World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the efficacy of anticoccidial drugs in chickens and turkeys

These guidelines have been written to aid in the design, implementation and interpretation of studies for the assessment of drug efficacy against Eimeria species in chickens and turkeys. The information provided deals with many aspects of how to conduct controlled studies in battery cages (dose determination), floor pens (dose confirmation), and commercial facilities (field effectiveness studies), the selection of birds, housing, feeding, preparation of medicated rations, record keeping, diagnostic techniques, and methods for the preparation, maintenance and use of parasites. These guidelines are also intended to assist investigators in conducting specific studies, provide specific information for registration authorities involved in the decision-making process, assist in the approval and registration of new anticoccidial drugs, and facilitate the world-wide adoption of standard procedures.

Comparative testing of anticoccidials in broiler chickens: the role of coccidial lesion scores

The relationship between oocyst dose and lesion score was evaluated in trials involving five field isolates each of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Each trial included an uninfected, unmedicated treatment, and at least three treatments of unmedicated birds given different doses of oocysts from a single isolate. In four trials each with E. acervulina and E. tenella, and all five trials with E. maxima, infected, salinomycin-medicated (60 ppm) treatments were included. Each treatment consisted of five cages with eight male broiler birds per cage using a randomized complete block design. The relationship between oocyst dose and lesion score was examined within each coccidial species using the linear model: Y = beta0 + beta1(log(n) oocyst dose + 1). The results demonstrated that in unmedicated birds, low oocyst doses caused mean lesion scores up to 2.0, but the numbers required to cause higher mean scores were many times greater. Second, the estimated oocyst dose in salinomycin-medicated birds for any given mean lesion score was substantially more than the corresponding estimate for unmedicated birds. These results indicated that there could be wide differences in levels of oocyst dose between unmedicated and medicated birds that lesion scores failed to measure. If lesion scores are used in trials comparing anticoccidial drugs, an alternative design may be to include three infected, unmedicated treatments each given a different level of inoculum (e.g., low, medium, and high). Medicated treatments, given the highest oocyst dose only, would then be compared to each of the infected, unmedicated treatments.

Comparison of arithmetic and geometric means as measures of a central tendency in cattle nematode populations

Efficacy calculations in anthelmintic studies require estimates of the central tendency for the nematode populations. Confusion exists among practitioners regarding which measures of central tendency are most appropriate; although the arithmetic mean is frequently used, there are theoretical reasons for preferring the geometric mean. To investigate this controversy, arithmetic and geometric means were compared for their suitability for use in measuring efficacy. Arithmetic and geometric means were compared as measures of central tendency for skewed distributions. The following criteria were developed to facilitate the comparison: (1) probability around the parameter, (2) influence of extreme values, and (3) proximity to the median. Under log-normality, theoretical results demonstrated the superiority of the geometric mean. Modified-bootstrap simulations using empirical data from cattle were used to confirm theoretical expectations. Simulations on log-normal data supported the geometric mean as the better indicator of the central tendency. Additionally, for data not confirmed as log-normal, the superiority of geometric means was demonstrated. In a comparison of precision, it was shown that mean squared error was always smaller for sample geometric means than for arithmetic means when n> or =2. Simulation results added support to that conclusion.

Effect of lasalocid, monensin and thiopeptin on rumen protozoa

The effects of lasalocid, monensin and thiopeptin on the total number and the generic composition of rumen protozoa were determined in vivo and in vitro. Feeding lasalocid or monensin to cattle on either high grain or high roughage diets reduced total protozoal counts. Addition of lasalocid or monensin (6 to 48 micrograms ml-1) to the in vitro rumen fermentation resulted in marked reduction in protozoal numbers. The inhibition was dose dependent. Thiopeptin had no effect on rumen protozoa either in vivo or in vitro. Among the protozoal types, holotrichs (Dasytricha, Isotricha and Charonina) were unaffected by either lasalocid or monensin. Among the entodiniomorphs, Entodinium, Diplodinium and Ophryoscolex were more sensitive than the other types. Ophryoscolex purkynei was more sensitive to monensin than to lasalocid. Protozoal inhibition by lasalocid and monensin was transient because prolonged antibiotic feeding resulted in the selection of a resistant population in the rumen of cattle.

