The effect of abrupt weaning of suckler calves on the plasma concentrations of cortisol, catecholamines, leukocytes, acute-phase proteins and in vitro interferon-gamma production.

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Social group disruption and maternal separation result when calves are abruptly weaned. This study evaluated the effects of these stressors on the physiology of the calves. Calves were either abruptly weaned or not. Plasma cortisol concentration and neutrophil:lymphocyte concentrations increased and leukocyte concentration and immune response decreased for calves that had experienced social disruption. The behavioural response to handling did not change as a result of weaning or sex. There was an interaction between weaning and sex and time and sex on plasma noradrenaline concentration. Male calves showed an increase at weaning and each sampling time after, but heifers did not show an increase due to weaning. Leukocyte concentration was not affected by weaning or sex. Following weaning, the neutrophil:lymphocyte ratio increased, and this was affected by sex. Immune response was weakened due to weaning. The alterations in physiological responses indicate that abruptly weaning suckler calves makes them sensitive to stress associated with social disruption and weaning. Some of the physiological effects of the stress were still apparent a week after weaning. Therefore, efforts should be made to reduce social stress, and allow the calves time to adjust before imposing other management stressors.

Economic weights for feed intake in the growing pig derived from a growth model and an economic model

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The aim of this paper is to derive economic weights for parameters of the Technisen Model Varkersvoeding (TMV) growth model, in particular for feed intake and to illustrate the effects of different levels in these parameters on performance traits and economic weights for parameters of the growth model. It is found that economic weights for parameters of the growth model depend on the level of feed intake in relation to the optimum feed intake, while conventional breeding objectives always put a negative economic weight on feed intake. Advances in performance recording procedures to obtain information necessary to implement growth models into breeding programs are required. Electronic feeders that are able to control the level of feed intake for individual pigs together with electronic
scales and video images allow recording of the information necessary to implement growth models in genetic
evaluation systems.

Quantitative analysis of acid-base balance in Bos indicus steers subjected to transportation of long duration.

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Transport stress has led to live weight loss and greater carcass loss, whereas it is also accepted that animals dehydrate with increasing transit time. Management strategies for dealing with problems caused by transport stress have included rest periods during and after transport, the use of supplemental potassium and the use of electrolyte solutions. However there is lack of information pertaining to the effects of transport stress on the acid-base physiology of ruminants. The objective of this study was to evaluate the effect of transportation and/or feed and water deprivation on acid-base balance of Bos indicus steers. Steers were evaluated in three experimental groups. The control group received ad libitum access to feed and water. The second group was deprived of feed and water for 60 hours. The third group was transported for 48 hr following withdrawal of feed and water for 12 hours. Blood gases, electrolytes, lactate, total protein, albumin, anion gap, strong ion difference, and total weak acids were determined at the conclusion of transportation. It is concluded from the results of this study that Bos indicus steers transported for 48 h are able to maintain their acid-base balance within normal values. The primary challenge to these animals seems to be the elevation of total weak acids via an increase in plasma albumin concentration as a result of dehydration. The loss of electrolytes had little effect on the acid-base balance of the animals.

The ability of domestic hens to jump between horizontal perches: effects of light intensity and perch colour.

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Typically commercial laying houses use lower lighting intensities to reduce feather pecking, however the low light intensity may negatively affects the hens’ ability to see objects within the environment. The low light intensity may also prevent the hens from moving throughout the pen and could possibly lead to increased injury. This study compared the hens’ ability to jump between perches based on light intensity, perch colour and distance between the perches.

The Battle of the Bugs and Other Alternatives to Antibiotics in Pork Production

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Even though disease is just as existent today than ever before, alternatives to antibiotics need to be developed in order to prevent super bugs from developing. Bacteria are able to develop immunity to these antibiotics and even pass on these immunity genes. The immune species can then travel between animals and sometimes even to humans (zoonotic). Bacteria that develop the immunity can be spread to humans, and some are harmful to humans. The past 35 years has seen a move to stop the use of antimicrobial growth promotants in animal feed.

