Evaluation and comparison of acid-base findings obtained using the partial and Astrup's technic in cattle]

The aim of the study was to compare the acid-base (AB-) findings in cattle obtained parallelly by the equilibration method after Astrup and the partial method (titration determination of total carbon dioxide in blood plasma) and at the same time to determine pH, net acid-base exudate in urine and the specific weight of urine. Altogether we made 65 parallel examinations in three groups of cows according to phases of reproduction. In 70.8% of cases correlation between the two results was very good or good, however under the condition that in many cases it was necessary to know also blood pH for the employment of the partial method. Without the knowledge of the blood pH good correlation would be obtained only in 33.8% of all cases. The partial method does not provide satisfactory results mainly in diagnosing respiratory disturbances and in determining compensatory degree of acid-base disturbances. We analysed two alternative values for the top, reference limit of vol. % CO2 in plasma: 60.0 or 55.0. The results imply that from the aspect of correct partial method interpretation it is more accurate to use the value 60.0. A high interpretation correlation between pH and net acid-base urine exudate was also confirmed and that independent urine pH values may be used in a complex acid-base examination to obtain acid-base findings. The representation of the basic types of acid-base disturbances indicates that metabolical acidoses are most frequent in highly pregnant cows (36.9%) mostly without proved compensation. The largest proportion of normal acid-base findings (43.4%) was determined in cows after calving in which also the compensatory mechanisms were most often activated. In connection with these findings the possibilities of impaired health of calves are discussed.     

Studies on nitrogen and amino-acid absorption in the swine. Part 1. Passage of the chyme in the small intestine

Three female pigs of about 50 kg liveweight were provided with re-entrant canulas in the upper and lower sections of the small intestine and were catheterized to collect urine and blood (vena jugularis). After feeding once the experimental diet containing 15N-labelled, fat extracted dry curd as protein component, it was possible to determine, on two days, the chyme passed through the canulas and to separate aliquote portions thereof for analysis. The cellulose contained in the food was used as indicator for the passage rate of the chyme in the small intestine. The passage rates in the small intestine calculated from the amounts of cellulose and chyme were found to agree fairly well. The passage rates in the upper part of the small intestine were characterized by strongly marked, short-time peaks, right after feed intake, and by periods of relatively even chyme flow some eight hours after feeding. At the end of the small intestine almost constant chyme passage rates were observed over the whole experimental period.     

Studies on nitrogen and amino-acid absorption in the swine. Part 2. The course of 15 N labeling in the chyme, urine and blood

Three female pigs provided with re-entrant canulas at the beginning and the end of the small intestine and catheterized for blood and urine collection were once fed a 15N-labelled mixed diet. Until 48 hours after feed intake chyme from the canulas and urine and blood were collected at varying intervals. All 15N-frequencies measured in the duodenal chyme were found to be below the labelling of the feed protein. Until 11 hours after intake of the labelled feed, the residue obtained by centrifugation of the intestinal contents revealed the highest 15N-labelling. Only slight differences were found in the frequencies of the other fractions (proteins, peptides, free amino acids). The almost constant labelling of all fractions in that period is indicative of a dilution with endogenous nitrogen being constant in comparison with food N. The 15N-frequencies of the chyme fractions observed at the end of the small intestine allowed to conclude that the breakdown of the food proteins is more complete than the disintegration of the endogenous proteins.     

Studies on growing pigs to determine the true digestibility of variously prepared potatoes. 2. Technically dried potatoes]

There are two kinds of damage to potato proteins that may arise in the process of beat drying. Decreases in the gross lysine content are accompanied by a still much more pronounced depression of digestibility. If, for example, the gross lysine content of dried potatoes was only 50% of that of steamed potatoes then the average value for the true lysine digestibility was 15%; in some cases the content of truly digestible lysine was 0% when compared to that of steamed potatoes. Similarly, it was found that some types of dried potatoes with a dry matter content of about 88% had already lost about 43% of the truly digestible lysine contained in steamed potatoes.     

