https://commons.ru.ac.za/vital/access/manager/Index en-us 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:34262 0.05) conception rate following oestrous synchronisation and timed artificial insemination. However, conception rate was not independent (P < 0.05) of provinces, body condition score and body frame size. Cows in KwaZulu-Natal (66 percent) had significantly higher (P < 0.05) conception rates than those in Limpopo (44 percent) and Mpumalanga (60 percent). Cows of body condition score of ≥ 3.5 (72 percent) had a significantly higher (P < 0.05) conception rate than those of body condition score of ≤ 2.5 (66 percent) and 3 (48 percent). Large (82 percent) framed cows had a significantly higher (P < 0.05) conception rate than small (49 percent) and medium (55 percent) framed cows. Cows in Mpumalanga had more chances to conceive than those of Limpopo and KwaZulu-Natal with odds ratio of 0.605 and 0.863, respectively. Cows in KwaZulu-Natal were in much better body conditions than those from the other two provinces. Cows of body condition score of ≥ 3.5 had more chances to conceive than those of body condition score of ≤ 2.5 and 3 with odds ratio of 0.592 and 0.388, respectively, and the difference was significant (P < 0.05). The study recorded a 100 percent calf survival rate following synchronisation and timed artificial insemination. The breed type, parity, age frame size and lactation status did not significantly influence calving response following oestrous synchronisation and timed artificial insemination (P > 0.05). However, calving rate was not independent of provinces, districts and body condition score (P < 0.05). Calving rate in Mpumalanga (58 percent) and KwaZulu-Natal (54 percent) was significantly higher (P < 0.05) than that recorded in Limpopo Province (36 percent). Calving rate of Gert Sibande (61 percent) and Ehlanzeni (50 percent) districts in Mpumalanga and Zululand (50 percent) and Harry Gwala (61 percent) in KwaZulu-Natal was significantly higher (P < 0.05) than that of the Capricorn (32 percent), Mopani (23 percent and Waterberg (30 percent) in Limpopo Province with the exception of Vhembe (44 percent). Cows with body condition score of ≤ 2.5 (60 percent) had a significantly higher (P < 0.05) calving rate than those with a body condition score of 3 (43 percent). Cows in Mpumalanga had more chances to calve than those in Limpopo and KwaZulu-Natal with odds ratio of 0.076 and 0.537, respectively. Additionally, quantitative data was collected through in-depth interviews using a semi-structured questionnaire. Data collected was managed and coded into themes using the Nvivo Version 11 software programme. Themes and issues that emerged were analysed and interpreted using critical social thinking and systems thinking. The results of the study revealed many factors that could compromise the implementation and adoption of ARTs in the study areas. The general feeling amongst cattle farmers interviewed was that government should address these challenges. A shortage of bulls was the main cause of the low cattle reproduction rate. The Nguni breed type cattle was perceived as the ideal cattle breed for rural areas by respondents. Oestrous synchronisation and artificial insemination can be applied under communal and emerging farming systems with success. From the study results, breeding with small framed animals such as the Nguni type breed under communal and emerging farming systems makes a lot of sense because the breed is known for its low feed maintenance requirement. Furthermore, cattle stakeholders should co-operate and work together to address many of the constraints facing cattle productivity and the implementation and adoption of ARTs in rural areas.]]> Wed 12 May 2021 23:37:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:35964 Wed 12 May 2021 22:56:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34319 Wed 12 May 2021 22:51:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:21193 Wed 12 May 2021 20:18:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28085 Wed 12 May 2021 19:51:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4318 Wed 12 May 2021 19:44:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2361 Wed 12 May 2021 19:24:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4132 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.]]> Wed 12 May 2021 18:32:30 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3825 Wed 12 May 2021 17:52:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1961 Wed 12 May 2021 17:36:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:35963 Wed 12 May 2021 17:31:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3970 Wed 12 May 2021 17:15:50 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:40034 Wed 12 May 2021 14:55:19 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30400 Thu 13 May 2021 07:07:53 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:20625 Thu 13 May 2021 06:24:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3793 Thu 13 May 2021 05:42:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30798 Thu 13 May 2021 05:31:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:721 Thu 13 May 2021 04:33:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:39111 Mon 06 May 2024 15:41:48 SAST ]]>