Comparison of postmortal changes in the ultrastructure of the masseter muscle and the longissimus dorsi muscle in pigs with PSE-meat]

Samples of the two muscles were taken from 8 Landrace fattened pigs, affected with pale, soft exudative meat, during stunning and 15, 30, 45 and 60 minutes after death; also 2, 3, 6, 12, 24 and 48 hours after slaughter, with storage at 20 degrees C for the first six hours and 2-5 degrees C subsequently. Considerable changes were found during the first hour after death, or even in samples taken during stunning, in longissimus dorsi samples. These consisted of destruction of mitochondria and sarcoplasmic reticulum, breakdown of cell membranes, liberation of clumps of fibre protein, disappearance of glycogen, rigor and destruction of capillaries. Such changes would account for the features of pale, soft exudative meat such as water loss, brief rigor, pale colour, deficiency of energy-rich phosphates. By contrast, in the masseter muscles of the same animal these changes did not occur until later, or were in port absent. In both muscle the breakdown of fibres took place by destruction of the "I" bands and the "Z" strips, and this process also commenced in longissimus dorsi before masseter.     

THE USE OF FLUFF COUNTS IN A STUDY OF HYGIENE IN QUEENSLAND HATCHERIES

During 1972, 333 fluff samples were tested from 13 Queensland hatcheries and assessed according to the English standards for total count, coliforms and fungi. They were also assessed as being "standard" or "substandard", using a combination of the criteria of the English system. All hatcheries had at least 2 substandard samples and all the samples from 2 hatcheries were substandard.     

The role of histamine and fish meal in the incidence of gizzard erosion and pro‐ventricular abnormalities in the fowl

1. The role of certain fish meals in the production of localised gizzard erosion is confirmed.

2. Lesions typical of gizzard erosion could be produced by the addition of histamine to the diet.

3. The amount of histamine occurring naturally in fish meal depends on the species of fish and the extent and nature of bacterial spoilage.

4. These variables may explain why histamine has not been implicated previously and also why there have not been consistent associations between the condition and geographical source or common factors in bulk consignments of the meal.     

Q fever (Coxiella burnetii) investigations in dairy cattle: persistence of antibodies after vaccination.

The immune response and persistence of antibodies were investigated in dairy cattle vaccinated with formalin-inactivated phase (ph) I Coxiella burnetii vaccine agglutinating antibody geometric mean titer (GMT) of 193.2 at 1 month after vaccination compared to a GMT of 2.0 for nonvaccinated calves. The agglutinating antibodies gradually decreased in vaccinated cattle, but the GMT remained approximately 4 times higher than that for the nonvaccinated group for at least 20 months. Results of serotests at 2 months after revaccination indicated a rapid increase in the GMT to 177.0 with agglutinating titers between 1:64 and 1:512.     

Alterations of selected intestinal enzymes in hamsters with hamster enteritis syndrome.

Portions of duodenum, jejunum, and ileum from 21 hamsters clinically affected with enteritis were examined for enzymes. Utilizing a variety of techniques, the activities of alkaline phosphatase, nonspecific esterases, leucine aminopeptidase, beta-glucuronidase, and methyl green pyroninophilia were determined. The activities of enzymes normally associated with tissue proliferation and active protein synthesis were decreased, whereas those enzymes associated by cytolysis were increased.     

Elimination of sulfamethazine from edible tissues, blood, urine, and feces of turkey poults.

Sulfamethazine was administered to 8- to 10-week-old turkey poults intravenously (IV) at the dose level of 71.5 mg/kg of body weight, orally at the dose level of 143 mg/kg of body weight, or in the drinking water at the concentration of 0.1% over a 6-day period. The concentrations of free sulfamethazine in blood, muscle, skin, kidney, and liver were determined and semilogarithmic plots of concentration vs time for the various tissues indicated that the curve had a linear portion within the first 72-hour period of drug withdrawal. The rates of disappearance of sulfamethazine from the various tissues were proportional to the concentration in the tissues. After 72 hours of withdrawal and for as long as 14 days, sulfamethazine concentrations in kidney, liver, and skin of turkeys given the drug in the drinking water fluctuated between 0.1 and 0.4 ppm. Only 8.6% of the oral dose (143 mg/kg) and 16.5 to 17% of the IV dose (71.5 mg/kg) were recovered in urine and feces as the parent compound during the initial 72-hour period.     

Behavior of 14C oryzalin in soil and plants

Radiochemical studies of field soil treated with ¹⁴C oryzalin (3,5-dinitro-N⁴,N⁴-dipropylsulfanilamide) indicated that the compound was readily degradable. One year after soil treatment with oryzalin, 45% of the original radioactivity had dissipated, 25% was extractable, and 30% was “soil bound”. The extractable fraction contained oryzalin and several degradation products, some of which were isolated and identified. No single degradation product accounted for more than 3% of the applied oryzalin. The “soil-bound” radioactivity was extractable with hot alkali. No significant radioactive residues were detectable in either seed or forage of soybean and wheat plants. No specific metabolites of oryzalin were identified in soybean plants. Trace amounts of radioactivity found in plant tissue appeared to be associated with the various plant constituents.     

Alfalfa metabolism of propham

Root-treated alfalfa absorbs, translocates, and metabolizes [phenyl-¹⁴C]isopropyl carbanilate ([¹⁴C]propham). After 7 days of root treatment, the distribution of radiolabel was 73% for shoots and 27% for roots. Shoots and roots were extracted and separated into the polar, nonpolar, and solid residual components using a mixture of chloroform, methanol and water. The insoluble residues accounted for approximately 40% of the ¹⁴C found in shoots and roots. The nonpolar fraction (6.1% of the radiolabel in shoots and roots) was not characterized, but was shown to be some component other than parent propham. Propham was not found in either shoots or roots. The polar metabolites were partly purified on Amberlite XAD-2. Cellulase-liberated aglycones were derivatized and separated by high-performance liquid and gas-liquid chromatography. The infrared, nuclear magnetic resonance, and mass spectral data showed that the polar metabolites of alfalfa shoots and roots were glycoside conjugates of isopropyl 2-hydroxycarbanilate (2-hydroxypropham) and isopropyl 4-hydroxycarbanilate (4-hydroxypropham). Conjugated 4-hydroxypropham accounted for 45.9% of the ¹⁴C in the shoots and 3.4% of the ¹⁴C in the roots. Conjugated 2-hydroxypropham accounted for 3.4% of the ¹⁴C in the shoots and 1.4% of the ¹⁴C in the roots.