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The aim of the study was to compare the shares of MHC isoforms in the muscle tissue of bulls differing in terms of breed and age using SDSPAGE. The share was analysed as a factor which could have modified tenderness and water holding capacity of meat. Investigations were conducted on 73 young bulls of the Black-and-White, Polish Red, Hereford and Limousine breeds, slaughtered at the age of 6, 9 and 12 months, generally with 5 animals in each age group. The composition of MHC isoforms (type 2a, 2x and I) in the muscle tissue of the analysed cattle was related to the instrumental tenderness evaluation, as well as water holding capacity of meat on the basis of drip loss at 48, 96 and 240 h after slaughter. It was shown that better tenderness and water holding capacity of meat from Hereford bulls aged 12 months were accompanied by an increased share of MHC isoform type 2a, corresponding to fast-twitch, intermediate, oxygen glycolytic fibers.
This paper presents the results of empirical research on high quality beef production on the basis of the Cooperative "Agrofirm" Witkowo (Stargard Szczeciński poviat) and the individual farm Wyszobór. The research had been conducted on young crossbreed beef bulls with different genotypes in relatively intensive feeding conditions. The aim of the paper was the cost calculation of fodders per 1 kg gain in body weight in different raising systems. The first experiment consisted of young bulls genetically mixed of two or three races between Black-and-White x Red Angus crossed cows and Limousin meat breed bulls- (group I), Red Angus (group II) and Salers (group III). The second experiment consisted of young bulls from, group I - Charolais cows with Charolais bulls, group II - Hereford cows with Charolais bulls and group III - Simmental cows with Charolais bulls. In both cases young bulls from all the groups had a very good daily gain. A lower cost of fattening was noticed for the animals from experiment no. 2, where the animals had been raised in a pasture system with cow-mothers and had been better prepared for fattening.
The experimental group consisted of 57 young Holstein bulls kept in the Czech Republic; 35 bulls were tethered and 22 bulls were loose housed. The aim of the study was to analyse and compare the effect of different housing systems on feedlot performance, carcass value and meat quality and their mutual relationship. The overall average values were as follows: feedlot performance parameters live weight at slaughter 434.3 kg, age at slaughter 455.8 days, total weight gain 319.3 kg, duration of fattening 342.1 days, daily weight gain 941 g; carcass value parameters dressing percentage 51.0%, net daily weight gain 482 g, weight and proportion of kidney fat 3.9 kg, 1.8% resp., weight and proportion of fat trim 2.2 kg and 2.0% resp.; meat quality parameters dry matter, fat and collagen content in muscle 23.8, 1.46 and 1.13% resp., pH24 6.08, drip loss 0.849% and remission (525 nm) 6.4%.
This study was conducted to determine the influence of high-voltage electrical stimulation on quality of cooked beef hams produced from semitendinosus muscle of heifers and young bulls. Texture evaluation of hams was conducted with the universal testing machine Instron type 4301. Additionally, puncture and shear tests were performed. Six trained panelists conducted sensory analysis. The attributes evaluated were as follow: appearance, structure and consistency, taste and flavour as well as tenderness. The results of sensory examination and instrumental measurement revealed that the influence of high-voltage electrical stimulation on cooked hams depends on animals’ sex. The most significant difference in quality of hams was observed between stimulated and non-stimulated hams produced from semitendinosus muscle of heifers.
Changes in textural parameters of selected muscles (m. longissimus lumborum – LL, m. semitendinosus – ST, m. semimembranosus – SM, m. biceps femoris – BF) of pure-breed cattle Charolaise (CHL) and two groups of cross breeds: Hereford×Charolaise (HEF×CHL) and Simental×Charolaise (SIM×CHL) taken on the 3rd, 7th and 12th day of post-mortem cold storage were estimated. Of the four muscles tested, the highest hardness, springiness and chewiness were found in BF, which at the same time showed the highest stringiness, perceptible of connective tissue, cooking loss, and the lowest juiciness. Post mortem ageing resulted in a reduction of hardness, springiness and cooking loss and in an increase of tenderness and purge loss. The rate and dimension of tenderization were relative to the both cattle genotype and muscle tested on the one side, and stage of tenderization on the other.
The muscles semitendinosus (ST) and psoas major (PM) were removed from young bull carcasses 24 h after slaughter and stored at 4°C. On the 1st, 6th, and 12th day of post-mortem ageing the chemical composition (moisture, fat, protein) and contents of total and soluble collagen were estimated. The muscle steaks were boiled at 100°C, roasted at 170°C or fried in vegetable oil at 160°C to the internal temperature of 75°C in each case. The heated muscles were stored at 4°C for 6 days and reheated in the same heating environment to the internal temperature of 60°C. In heated and reheated muscles determinations of total and soluble collagen, WB shear force measurements and texture profile analysis (TPA) were conducted. The raw PM muscle contained two times less intramuscular collagen than ST muscle. The solubility of PM muscle collagen was higher than the solubility of ST muscle collagen. During post-mortem ageing the collagen solubility of both muscles increased. In the boiled muscles the level of soluble collagen was lower than in the roasted or fried ones. During post-mortem ageing the WB shear force, TPA hardness and TPA chewiness values of both muscles decreased. At the same time of post-mortem ageing, WB shear force values were the highest for boiled, middle for roasted and the lowest for fried muscles. The roasted muscles had the highest and fried ones the lowest values of TPA hardness, whereas values of TPA chewiness were similar, independently of the heating method used. The reheating of muscles after 6 days of cold storage had no effect on the WB shear force, although their TPA hardness and TPA chewiness values increased.
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