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.     

Type-I hypersensitivity as a component of eosinophilic myositis (muscular sarcocystosis) in cattle

Eight bovine hearts with lesions of eosinophilic myositis (EM) and 2 bovine hearts without EM lesions were collected at slaughter. Blood samples from these 10 hearts, and the heart of a newborn calf also were collected. Histologically, Sarcocystis cruzi was identified in the 8 hearts with EM lesions and the 2 hearts without EM lesions, but not in the heart of the newborn calf. Serum was harvested from the 10 blood samples and was used in homologous, modified, passive cutaneous anaphylaxis tests. Antigen was prepared from S cruzi bradyzoites isolated from the 2 hearts without EM lesions. Serum samples from the 8 cattle with EM lesions reacted positively to S cruzi antigen. When heat-inactivated IgE in serum (56 C for 4 hours) was used, all passive cutaneous anaphylaxis responses were considered negative. Using ELISA, serum IgE concentrations from the 10 cattle with and without EM lesions were 2.2 to 9 U/ml. As determined by radial immunodiffusion, IgM concentrations were 80 to 215 mg/dl. Immunoglobulin G concentrations were 420 to 2,050 mg/dl, but most were less than or equal to 1,700 mg/dl. Immunoglobulin A concentrations were 0 to 62 mg/dl; 1 steer with EM lesions had 0 mg/dl. Double-gel immunodiffusion confirmed the presence of Sarcocystis-specific precipitating antibodies. Sera from the 10 cattle with and without EM lesions formed at least 1 precipitin band.     

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)     

Arthropathy associated with Brucella abortus strain 19 vaccination in cattle. II. Experimental studies

Attempts to reproduce in calves the arthropathy associated with Brucella abortus strain 19 (S19) vaccination by direct intra-articular injection of S19 or virulent Brucella cells were unsuccessful. Intra-articular injection of rabbits and a calf with immune complexes isolated from the synovial fluid of a field case produced clinical and histological signs of arthropathy accompanied by the development of rheumatoid factor.     

Enzyme-linked immunosorbent assay for the detection of circulating antigens of Toxoplasma gondii in the serum of cats

An ELISA was developed to detect circulating antigens of Toxoplasma gondii in the serum of cats. For the experiment, toxoplasmosis was induced in a group of cats by oral administration of bradyzoites. An ELISA that detects anti-Toxoplasma IgG, an ELISA to detect circulating antigens, and fecal examinations were performed on samples from each cat for 1 year after inoculation. When coupled with IgG-class antibody measurement, antigen detection can aid in the diagnosis of some cases of subclinical feline toxoplasmosis.     

Unilateral arytenoid lateralisation: An assessment of technique and long term results in 62 dogs with laryngeal paralysis

Sixty-two dogs with laryngeal paralysis were presented over a three year period. Presenting clinical signs included inspiratory stridor (100 per cent), exercise intolerance or syncopal episodes (81 per cent), loss or alteration in phonation (48 per cent) and coughing or gagging when eating (29 per cent). Causes of the paralysis were determined as traumatic (two dogs), neoplastic (two dogs), iatrogenic (two dogs), congenital (one dog) and idiopathic (55 dogs). Unilateral arytenoid lateralisation was performed in all dogs. The perioperative complication rate was approximately 10 per cent, while the success rate as judged by owners one year postoperatively was greater than 90 per cent. The technique avoided many of the recorded complications of intralaryngeal surgery. Operative times were short and the requirement for postoperative monitoring was minimal. Increasing familiarity with the technique favourably influenced the incidence of complications and the success rate.     

Restoration of the anterior dentition of a Canadian beaver (Castor canadensis)

An eight-year-old beaver lost one of its upper central incisors through unknown causes. As the anterior teeth of this species continually erupt in a similar manner to rodents' teeth, the unopposed lower incisor had over-erupted perforating the palate and entered the nasal cavity. The height of the lower incisor tooth was reduced and a cobaltchromium alloy bridge was constructed which was attached to the remaining upper incisor. The occlusal surface of the bridge was of sufficient width that both incisors could contact it. It was cemented into place with composite resin cement and cross-pinned through the labial surface of the metal into the tooth substance. It is unknown how such treatment will affect the biological processes underlying the continually erupting incisor and the animal is being monitored for any adverse effects.