Outbreaks of proliferative haemorrhagic enteropathy on two pig farms

SUMMARY Clinical signs of proliferative haemorrhagic enteropathy (PHE) including anaemia, dysentery and sudden death were observed in finisher pigs and young breeding stock on 2 farms. On farm A, PHE occurred 12 months after repopulation of the farm. Other outbreaks of PHE occurred after the withdrawal of therapeutic concentrations of in-feed antibacterial agents (farm A), or after monensin sodium (100 g/t) replaced olaquindox (100 g/t) in feed (farm B). The outbreaks, the possible sources of contamination and the role of antibacterial feed additives in the treatment and control of PHE are described.     

Clinical exercise testing in the normal Thoroughbred racehorse

To evaluate normal cardiorespiratory and metabolic responses of Thoroughbred horses to a standardised treadmill exercise test, we examined 28 horses ranging in age from 1 to 4 years. The group consisted of eight yearlings, eight 2-year-olds and twelve 3 and 4-year-olds. All horses except the yearlings were in training, and either racing or ready to race, at the time of examination. None of the horses had histories of performance problems. On the first day the horses received a full physical examination, resting electrocardiogram, upper respiratory tract endoscopy and either one or two acclimatisation runs on the treadmill. The following day they were given an exercise test on a treadmill inclined at 6 degrees (+10% slope). The test consisted of 3 min at 4 m/sec, 90 sec at 6 m/sec and 60 sec intervals at 8, 10, 11, 12 and 13 m/sec. During the last 15 sec of each step, blood samples were collected for plasma lactate determination, expired respiratory gases were obtained using an open flow mask system for measurement of oxygen uptake, and heart rate was measured using telemetry electrocardiogram. From these measurements, various derived values were calculated, which have been used by others as indices of exercise capacity. These values included: V200 (speed at HR of 200 bpm), VHRmax (speed at which horses reached maximum HR), VO2-200 (oxygen uptake at a HR of 200 bpm), VO2max (maximum oxygen uptake), VLA4 (speed at which horses reached a plasma lactate of 4 mmol/l) and HRLA4 (HR at which horses reached a plasma lactate of 4 mmol/l). The yearlings had significantly lower values than the older age groups for most of the derived values.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dairy manure N mineralization estimates from incubations and litterbags

A laboratory incubation trial and a field litterbag study were conducted to determine the rate and magnitude of mineralization of dairy manure N components in a south central Wisconsin silt loam. Dairy manure components (urine, feces, or bedding, each ¹⁵N-labeled and the other components left unlabeled) were incubated in soil at 11, 18, or 25°C. Samples were taken at 14, 21, 42, 84, and 168 days and analyzed for mineralized N ( and ) and ¹⁵N abundance in the inorganic and organic fraction (at day 168 only). In the field study, nylon mesh (38 μm) litterbags filled with ¹⁵N-labeled manure (2000) or unlabeled manure (2000 and 2002) were placed 7.5 cm below the surface and excavated at 7, 14, 21, 28, 35 (2000 only), 42, 56, 84, 98, and 126 days after burial and at corn (Zea mays L.) harvest, after 142 days in 2002 and 154 days in 2000. In the incubation study, 50−60% of applied urine N was mineralized showing the importance of this manure N component as a source of plant available N. About 14−19% of applied N was mineralized from the fecal and bedding components. In the litterbag experiment, approximately 70% of the dry mass and 67% of the N was mineralized from the litterbags with similar amounts measured using either labeled or unlabeled N. Rates of manure organic matter decomposition and N mineralization were best predicted using single exponential models for both years with most of the release occurring during the first 21 days.