144 INFLUENCE OF REPEATED OVUM PICKUP ON BUFFALO WELFARE

Abstract

The aim of this work was to evaluate the effect of repeated ovum pickup (OPU) on buffalo welfare. The OPU was carried out as previously described (Neglia et al. 2003 Theriogenology 59, 1123–1130) twice per week on 11 buffalo cows at 121 ± 15 days in milk for 2 months (end of October–end of December). Blood samples were collected before the beginning of the trial (time 0), after 1 month (time 1), and after 2 months (time 2) in animals that had undergone OPU and in control animals (n = 10) of the same herd. The following parameters of clinical immunology were evaluated on sera: haemolytic complement (Arya et al. 1992 Vet. Immunol. Immunopathol. 30, 411–418), lysozyme, bactericidal capacity (Amadori et al. 1997 J. Vet. Med. 44, 321–327), and haptoglobin (Phase Haptoglobin Colourimetric Assay kit, Tridelta Development Ltd., Maynooth, County Kildare, Ireland). Data, here reported as means ± s.e.m., were analysed by ANOVA taking into account treatment, time, and the interaction. The number of aspirated follicles and collected oocytes per buffalo per session was 6.6 ± 0.2 and 3.6 ± 0.2, respectively. Interestingly, the OPU treatment did not affect haptoglobin (a reliable marker of acute stress), lysozyme, complement, and bactericidal capacity, whereas the time influenced (P < 0.05) only the complement. In animals that had undergone OPU, no differences among times 0, 1, and 2 in lysozyme (3.9 ± 0.3, 4.0 ± 0.6, and 3.6 ± 0.4 μg mL^–1, respectively), bactericidal capacity (92.8 ± 0.8, 92.1 ± 0.8, and 92.2 ± 0.9%, respectively), and haptoglobin (1.8 ± 0.4, 1.4 ± 0.2, and 1.9 ± 0.6 mg mL^–1, respectively) were found. Likewise, similar values were recorded at times 0, 1, and 2 in the control group in lysozyme (3.2 ± 0.3, 2.9 ± 0.3, and 3.1 ± 0.8 μg mL^–1, respectively), bactericidal capacity (94.2 ± 0.6, 93.0 ± 1.1, and 89.2 ± 3.2%, respectively), and haptoglobin (0.7 ± 0.5, 1.3 ± 0.5, and 1.4 ± 0.4 mg mL^–1, respectively). A significant decrease (P < 0.05) of complement (UE/150 mL) in OPU-treated animals was recorded at times 1 (33.6 ± 1.4) and 2 (35.9 ± 2.9) compared to time 0 (67.3 ± 3.3). However, the same pattern was observed in the control (62.8 ± 4.0, 31.3 ± 0.3, and 31.0 ± 0.8, respectively at times 0, 1, and 2; P < 0.05). Therefore, it is not possible to rule out that the decrease was due to other factors, such as the cold winter temperatures incoming, as previously reported. Furthermore, the values recorded at times 1 and 2 fall in the physiological ranges of the species (De Carlo et al. 2011 Joint Annual Meeting, Riccione, Italy). During the whole period of the experiment (and few weeks after), there were neither signs of behavioural modifications nor clinical signs of any disease. Furthermore, there were no differences in average daily milk production between treated and control buffaloes both at the start (9.1 ± 0.8 v. 9.4 ± 0.8) and at the end of the trial (7.6 ± 0.6 v. 6.5 ± 0.7), and all the animals that had undergone OPU conceived within 113.0 ± 25.4 days from the last OPU session. These preliminary results indicate that a regimen of OPU carried out twice per week for 2 months do not affect the welfare of buffaloes.