Major events that led to acceptance of 30 to 300 as the most suitable number of colonies on plates for counting were reviewed. Three new sets of data were collected, involving triplicate plates of fifteen 1: 1.4 serial dilutions of 65 samples of raw milk. Statistical methods were developed to analyze bias (variability introduced primarily by crowding and analyst counting errors) and variance (sampling and dilution errors). Bias and variance were combined as mean-squared error, which was expresed as a function of the number of colonies per plate, The counting range that minimized the mean squared error could then be determined for selected dilution series. For two-fold, five-fold and ten-fold dilution series, respectively, the most suitable limits on plates for counting were 70 to 140, 40 to 200 and 25 to 250 colonies/plate. A range of 25 to 250 colonies/plate was suggested for the analysis of dairy products. Limitations in application of the data to other systems are discussed.

Tissues of the nasal mucosa were utilized from 20 dogs, for histochemistry, quantitative measurements and scanning electron microscopy. Attention was given to the type of epithelium, organization of submucosal tissues, distribution of vascular structures and glandular organization. These features are characterized and discussed in regard to the respiratory and immune functions of the nasal mucosa. Introduction Descriptions of the mucous membrane of the canine nasal cavity include that of olfactory epithelium (ANDRES, 1966; MULLER, 1955; OKANO, WEBER and FROMMES, 1967; SEIFERT, 1970), nasal vasculature (CHRISTENSEN and TOUSSAINT, 1957; DAWES and PRICHARD, 1953; HEGNER, 1962; SWINDLE, 1937), lateral nasal gland (ADAMS, DEYOUNG and GRIFFITH, 1981; EVANS, 1977), innervation (FRANKE, 1966) and maxillary recess (BAST, 1924). Studies of permeability (JACKSON, and BURSON, 1977) and blood flow (HALL and JACKSON, 1968; JACKSON and MARTINEZ, 1965; SCHONBAUM, VARGAFTIG, LEFORT, LAMAR and HASENACK, 1975; STOVALL and JACKSON, 1967) in the canine nasal mucosa treat the entire respiratory portion of the nasal cavity as a single functional entity. Non-olfactory and non-"respiratory" epithelial types line portions of the nasal fossa in some mammals ( ADAMS, 1972; NEGUS, 1956). However, little information is available concerning the diversity in mucosal character over the complex nasal fossa of the dog.The objective of this study was to examine the structural basis of various regions of the canine nasal mucosa for changes in airway resistance, heat and water exchange, synthesis of immunoglobulins, and for mast cell response to allergens. Material and MethodsTwenty dogs representing both sexes, various ages and breeding were prepared for microscopic examination: 6 for routine histochemical study, 5 for examining nasal tissues of young dogs, 4 for quantitative measurements on sections from mature dogs, and 5 for observations with the scanning U.S.

Pure cultures of Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus and two lactic starters were plated with laboratory media containing 0.5% of a food grade poly-or pyrophosphate. Heated or unheated tetra sodium pyrophosphate (TSPP) was highly inhibitory or lethal to all cultures tested, followed by unheated sodium tripolyphosphate (STPP) and sodium polyphosphate glassy (SPG), while sodium acid pyrophosphate (SAPP) was not inhibitory or enhanced recoveries. Heating reduced the effectiveness of phsophates as inhibitors.

Three methods of feeding calves were compared as follows: 1) milk replacer only with restricted movement, 2) milk replacer only with freedom of movement, and 3) hay, grain, and water with freedom of movement. No significant differences were noted for variables of acid-base balance (sampled while resting). An Fe deficiency, microcytic, hypochromic anemia, developed in the calves receiving milk replacer only. Average daily gain, carcass grade, and sale price were superior for calves receiving only milk replacer with freedom of movement as compared with those with restricted movement. A fourth method (calves nursing cows), represented by calves having a different origin, was compared as a supplemental group. Absolute numbers for lymphocyte and neutrophils were significantly higher for calves nursing cows than for calves reared by the other methods.

Pale, soft, exudative (PSE), dark cutting, and normal colored pork were compared to determine differences in susceptibility to microbial growth. Chops were packaged and stored under simulated retail conditions. Color, marbling, pH, numbers of total aerobic mesophiles, psychrotrophs, proteolytic and lipolytic bacteria and fluorescent Pseudomonas and incidence of Salm&ella and coagulase positive Staphylococcus were recorded for pork chops as storage time progressed. Data were statistically analyzed. Differences in pH between PSE and normal chops, after aging, were significant, and dark chops had significantly higher pH values than normal chops. Development of microorganisms during storage was influenced by pH. Most rapid growth of organisms occurred on dark meat and slowest bacterial growth on PSE pork, although exudative conditions of the latter provided the highest expressible juice. pH of the meat also seemed to have a selective action on the microflora. Marbling of the meat did not influence growth of lipslytic bacteria. Relevance of various stages of processing as sources of contamination for the meat is discussed.