a separate genetic analysis. The fixed effects identified as having a significant (P<0.05) effect on all traits studied were production year, age of dam, lactation length, parity number, herds (owners) and year of birth. Although some significant interactions were found, they were ignored as their effects were very small. Additive genetic variances and heritability estimates were obtained by ASREML procedures fitting three models. Estimates were generally in accordance with values found in the literature although estimates for fat and protein percentage were lower than expected when compared to dairy cow data. This could be explained by pedigree information lacking in the data set. The h2 estimate for milk yield using all records, first parity records, second parity records and records from a commercial herd were 0.21±0.05, 0.32±0.08, 0.20±0.10 and 0.31±0.06, respectively. Heritability estimates for fat percentage showed a large variation and were 0.19±0.05, 0.67±0.08, 0.34±0.12 and 0.12±0.05, respectively for similar data sets as previously mentioned. In contrast to this protein percentage varied little between data sets and were 0.30±0.06, 0.32±0.00, 0.24±0.11 and 0.28±0.07, respectively. Genetic and phenotypic correlations among production traits were positive and high for all data sets. As for dairy cows, milk fat and protein percentages were negatively related to milk yield. Genetic correlations between milk fat and protein percentages were positive and moderate to high. Increasing milk volume would have a negative effect on fat and protein percentages although it would increase fat and protein yields. Reproduction parameters, i.e. age at first kidding (AFK), age at last kidding (ALK), productive life (PL) and number of lactations (NL) were derived from milk recording data. Mean values for these parameters were 457±171 days, 1046±718 days, 19.3±13.9 months and 2.24±1.37 kiddings, respectively. Kidding interval had no genetic basis and is controlled by management. Heritability estimates were in accordance with literature values and were 0.25±0.04, 0.28±0.04, 0.08±0.04 and 0.05±0.03 for AFK, ALK, PL and NL, respectively. The genetic correlation between AFK and ALK was as expected positive and high, i.e. 0.61±0.10, although the correlation between AFK and PL was negative indicating similar to dairy cows that PL is shortened by a later AFK. The genetic trend for milk, fat and protein yield were positive, although it did not differ from zero. Large variations were observed between years (R2 <0.13). Genetic trends for fat and protein percentages were positive and negative (P<0.05), respectively. These trends are in contrast to trends observed in other countries such as France, The Netherlands and the USA where positive trends were generally observed. This may indicate a higher selection emphasis on milk yield parameters or more complete data sets in terms of pedigree information. The dairy goat industry in South Africa should address some of the problems that were encountered in the analysis of the data. These include factors such as a large number of small herds, many short lactations, a large number of animals lacking production data linked to pedigree information, incomplete pedigrees, few does that have completed three or more lactations, little genetic ties between herds and a small number of progeny for bucks. Some organizational and logistic issues concerning pedigree and milk recording need to be addressed by the South African Milch Goat Society to enable the accurate estimation of the genetic merit of animals in the national herd.

MSCAGR (Animal Science) / Department of Animal Science

MSCAGR / Department of Animal Science

MSCAGR (Animal Science) / Department of Animal Science / The objectives of the study were to evaluate the effect of two extenders (Triladyl® and Bioxcell®) and the removal of seminal plasma on goat buck semen. Six ejaculates were collected from six indigenous bucks by means of electro-ejaculator method, and semen was pooled, and replicated 10 times. Raw semen were randomly allocated into six groups as follows: (i) Raw non-washed, (ii) Raw washed, (iii) Triladyl®-washed, (iv) Triladyl®-non-washed, (v) Bioxcell®-washed and (vi) Bioxcell®-non-washed. All six groups were analysed for spermatozoa motility rates using computer-aided sperm analysis (CASA). The spermatozoa viability for all groups were assessed using Eosin-Nigrosin, acrosome integrity using Spermac, chromatin structure using Acridine Orange, and mitochondria using JC-1 staining solutions. Both the Triladyl® and Bioxcell® washed semen groups were diluted (1:4) with Phosphate Buffered Saline (PBS) then centrifuged at 1500 x g for ten min and seminal plasma was aspirated using 1 mL sterile plastic pipette. Semen samples were diluted (1:4) as follows: Triladyl® (washed and non-washed) or Bioxcell® (washed and non-washed) and then equilibrated at 5 ºC for 2 hours. Following equilibration, semen parameters were analysed. Thereafter, the semen samples were loaded into straws and placed 5 cm above a liquid nitrogen vapour for 10 min, and then stored at -196 ºC until use. Following one month of storage, frozen semen straws per treatment group were thawed at 37 ºC for 30 seconds, then semen parameters were analysed again. Significant differences among the mean values of semen parameters were determined by Tukey’s test using ANOVA, GLM procedure of SAS version 12.1 of 2010. Total Spermatozoa motility rate of Bioxcell® (92.5±4.6), (68.2±13.5) and Triladyl® (94.9±5.5), (63.1±15.1) were significantly reduced (P < 0.05) following equilibration and freeze-thawing process, respectively on washed semen groups. Live and normal spermatozoa percentages were drastically reduced in Bioxcell® (5.2±4.9) and Triladyl® (6.9±8.6) washed semen groups, following freeze-thawing. There was a significantly lower number of spermatozoa with high mitochondrial membrane potential in non-washed semen extended with Triladyl® (68.7±26.8) compared to non-washed semen extended with Bioxcell® (49.8±20.1) following the freeze-thawing process. In conclusion, the freezing-thawing process did reduce the indigenous buck semen parameters irrespective of removal or non-removal of seminal plasma. However, Bioxcell® extender was found to be more suitable for preserving spermatozoa during equilibration and freezing/thawing process of buck semen.