Physiological response of Zebu and taurine oxen to draught work.

Four Zebu and four Simmental oxen were submitted to continuous and to graded draught work. Venous blood samples were taken before, during, and after exercise at intervals of 2-5 min. Anaerobic threshold was reached at a draught power of 1.6 +/- 0.06 kW for Zebu and 0.7 +/- 0.07 kW for Simmental. Corresponding plasma lactate concentrations were 1.7 +/- 0.2 mmol/liter and 1.6 +/- 0.3 mmol/liter, respectively. Partial pressure of oxygen (pvO2), carbon dioxide (pvCO2), and plasma free fatty acids (FFA) during and after work differed between breeds (P approximately .001) and individuals (P approximately .05). After work, an up to 8-fold increase in FFA was found. Highest plasma lactate concentrations during continuous maximal draught were 3.75 +/- 1.76 (Zebu) and 6.01 +/- 0.88 mmol/liter (Simmental). Acid-base-state during and after exhaustive work remained stable. Heart rate in both breeds did not exceed 190 min-1. It is concluded that 1) even during heavy draught work, anaerobic energy formation plays a minor role for cattle, 2) fatigue in working oxen may be related to cardiovascular limitations, and 3) the physical fitness of European beef-breed oxen is lower compared to multipurpose African Zebu oxen.

Why the denervated gastrocnemius muscle flap should be encouraged.

The superiorly based, denervated gastrocnemius muscle flap is able to perform an aesthetically excellent and functionally good cover for defects of the upper one-third of the calf, including the knee, and the lower one-third of the thigh. A consecutive series of 41 muscle and musculocutaneous gastrocnemius flaps was analyzed. Thirty-six patients (88% of the patients who underwent surgery) could be reexamined. The mean follow-up time was 36 months, with a minimum time of 12 months. At the time of examination, all skin defects as well as the incidental concomitant osteomyelitis had completely healed; however, 40% of the patients have required secondary operations. One-half of the patients have a functional deficiency, and 20% showed areas with loss of sensation. After surgery with musculocutaneous flaps, all patients complained about the sensory loss of the saphenous nerve, and peripheral edema was seen more often than after surgery with a simple muscle flap. Muscle flaps with residual innervation showed more secondary wound breakdown and more contraction pain, due to spasms. The best results concerning function and aesthetics are achieved with denervated muscle flaps covered by a split-thickness skin graft. In this variation, the flap showed good and stable coverage without bulk, as well as minimal donor-site deformity; therefore, primary denervation must be considered. The anatomy of the motor nerves to the gastrocnemius muscle is shown.