19 research outputs found

    Plasma Hormones and Metabolites in Cattle in Relation to Breed (Belgian Blue Vs Holstein) and Conformation (Double-Muscled Vs Dual-Purpose Type)

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    Four Belgian Blue double-muscled type (BBDM) bulls, four Belgian Blue dual-purpose type (BBDP) bulls and four Holstein bulls were used in a fattening trial in order to relate differences in the extent of muscle development and adiposity to differences in digestibility, endocrine status, protein and lipid metabolism. The larger muscle development in BBDM animals was associated with a trend to higher nitrogen retention, higher food conversion efficiency (p < 0.05) and lower apparent digestibility (p < 0.05). No difference was found between the groups for plasma glucose concentration. Higher creatinine, lower alpha-amino nitrogen, lower triglycerides and higher non-esterified fatty acid plasma levels were observed in BBDM as compared to Holstein bulls (p < 0.05), the BBDP group being intermediate. A trend to a higher cholesterol plasma level was found in BBDM animals. There was no difference between the three groups in plasma fatty acid composition, except for the C14:0 content. Some of the differences in plasma metabolites were related to carcass composition and endocrine regulation, a decrease in muscle development and an increase in adiposity being associated with lower growth hormone production (p < 0.05) and higher insulin (p < 0.05) and IGF secretions. The insulin/growth hormone ratio at the end of the fattening period was 0.0011, 0.0018 and 0.0069 in BBDM, BBDP and Holstein bulls, respectively, and was directly associated with fat deposition

    Review: On-farm and processing factors affecting bovine carcass and meat quality.

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    peer reviewedThis paper reviews the current state of knowledge on beef carcass and meat quality, with particular emphasis on on-farm and processing factors associated with its high and inconsistent variability. The diversity of livestock systems comes from the diversity of breeds (dairy or beef), ages and gender (bulls, steers, heifers, cull cows) used to produce either mainly beef or beef and milk. In addition, there are factors linked to farming practices (including diet, especially grazing) which significantly influence the sensory, nutritional, technological and extrinsic (such as image) quality attributes of meat. These can become factors of positive differentiation when controlled by the application and certification of technical specifications. Finally, preslaughter (such as stress), slaughter (such as the chilling and hanging method of carcasses) and postslaughter (such as ageing, packaging and cooking) conditions have a strong influence on the microbiological, sensory, technological and image quality attributes of beef. In this review, potential synergisms or antagonisms between the different quality attributes are highlighted. For example, finishing cattle on grass, compared to indoor fattening on a high concentrate diet, has the advantage of producing leaner meat with a higher proportion of omega-3 fatty acids while exhibiting superior oxidative stability, but with the consequence of a darker meat colour and lower productivity, as well as higher seasonality and land surface requirements. Moreover, the control of on-farm factors is often guided by productivity (growth rate, feed conversion ratio) and carcass quality attributes (weight, conformation and fatness). Genetic selection has often been oriented in this direction, without taking other quality attributes into account. Finally, the interactions between all these factors (and especially between on-farm and slaughter or processing factors) are not considered in the quality grading schemes in European countries. This means that positive efforts at farm level may be mitigated or even eliminated by poor slaughtering or processing conditions. All these considerations explain why between-animal variability in quality can be high, even when animals come from the same farming system. The ability to predict the sensory and nutritional properties of meat according to production factors has become a major objective of the supply chain

    Effets du clenbuterol dans l'engraissement de deux jumeaux monozygotes Pie-Noir

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    Deux taureaux Pie-Noir jumeaux monozygotes obtenus par section d'un même embryon ont été utilisés et maintenus dans les mêmes conditions expérimentales. L'un a été traité au clenbutérol, l'autre a servi de témoin. En ce qui concerne les performances zootechniques, ce sont essentiellement le rendement et la qualité de la carcasse -augmentation de la proportion de viande au détriment de la graisse- qui ont été améliorés par le traitement. Les paramètres sanguins ont peu varié. Par contre, le bilan azoté a augmenté de façon nette chez l'animal traité. Une analyse histologique de fragments musculaires a montré que la surface des fibres était plus importante chez l'animal qui avait reçu le clenbutérol

    Compensatory growth in Belgian Blue bulls previously grazed at two stocking rates: animal performance and meat characteristics

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    peer reviewedA comparison was made between finishing systems with Belgian Blue bulls of the double-muscle type, in order to assess the response in terms of compensatory growth when bulls were grazed at a high stocking rate. Two groups of 8 bulls (256.5 kg liveweight) were grazed on Lolium perenne and Trifolium repens pasture during an initial period of 135 days (period I). One group grazed at a stocking rate of 6/ha allowing for normal growth at pasture (NGP); the other group grazed at a stocking rate of 10/ha (low growth at pasture, LGP). Both groups were then finished indoors (period II) with a concentrate based on dried sugarbeet pulp. Eight control bulls were also finished indoors on the concentrate diet during periods I and II (CG). Bulls were slaughtered according to a similar finishing state. Liveweight gains were 1.47, 1.10 and 0.52 kg daily (P<0.001) during period I in CG, NGP and LGP groups respectively. Corresponding liveweight gains during period II were 1.22, 1.37 and 1.50 kg daily. The LGP group had lower feed conversion ratios, slaughter weights (P<0.05) and dressing proportions (P<0.01). The meat from the grazed bulls had lower cooking losses (P<0.05) and tended to have lower drip losses and higher tenderness. It also had a higher cholesterol (P<0.05) content. Large differences were observed in the fatty acid composition according to fat location (subcutaneous, intermuscular or intramuscular). The proportions of mono and polyunsaturated acids increased in the adipose tissue of those previously grazed
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