Evidence that enforced sunlight exposure can cause hyperthermia in cattle ingesting low levels of ergot of rye (Claviceps purpurea), when air temperature and humidity conditions are only moderate

Abstract. A review of the literature was conducted on the effects of high temperature and low pH (HTLP) on meat quality, with a focus on interventions that increase the rate of cooling post slaughter. HTLP can potentially change meat tenderness, water-holding capacity and colour due primarily to protein denaturation during the first 5 h post mortem. Deep muscles in large carcasses are susceptible to HTLP when cooled conventionally. Ante mortem and post mortem solutions that increase the rate of carcass cooling are discussed. Ante mortem solutions include access to feed and water, showering with water and provision of shade. Post mortem solutions included vascular flushing, hot fat trimming, opening seams, hot boning, spray chilling, blast chilling, immersion cooling, and very fast chilling. Accelerating rigor with electrical stimulation before HTLP remains controversial. Combinations of different techniques, that suit the specific requirements of a particular processing plant, is the likely best solution to HTLP, but further development of commercial solutions is suggested.

Section: Provision Of Shadementioning

confidence: 94%

Techniques to reduce the temperature of beef muscle early in the post mortem period – a review

Jacob

Hopkins

2014

“…The impact of ergot is more serious in lot-fed conditions, and serious mortalities occurred in several Western Australian feedlots in 1990 from feeding barley containing 0.06% rye grass ergot (Peet et al 1991). Bourke (2000) reviewed more cases in central NSW in 1998 and 1999. Here we report further cases from central NSW and South Australia in 2001 and 2002, involving some mortalities.…”

Section: Cases Of Ergotismmentioning

confidence: 99%

“…Poisoning of livestock occurs only occasionally and in a few localities, usually as a result of grazing infected rye grass (Jessep et al 1987). However, it also occurs from feeding contaminated grain to livestock, if rye grass is not controlled in winter cereal crops, which are then contaminated by ergot sclerotia produced in the rye grass (Peet et al 1991;Bourke 2000). Rye grass ergot sclerotia in grain traded by bulk handlers are limited by industry trading standards and some state government regulations, but toxicity problems can result from direct sales from farm to farm.…”

Section: Introductionmentioning

confidence: 99%

Alkaloids in Australian rye ergot (Claviceps purpurea) sclerotia: implications for food and stockfeed regulations

Blaney¹,

Molloy²,

Brock³

2009

Rye ergot (Claviceps purpurea) occasionally causes toxicity (chiefly expressed as hyperthermia) in Australian livestock, either as a result of grazing infected annual (Lolium rigidum) and perennial (L. perenne) rye grasses, or if the ergot sclerotia produced in rye grasses contaminate grain crops used as stockfood. Alkaloids in 30 samples of Australian rye ergot sclerotia taken from rye grasses and grain screenings, and some feed samples contaminated with rye grass ergot sclerotia, were assayed by high performance liquid chromatography. Samples originated from across southern Australia. Ergotamine was the dominant alkaloid in all samples, followed by a-ergocryptine, ergocornine, ergosine and their respective -imine epimers. Ergotamine concentrations in sclerotia ranged up to 2257 mg/kg (as received basis). Ergocristine was a very minor component (<50 mg/kg) in all samples. Total alkaloids in freshly collected sclerotia ranged from 1003 to 3321 mg/kg (0.10 to 0.33%), and up to 3766 mg/kg with epimers included, although lower concentrations were found in samples stored for some time. Alkaloid profiles in sclerotia were all very similar, and concentrations did not appear to be related to size of sclerotia, source region, nor to the rye grass or grain from which they were taken. Previous cases of toxicity in livestock are reviewed and several new cases are reported. The implications of variable alkaloid contents of rye ergot sclerotia are discussed in terms of Australian food and stockfeed regulations.

“…However, he concluded that stock exposure to sunlight appears to be a critical factor in a particularly lethal form of hyperthermia in cattle and sheep and that toxins other than ergot alkaloids could be involved such as the ergochromes (Franck 1969;Buchta and Cvak 1999). Bourke (2003) suggested that feed likely to contain rye ergot should be avoided for ruminant feed, particularly in feedlot rations. For practical purposes it is preferred to propose a low level rather than a zero tolerance and a level of 0.01% ergot sclerotia in the total diet of cattle, goats and sheep is proposed, with an equivalent alkaloid content limit of 0.2 mg/kg.…”

Section: Ergot Alkaloidsmentioning

confidence: 99%

A review of potential contaminants in Australian livestock feeds and proposed guidance levels for feed

MacLachlan¹,

Blaney²,

Cook³

et al. 2013

Abstract. Contaminants of man-made and natural origin need to be managed in livestock feeds to protect the health of livestock and that of human consumers of livestock products. This requires access to information on the transfer from feed to food to inform risk profiles and assessments, and to guide management interventions such as regulation or Hazard Analysis Critical Control Point approaches. This paper reviews contaminants of known and potential concern in the production of livestock feeds in Australia and compares existing but differing state and national regulatory standards with international standards. The contaminants considered include man-made organic chemical contaminants (e.g. legacy pesticides), elemental contaminants (e.g. arsenic, cadmium, lead), phytotoxins (e.g. gossypol) and mycotoxins (e.g. aflatoxins). Reference is made to scientific literature and evaluations by regulators to propose maximum levels that can be used for guidance by those involved in managing contamination incidents or developing feed safety programs.