Lasalocid toxicity in cattle: acute clinicopathological changes

Thirty-six steers (148 to 500 kg) divided into six equal groups were used in a toxic syndrome study of lasalocid and monensin given as a single oral dose. One group was given a placebo, a second group received monensin (25 mg/kg body weight) and the other four groups received lasalocid at 1, 10, 50 or 100 mg/kg body weight (bw). No toxic signs developed in cattle given placebo or lasalocid at 1 or 10 mg/kg bw dose. The earliest toxic signs were muscle tremors, tachycardia and rumen atony. After 24 h, the cattle were dehydrated, anorectic and had diarrhea. Deaths occurred between d 1 and 22.5 in the groups receiving lasalocid at 50 and 100 mg/kg bw and monensin. Altered values in blood leucocytes, erythrocytes, hemoglobin, hematocrit, total protein, albumin, creatinine, urea nitrogen, total bilirubin, creatine kinase, lactic dehydrogenase, calcium, chloride and inorganic phosphate occurred 1 d after dosing: urine pH and specific gravity also changed 1 d after dosing. Maximum changes occurred at d 3. Most of the changes were indicative of dehydration rather than specific organ damage.

Effect of supplemental vitamin E on the immune system of calves

The effect of vitamin E on immune responses of Holstein calves was investigated. Treatments were: 0,1400, and 2800 mg of dl-alpha-tocopheryl acetate given orally at weekly intervals or 1400 mg of dl-alpha-tocopherol weekly by injection. Calves were fed milk for 6 wk and then fed a complete calf starter ad libitum. Calves were on experiment until they were 12 wk of age. Lymphocyte stimulation indices were significantly higher for calves given the high amount of oral supplementation and for injected calves than for unsupplemented calves. There were no significant differences at any of the individual weeks between unsupplemented and orally supplemented calves. Injected calves showed significantly higher values than unsupplemented calves at wk 4 and than all other calves at wk 8. There were no significant differences in the concentrations of immunoglobulins G1 and G2 among treatments. Immunoglobulin M was significantly higher at wk 6 in calves given the high amount of oral supplementation than in all other calves. At wk 12, serum from calves given the high amount of oral supplementation and calves given injections inhibited infectious bovine rhinotracheitis viral replication in tissue cultures as compared with those of unsupplemented calves. In supplemental experiments serum alpha-tocopherol and lymphocyte stimulation indices of yearling heifers determined 7 d after a single injection of 2000 IU of dl-alpha-tocopherol were significantly higher than preinjection values. In vitro addition of vitamin E to lymphocyte cultures did not increase phytohemagglutinin-induced blastogenesis.

Mononuclear phagocytes of transport-stressed horses with viral respiratory tract infection

Twelve horses comprised 3 treatment groups; all horses in 2 of the groups had recently been transported and had clinical and laboratory evidence of respiratory tract infection, with equine influenza type 2 virus being the principal pathogen. Mononuclear phagocytes and other leukocytes from blood, lung, and peritoneal cavity were studied in phagocytosis and erythrocyte-antibody (EA) rosette assays. Total numbers of pulmonary alveolar macrophages were increased over control values in bronchoalveolar lavage (BAL) fluid of group 3 horses after recovery from influenza (P less than 0.02), whereas the increase in neutrophils in the fluid of those horses approached significance. Lymphocytes in BAL fluid of group 3 horses (after recovery from influenza) were in larger proportion than those in fluid of group 1 horses during acute influenza (P less than 0.05). Pulmonary alveolar macrophages of group 1 horses formed a lower percentage of EA rosettes than did those of controls (P less than 0.01) or group 3 horses (P less than 0.02). The differential counts of peritoneal macrophages and neutrophils in horses of groups 1 and 3 were virtually identical at the first collection, but differed from controls at the second collection 4 weeks later; peritoneal macrophages were reduced (P less than 0.01), whereas peritoneal neutrophils were increased (P less than 0.01). Peritoneal macrophages and peritoneal neutrophils of horses with acute influenza were phagocytic in larger proportion than were those in controls at both collection times (P less than 0.01 and P less than 0.01 for peritoneal macrophages, and P less than 0.01 and P less than 0.05 for peritoneal neutrophils, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of supplemental vitamin E on the performance and metabolic profiles of dairy calves

Twenty-eight Holstein heifer calves were allotted at birth to one of four treatments: 1) 0 mg, 2) 1,400 mg, or 3) 2,800 mg of dl-alpha-tocopherol acetate given orally at weekly intervals, or 4) 1,400 IU of dl-alpha-tocopherol weekly by intramuscular injection in order for us to study their performance and metabolic profile. Calves were fed milk at 8% of birth weight until they were weaned at 6 wk of age and fed a complete calf starter ad libitum from birth. Calves were on experiment for 12 wk. There were no significant differences in weekly weight gains, starter consumption, and fecal scores among treatments. However, there was a trend toward greater starter consumption and weight gains in supplemental calves. Serum alpha-tocopherol concentration measured after 7 d of each administration was significantly higher at wk 4 in calves given the high oral supplementation and at wk 2, 4, 6, and 8 higher in injected calves than in unsupplemented calves. Creatine kinase activity was higher in unsupplemented calves and negatively correlated with serum alpha-tocopherol until wk 8, suggesting preclinical muscular dystrophy. Alkaline phosphatase activity was higher with the high oral supplementation. Serum carbon dioxide values showed a trend toward positive correlation with those for serum tocopherol; however, the values were within normal range. There were no significant differences in creatinine, glucose, phosphorus, calcium, urea nitrogen, chloride, sodium, potassium, albumin, and total protein among treatments. Serum glucose was higher in all calves at wk 10 and 12 than at wk 4, 6, and 8. Calves may not get enough vitamin E with conventional calf starters, and supplementation may be essential to obtain maximum performance.

