Technical note: Assessment of an alternative technique for measuring body temperature in pigs.

Core body temperature (CBT) is one of the main vital signs that is used to evaluate the health status of pigs. The most common and feasible method for assessing CBT in pigs is rectal temperature (RT). Obtaining RT is stressful for animals, may generate inaccurate results, and has the risk of spreading disease. Infrared imaging (IR) thermography of the body of pigs may be a safer and less stressful alternative to RT. The objective of the current study was to evaluate the efficacy of using IR as an alternative for monitoring CBT in pigs. Twenty-three gilts (30.5 ± 5.62 kg BW) were housed in metabolism crates in an environmentally controlled facility and fed an 860 g/d grower diet. After 4 d of adaptation, the febrile response was induced by intramuscular injection of lipopolysaccharide (LPS; 25 µg/kg BW). Each pig's body temperature was recorded at 0, 2, 4, 6, 8, 10, and 24 h after LPS challenge using the following 3 methods: 1) RT, 2) IR of the eye and ear, and 3) CBT using an orally administered digital temperature sensor. Statistical analysis was performed in a completely randomized design in SAS using Mixed, Correlation, and Regression procedures. Relative to time 0 h, LPS increased the eye temperature, CBT, and RT by 0.92, 1.32, and 1.48°C, respectively ( < 0.01), but had no significant effect on ear temperature. Eye temperature, RT, and CBT, but not ear temperature, were highly correlated ( ≥ 0.96) during the course of the study ( < 0.01). Estimated regression parameters (α and ß) for predicting CBT using eye temperature were -28.2 ± 8.70 and 1.76 ± 0.221, respectively, and for RT were -24.5 ± 7.69 and 1.65 ± 0.196, respectively ( ≥ 0.96; 95% confidence interval). Collectively, these results indicated a strong relationship between eye temperature, RT, and CBT in pigs. Therefore, IR of the eye can be used as a precise, noncontact alternative to RT measurements for monitoring CBT in swine.

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.

Clinical assessment of selenium status of livestock.

Assessment of the selenium status of livestock is an important aspect of production medicine, but variations in reported values between laboratories and between methods may be > 30%. Reliable interpretations require considerable experience with an assay and an extensive database from field and research case samples of a variety of species. The Michigan State University Animal Health Diagnostic Laboratory (MSU-ADHL) has offered Se analyses by acid-digestion and fluorometric detection since 1982. This laboratory expects serum Se values (nanograms per milliliter) of livestock to increase gradually with age from starting ranges for neonates of 50 to 80 for calves and sheep and 70 to 90 for foals and pigs. Expected or "normal" values for the adults are in the ranges of 70 to 100 for cattle, 120 to 150 for sheep, 130 to 160 for horses, and 180 to 220 for swine. Normal liver Se concentrations are considered to range between 1.2 and 2.0 micrograms/g on a dry weight basis, regardless of the species or age. Based on samples submitted to MSU-AHDL between September 1990 and August 1991, contemporary feeding practices in the Michigan area resulted in mean serum Se values (nanograms per milliliter) of 75 +/- 19 for adult Holsteins, 170 +/- 27 for adult swine (mixed breeds), and 137 +/- 30 for adult race horses. Within that period of time, two field cases of Se toxicity were diagnosed. One involved feeder pigs with a recorded high serum Se value of 1,525 ng/mL due to a commercial premix manufacturing error.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk assessment of ochratoxin A residues in food.

Ochratoxin A is a mycotoxin that has been found to occur in foods of plant origin, in edible animal tissues and in human sera and tissues. The ability of ochratoxin A to move up the food chain is associated with its long half-life in certain edible animal species. In this presentation, approaches for the evaluation of the health risks due to the presence of ochratoxin A in food products are described. The major target for ochratoxin A toxicity in all mammalian species tested is the kidney, and endemic nephropathies affecting livestock as well as humans have been attributed to ochratoxin A. Ochratoxin A is also teratogenic, and in the fetus the major target is the developing central nervous system. Recent studies have provided 'clear evidence' for the carcinogenicity of ochratoxin A in two rodent species. It was found to be non-mutagenic in various microbial and mammalian gene mutation assays, but weak genotoxic activity to mammalian cells was noted. In addition, ochratoxin A was found to suppress immune function. On the basis of a carcinogenicity study with ochratoxin A in rats, reported from the National Toxicology Program in the USA, the estimated tolerable daily intake of ochratoxin A in humans ranges from 1.5 to 5.7 ng/kg bw per day, depending on the method of extrapolation used. The worst-case estimate for daily exposure to ochratoxin A from the consumption of pork-based food products and cereal foods for young Canadian children, the highest consumption group on a body weight basis, is probably less than 1.5 ng/kg body weight per day (mean of eaters). In view of the toxic properties of ochratoxin A, it is recommended that exposure to this toxin be kept to a minimum.

