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| Author(s): |
Lindsay Unno Gimenes
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2006-07-28 |
| Examining board members: |
Pietro Sampaio Baruselli;
Ciro Moraes Barros;
Guilherme de Paula Nogueira
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| Advisor: | Pietro Sampaio Baruselli |
| Abstract | |
Present study is presented in Chapter 1 (Follicle deviation; FD) and 2 (Ovulatory capacity). Each chapter includes two experiments [1 - in buffaloes (Bubalus bubalis); 2 - in zebu cattle (Bos indicus)]. In Chapter 1, aims were to determine moment and diameter deviation and to evaluate FSH and LH plasmatic profiles encompassing follicle selection. In Experiment 1, ovulation was considered day 0 (D0). From D0, 10 Murrah heifers were examined by ultrasound (US) each eight hours (h) until D4 and then, every 24h until D6. FD evaluation was performed by visual analysis (Ginther et al., 1996) and by segmented linear regression (Bergfelt et al., 2003). Blood samples were harvested each 8h in the first 24h post ovulation. From this moment blood collections were performed every 4h until D4 and after that, each 12h until D6. Interval ovulation-FD, dominant (DF) and subordinate follicle (SF) diameters, by visual method, were, respectively, 63.2±5.7h; 7.2±0.3mm and 6.4±0.3mm (mean±SEM). These same end points, by mathematical method, were, respectively, 61.9±4.9h; 7.3±0.3mm and 6.3±0.3mm. No differences between both methods of FD evaluation (P>0.05) were found. No changes in plasmatic FSH and LH levels along the time (P>0.05) were found. In Experiment 2, 12 Nelore heifers were submmited to US each 12h until D5, and these same intervals were used to blood harvests (FSH and LH profiles). Interval ovulation-FD, dominant (DF) and subordinate follicle (SF) diameters, by visual method, were, respectively, 61.0±5.8h; 6.2±0.2mm and 5.8±0.2mm. These same end points, by mathematical method, were, respectively, 57.2±6.0h; 6.2±0.3mm and 5.9±0.3mm. No differences between both methods of FD evaluation (P>0.05) were found. No changes in plasmatic FSH and LH levels along the time (P>0.05) were found. In Chapter 2, aim was to evaluate diameter in which DF acquires ovulatory capacity after administration of 25mg of LH. The animals were assigned in groups according to DF diameter at LH treatment (7.0-8.4mm; 8.5-10.0mm and >10.0mm, in both experiments). In Experiment 1, 29 Murrah x Mediterrâneo heifers were used. From D3 (post ovulation), US examinations were performed each 12h until 48h after LH treatment. Follicle diameters at LH chalenge in groups 7.0-8.4mm, 8.5-10.0mm and >10.0mm, were 7.8c±0.1, 9.3b±0.2 and 11.0a±0.3mm, and ovulation rates were 0.0%b (0/10), 50.0%SUP>a (5/10) and 55.6%a (5/9), respectively. In Experiment 2, 29 Bos indicus heifers were monitored by US every 24h from ovulation until LH chalenge, and then each 12h during 48h. Follicle diameters at LH treatment in groups 7.0-8.4mm, 8.5-10.0mm and >10.0mm, were 7.6c±0.1, 9.6b±0.1 and 10.9a±0.2mm, and ovulation rates were 33.3%b (3/9), 80.0%a (8/10) and 90.0%a (9/10), respectively (AU) | |