The effect of organizational level and practice area on managerial work in hospital dietetic services

All areas of practice in hospital dietetic services include a management component; however, the nature of the managerial role in various areas of dietetic practice has not been identified clearly. The definition of dietetic practice in the Conceptual Framework for the Profession of Dietetics supports the importance of managerial skills. The effect of organizational level and practice area on managerial activities and roles of professional staff in hospital dietetic services was examined in this study. The nationwide sample included professionals in hospitals with 300+ beds. A total of 3,280 dietetic professionals participated. Five groups were defined: low administrative, low clinical, middle administrative, middle clinical, and upper administrative. Mintzberg identified 10 managerial roles and categorized them as interpersonal, informational, or decisional. The 10 roles were used as the basis for developing an 80-item instrument on which respondents rated each item for importance and time demand. Perceived importance of managerial activities tended to be greater at higher organizational levels. The managerial aspects of the lower clinical and upper administrative position were the most clearly defined. The lower clinical group tended to rate all of the managerial roles as significantly less important than did those in other positions; however, the middle clinical position included a substantial managerial responsibility.

Effect of prepartum vaccination with K99 Escherichia coli vaccine on maternal and calf blood antibody concentration and calf health

One hundred and two dry, pregnant Holstein cows were identified alternately as vaccinated or nonvaccinated (Group 0) animals. Vaccinated cows were scheduled for vaccination at 6 and 3 wk prior to expected calving date with Vicogen, a commercial vaccine produced for the prevention of calf scours caused by enteropathogenic Escherichia coli that possess the K99 antigen. Group 1 included cows that were less than 6 wk from freshening when the experiment started and, therefore, received only one vaccination and cows that received two vaccinations with less than 5 days between the second vaccination and freshening. Those cows with interval between the second vaccination and parturition greater than 5 days were classified as Group 2. Soon after birth, each calf was given 2 liters of colostrum from its dam. For at least 3 days, and longer when available, calves from control cows received pooled colostrum from control cows and calves from vaccinated cows received pooled colostrum from vaccinated cows. Anti-K99 antibody titers were determined by an agglutination test on blood from cows and calves and on colostrum. Other measurements were made by standard procedures. Results from Groups 0, 1, and 2 were cow blood titer at freshening 21, 355, 306; calf total plasma protein at 24 h of age 6.45, 6.31, 6.22; calf packed cell volume at 24 h of age 32.9, 30.0, 30.2; calf blood titer at 24 h of age 34, 762, 1114; colostrum titer 74, 1637, 3404. For 93 calves, mortality was 10.6, 11.1, and 7.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

Physical measurements of 9- to 12-year-old children in Kansas

Measurements of height, weight, triceps, skinfold, and arm circumference were obtained from 3,231 Kansas children 9 to 12 years old as part of the Nutrition Education and Training Needs Assessment Project. Data were collected in 97 schools randomly selected throughout the state. Participating fifth grade students were divided equally between boys and girls; approximately 95% were Caucasian, 3.4% were black, and the remainder were from other ethnic groups, a profile similar to that of the Kansas population. Girls and boys in the study sample tended to be taller and to weigh more than girls and boys of similar age in national studies. Because of adolescent growth spurts, which differ among individuals, the data would need to be interpreted with caution if individual students' growth patterns were being assessed. Kansas girls and boys also tended to have larger triceps skinfold and arm fat area measurements than their counterparts in the NHANES I study. Those data, coupled with the tendency toward greater weight, suggested a greater incidence of overweight among Kansas children than among elementary school children nationally.

Effect of dietary niacin supplementation on phlorhizin and 1,3-butanediol-induced ketonemia and hypoglycemia in steers

1,3-Butanediol and phlorhizin were used to induce ketonemia and hypoglycemia in steers. Oral administration of butanediol increased blood beta-hydroxybutyrate (BHB) and plasma nonesterified fatty acids (NEFA) and decreased serum glucose. Subcutaneous injections of phlorhizin, given in addition to butanediol orally, further increased NEFA and BHB concentrations and decreased glucose. Dietary niacin supplementation of steers given phlorhizin and butanediol caused serum glucose concentration to increase and blood BHB and plasma NEFA concentrations to decrease.