[The role of veterinary toxicology in farm animals]. / De positie van de veterinaire toxicologie bij landbouwhuisdieren.

The history of veterinary toxicology in farm animals, like that of human toxicology, is marked by a number of classical, large-scale cases of poisoning, which have become widely known. A number of these cases are briefly reported, attention being drawn to the specific problems to which they give rise. Publicity, liability, diagnostic problems and amount of loss often have a delaying effect on settlements. Methods which might improve this situation are broadly outlined.

[Disease and depression of productivity in raising swine caused by mycotoxins]. / Krankheit und Leistungsdepression in der Schweinehaltung durch Mykotoxine.

Mycotoxins are natural substances, which are poisonous for man and animals. Mycotoxicological investigations, carried out from 1982 to 1986, showed that aflatoxins (B1, B2, G1, G2), trichothecenes (T-2 toxin, HT-2 toxin, diacetoxyscirpenol, monoacetoxyscirpenol, neosolaniol and deoxynivalenol) ochratoxin A and zearalenone are to be expected in feedstuffs. Further, sclerotia of Claviceps purpurea were found in cereals repeatedly, which demonstrates that also ergot alkaloids can be found in feedstuffs. The determined toxin concentrations often do not suffice to produce the described "classic" clinical symptoms and pathological changes. On the contrary the continuous intake of small amounts leads to chronic intoxications which are characterized by loss of weight, insufficient gain in weight, fertility disorder or increased susceptibility for infectious diseases. As feedstuffs are mostly contaminated by different kinds of toxinogenic fungi and as fungal strains are frequently able to produce several mycotoxins simultaneously, it must be assumed that naturally occurring mycotoxicoses are not monocausal, but multitoxic diseases. Although we have improved analytical methods, naturally occurring mycotoxicoses still cannot always be cleared up completely.

Assessment of a general therapeutic protocol for the treatment of acute T-2 toxicosis in swine.

T-2 toxin, a trichothecene mycotoxin suspected of being used as a chemical warfare agent, was administered iv to swine at a dose of 3.6 mg/kg body weight (iv LD50 approximately 1.2 mg/kg). Four different therapeutic protocols were assessed for their efficacy in the treatment of the resultant acute T-2 toxicosis syndrome. One therapeutic protocol included the combined use of metoclopramide, activated charcoal, magnesium sulfate, dexamethasone sodium phosphate, sodium bicarbonate and normal saline. The other 3 protocols utilized the same agents less 1 of the following: the combination of activated charcoal and magnesium sulfate, sodium bicarbonate, or normal saline. All 4 treatment groups showed improved survival times compared to a positive T-2 control group. Within the limits of the study, it would appear that the removal of activated charcoal and magnesium sulfate was most detrimental to the T-2 toxin-dosed swine.

Relationships between the H and A-O blood types, phosphohexose isomerase and 6-phosphogluconate dehydrogenase red cell enzyme systems and halothane sensitivity, and economic traits in a superior and an inferior selection line of swiss landrace pigs.

Associations between production traits and the genes for halothane sensitivity (HAL), S, A and H blood group systems and phosphohexose isomerase (PHI) and 6-phosphogluconate dehydrogenase (6-PGD) enzyme systems were investigated in two lines of pigs selected for an index. The phenotypic variance-covariance matrix of the index included backfat thickness and daily gain, whereas the genetic variance-covariance matrix included daily gain, feed conversion and percentage of lean meat. The experiment was conducted at the experimental station of the Institute of Animal Production and has been underway since 1973. The same index was applied but in two opposite directions to give a superior and inferior line in relation to the production traits. One hundred twenty-nine animals of the superior line in the seventh generation and 88 animals of the inferior line in the sixth generation were studied. Forty-two percent (54/129) of the animals of the superior line were halothane-positive. No animals in the inferior line were halothane reactors. Of the halothane-positive pigs, 70.4% (38/54) in the superior line had the HaHa and 94.4% (51/54) had the SsSs genotype, whereas only 4% (3/75) of the HaHa and 12% (9/75) of the SsSs pigs were halothane-negative. By practicing selection at the H and S loci, it seems possible to efficiently reduce halothane sensitivity in Swiss Landrace pigs. In pigs of the superior line, there were significant differences in percentage of lean meat, carcass length, pH1 (pH value at 45 min to 1 h postmortem, M. longissimus) and reflectance values among genotypes of the HAL, S and H systems and among some genotypes of the 6-PGD system. Poorest meat quality, highest percentage of lean meat and shortest carcass length were observed in pigs homozygous for the alleles HALn, Ss, Ha, PHIB and 6-PGDA. In the inferior line, these associations were absent. As the HAL locus is associated with the above mentioned production traits, linkage disequilibria may explain the observed associations among the H, S, PHI and 6-PGD types and production traits.