The Canadian Society of Animal Science Annual Conference, The Westin Ottawa, Ottawa, Ontario, Canada, 5–7 May 2015

Liver abscesses are a prominent concern in cattle fed high-energy finishing rations.Challenges to the beef industry include impairment in productivity and loss of condemned organs.The increasing demand for enhanced productive performance in beef cattle with ensured food safety drives the need for complementary methods of monitoring health before slaughter.Our objective was to examine variation in biliary and blood plasma indicators of hepatic function to indirectly identify the presence or absence of liver abscesses.A total of 30 crossbred beef bulls (399 ± 29 d; 584 ± 128 kg at slaughter) were tested for productive performance.Samples of blood and bile collected at slaughter were evaluated for a panel of metabolites related to hepatic metabolism.The presence (n = 9) and absence (n = 21) of liver abscess served as criteria for classifying the bulls.Means comparisons between groups of bulls based on presence or absence of abscess were tested using the general linear model procedure in SAS.Plasma albumin was lower in bulls with abscess (32.11 g L -1 vs. 36.67g L -1 , P = 0.01).Thyroxine levels were also lower in plasma of the abscessed bulls (89.43 nmol L -1 vs. 101.52nmol L -1 , P = 0.02), as were blood plasma cholesterol levels (2.43 mmol L -1 vs. 3.08 mmol L -1 , P = 0.01).A retrospective analysis of blood parameters taken at eight occasions up to 34 d prior slaughter indicated lower blood plasma metabolites in bulls with abscessed livers, including glucose (4.66 mmol L -1 vs. 4.79 mmol L -1 , P = 0.03) and potassium (4.24 mmol L -1 vs. 4.49 mmol L -1 , P = 0.001); chloride was instead higher in the abscessed group (95.54 mmol L -1 vs. 94.43 mmol L -1 , P = 0.04).Carbon dioxide and urea were lower in abscessed bulls (22.19 mmol L -1 vs. 22.85 mmol L -1 , P = 0.005 and 3.69 mmol L -1 vs. 4.07 mmol L -1 , P < 0.01, respectively), as were levels of alkaline phosphatase (107.23 U L -1 vs. 123.26U L -1 , P < 0.01).Bulls with the presence or absence of liver abscess did not differ in age (395 ± 29 d vs. 400 ± 29 d, P = 0.63) or productive performance traits (i.e., feed efficiency, feed intake and average daily gain).Our results indicate that changes in hepatic function and intermediary metabolism accompanying liver abscesses can be represented by variations in corresponding blood plasma metabolites.Future work may be aimed at establishing profiles of healthy and diseased livers that may have application in the beef industry to ensure profitability and promote animal health.002-GS Storage characteristics, nutritive value and in vivo digestibility of large round bales of alfalfa hay treated with fibrolytic enzymes.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.