Fatty liver haemorrhagic syndrome occurrence in laying hens: impact of production system

Abstract

Surveys were conducted with cage and alternative layer production systems to assess the prevalence of fatty liver haemorrhagic syndrome (FLHS). Commercial caged laying hens of different ages from three farms in Queensland were monitored for three months. The mortality rate of flocks ranged from 0.8% (the youngest flock) to 11.6% (the oldest flock). Six hundred and fifty-one birds were necropsied, and approximately 40% of hens died due to FLHS. Hens kept in cages in a controlled environment shed, were at a similar risk of developing FLHS to hens kept in naturally controlled sheds, however, the heavier birds in a flock were more likely to have the condition than lighter birds. In another study, layer flocks kept in cage, barn and free-range housing systems at the University of Queensland facility, were monitored for 50 weeks. Data from necropsies and performance records showed no significant differences in mortality rates between the housing systems (6.1%, 6.4% and 5.8%, for cages, barns and free-range, respectively), but the cause of mortality was different. In cages, 74% of necropsied hens died due to FLHS. In the other systems, only 0-5% of dead hens were diagnosed with the condition. These results are in agreement with previous Australian and overseas findings which have shown that FLHS is one of the main causes of hen death in caged flocks. Factors associated with husbandry practices in different production systems, such as restricted movement, increased production and temperature variations, influence hepatic lipid metabolism and predispose hens to FLHS.

Alpha‐lipoic acid improves the reproduction performance of breeder hens during the late egg‐laying period

“…Laying hens' fats (triglycerides, cholesterol and phospholipids) are synthesized and transported in the liver, increasing the risk of fatty liver syndrome (Trott et al, 2014). Deserved to be mentioned, fatty liver is particularly prominent in aged laying hens (Lv et al, 2018;Shini & Bryden, 2009). In fattening pigs and broilers, adding appropriate amount of ALA to the diet can reduce TG in serum (Bai, Ma, Ma, Zhao, Xi, & Ji, 2012;Sohaib et al, 2018), which is similar to the results of our experiment.…”

Influence of a Sustained Release Deslorelin Acetate Implant on Reproductive Physiology and Associated Traits in Laying Hens

“…Laying hens often suffer from a variety of diseases such as osteoporosis (FAWC, 2010), keel bone fractures and deviations (Fleming et al, 2004; Rodenburg et al, 2008; Käppeli et al, 2011b; Wilkins et al, 2011; Petrik et al, 2015), and fatty liver hemorrhagic syndrome (Shini and Bryden, 2009). The high laying performance might be a related factor to these medical conditions.…”

Managing Free-Range Laying Hens—Part B: Early Range Users Have More Pathology Findings at the End of Lay but Have a Significantly Higher Chance of Survival—An Indicative Study

“…Interestingly, in three of the five flocks, significantly more stayers exhibited liver discoloration compared to roamers and rangers, indicating a higher prevalence of Fatty Liver Syndrome. Clinical symptoms of Fatty Liver Syndrome are usually not seen in live birds and hens die peracute due to haemorrhage and liver capsule rupture [ 42 , 43 ]. Fatty Liver Syndrome has previously been shown to be most common in caged hens where 74% of the mortality was caused by the Fatty Liver Syndrome compared to 5% and 0% of hens from barn and free-range housing [ 44 ].…”