添加甘氨酸铁螯合物对母猪血红蛋白含量、红细胞压积和繁殖性能的影响

本试验旨在研究甘氨酸铁螯合物对妊娠晚期和哺乳期母猪繁殖性能的影响。产仔前在母猪料中添加62.5g/t的甘氨酸铁,分别饲喂0（对照组）、2、4、6、8周,测定母猪和所产仔猪的血红蛋白含量和红细胞压积值,记录并计算分娩活仔数、断奶活仔数、初生重、死亡率、木乃伊胎儿率、哺乳仔猪生长率和断奶体重,观察母猪及仔猪的贫血发生率。母猪的红细胞压积平均为33.7±2.7%,仔猪的红细胞压积平均为32.2±3.9%,母猪血红蛋白含量为11.3±0.9g/100mL,仔猪血红蛋白含量为10.8±1.3g/100mL。母猪和仔猪贫血症（血红蛋白含量低于8g/100mL）的发病率很低,各组间的差异不显著。整个试验期间,母猪和仔猪都没有发生附红细胞体病。母猪和仔猪的红细胞压积和血红蛋白含量间存在显著的相关性。初生活仔数、初生重、断奶活仔数各组间没有显著差异,但对照组窝产死仔率和木乃伊胎儿率在各组中最高,而且试验组哺乳仔猪生长率显著高于对照组。试验结果显示在母猪日粮中添加螯合铁有利于哺乳仔猪的生长。     

In vitro and in vivo association of African swine fever virus with swine erythrocytes

The association of African swine fever virus (ASFV) with swine erythrocytes in vivo, in high titers, was verified by inoculating 30 pigs with 17 ASFV isolates and assaying their plasma and washed erythrocyte fractions for residual virus. Viral antigens were specifically localized on the surface of in vitro and in vivo swine erythrocytes, using the fluorescent antibody technique and 3 monoclonal antibodies specific for ASFV. The same monoclonal antibodies immunoprecipitated virus-specific polypeptides of molecular weights 13 kd and 73 kd from ASFV-infected Vero cells. Erythrocytes from viremic swine infected with Lisbon-60, Dominican Republic, Badajoz-M98, or Cameroon isolates of ASFV were studied by transmission electron microscopy. Virus was found in membrane depressions at the surface of erythrocytes. These surface depressions resembled stages of smooth surfaced pits. Erythrocytes from viremic pigs were fragile osmotically.     

The concentration of swine production. Effects on swine health, productivity, human health, and the environment.

The concern about environmental issues centering around CAFOs is appropriate. The veterinary profession can be an important force in meeting these challenges by broadening its scope of knowledge and practice into the broader environmental field. Although animal agriculture's contribution to environmental concerns is the focus of this article, it is only one of several sectors that contributes to environmental degradation. Crop production, as well as livestock production industries, contribute to pollution. Manufacturing industries, municipalities, private individuals, our consumptive lifestyles, and agriculture all contribute to the degradation of our environment. One must keep in mind the huge importance of our agricultural industry and not single it out to the detriment of its progress. We have an abundance of high-quality foods at the lowest cost to the individual of any industrialized nation. We export over 40 billion dollars in agricultural products yearly. Agriculture sustains our rural economies and provides opportunities for over 2 million private enterprises scattered across the country; however, there is a goal that we have a sustainable agriculture. A big part of that depends on development and enhancement of an agriculture that does not pollute, that sustains its farm operators and workers, and that does not make the area residents ill or degrade their quality of life; however, the current situation is not promising. Much remains to be learned about the actual acute and long-term health consequences of animal agricultural pollution. Many health concerns are speculative, even though based on sound facts. We know that many surface waters have excess N and P that leads to eutrophication and possibly enhanced growth of undesirable organisms such as Pfiesteria piscicida. We know that other animal pathogens, such as cryptosporidia, have caused large community outbreaks. There are other potential pathogens, such as Salmonella sp, for which we do not know the hazard. We know that our soils may become excessively laden with P, Cu, and Zn, which retard plant growth and create toxic conditions for grazing animals. There are concerns about air pollution. Odors have negative sensory and physical health consequences. H2S and dust may cause toxic effects on neighbors. NH3 vaporizing from manure sources may be carried with precipitation to cause eutrophication in lakes or altered ecosystems in natural areas. CH4 escaping from degrading manure contributes to greenhouse gases. Workers in confined livestock structures have high risk for a variety of chronic respiratory conditions. They also are at risk for acute poisoning from H2S in operations where liquid manure is stored in confined spaces. There have been numerous health complaints in recent years from community neighbors of large-scale livestock operations. One study showed adverse altered mood states, and another showed evidence of respiratory illness similar to what workers experience. Although it has not been possible to objectively measure conditions and know toxic levels of substances causing these illnesses, there are so-called extratoxic mechanisms, such as inherent aversion to putrefactive odors and exacerbation of preexisting conditions that lower the tolerance threshold. Environmental concerns regarding livestock production are not new. In the early and mid-1970s, there were many conferences and publications regarding odors and water contamination from livestock operations. Although most of what is known in this area has been known for 20 years, relatively little effective efforts have been made to correct the concerns. In fact, trends over this past decade have increased the concerns. This past decade has seen a tremendous acceleration in the concentration and consolidation of agriculture, capping a slow trend over the past 50 years toward larger, fewer, and more-specialized farms. This trend has gone against the old saying that "dilution is the solution to pollution.     

