Exercise-induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. III. Subgross findings in lungs subjected to latex perfusions of the bronchial and pulmonary arteries

Latex was injected under pressure into bronchial and pulmonary arteries of the inflated lungs of Thoroughbreds and transverse sections taken to calculate the area of lesions resulting from exercise-induced pulmonary haemorrhage. Extensive areas of dense brown haemosiderin varying from 0 to 45 per cent of total lung volume were identified, predominantly in the dorsocaudal lungfields. Bronchial arterial proliferation appeared to have replaced the pulmonary supply in affected areas of the lung. Closely associated with the staining and bronchial arterialisation, there was widespread small airway disease. The most severely affected bronchioles contained thick gelatinous or mucous exudate or mucoid plugs and had grossly thickened walls. These lesions suggest that the source of haemorrhage in exercise-induced pulmonary haemorrhage is from alveolar capillaries anomalously supplied by the bronchial arterial circulation through the development of pathological shunts. Small airway disease is suggested as being of major importance in the pathogenesis of the disease and may have led to the initial proliferation of the bronchial circulation.     

Clinical pathologic alterations in horses during a water deprivation test

A 72-hour water deprivation test was performed in 12 horses to determine clinical pathologic changes. Reference values for electrolyte (X) clearance, expressed as a percentage of creatinine clearance (CLCR; %CLCRX), were also determined. A comparison was made between urine concentration measurement techniques. Results of %CLCRX determination in 12 horses before water deprivation were 0.034 +/- 0.095 %CLCRNa, 42.4 +/- 9.8 %CLCRK, 0.352 +/- 0.190 %CLCRCl, and 0.710 +/- 0.250 %CLCRP. During water deprivation, there was individual variation for electrolyte clearances, but Na excretion increased significantly (P less than 0.01) at 24 and 48 hours. After 48 hours' water deprivation, %CLCRNa decreased significantly, but was still greater than the initial clearance. Plasma protein was a better indicator of water deprivation (dehydration) in the horse than was PCV. Electrolyte concentrations in serum and urine were determined. Little significant (P less than 0.01) change in acid-base values was noticed after 72 hours' water deprivation. Urine osmolality (as determined by osmometry) was compared with sp gr (determined by refractometry) in determining urine concentration. Initially, sp gr correlated well with urine osmolality determinations, but this correlation decreased after 48 hours.     

Response of egg weight to the inclusion of various fats in layer diets

1. Brown egg layers were fed diets differing in oil content, oil source and linoleic acid concentration and the effect on performance from 22 to 69 weeks of age was studied.

2. The birds responded with an increasing mean egg weight up to a linoleic acid intake of 2.75 g/bird d.

3. Increasing the intake of readily absorbable oil without increasing linoleic acid concentration did not increase mean egg weight.     

Oesophagogastric parakeratosis in the growing pig: effects of the physical form of barley-based diets and added fibre

In four experiments a total of 288 individually fed pigs were given barley-based diets for about 100 days from about 20 kg liveweight. Fine grinding of barley increased the number and severity of oesophagogastric lesions. Pelleting a diet based on coarsely ground barley had a similar effect. Coarser grinding of the barley and substituting small proportions of oat husk, but not of bran, gave lower incidences and severities of lesions. The performance responses of the pigs differed and give a framework for deciding on the balance to be struck between optimal performance and the risk of lesion development.     

Endogenous opioid suppression of release of luteinizing hormone during suckling in postpartum anestrous beef cows

Beef cows were used to determine if suckling influences release of LH via endogenous opioids at 28 +/- 4 d after parturition. Cows of similar weight and body condition (6.8 +/- .1, 1 = emaciated, 9 = obese) were assigned randomly to five groups (n = 6 to 7): 1) control-suckled/saline (suckled 15 min every 6 hr for 48 hr); 2) control-suckled/naloxone; 3) calf-removal/saline (calf removal for 52 hr); 4) calf-removal/naloxone; and 5) control-suckled/GnRH (Gonadotropin-Releasing Hormone). At 0 hr, saline was administered to all cows. This treatment was continued at 6 hr intervals for 24 hr. Either naloxone (0.5 mg/kg), GnRH (40 ng/kg) or saline was administered to cows in their respective groups every 6 hr during the ensuing 24-hr period in calf-removal groups, or immediately preceding each suckling episode in the control-suckled groups. Blood samples for analysis of luteinizing hormone (LH) were collected at 15-min intervals for 1 hr prior to and 3 hr after treatment at 0, 24, 36 and 48 hr. Cows were observed for estrus twice daily. All cows in the control-suckled/GnRH group released LH (P less than .05) in response to exogenous GnRH, indicating the presence of releasable quantities of the gonadotropin. Mean concentrations of LH were not effected (P greater than .05) by the control-suckled regime. However, calf-removal alone, or in combination with naloxone, increased (P less than .05) mean concentrations of LH by 48 hr.(ABSTRACT TRUNCATED AT 250 WORDS)