Fear-related responses of white Leghorn hens of several genetic stocks in five-bird cages and associations with quantitative traits

Hens of 8 genetic stocks derived from a common foundation population were compared at three ages for latency to recover from tonic immobility (TI) and from an avoidance response following exposure to a metronome. Body weight, feather score, and egg-production traits also were measured. A total of 350 hens was involved and individuals of the same genetic stock were kept together in 5-hen cages from 19 to 70 weeks old. The TI and metronome avoidance tests were conducted in three rounds at mean ages of 35, 48, and 61 weeks. Hens of stocks with increased egg mass, resulting from selection, did not differ from unselected controls for TI or avoidance responses. Straincross hens also did not differ from parental strain means for these fear-related behaviors. Time to recover from induced TI decreased with repeated testing at 13-week intervals. Hens exposed to the metronome a second time within the first round recovered more rapidly than did those tested in this way for the first time. Previous indirect exposure to the metronome also resulted in reduction in avoidance time. Correlation analysis revealed only a moderate association between TI and avoidance responses (r = .23, P less than .01). Avoidance responses were not associated with any other quantitative trait in the 5-hen cage environment. Duration of TI was moderately associated with body weight (r = .22, P less than .01) and had a complex relationship with total egg mass produced, which was associated with the interval in cages prior to testing. There was no apparent correlation of TI and egg mass when TI was measured on 35-week-old hens, heterogeneity of correlations was present among genetic stocks tested at 48 weeks, and a negative association was detected when TI tests were conducted at 61 weeks (r = -.46, P less than .01).

Effect of dietary niacin supplementation on serum constituents of periparturient dairy cattle

A total of 60 multiparous periparturient Holstein cows were used to determine the differences in serum constituents between cows given supplemental niacin in the diet and cows not given supplemental niacin. Serum inorganic phosphorus concentration was consistently higher (P less than 0.10) and serum potassium, total calcium, and sodium concentrations and alkaline phosphatase activities were consistently lower in cows given supplemental niacin than in cows not given supplemental niacin. Serum chloride, creatinine, and albumin values also tended to be lower in niacin-supplemented cows. Serum total protein tended to be slightly higher in niacin-supplemented cows. There was no consistent difference in urea nitrogen between groups of cows.

Tonic immobility responses of white leghorn hens affected by induction techniques and genetic stock differences

Tonic immobility (TI) was induced in about 70% of While Leghorn hens caught and immediately restrained in the dorsal position for a single 15 sec period. Temporary confinement of hens housed in floor pens in single-bird cages prior to restraint reduced initial induction of TI to 46%. Eye closure during TI occurred in less than or equal to 15% of hens and vocalization, jumping up, or both on termination was present about 80% of the time. Induction of TI on first restraint was greater when less support was provided for the hen's body. Latency until first gross leg and head movement after TI induction decreased with increased time required for catching of hens in floor pens, but righting time (until hens stool up) was unaffected. Correlations among the three latency measures revealed the following: between leg and head movement, r .41 to .71 (P less than .01); leg movement and righting, r .51 to .99 (P less than .01); head movement and righting, r -.62 (P less than .05) to .96 (P less than .01). Genetic differences were detected consistently by latency to first gross head movement and by righting time only. Strains selected for part-year egg mass showed more prompt head movement than did unselected controls. Random genetic drift between strains selected alike apparently was responsible for differences in righting time. Although strains within selection schemes differed, crosses between strains did not differ from the mean of the parental strains, providing evidence that genetic variance for righting time tends to be more additive than nonadditive.

Effects of Ascorbic Acid on Display Life of Ground Beef

Fresh ground beef containing 20 and 25% fat was either treated with 0.01, 0.05 or 0.10% crystalline ascorbic acid or remained as non-treated controls. Samples were displayed in polyvinyl chloride (PVC) film for up to 10 d (24 h/d) at 2 to 3°C under 1076 lux G. E. Natural light. Measures of display life included visual color scores, reflectance measurements, sensory panel scores, thiobarbituric acid (TBA) values and microbial standard plate counts (SPC). At days 1, 3 and 5 of display, average and worst point visual color scores were judged brighter for all ascorbic acid treatments compared to controls. Lower metmyoglobin percentages, higher %R630nm/%R580nm and higher CIE a^* readings at days 3, 5 and 10 for the ascorbic acid-treated product supported visual color results. Higher fat (25%) and higher ascorbic acid levels (0.05 and 0.10%) gave brighter visual color responses at 5 d of display than the 20% fat product and that containing 0.01% ascorbic acid. More intense sensory panel beef flavor was associated with the 0.05 and 0.10% ascorbic acid treatments. More off-flavor was found in the higher fat product (25%). TBA values were not different for fat level comparisons, but were lower for the 0.05 and 0.10% ascorbic acid treatments. At day 5 of display, SPC were not affected by ascorbic acid treatment. The 25% fat product had lower SPC at day 5.

