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The aim of the study was to compare slaughter value, collagen profile, shear force and sensory quality of muscles originating from carcasses of heifers and single-calf cows of Polish Holstein-Friesian x Limousine crossbreds. Eight heifers (540 days old) and eight single-calf cows (836 days old), which were produced in a semi-intensive system, were included in the study. Single-calf cows were heavier than the heifers, which had higher dressing percentages and average daily gains. Calving and age at slaughter did not influence cooking loss of semimembranosus (SEM) and infraspinatus (INF) muscles or the shear force of SEM. The ventral part of the INF muscle from single-calf cows exhibited higher shear force values. In both muscles, higher water-soluble and lower acid-soluble collagen contents were noted in heifers compared with single-calf cows. There were no differences in sensory quality of SEM obtained from the carcasses of single-calf cows and heifers, whereas cross-section appearance, tenderness, juiciness and overall acceptability of INF were scored higher for single-calf cows than for heifers. Thus, it can be concluded that heifers and single-calf cows produce meat with similar eating quality. [ABSTRACT FROM AUTHOR]

Eating-quality attributes of meat from Ankole cattle and their Friesian and Boran crossbreds finished in different feeding systems were evaluated. Seventy two 8-month-old bulls (24 each of pure Ankole (A), Ankole x Boran (B) and Ankole x Friesian (F) (191 ± 9.6 kg average weight) were allotted to three feeding systems in a completely randomized design with a 3 x 3 factorial treatment, and were slaughtered after 120 days. The longissimus dorsi muscle was excised from the carcasses and divided into five samples for sensory and shear force analysis. Samples aged 2, 7, 14 and 21 days were subjected to the Warner Braztler shear force (WBSF) machine for textural tenderness determination. Steaks from Ankole and Friesian crossbreds attained WBSF values below 55N within 7 days of post mortem storage, whereas Boran crossbreds attained a similar level of tenderness at 14 days. Steaks from Ankole and Friesian crossbreds were rated more tender, juicy and acceptable than Boran crossbreds by panelists. Steaks from grazed bulls were rated less tender, juicy and palatable than steaks from supplemented and feedlot finished bulls. It was concluded that when grazed and supplemented or finished in a feedlot and meat aged for 7 days, Ankole bulls produce tender meat of an as high eating-quality as their Ankole x Friesian crossbreds. [ABSTRACT FROM AUTHOR]

Rumen fluid collected from three rumen fistulated N'Dama and three crossbred animals fed three different diets at medium supplementation level, was used to compare the plant cell wall degrading community of the two breeds of cattle. In vivo digestibility was also examined and compared using 12 animals (six of each breed) fed the same diets. The microbial community of the rumen was analyzed by 16S rRNA hybridisation, using phylogenetic probes of different levels: a universal probe, domain-specific probes for Bacteria, Eukarya and Archaea, and probes targeting cellulolytic organisms: Chytridiomycetes, Fibrobacter spp., Ruminococcus albus and Ruminococcus flavefaciens. In vivo, organic matter (OM) and neutral detergent fibre (NDF) digestibility were significantly higher in N'Dama compared to crossbred animals when they were fed either baby corn stover and concentrate, or groundnut hay and moringa. In contrast, when the animals were fed groundnut hay and concentrate there was no difference in OM and NDF digestibility between the two breeds. Results of the microbial community analysis showed that RNA concentration of total Bacteria and Archaea was not affected by the breeds of animal, but were significantly affected by diet. The eukaryotic RNA concentration was higher in crossbred animals compared to the N'Dama and was not affected by the diet. Fibrobacter and R. flavefaciens RNA concentrations (μg/mL) were significantly dependent on diet and breed. Ruminococcus albus and Chytridiomycetes RNA concentrations were neither affected by the breed, nor by the diet of the animals. This suggested that the differences between breeds observed in digestibility could be partially explained by the composition of the cell wall degrading community. [ABSTRACT FROM AUTHOR]