Animal Health Research Reviews 

About: Animal Health Research Reviews is an academic journal published by Cambridge University Press. The journal publishes majorly in the area(s): Immune system & Virus. It has an ISSN identifier of 1466-2523. Over the lifetime, 415 publications have been published receiving 20788 citations.

Escherichia coli in postweaning diarrhea in pigs: an update on bacterial types, pathogenesis, and prevention strategies.

Abstract: Escherichia coli is one of the most important causes of postweaning diarrhea in pigs. This diarrhea is responsible for economic losses due to mortality, morbidity, decreased growth rate, and cost of medication. The E. coli causing postweaning diarrhea mostly carry the F4 (K88) or the F18 adhesin. Recently, an increase in incidence of outbreaks of severe E. coli-associated diarrhea has been observed worldwide. The factors contributing to the increased number of outbreaks of this more severe form of E. coli-associated diarrhea are not yet fully understood. These could include the emergence of more virulent E. coli clones, such as the 0149:LT:STa:STb:EAST1:F4ac, or recent changes in the management of pigs. Development of multiple bacterial resistance to a wide range of commonly used antibiotics and a recent increase in the prevalence and severity of the postweaning syndromes will necessitate the use of alternative measures for their control. New vaccination strategies include the oral immunization of piglets with live avirulent E. coli strains carrying the fimbrial adhesins or oral administration of purified F4 (K88) fimbriae. Other approaches to control this disease include supplementation of the feed with egg yolk antibodies from chickens immunized with F4 or F18 adhesins, breeding of F18- and F4-resistant animals, supplementation with zinc and/ or spray-dried plasma, dietary acidification, phage therapy, or the use of probiotics. To date, not a single strategy has proved to be totally effective and it is probable that the most successful approach on a particular farm will involve a combination of diet modification and other preventive measures.

Porcine circovirus diseases.

Abstract: Porcine circovirus type 2 (PCV2) is a member of the family Circoviridae, a recently established virus family composed of small, non-enveloped viruses, with a circular, single-stranded DNA genome. PCV2, which is found all over the world in the domestic pig and probably the wild boar, has been recently associated with a number of disease syndromes, which have been collectively named porcine circovirus diseases (PCVD). Postweaning multisystemic wasting syndrome (PMWS), porcine dermatitis and nephropathy syndrome (PDNS) and reproductive disorders are the most relevant ones. Among them, only PMWS is considered to have a severe impact on domestic swine production. PMWS mainly affects nursery and/or fattening pigs; wasting is considered the most representative clinical sign in this disease. Diagnosis of this disease is confirmed by histopathological examination of lymphoid tissues and detection of a moderate to high amount of PCV2 in damaged tissues. Since PMWS is considered a multifactorial disease in which other factors in addition to PCV2 are needed in most cases to trigger the clinical disease, effective control measures have focused on the understanding of the co-factors involved in individual farms and the control or elimination of these triggers. PDNS, an immuno-complex disease characterized by fibrino-necrotizing glomerulonephritis and systemic necrotizing vasculitis, has been linked to PCV2, but a definitive proof of this association is still lacking. PCV2-associated reproductive disease seems to occur very sporadically under field conditions, but it has been characterized by late-term abortions and stillbirths, extensive fibrosing and/or necrotizing myocarditis in fetuses and the presence of moderate to high amounts of PCV2 in these lesions. Taking into account that scientific information on PCV2 and its associated diseases has been markedly expanded in the last 8 years, the objective of this review is to summarize the current state of knowledge of the most relevant aspects of PCV2 biology and PCVD.

Biology and epidemiology of Toxoplasma gondii in man and animals

Abstract: Toxoplasma gondii is a coccidian parasite which utilizes felids as definitive hosts, and which has an unusually wide intermediate host range The parasite was initially described by Nicolle and Manceaux in 1908 from the rodent, Ctenodactylus gundi Infection with T gondii is one of the most common parasitic infections of man and other warm-blooded animals It has been found worldwide from Alaska to Australia Nearly one-third of humanity has been exposed to this parasite; serologic surveys indicate that T gondii infections are common in wild carnivores, including pigs, bears, felids, fox, raccoons, and skunks Clinical and subclinical toxoplasmosis has been reported from wild cervids, ungulates, marsupials, monkeys, and marine mammals Southern sea otter populations have been severely impacted by Toxoplasma infections

Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review.

Abstract: With the increase in regulations regarding the use of antibiotic growth promoters and the rise in consumer demand for poultry products from ‘Raised Without Antibiotics’ or ‘No Antibiotics Ever’ flocks, the quest for alternative products or approaches has intensified in recent years. A great deal of research has focused on the development of antibiotic alternatives to maintain or improve poultry health and performance. This review describes the potential for the various alternatives available to increase animal productivity and help poultry perform to their genetic potential under existing commercial conditions. The classes of alternatives described include probiotics, prebiotics, synbiotics, organic acids, enzymes, phytogenics, antimicrobial peptides, hyperimmune egg antibodies, bacteriophages, clay, and metals. A brief description of the mechanism of action, efficacy, and advantages and disadvantages of their uses are also presented. Though the beneficial effects of many of the alternatives developed have been well demonstrated, the general consensus is that these products lack consistency and the results vary greatly from farm to farm. Furthermore, their mode of action needs to be better defined. Optimal combinations of various alternatives coupled with good management and husbandry practices will be the key to maximize performance and maintain animal productivity, while we move forward with the ultimate goal of reducing antibiotic use in the animal industry.

Conjugated linoleic acid

Abstract: Conjugated linoleic acid (CLA), first positively identified in 1987 (Ha et al.), is a collective term describing the positional and geometric conjugated dienoic isomers of linoleic acid. Linoleic acid (C18:2) has double bonds located on carbons 9 and 12, both in the cis (c) configuration, whereas CLA has either the cis or trans (t) configuration or both located along the carbon chain. Sources of CLA have been shown to elicit many favorable biological responses including: (i) increased rate and (or) efficiency of gain in growing rats (Chin et al., 1994) and pigs (Dugan et al., 1997; Thiel et al., 1998; O’Quinn PR, Waylan AT, Nelssen JL et al., submitted for publication); (ii) reduced fat deposition and increased lean in mice (Park et al., 1997) and pigs (Dugan et al., 1997; Thiel et al., 1998; O’Quinn et al., 2000a); (iii) improved immune function in rats and chicks (Cook et al., 1993; Sugano et al., 1998); and (iv) reduced atherosclerosis in rabbits (Lee et al., 1994) and hamsters (Nicolosi et al., 1997). Conjugated linoleic acid is also a potent anticarcinogen in vivo and in vitro (Ha et al., 1990; Ip et al., 1991; Durgam and Fernandes, 1997) and may exhibit some antioxidant properties (Decker, 1995), possibly as a result of its involvement in the metabolism of a-tocopherol (O’Quinn et al., 1999). Additionally, CLA increases adipocyte insulin sensitivity (Houseknecht et al., 1998b) and, therefore, has become a highly studied factor for the management of type I (Collier et al., 1988) and type II (Hendra et al., 1991; Singh et al., 1992) diabetes mellitus, a disease affecting over 100 million people in the United States alone (Pickup and Crook (1998).