Studies on the absorption of homologous and heterologous IgG in artificially reared newborn pigs

The interaction of homologous and heterologous IgG during intestinal absorption was investigated using five groups of newborn piglets (50 animals in total). The diet, given via a stomach tube, was different in each group during the first 24 h. Group I received bovine colostrum, group II bovine colostrum and porcine IgG solution, group III bovine and porcine colostrum, group IV bovine colostrum and intraperitoneally applied monomeric porcine IgG, and group V received a glucose diet with no immunoglobulins. Feeding was based on bovine colostrum between the 2nd and 6th days after birth, followed by a milk replacer during the rest of the experimental period. The serum concentrations of homologous and heterologous IgG were monitored from birth to 10 weeks of age. The total serum IgG content (homologous + heterologous) of newborns was almost equal in groups I–IV at 24 h. Porcine IgG from endogenous synthesis was detectable in the serum of groups I and V two weeks postpartum. The heterologous IgG absorbed from bovine colostrum produced nearly the same serum concentration in groups II and III: hence the different components of porcine colostrum did not influence the absorption of heterologous IgG. Intraperitoneal application of 1.3 g porcine IgG in group IV resulted in a delay of the synthesis of endogenous IgG. The average half-life of heterologous IgG in the serum of groups I–IV was almost exactly the same, showing that the porcine colostrum or IgG solution did not modify the half-life of bovine IgG. The ingestion of the glucose diet within the first 24 h completely blocked the absorption of IgG from bovine colostrum applied from the second day. Possible explanations of the phenomena investigated are discussed.     

Studies on the true amino acid digestibility in pigs of various wheat varieties from the Soviet Union]

Studies were carried out with pigs for determining, with classical methods, the true digestibility of amino acids contained in 5 intensively grown wheat varieties imported from the Soviet Union and in one wheat variety grown in the GDR. Of all the varieties tested the variety Mironovskaya 808 exhibited the best characteristics. An extremely low true lysine digestibility was established for the variety Avrora (68%). If this variety is to be more extensively grown and used for feeding purposes further studies will have to be made to see whether this low lysine digestibility is really characteristic of this variety.     

Genetic parameters for various random regression models to describe the weight data of pigs

Various random regression models have been advocated for the fitting of covariance structures. It was suggested that a spline model would fit better to weight data than a random regression model that utilizes orthogonal polynomials. The objective of this study was to investigate which kind of random regression model fits best to weight data of pigs. Two random regression models that described weight of individual pigs, one using orthogonal polynomials, and the other using splines, were compared. A comparison with a multivariate model, Akaike's information criterion, and the Bayesian-Schwarz information criterion were used to select the best model. Genetic, permanent environmental, and total variances increased with age. Heritabilities for the multivariate model ranged from 0.14 to 0.19, and for both random regression models the heritabilities were fluctuating around 0.17. Both genetic and phenotypic correlations decreased when the interval between measurements increased. The spline model needed fewer parameters than the multivariate and polynomial models. Akaike's information criterion was least for the spline model and greatest for the multivariate model. The Bayesian-Schwarz information criterion was least for the polynomial model and greatest for the multivariate model. Residuals of all models were normally distributed. Based on these results, it is concluded that random regression models provide the best fit to pig weight data.     

Collection and cultivation of and phagocytosis by pulmonary macrophages obtained from hysterectomy-derived pigs.

Methods were developed for procuring phagocytically active macrophages from porcine lung with minimal damage to respiratory tissues. Procedures included anesthetizing, surgically introducing a T-shaped tracheal catheter, and repeatedly flushing the respiratory tract. Macrophages collected in this manner were characterized as to numbers, types, and phagocytic activity, nonselective lavage of the pulmonary airways of unstimulated and stimulated (evoking agent: thioglycolate medium) animals yielded 5 X 10(7) and 11 X 10(7) respiratory cells per pig, respectively. Because sufficient quantities (300 to 600 cells/test) of unstimulated cells were collected, stimulated cells contaminated with thioglycolate were not further tested. Morphologically, unstimulated macrophages were mainly spherical and mononucleated by variable in size, ranging from 9 to 30 micrometer. Culturally, macrophages adhered to plastic or glass surfaces and readily phagocytized fungal spores, staphylococci, and latex particles in an enrichment medium containing greater than or equal to 20% bovine fetal serum. Macrophages failed to replicate during a 3-week maintenance period. The data suggest that porcine phagocytes of the pulmonary system comprise a free-cell population that is a major surface-constitutive part of the luminal surface of the airways.     