Establishing the need for nutrition education: IV. Evaluation of dietary intakes of elementary school children

Levels of energy intake and selected nutrients in the diets of elementary school children, as observed in a Kansas Nutrition Education and Training Program needs assessment project, are reported. For almost half of the girls and boys in the study, energy intakes exceeded 100% of the Recommended Dietary Allowance (RDA); for most of the students, protein intakes exceeded 125% of the RDA. Magnesium, iron, and vitamin B6 were the nutrients most limiting in the diets. Implications for nutrition education are discussed.

Effect of niacin supplementation on milk production and ketosis of dairy cattle

In two experiments with Holstein cows effects of dietary supplementation of niacin to periparturient cattle on subsequent milk production and ketosis were examined. In Experiment 1, 20 cows were assigned to two groups. The treatment group received niacin at 6 g per head per day for 2 wk prepartum and 12 g per head per day for 4 wk postpartum. The control group received no niacin. In Experiment 2, 40 cows were assigned to four groups of 10 cows. One group served as the control and the other three received 3, 6, or 12 g niacin per head per day for 10 wk postpartum. In both experiments niacin-supplemented groups produced slightly more milk than controls. There were no consistent changes of milk composition with treatment. Glucose concentration in blood serum was higher for cows receiving niacin. Concentrations of beta-hydroxybutyrate and nonesterified fatty acids in blood and plasma were generally lower for niacin-supplemented groups. Niacin supplementation had no effect on feed intake or body weight changes. In Experiment 1 there was a significant reduction of niacin concentration in red blood cells of postpartum cows not receiving supplemental niacin. Insulin concentration in blood serum in Experiment 2 was unaffected by niacin supplementation.

Duration of tonic immobility affected by housing environment in White Leghorn hens

Duration of tonic immobility, recognized as a criterion of fearfulness, was greater for hens kept in 17-bird cages than for hens kept in floor pens, single bird cages, and 5-bird cages.

Establishing the need for nutrition education: II. Elementary teachers' nutrition knowledge, attitudes, and practices

Nutrition knowledge, attitudes, and practices and nutrition education practices of elementary teachers were assessed to provide data for planning a Kansas Nutrition Education and Training Program. Teachers from a random sample of elementary schools throughout the state were surveyed. The nutrition knowledge test scores of the teachers statewide or among the districts and schools did not differ significantly. Teachers who had completed one or more college or continuing education nutrition courses or who were teaching nutrition currently had higher scores on nutrition knowledge, attitudes, and practices and on nutrition education practices than did teachers who had no nutrition training or were not teaching the subject. In general, nutrition knowledge scores correlated positively with scores on nutrition-related attitudes and practices and on nutrition education practices. Kansas elementary teachers tended to have favorable attitudes toward nutrition. Almost all of the teachers indicated that nutrition should be taught in all elementary grades; however, few teachers taught nutrition concepts. Nutrition was integrated in science, health, and social studies more often than in other subjects. Teachers rarely or never used school food service personnel as resource people in the classroom or used the school cafeteria as a laboratory for instruction. However, in those schools with on-premise food production facilities, teachers tended to work with the school food service personnel and use the cafeteria as a laboratory for instruction more frequently than did teachers in schools with only satellite service centers. Attending nutrition workshops during the school year and having access to more nutrition education materials were listed by teachers as the preferred ways to receive additional nutrition training.(ABSTRACT TRUNCATED AT 250 WORDS)

Establishing the need for nutrition education: I. Methodology

Developmental and data collection phases for a comprehensive needs assessment project designed to provide baseline data for planning a statewide nutrition education and training project are summarized. To meet project objectives, 97 Kansas elementary schools were selected randomly as sampling units. A mail questionnaire was used to assess nutrition knowledge and attitudes and dietary and nutrition education practices of elementary teachers and food service personnel. Data from fifth grade students were collected on-site at each school. A written test was used to measure students' nutrition knowledge, attitudes, and practices. Students' nutritional status was partially assessed by measuring their height, weight, skinfold thickness, and upper arm circumference. As an additional assessment, 24-hour dietary recall interviews were conducted with a random sample of the students. In this article, each aspect of the data collection methodology is described in detail. As emphasized by authorities in the field, more complete information is needed in many nutrition survey reports to assist in useful interpretations and for comparisons among studies.

