Modelling of beef sensory quality for a better prediction of palatability

Despite efforts by the industry to control the eating quality of beef, there remains a high level of variability in palatability, which is one reason for consumer dissatisfaction. In Europe, there is still no reliable on-line tool to predict beef quality and deliver consistent quality beef to consumers. Beef quality traits depend in part on the physical and chemical properties of the muscles. The determination of these properties (known as muscle profiling) will allow for more informed decisions to be made in the selection of individual muscles for the production of value-added products. Therefore, scientists and professional partners of the ProSafeBeef project have brought together all the data they have accumulated over 20 years. The resulting BIF-Beef (Integrated and Functional Biology of Beef) data warehouse contains available data of animal growth, carcass composition, muscle tissue characteristics and beef quality traits. This database is useful to determine the most important muscle characteristics associated with a high tenderness, a high flavour or generally a high quality. Another more consumer driven modelling tool was developed in Australia: the Meat Standards Australia (MSA) grading scheme that predicts beef quality for each individual muscle × specific cooking method combination using various information on the corresponding animals and post-slaughter processing factors. This system has also the potential to detect variability in quality within muscles. The MSA system proved to be effective in predicting beef palatability not only in Australia but also in many other countries. The results of the work conducted in Europe within the ProSafeBeef project indicate that it would be possible to manage a grading system in Europe similar to the MSA system. The combination of the different modelling approaches (namely muscle biochemistry and a MSA-like meat grading system adapted to the European market) is a promising area of research to improve the prediction of beef quality. In both approaches, the volume of data available not only provides statistically sound correlations between various factors and beef quality traits but also a better understanding of the variability of beef quality according to various criteria (breed, age, sex, pH, marbling etc.)

Isolation and characterization of novel lipases/esterases from a bovine rumen metagenome

Improving the health beneficial fatty acid content of meat and milk is a major challenge requiring an increased understanding of rumen lipid metabolism. In this study, we isolated and characterized rumen bacterial lipases/esterases using functional metagenomics. Metagenomic libraries were constructed from DNA extracted from strained rumen fluid (SRF), solid-attached bacteria (SAB) and liquid-associated rumen bacteria (LAB), ligated into a fosmid vector and subsequently transformed into an Escherichia coli host. Fosmid libraries consisted of 7,744; 8,448; and 7,680 clones with an average insert size of 30 to 35 kbp for SRF, SAB and LAB, respectively. Transformants were screened on spirit blue agar plates containing tributyrin for lipase/esterase activity. Five SAB and four LAB clones exhibited lipolytic activity, and no positive clones were found in the SRF library. Fosmids from positive clones were pyrosequenced and twelve putative lipase/esterase genes and two phospholipase genes retrieved. Although the derived proteins clustered into diverse esterase and lipase families, a degree of novelty was seen, with homology ranging from 40 to 78 % following BlastP searches. Isolated lipases/esterases exhibited activity against mostly short- to medium-chain substrates across a range of temperatures and pH. The function of these novel enzymes recovered in ruminal metabolism needs further investigation, alongside their potential industrial uses

Increasing the concentrations of beneficial polyunsaturated fatty acids in milk produced by dairy cows in high-forage systems

v2006o

Partitioning of nutrients for growth in ruminants fed on forages

SIGLEAvailable from British Library Document Supply Centre-DSC:4363.3965(2) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Growth and carcase parameters of lams sired by extreme muscle density lambs at differing end points

In vivo measures of carcase quality can aid selection. Muscle density, (measured by computer tomography) has strong negative genetic and phenotypic correlations with intramuscular fat. The aim of this study was to evaluate growth and carcase parameters of lambs, sired by five high and low muscle density Terminal sire rams, using three different covariates. Progeny (n=394) were recorded for live weight at: birth; 8 weeks, 16 weeks and immediately pre-slaughter. Ultrasonic measurements were made at the third lumbar vertebrae, pre-slaughter. Carcase records include carcase weights, EUROP classification scores for fatness and conformation. Data were analysed using GENSTAT 15, using a sire nested within muscle density ANOVA design model, fitting sex; dam age (slaughter batch for carcase traits); birth/rear type and MyoMaxTM carrier status. The model was adjusted for the covariates, age at measurement (age): live weight at slaughter (Slwt); or slaughter fat grade (fat). Low muscle density sired lambs were heavier at 8 weeks (age P=0.022; Slwt P=0.043: fat P=0.04) and 16 weeks (age 0.014; Slwt P=0.05; fat P=0.036). However high muscle density sired lambs had increased ultrasonic muscle depth (age 0.0 19: Slwt P=0.017; and fat P=0.017), heavier hot carcase weight (age P=0.004; Slwt P<0.001; fat P=0.004), 48 h cold carcase weight (age P=0.027; Slwt P<0.001: fat P=0.013), higher killing out percentages (age, Slwt and fat P<0.001), and improved carcase conformation (age, Slwt and fat P<0.001). It is proposed that when compared at the same end point, high muscle density sired lambs have increased lean tissue which is expressed as higher carcase weight rather than live weight. Further data analysis is underway to investigate primal yields, waste data and eating quality

Partitioning of nutrients for growth in ruminants fed on forages

SIGLEAvailable from British Library Document Supply Centre-DSC:4363.3965(2) / BLDSC - British Library Document Supply CentreGBUnited Kingdo