Preparation of porcine IgA and its detection using the fluorescent antibody technic]

The preparation of immunoglobulin A (IgA) from porcine colostrum, intestinal content and serum is described. The best results were achieved with colostrum, from which an antigen of satisfactory purity was prepared by purification on Sephadex G-200, on DEAE cellulose and subsequent filtration on Sephadex G-200. The serum to this antigen raised in rabbits was adsorbed to an immunoadsorbent from porcine serum (PS) or porcine IgG. The adsorbtion of the serum against secretory IgA (SIgA) to PS removed its undesirable heterologous and nonspecific reactivity. The anti-SIgA serum adsorbed in this way still reacted with IgA from porcine serum. In the direct and indirect immunofluorescent staining we detected the main antigenic determinants of the SIgA molecule, i. e. the heavy chains and the secretory component.     

Influence of sex and live body mass on the true protein and amino-acid digestibility of various animal feeds in pigs. 1. Comparative studies between barrows and female pigs

Growing barrows and female pigs of 3 liveweight ranges (20-30 kg, 50-60 kg, 80-90 kg) were used to study the true digestibility of protein and essential amino acids from 4 cereal species and 4 high-protein concentrate using the fecal analysis method and regression techniques. No significant differences were found between the females and the barrows in the true digestibility of the protein and most of the amino acids from the protein carriers under study. In the 3rd liveweight range, the true digestibility of some amino acids of the cereals proved somewhat lower in tendency with female animals. In comparison with the true digestibility of protein, in the cereals under study that of lysine gave significantly lower, and that of cystine, arginine, phenylalanine and histidine significantly higher values. The relative values (protein = 100%) were 85.0, 110.6, 106.8, 106.5 and 105.5 for lysine, cystine, arginine, phenylalanine and histidine, respectively. The true digestibility of the remaining amino acids is comparable to that of protein.     

Studies on the protein and amino-acid metabolism of laying hens using 15N-labelled casein. 15N-incorporation into N-fractions and amino acids of various parts of the body

Four colostomized Leghorn hens were fed, during 6 days, 15N-labelled casein as sole protein source. Two animals were slaughtered 48 hours, the other two 144 hours after the last 15N-application. The share of TCE-soluble N in total N averaged 16% for the body parts analysed, i.e. meat, bone, liver, kidneys, oviducts, residual viscera and other. The variation of the lysine, histidine and arginine levels in the body parts ranged from 3.6 to 7.9 g, 1.1. to 3.7 g and 6.4 to 7.4 g in 16.7 g hydrolysate N, respectively. Except for feathers, the analysed body parts contained and excess amount of heavy nitrogen. The degree of labelling was found to depend on the time of slaughtering after the tracer application. In the liver and in the oviduct being metabolically active organs, the 15N-excess in the total N fraction decreased by 45% between the 2nd and the 6th days after 15N-feeding, whilst in the meat it went down by 20%. The decline of the 15N-concentration in the TCE-soluble N compounds was faster than in the total N-fraction. Out of the body samples analysed, the lysine of the liver having 0.26 atom % 15N-excess was found to be more strongly labelled in hens 1 and 2. The amino acid arginine reached about the same level of labelling, the 15N-frequency of histidine being the lowest.     

Functional additive effect of H blood group alleles on carcass length in Danish landrace pigs.

Previous investigations have revealed statistically significant associations between H blood group genotypes and carcass length in Danish Landrace pigs. The same data were subjected to an analysis aimed at a genetic interpretation of the associations. The regression of the average carcass length (in cm) on the average number of H- alleles for individuals within three genetically characterized classes was 0.725 and the correlation coefficient was 0.995. The results indicate that the associations can be interpreted as being due to an additive effect of the H blood group alleles on carcass length. The additive effect is designated as being functional. A similar effect is expected with respect to any allelic pair exhibiting linkage disequilibrium with alleles at the H locus.