Relation of rumen ATP concentration to bacterial and protozoal numbers

Cultures of Streptococcus bovis and mixed populations of rumen bacteria were used to investigate the concentration of ATP and rumen bacterial numbers at various stages of growth. ATP, extracted with Tris buffer, was analyzed using the firefly luciferin-luciferase bioluminescent reaction. ATP concentrations of S. bovis and mixed cultures of rumen bacteria significantly correlated with live cell counts during the log phase of growth but not during the stationary phase. The average cellular ATP concentration of rumen bacteria was calculated to be 0.3 fg of ATP per cell. Studies done with in vivo artificial rumen apparatus revealed that the protozoal contribution to rumen fluid ATP pool size was much more substantial than was the bacterial contribution. The rumen fluid ATP concentration was greater in cattle with protozoa than in those that were defaunated. Differences in ATP concentration due to size differences of ciliate protozoa were observed. Due to the unbalanced distribution of ATP in rumen microbes, ATP appears to be an unsuitable indicator of rumen microbial biomass.

Effects of lasalocid or monensin on legume or grain (feedlot) bloat

Doses of .66 to .99 mg monensin/kg body weight reduced legume bloat in cattle about 66% when compared with pretreatment bloat scores. Similar doses of lasalocid reduced legume bloat about 26%. A dose of 44 mg poloxalene/kg body weight (recommended dose for field use) reduced legume bloat 100%. Monensin or lasalocid combined with 25 or 50% of the recommended dose of poloxalene reduced bloat under that of the antibiotics alone, but did not achieve 100% reduction. The antibiotic thiopeptin provided no preventive effect on legume bloat. Lasalocid, monensin or an experimental polyether antibiotic (X-14,547 A) at a dose of 1.32 mg/kg body weight when tested on cattle bloated on high grain diets reduced bloat by 92, 64 and 25%, respectively. Lasalocid at .66 mg/kg effectively prevented bloat from developing when given to animals before the feeding of high grain diets; however, a 1.32-mg dose was required to control bloat in cattle that were already bloating before they were given lasalocid. A dose of 1.32 mg salinomycin was ineffective in controlling grain bloat.

Effect of energy concentration and source of nitrogen on numbers and types of rumen protozoa

Two rumen-fistulated Holstein heifers were fed three protein-free semipurified diets: 70% roughage, 30% concentrate; 50% roughage, 50% concentrate; and 30% roughage, 70% concentrate. Wheat straw was the roughage, and the concentrate was a pelleted mixture of corn starch, dextrose, fat, urea, vitamins, and minerals. Each animal received the three dietary treatments in a randomized complete block design. On days 1, 3, and 5 following a 21-day adaptation, rumen fluid samples were taken before feeding and at 1, 2, 3, 4, and 5 h after feeding. Total protozoa concentrations for low, medium, and high concentrate diets were 1.5, 2.5, 4.1 X 10(5)/ml. Dasytricha concentrations were not affected by diet, but Entodinium, Diplodinium, Isotricha, Epidinium, and Ophryoscolex increased with increases of the concentrate proportion of the diets. Entodinium, the predominant protozoa with all diets, increased as concentrate proportion of the diet increased. In a second experiment the two heifers from Experiment 1 were fed semipurified diets that contained either urea or soybean meal as the nitrogen source. There were larger populations of Dasytricha and Isotricha when the diet contained soybean meal, and larger populations of Charon, Entodinium, and total protozoa when the diet contained urea. In both experiments, holotrichs were highest 1 to 2 h after feeding, and entodiniomorphs were highest before feeding and 4 to 6 h after feeding. An active protozoan population can exist in the rumen of cattle fed diets virtually devoid of natural protein, and protozoa are influenced by energy and nitrogen source.

Effect of diet on amino and nucleic acids of rumen bacteria and protozoa

Amino acid composition and nucleic acid content of pure cultures of rumen bacteria (17 species) were analyzed. Amino acid composition between gram-positive and -negative organisms was not different. The total nitrogen content of gram-negative bacteria (10.8%) was significantly higher than gram-positive organisms (9.9%). Deoxyribonucleic acid-nitrogen: total nitrogen (mg/g) differed between gram-positive (8.8) and gram-negative (18.9) bacteria, but there was no significant difference in ratio of ribonucleic acid-nitrogen to total nitrogen. In a second experiment six rumen-fistulated cattle were fed either a high roughage (85% alfalfa hay plus 15% concentrate) or high concentrate diet (15% alfalfa hay and 85% concentrate). Cattle were adapted 14 days and rumen contents sampled on 3 consecutive days. Nitrogen content was higher in protozoa from cattle fed low concentrate (8.4%) than in protozoa from cattle fed high concentrate (7.9%) but was similar in bacteria for both diets. Deoxyribonucleic acid nitrogen: total nitrogen (mg/g in bacteria decreased from 27.2 in cattle fed the low concentrate diet to 20.9 in those fed the high concentrate diet. Differences between sampling days were significant for both bacteria and protozoa for ratio of deoxyribonucleic acid-nitrogen to total nitrogen but were significant only in protozoa for ratio of ribonucleic acid nitrogen to total nitrogen. Ribonucleic acid may serve as a marker for estimating microbial production in the rumen if sources of variation are recognized and corrected adequately.