There is also a concern of antibiotics in the environment. This would come from undigested antibiotics passing through animals via urine and feces. Some commonly used antibiotics can survive in the environment for up to a year.

Probiotics are an alternative currently being investigated. Probiotics are “good” bacteria that are fed to animals to exert a positive effect on the animal. Probiotics prevent “bad” bacteria from attaching to the gut wall and causing disease to the animal. They compete with “bad” bacteria for nutrients and gut space, so as long as the “good” bacteria dominate, the animal will remain healthy. This will result in increased growth rate, improved digestibility, improved feed consumption and improved feed utilization efficiency.

Prebiotics are another alternative. These feeds are not digestible and provide a suitable environment for good bacteria to live and grow. This will work to maintain the already established good bacteria in the gut and help to keep the animal healthy.

Other alternatives to antibiotics include enzymes (to improve nutrient and feed utilization), diet acidification (a low pH will create an environment in the feed unfavorable to bacteria), liquid and fermented feed (will create an acidic environment in the intestine, which is unfavorable to bacteria), minerals, nutraceuticals (derived from food, but not considered food), novel antibodies (obtained from chicken eggs), and vaccinations.

Gastric Ulcers: An Under-Recognized Cause of Mortality and Morbidity

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Ulceration of the pars oesophagea is a cause of sow and grow-finish mortality. The mortality rate due to gastric ulceration has increased in the past decade and is one of the most important causes of death. Many hogs at slaughter have some degree of ulceration. It is difficult to address the severity of the ulceration by inspection alone. Unless ulcerations are severe and chronic, there seems to be no relationship between growth rate and stomach lesions. If feed particle size is too small it will increase the incidence of death by ulceration, but the feed-to-gain efficiency improves. Anything less than 700 to 750 microns is the point where ulceration begins. Small feed particles pass through faster and increase the fluidity of the stomach, which allows more contact of stomach acids with the stomach wall lining. The most practical solution is to ensure there is no disruption in the feeding program. Respiratory disease in a grow-finish barn is recognized as resulting in an increase in ulcers. Alkaline salts have been investigated as practical feed additives to help neutralize acidity in the stomach and improve structure of the gut. Surprisingly, gastric ulcers are highly heritable. There is some belief that ulcers are infectious. Many pigs that had ulcers housed certain bacteria that are thought to lead to ulceration.

MANURE VALUE, PRICING SYSTEMS, AND SWINE PRODUCTION DECISIONS

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Response of weaner pigs to feed rationing and frequency of feeding

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Nutritional manipulation increases intramuscular fat levels in the Longissimus muscle of female finisher pigs

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Performance of Swine Waste Lagoons for Removing Salmonella and Enteric Microbial Indicators

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The influence of zoonotic pathogens in animal manure on human health and well-being as a direct or indirect cause of human enteric illness is examined. Available international data are considered, but the study is focused on the developing situation in western Canada, where it is certain there will be further rapid growth in livestock numbers, particularly hogs. Major pathogens considered are Escherichia coli O157:H7, Salmonella, Campylobacter, Yersinia, Cryptosporidium, and Giardia. Canada is now the leading exporter of pork internationally, but recent increases in production contrast with constant domestic levels of pork consumption and declining levels of foodborne illness caused by pork. Effects of increased levels of manure production are not quantifiable in terms of effects on human health. The presence of major pathogens in manure and movement to human food sources and water are considered on the basis of available data. Survival of the organisms in soil, manure, and water indicate significant variability in resistance to environmental challenge that are characteristic of the organisms themselves. Generally, pathogens survived longer in environmental samples at cool temperatures but differences were seen in liquid and solid manure. Based on actual data plus some data extrapolated from cattle, manure environments, holding manure at 25degreeC for 90 d will render it free from the pathogens considered above.