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Twenty-seven Holstein cows were fed total mixed rations (TMR) supplemented with protected palm fat (PPF), rapeseed cake (RC) or extruded soyabean (ESB) for 14 weeks. Feed intake and milk yield were recorded. Samples of milk were taken weekly and analysed. Jugular blood was taken three times two hours after feeding. Cows of the PPF group consumed significantly less feed and produced more milk than cows of the RC and ESB groups (32.9, 31.7 and 30.7 kg fat-corrected milk/d, respectively). Milk fat from cows fed diets supplemented with RC and ESB contained more stearic, vaccenic and conjugated linoleic acids, and less palmitic acid than milk fat of cows fed the PPF diet (P<0.05). The content of polyunsaturated fatty acids (PUFA) in milk fat of cows fed ESB was higher, and the atherogenicity of its fatty acids, lower than in milk fat of other cows. This was, however, accompanied by lower oxidative stability of milk fat. Supplementation of TMR with RC increased the spreadability index of manufactured butter (P<0.025). Both milk and blood urea concentrations were significantly lower for cows fed the ESB diet. This suggests that crude protein in this diet was less degradable than in other diets. Body weights of cows on diets RC and ESB increased by 11.3 and 15.6 kg, respectively, whereas the body weight of cows on the PPF diet decreased by 1.7 kg, on average. It can be concluded that feeding oilseed-based supplements to dairy cows decreased milk yield and milk production efficiency somewhat, but improved the nutritional quality of milk fat.

A total of thirty-four Czech Fleckvieh (CF), Charolais (CH) and Charolais × Czech Fleckvieh (CH × CF) bulls with an average weight of 284 kg were included in the experiment and fed ad libitum two mixed diets: MS (based on maize silage) and LCS (based on legume-cereal and lucerne silages) with different concentrations of dietary energy until slaughter at the target live weight of 600 kg. The CF bulls consumed more dry matter (DM) of feed daily than the CH bulls (P < 0.05) and gained weight less efficiently than the CH × CF and CH animals (P < 0.01) during the entire experiment. The killing-out percentage was lower in the CF than in the CH × CF and CH (P < 0.05). The CH bulls received a higher score for carcass conformation and a lower score for carcass fatness (P < 0.01) than the CF bulls, had lower proportions of kidney and cod fat (P < 0.01) than the CH × CF and CF bulls, and produced the highest percentage of high-priced meat (P < 0.05) and the lowest percentage of separable fat (P < 0.001). The bulls on the MS diet were younger than the others at the end of the experiment (P < 0.01), gained weight more rapidly (P < 0.001), consumed less DM (P < 0.001) daily, utilized nutrients more efficiently over the entire experimental period (P < 0.001), and had a higher proportion of internal fat than the LCS bulls. It can be concluded that purebred CH bulls were superior to the other breed groups in most of the traits observed. The intensive diet based on maize silage increased average daily gains, reduced the time needed to achieve the target slaughter weight, and improved the feed efficiency of bulls.

An experiment was conducted to evaluate the effect of ruminally protected methionine (Mepron ® , Degussa AG, Germany) in dairy cows. Three weeks before calving 36 cows (Holstein and Czech Fleckvieh breeds) were assigned to one of the two dietary treatments (M and O), and received a total mixed ration with protected methionine at 18.2 g per head per day or without this supplement. After calving, both groups were divided into two subgroups and fed a diet for dairy cows based on ensiled feeds and concentrates for 90 days. A half of the cows received protected methionine (subgroups MM and OM), the other cows were fed the same diet without protected methionine (subgroups MO and OO). Milk yield in cows fed protected methionine for the whole experiment duration (cows MM) was higher and feed intake was lower than in cows of the other groups. The effect of protected methionine on milk yield was not, however, statistically significant (P > 0.05). Effects of protected methionine on milk fat and protein were small and inconsistent. Supplemental methionine significantly increased the methionine concentration in serum (P < 0.05) while the methionine concentration in milk was not increased quite significantly (P < 0.10). Concentrations of essential amino acids in milk were significantly or marginally significantly higher in cows fed protected methionine. In summary, the supplementation of ruminally protected methionine at 18.2 g per head per day had beneficial, but small and mostly statistically insignificant effects on milk performance and milk composition.

ABSTRACT:The effects of breed and diet containing different types of silages on meat quality parameters and fatty acid profile of m. longissimus lumborum (MLL) were evaluated in a total of 30 Czech Fleckvieh (CF), Charolais (CH) and Charolais × Czech Fleckvieh (CH × CF) bulls. The animals were fed two mixed diets: MS (based on maize silage) and LCS (based on legume-cereal mixture silage and lucerne silages) with different concentrations of dietary energy and fatty acids. The MLL from CH bulls had the lowest content of dry matter (P < 0.01), less protein (P < 0.01) and lighter meat (P < 0.01) compared to the CF. The extensive LCS diet reduced dry matter (P < 0.01) and intramuscular fat (P < 0.01) and increased the content of hydroxyproline (P < 0.05). The CH bulls exhibited higher PUFA n-3 (P < 0.05) and lower MUFA (P < 0.05) compared to the CF, with the CH × CF being intermediate. The LCS diet enhanced the proportions of PUFA (P < 0.05) and PUFA n-3 (P < 0.001) and reduced MUFA (P < 0.001). In conclusion, both breed and diet affected the meat quality and fatty acid profile of the intramuscular fat of the bulls. The replacement of maize silage with the legume-cereal mixture and lucerne silages in the diet reduced the concentration of intramuscular fat and improved its fatty acid profile from the human nutrition perspective.

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BACKGROUND: The effect of breed and whole sunflower seed on performance, carcass traits and the composition of meat was evaluated in Charolais (CH) and Simmental (SI) bulls. Samples of musculus longissimus lumborum (MLL) and musculus infraspinatus (MIS) were analysed.

The aim of this study was to compare 2 dry-cow management strategies and evaluate the effect of shortened dry period strategy on feed intake, metabolism, and postpartum performance of dairy cows in early lactation. Twenty-nine high-yielding dairy cows were divided into 2 groups. The control (CON) group (n=14) was assigned to a traditional dry period of approximately 60 d (57±5.9 d) and was fed a far-off dry cow ration from dry-off to -21 d relative to expected parturition. From d -21 relative to expected parturition, the cows were switched to a precalving ration containing an additional 3kg of concentrates. The cows of the experimental group (n=15) were assigned to a shortened dry period (SDP; 35±6.3 d) and were continuously fed a late-lactation diet from d -60 d relative to expected parturition until calving. After calving, both groups were fed the same lactation diet corresponding to their lactation requirements and cows were followed for 100 d of lactation. Prepartum dry matter intake of the cows assigned to an SDP and fed a late-lactation diet was approximately 4.11kg/cow per day greater compared with the CON group during the 60 d. However, no effect of dry period strategy on postpartum dry matter intake was detected. The cows with an SDP produced approximately 2.78kg/d (6.9%) less milk in the first 100 d of lactation than CON cows; the difference was not statistically significant. No differences were observed in live body weight, body condition score, or back-fat thickness between the treatments. Similarly, no differences existed in concentrations of plasma metabolites. The cows of the SDP group showed lower pH and increased concentrations of lactic acid and volatile fatty acids prepartum than the CON cows. Postpartum concentrations of lactic acid, volatile fatty acids, and NH3 and pH in rumen fluid did not differ between the treatments. Shortening of the dry period did not affect the colostrum quality or birth weights of the calves. Based on the results of this study, a traditional dry period management strategy appeared to be more favorable, considering the dry matter intake and milk production, compared with an SDP and feeding a late-lactation diet throughout the dry period.