Effect of lasalocid, monensin or thiopeptin on lactic acidosis in cattle

Lasalocid, monensin or thiopeptin was administered intraruminally each at .33, .65 or 1.3 mg/kg body weight and evaluated for its effectiveness in preventing experimentally induced lactic acidosis in cattle. Four rumen-fistulated cattle were used for each dosage level and the design was a 4 x 4 Latin square with each animal receiving lasalocid, monensin, thiopeptin or no antibiotic. Acidosis was induced by intraruminal administration of glucose (12.5 g/kg body weight). Control cattle exhibited the typical drop in rumen pH and concurrent increases in L(+) and D(-) lactate concentrations commonly observed in cases of lactic acidosis. Alkali reserves were depleted in the control cattle as evidenced by a decrease in blood bicarbonate and a negative shift in base excess. In all three trials, cattle given lasalocid had higher rumen pH and lower lactate concentrations than did control cattle or cattle given monensin or thiopeptin. Cattle given monensin had a significantly higher rumen pH and a lower lactate concentration than the controls only at the .65 and 1.3 mg/kg body weight dosages, whereas thiopeptin was effective only at the 1.3-mg dosage. Concentrations of total VFA in rumen fluid decreased in the controls but remained unchanged in cattle given antibiotics. A significant reduction in the molar proportion of acetate and an increase in the molar proportion of propionate were observed in the rumen fluid of the cattle given antibiotics. Colony counts of Streptococcus bovis and Lactobacillus were significantly reduced in rumen fluid of cattle given 1.3 mg antibiotic/kg body weight. Counts of lactate-utilizing bacteria increased in both control cattle and cattle given antibiotics. Cattle given antibiotics showed no evidence of lacticacidemia, hemoconcentration or change in acid-base balance.

Prevention of lactic acidosis in cattle by lasalocid or monensin

Intraruminal administration of lasalocid or monensin (1.3 mg/kg body weight) effectively prevented in glucose- or corn-induced lactic acidosis in cattle. Administering the antibiotics for 7 days before experimentally inducing acidosis with corn (27.5 g/kg body weight), effectively prevented acidosis, while 2 days' were sufficient to prevent glucose-induced acidosis (12.5 g/kg body weight). The different responses observed in the two trials probably stemmed from the difference in amounts of carbohydrate used to induce acidosis. Antibiotic-treated cattle had higher rumen pH values and lower L(+) and D(-) lactate concentrations that control cattle that received no antibiotics. Ruminal VFA in control cattle decreased, while total VFA and the molar proportion of propionate increased in antibiotic-treated cattle after grain engorgement. Control cattle exhibited classic signs of acidosis, such as lowered blood pH; increased blood lactate, particularly D(-) isomer; hemoconcentration, and depleted alkali reserve with a pronounced based deficit. Antibiotic-treated cattle exhibited no signs of systemic acidosis.

Effect of nicotinic acid on microbial protein synthesis in vitro and on dairy cattle growth and milk production

The effect of nicotinic acid (niacin) on microbial fermentation was tested in vitro. Microbial protein synthesis was greater with niacin and soybean meal than with niacin and urea. Otherwise, in most instances niacin decreased synthesis with urea. These responses to niacin with soybean meal occurred regardless of roughage type or ratio of roughage to concentration, except when the substrate contained 50% roughage from alfalfa; then the opposite was true. Adding niacin to urea-containing rations of heifers weighing 375 or 114 g failed to improve the heifers' weight gain or feed efficiency. In one of two lactation studies with cows in midlactation fed urea-containing rations, a slight increase in milk production was attributable to niacin; in the other, a slight improvement in milk protein production was attributable to niacin. In a third lactation study, but with fresh cows, milk production increased in cows receiving niacin and soybean meal but not in those receiving niacin and urea. In a fourth lactation study with fresh cows fed soybean meal, cows receiving niacin gave slightly more milk than did those receiving none. Response to niacin is greater in fresh cows than in those in midlactation and is greater in cows fed natural protein than in those fed urea.

