Use of topical local anesthetics to control pain during treatment of hoof lesions in dairy cows.

Hoof pathologies in dairy cows have a major effect on both production and animal welfare. Trimming of excess or diseased hoof tissue is essential for the treatment of many of these conditions. Trimming hoof lesions can cause severe pain, resulting in adverse behavioral responses with risk for animal and human safety. Interventions are usually carried out by nonveterinary technicians in the absence of pain management training. Pain control during trimming is not only an ethical obligation but also allows for better manipulation and more meticulous treatment. The aim of this study was to test the efficacy of Tri-Solfen (Bayer Australia Ltd., Pymble, NSW, Australia), a combination of local anesthetics in a topical gel form, containing lidocaine, bupivacaine, adrenaline, and cetrimide, for the treatment of pain associated with trimming of hoof lesions. Sixty-two Holstein-Frisian cows were selected for trimming at the drying-off period and were visually scored for lameness before entering the chute. After diagnosis of the hoof lesion but before deep trimming was initiated, each animal was randomly distributed to 2 groups: C, usual trimming with no pain control, and T, trimming with a local anesthetic formulation being applied immediately after live corium was exposed. During curative trimming, behavior observation was conducted by 2 observers blind to treatment. In 27 cows, algometry measurements were performed before and after the procedure to assess animal reaction to pressure. Lameness scoring was again performed as the cow left the chute. Nonparametric tests and ANOVA were performed. Results showed that use of the topical anesthetic formulation significantly reduced reaction to trimming and lameness score after trimming when compared with nontreated animals. Algometry values showed increased pressure threshold after application of topical anesthetics. This study suggests that the use of topical local anesthesia with lidocaine and bupivacaine helps reduce pain associated with corrective trimming of severe hoof lesions, enhancing animal welfare and potentially ensuring safety of trimmers.

Cryopreservation of in vitro-produced sheep embryos: Effects of different protocols of lipid reduction.

UNLABELLED: The low survival of sheep in vitro-produced (IVP) embryos after cryopreservation is a key limiting step to the widespread of this technology. In the present work, different approaches for enhancing cryosurvival of these embryos were compared: embryo delipidation by centrifugation in the absence or presence of cytochalasin D, a cytoskeleton stabilizer or by embryo culture in the presence of different doses of the trans-10 cis-12-conjugated linoleic acid isomer (CLA). Three experiments were conducted. In experiment 1, IVP blastocysts before vitrification were randomly distributed into four groups: control; centrifuged (cent), cytochalasin D (cyto-D), centrifuged + cytochalasin D (cent + cyto-D). In experiment 2, different doses of CLA (25, 50, and 100 µM) were supplemented during embryo culture before vitrification of blastocysts. A control group ran simultaneously. A third experiment was performed to compare both approaches from the previous ones but without the groups with the worst results (groups: control, cyto-D, cent + cyto-D, CLA25, CLA50). In all experiments, embryos integrity and reexpansion were assessed after warming and after 3 hours of culture. In experiment 1, the postwarming integrity rate was the lowest (P < 0.05) in embryos from the cent group (cent: 50.6 ± 10.3% vs. CONTROL: 74.6 ± 9.2%, cyto-D: 92.3 ± 9.7%, and cent + cyto-D: 90.5 ± 11.2%), whereas the best (P < 0.05) reexpansion scores were obtained in cent + cyto-D embryos (cent + cyto-D: 2.6 ± 0.28 vs. CONTROL: 1.8 ± 0.08, cent: 1.9 ± 0.2, and cyto-D: 1.8 ± 0.31). In experiments 2 and 3, higher (P < 0.05) cleavage rates were observed in CLA25 (50.9 ± 6.2% and 49.2 ± 5.6%, respectively) and CLA50 (48.9 ± 6.2% and 47.6 ± 5.6%, respectively) than those in the control (41.8 ± 6.1% and 40.4 ± 5.4%, respectively) group. In experiment 2, CLA100 presented the lowest (P < 0.002) Day-6 and -7 embryo production rate and quality. After warming, superior (P < 0.02) expansion scores were achieved in CLA25 (3.1 ± 0.29) and CLA50 (3.8 ± 0.17) than in the control (1.9 ± 0.10) group. Similar results were attained in experiment 3. However, although cent + cyto-D embryos showed higher (P = 0.008) postwarming expansion scores than the control (2.8 ± 0.29 vs. 1.9 ± 0.07) group, this score was lower (P = 0.0009) than that in CLA50 embryos (3.8 ± 0.17). In conclusion, our results showed that different protocols of lipid reduction can be successfully applied to improve the cryotolerance of IVP sheep embryos.

Fat area and lipid droplet morphology of porcine oocytes during in vitro maturation with trans-10, cis-12 conjugated linoleic acid and forskolin.

Lipid droplets (LD) in porcine oocytes form a dark mass reaching almost all cytoplasm. Herein we investigated changes in fat areas, cytoplasmic tone and LD morphology during in vitro maturation (IVM) of porcine oocytes cultured with 100 µM trans-10, cis-12 conjugated linoleic acid (t10,c12 CLA) or 10 µM forskolin at different time periods. Four groups were constituted: control, excipient, t10,c12 CLA and forskolin, with drugs being supplemented during 44 to 48 h and the initial 22 to 24 h in Experiments 1 and 2, respectively. In Experiment 3, forskolin was supplemented for the first 2 h. Matured oocytes were inseminated with frozen-thawed boar semen and cleavage rate recorded. Before and during IVM, samples of oocytes were evaluated for LD, total and fat areas and fat gray value or for meiotic progression. Results showed that forskolin supplementation during 44 to 48 h or 22 to 24 h inhibits oocyte maturation (exp. 1: forskolin = 5.1 ± 8.0%, control = 72.6 ± 5.0%; exp. 2: forskolin = 24.3 ± 7.4%, control = 71.6 ± 5.6%) and cleavage (exp. 1: forskolin = 0.0 ± 0.0%, control = 55.4 ± 4.1%; exp. 2: forskolin = 8.3 ± 3.3%, control = 54.5 ± 3.0%). Forskolin also reduced oocyte and fat areas. In Experiment 3, forskolin negative effect on oocyte maturation and cleavage disappeared, although minor (P ⩽ 0.03) LD and oocyte fat areas were identified at 22 to 24 h of IVM. Oocytes supplemented with t10,c12 CLA during 44 to 48 h presented a lighter (P ⩽ 0.04) colour tone cytoplasm than those of control and forskolin. In conclusion, t10,c12 CLA and forskolin were capable of modifying the distribution and morphology of cytoplasmic LD during porcine oocyte maturation, thus reducing its lipid content in a time-dependent manner.