Predicted mean corpuscular volume as an indicator of bone marrow iron in anemic dogs

A predicted mean corpuscular volume (PMCV) was calculated from the reticulocyte percentage and compared to the actual mean corpuscular volume for the purpose of determining bone marrow iron depletion in the dog. A difference of greater than 10 fl between the pMCV and the actual measured MCV accurately predicted the absence of stainable iron in bone marrow aspirates (sensitivity 86%, specificity 93%). The difference (Diff) between the predicted and actual measured MCV may also be a valuable method for following response to iron therapy in dogs with iron deficiency anemia without the necessity for repeated bone marrow examination. The predicted MCV may be useful in determining which patients are not at risk for canine iron deficiency.     

Bioavailability, pharmacokinetics, and plasma concentration of tetracycline hydrochloride fed to swine

A 2 X 2 crossover design trial was conducted in gilts to determine the bioavailability and pharmacokinetics of tetracycline hydrochloride. The bioavailability of tetracycline hydrochloride administered orally to fasted gilts was approximately 23%. After intravascular administration, the disposition kinetics of tetracycline in plasma were best described by a triexponential equation. The drug had a rapid distribution phase followed by a relatively slow elimination phase, with half-life of 16 hours. Its large volume of distribution (4.5 +/- 1.06 L/kg) suggested that tetracycline is distributed widely in swine tissues. Total body clearance was 0.185 +/- 0.24 L/kg/h. Other pharmacokinetic variables were estimated. In a second trial, 3 gilts were fed a ration containing 0.55 g of tetracycline hydrochloride/kg of feed. Resulting plasma concentration of tetracycline was determined at selected times during 96 hours after exposure to the medicated feed. Plasma drug concentration peaked (0.6 micrograms/ml) at 72 hours after access to the medicated feed.     

Possible factors influencing the immunoglobulin G concentration in swine colostrum

The immunoglobulin (Ig) G concentration in swine colostrum was determined by the single radial immunodiffusion method, using 157 samples collected from farm-raised sows in the Yamaguchi Prefecture of Japan during 1976 and 1977. The mean IgG value was 53.03 mg/ml, and the maximum and minimum values were 101.39 mg/ml and 11.74 mg/ml, respectively. The amount of IgG varied greatly among sows. To clarify the possible factors influencing the amount of IgG in colostrum, the following items were surveyed: season, district, breed, age of sows, number of parturitions, udder section from which samples were collected, kind of feed, vaccinations of swine erysipelas live-organism vaccine, hog cholera live-virus vaccine, Japanese encephalitis live-virus vaccine, tramsmissible gastroenteritis liver-virus vaccine, type of farming, and number of sows raised on a farm. Relationships between the amount of IgG in colostrum and each of these 13 items were analyzed. Seemingly, strong correlations with the amounts if IgG in colostrum were found with five items (district, number of parturitions, kind of feed, type of farming, and number of sows). To the contrary, five items (age, udder section, and vaccinations of swine erysipelas live-organism vaccine, hog cholera live-virus vaccine, and Japanese encephalitis live-virus vaccine) had poor correlations. Other items had moderate correlations. The multiple correlation coefficient obtained was 0.5499.