Effect of nicotinic acid on rumen fermentation in vitro and in vivo

A series of in vitro studies tested effects of nicotinic acid on rumen fermentation. Urea was the nitrogen supplement for all substances. As expected, a substrate of corn produced the most gas and microbial protein followed by a substrate of corn plus brome hay (1:1). A substrate of brome hay produced the least amount of gas and microbial protein. Niacin had no effect on gas production but significantly increased synthesis of microbial protein. The most protein was synthesized with the corn substrate, but the greatest percentage increase due to niacin was with the substance of corn plus hay. Six rumen-fistulated cows were fed a ration of grain and grass hay (1:1) with 2.3% urea. The rations were supplemented with 0 or 200 ppm niacin. Niacin had no important effect on the concentration of rumen dry matter or lactic acid, or the molar proportions of acetic, butyric, or valeric acids. Niacin increased the concentration of rumen bacterial protein, ammonia, and propionic acid. Niacin reduced the rumen concentration of urea nitrogen. There were no differences in the amino acid composition of rumen bacteria due to niacin.

Yield and Curd Characteristics of Cottage Cheese Made by the Culture and Direct-Acid-Set Methods 1

We compared yield and curd characteristics of cottage cheese made by the short-set culture and direct-acid-set methods using three skim milk protein concentrations. 3.1, 3.5 and 3.9 ± .1%. For each method of manufacture, approximately 380 kg of the same skim milk were set per experimental vat. Representative samples of whey, wash water and curd were analyzed and the total quantities of each were measured. Solids and protein recovered in whey, wash water and curd were related to yields for each method. The same curd samples also were used to measure curd size distribution, curd firmness and dressing retention. Analysis of variance showed highly significant differences in curd yield between the two methods when the three protein concentrations were considered. There was approximately 5% more yield when cottage cheese was made from skim milk containing 3.1 or 3.5% protein, using the direct-acid-set method. This yield advantage was less than 1% when the skim milk contained 3.9% protein. Curd firmness did not differ significantly between methods (p < .01). Curd from the 3.1% protein-skim milk, however. was firmer (p < .01) than that from either 3.5 or 3.9% protein-skim milk. Direct-acid-set curd was more uniform in size than that of the short-set culture curd. It retained dressing better only when made from 3.1% protein skim milk, and when 1.25 × the normal amount of dressing was used.

Morphologic evaluation of IgM cells of the canine small intestine by fluorescence microscopy

Biopsies of small intestine from 7 dogs were examined by fluorescence microscopy to determine the number of IgM-containing cells in the lamina propria. Biopsies were taken from duodenum, jejunum, and ileium. (Cell counts were made by 2 persons to demonstrate reproducibility.) There were 452.24 +/- 60.09 cells per mm2 in the duodenum 572.68 +/- 62.13 cells per mm2 in the jejunum, and 107.47 +/- 59.57 cells per mm2 in the ileum. All sections were cut at 6 micrometer. The ileum had fewer cells than either duodenum or jejunum (P = 0.000038 and 0.00001, respectively), whereas duodenum and jejunum did not differ significantly in numbers of cells (P = 0.17528). Quantifying autofluorescent cells in the same sites showed no significant differences among the 3 tissues (P = 0.24697). The autofluorescent cells differed in intensity and morphology from the IgM cells. These two observations tend to support the contention that the autofluorescent cells did not bias the IgM cell counts at the 3 sites. Total autofluorescence (cells, collagen, and vessels) was higher in the ileum than in either the jejunum or the duodenum (P = 0.04967 and 0.03050, respectively). However, all 3 categories counted (IgM cells, autofluorescent cells, and autofluorescent structures) had significant dog-tissue interactions. This will necessitate determining normals for each age-sex-breed category of dog studied.

Coffee grounds. I. Effects of coffee grounds on ration digestibility and diuresis in cattle, on in vitro rumen fermentation, and on rat growth

Holstein steers were used to compare rations in which coffee grounds replaced grain at rates of 0, 5, 10, or 20%. The coffee grounds analyzed (%) dry matter 91.1, protein 11.8, fat 23.1, fiber 42.5, ash .7, and caffeine .13. Digestibility coefficients for dry matter, crude protein, and energy decreased, and ether extract increased progressively as concentrations of coffee grounds in the ration were increased. There was a significant decrease in nitrogen retention and utilization when the rations contained 10 or 20% coffee grounds. Coffee grounds depressed feed intake, increased urinary output, and increased water intake (based on dry matter intake). Coffee grounds caused diuresis and renal, urethral, and bladder irritation. Adding coffee grounds up to 35% of the substrate did not depress rumen microbial fermentation, as measured by in vitro gas production. Weight gain of rats fed rations containing 22.5% untreated coffee grounds was reduced significantly. Water extraction removed some undersirable factors in coffee grounds for rats, and ether extraction removed most of them. Incremental additions of coffee oil (1, 3, or 5%) to the basal diet resulted in incremental decreases in rat weight gain.