M.S. Barbagianni

Ultrasonographic findings in the ovine udder during lactogenesis in healthy ewes or ewes with pregnancy toxaemia.

Objective of the study was to record, by means of ultrasonographic examination, changes occurring during lactogenesis in the udder of healthy ewes and of ewes with pregnancy toxaemia. The work was carried out in 28 ewes, 16 with pregnancy toxaemia (group A) and 12 healthy controls (group B). B-mode and Doppler ultrasonographic examination of the udder of ewes was performed. During the last month of pregnancy, grey-scale intensity values of mammary parenchyma in group A were significantly greater than in group B (P = 0.007), as was also the progressive increase in grey-scale intensity values in both groups (P < 0.001). Blood mammary input was significantly greater in ewes of group B than in ewes of group A (P < 0.05), as was also the progressive increase in blood input in both groups (P < 0.001). Further, differences between the two groups were identified in pulsatility index (P = 0.007) and in mean blood velocity (P = 0.036), but only during the last fortnight of pregnancy. After lambing, grey-scale values decreased sharply compared to those in pregnancy (P < 0.01), whilst blood input, pulsatility index and mean blood velocity continued the same trend as at the last stage of pregnancy, with differences between the two groups still prevalent (P < 0.05). There was a reverse correlation between grey-scale intensity values and milk quantities (P < 0.035) and a correlation between blood input and milk quantities (P < 0.07). The progressive increase in the diameter of the external pudendal artery was significant (P < 0.001), but no significant differences were evident between the two groups (P > 0.35). Differences between group A and group B in all other haemodynamic parameters studied were not significant, neither throughout the last month of pregnancy (P > 0.25), nor during the first week of lactation (P > 0.06). However, their progressive changes during the last month of pregnancy were significant (P < 0.02).

Trematode infections in pregnant ewes can predispose to mastitis during the subsequent lactation period

Objective was to investigate if trematode infections predispose ewes to mastitis and/or metritis. We used 80 trematode-infected ewes: primigravidae in group P-A and multigravidae in M-A remained untreated, primigravidae in P-B and multigravidae in M-B were drenched with netobimin and multigravidae in M-C were given rafoxanide. We collected faecal samples for parasitological examination, blood samples for β-hydroxybutyrate concentration measurement and uterine content, teat duct material and milk samples for bacteriological examination. We found significant differences in blood β-hydroxybutyrate concentrations between M-A, M-B and M-C during pregnancy (P ⩽ 0.002). We did not observe significant differences between groups regarding development of metritis (P>0.83). We found that for M-A, M-B and M-C ewes, respectively, median time to first case of mastitis was 5.75, 21 and 6.75 days after lambing (P = 0.003) and incidence risk of mastitis was 0.308, 0.069 and 0.222 (P = 0.047). We postulate that trematode infections predispose ewes to mastitis; perhaps, increased β-hydroxybutyrate blood concentrations adversely affect mammary cellular defences. This is the first report associating parasitic infections with mastitis in sheep.

Combined treatment of eCG and a non-selective inhibitor of phosphodiesterases for enhancing reproductive performance in ewes

The aim of this study was to evaluate the effect of the non-selective phosphodiesterase inhibitor 3isobutyl-1-methyl-xanthine (IBMX) given concomitantly with eCG on reproductive performance of ewes. In trial 1, eighty ewes were allocated into 8 groups (AC, A1, A2, A3 and DC, D1, D2, D3). Oestruses were synchronized by progestagen sponges. At sponges removal all ewes of A groups received 400 IU of eCG. Concomitantly with eCG, ewes of groups A1, A2 or A3 received IMBX at the dose of 2.5, 5.0 or 25.0 mg, respectively. Ewes of D1, D2 or D3 groups received only IBMX at the same doses, respectively; in each case, ewes of AC or DC groups were controls (C). In trial 2, one hundred eighteen ewes were allocated into 4 groups (BC1, B1 and BC2, B2). Oestruses were synchronized by progestagen sponges. At sponges removal ewes of BC1 or B1 received 200 IU of eCG, while ewes of BC2 or B2 groups received 100 IU. At the same time only ewes of B1 or B2 groups received 2.5 mg IBMX. In both trials, 48 hours after hormonal treatment, ewes were mated. In trial 1, pregnancy or lambing rate did not differ among A or D groups (P > 0.05). Total lambs per ewe were significantly higher in A1 compared to AC, A2, A3 or D1 groups (P < 0.05), but did not differ among D groups (P > 0.05). In trial 2, pregnancy or lambing rate did not differ among B groups (P > 0.05). Total lambs per ewe were significantly higher (P < 0.05) in B1 and B2 compared to BC1 and BC2 groups, respectively. These results indicate that IBMX combined with eCG at the end of an oestrus synchronization treatment improves litter size probably by increasing ovulation rate in ewes. This latter effect seems to be mainly dependent on the amount of gonadotrophins used.