- Title
- Application of assisted reproduction technologies on the indigenous Nguni cows and heifers
- Creator
- Maqhashu, Ayanda
- Date
- 2013
- Type
- Thesis
- Type
- Masters
- Type
- MSc Agric (Animal Science)
- Identifier
- vital:11828
- Identifier
- http://hdl.handle.net/10353/d1016096
- Description
- The aims of the study were to compare superovulatory (SO) response rate and embryo quality recovered; consequently, correlate sperm motility with fertilization rate on superovulated stud Nguni cows and heifers. Furthermore, compare oestrous synchronization response and pregnancy rate of three breed type cows (Brahman, Bonsmara and Nguni) of different body condition scores following timed artificial insemination in KwaZulu-Natal (KZN) and Limpopo provinces. Nguni stud cows (n= 15) and heifers (n= 10) aged 4-6 and 2-3 years were used as embryo donors. Superovulation of donors involved insertion of a controlled internal drug release device (CIDR) and two injections of FSH daily 12 hours apart for 4 days on a decreasing dosage. Fresh Nguni semen was collected from proven Nguni stud bulls and assessed by computer aided sperm analysis (CASA) before artificial insemination (AI). The doses of AI were prepared and conducted twice, 12 hours apart on synchronized and superovulated Nguni cows or heifers. Embryos were flushed 7 days after AI using a non-surgical technique. Embryos were immediately evaluated under stereo microscope and classified according IETS standard codes (C1, C1- and C2). All transferrable embryos were vitrified. Two pilot study sites were chosen in Eastern Cape – Great kei; (n= 5) and Limpopo - Vuvha; (n=5) provinces for Embryo transfer. Each recipient cow was implanted with one frozen-thawed embryo. For oestrous synchronization, cows (Braman, Bonsmara and Nguni type) were selected in different villages, regardless of parity, age, breed and body weight following pregnancy diagnosis. Cows were grouped according to breed type and body condition scores (BCS) on a scale of 1-5. Group 1 had BCS of ≤ 2.5 in KwaZulu-Natal (n=81) and Limpopo n=71), Group 2 had BCS of ≥ 3 in KwaZulu-Natal (n=79) and Limpopo (n=100) cows. Cows were synchronized by inserting the controlled intravaginal drug release (CIDR) and removed on Day 8, followed by administration of prostaglandin. The white heat mount detectors (HMD) were placed on the individual cow’s tail head as an indicator for oestrous response if colour changed to red and inseminated twice at 12 hours interval. Pregnancy diagnosis was performed by an ultra sound scanner and rectal palpation 90 days after TAI in embryos and semen recipient cows. There was no significant difference on the superovulatory response rate between Nguni cows (40%) and heifers (40%). There was a significant difference on the ovary reaction (number of corpus luteum) of cows (11.33±1.41) and heifers (4.00±0.57). There were no significant differences observed on the embryo quality between Nguni cows (2.5±1.00 and 1.25±0.59) and heifers (0.83±0.41 and 1.00±0.36) for excellent (C1) and good (C1-). However, cows had more numbers of unfertilized ova (5.5±1.05 and 1.75±0.47) and degenerate embryos (3.66±1.00 and 1.25±0.39) than heifers. Village cows responded to oestrous synchronization successfully in KZN (100%) and Limpopo (99%) regardless of body conditions and breed type. The lowest pregnancy rate was recorded in Brahman and Bonsmara type cows with BCS of ≤ 2.5 regardless of Province. Interestingly, Nguni type cows with same body condition of ≤ 2.5 had higher average pregnancy rate of 59.5% in Limpopo and 53.5% in KZN. However, cows with BCS of ≥3 had better pregnancy rate regardless of cow breed type, and province. In conclusion, only 40% of both Nguni cows and heifers responded to superovulation. However, Nguni cows had better ovaries reaction compared to heifers. The quality of embryos recovered was similar for both Nguni cows and heifers. Moreover, there was a positive correlation between total sperm motility and fertilization rate bull 1 (93.7%) inseminated the cows (67.5%) and bull 2 (83.5%) inseminated the heifers (53.5%). Higher pregnancy rate (60%) was recorded in Limpopo compared to Eastern Cape (0%). Interestingly, more than 99% of village cows responded to synchronization and inseminated with frozen-thawed semen successfully. Village Nguni type cows were not affected by body condition scoring as they had higher and similar pregnancy rate as those that had body condition of ≥ 3. It is suggested that it is not advisable to breed synchronized Brahman and Bonsmara type cows with the body condition of ≤ 2.5 except in Nguni cow type as more than 57% average pregnancy rate was achieved.
- Format
- 98 leaves; 30 cm
- Format
- Publisher
- University of Fort Hare
- Publisher
- Faculty of Science & Agriculture
- Language
- English
- Rights
- University of Fort Hare
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