This study was conducted to evaluate animal performance, carcase characteristics and meat quality of young bulls and steers (Charolais × Holstein-Friesian), fattened until 15 and 18 months of age. One half of 40 young bulls were castrated at 2 or 3 weeks of age. Starting at 7 months of age, they received grass silage supplemented with concentrates. At the end of the fattening period, the animals were slaughtered, and carcase quality and the quality of meat from Musculus longissimus thoracis (MLT) were evaluated. Bulls had a higher carcase dressing percentage, and their carcases had higher lean meat content than steers. MLT from steers had higher intramuscular fat (IMF) content (by 0.89%); it was less tough, more tender and palatable. IMF from bulls had higher concentrations of polyunsaturated fatty acids (PUFAs) and a higher n-6/n-3 PUFA ratio than IMF extracted from steer meat. Older animals had higher carcase quality than those slaughtered at 15 months of age, and slaughtering at a later age had no negative influence on meat quality.

The effect of slaughter weight and fattening intensity on changes in carcass fatness in young Holstein-Friesian bulls

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A long-term (six year) field experiment was conducted in Poland to evaluate the effect of meat and bone meal (MBM), applied without or with mineral nitrogen (N) fertilizer, on crop yields, N content and uptake by plants, and soil mineral N balance. Five treatments were compared: MBM applied at 1.0, 1.5, and 2.0 Mg ha⁻¹, inorganic NPK, and zero-fert check. Mineral N accounted for 100% of the total N rate (158 kg ha⁻¹) in the NPK treatment and 50%, 25%, and 0% in MBM treatments. The yield of silage maize supplied with MBM was comparable with that of plants fertilized with NPK at 74 Mg ha⁻¹ herbage (30% DM) over two years on average. The yields of winter wheat and winter oilseed rape were highest in the NPK treatment (8.9 Mg ha⁻¹ grain and 3.14 Mg ha⁻¹ seeds on average). The addition of 25% and 50% of mineral N to MBM had no influence on the yields of the tested crops. The N content of plants fertilized with MBM was satisfactory (higher than in the zero-fert treatment), and considerable differences were found between years of the study within crop species. Soil mineral N content was determined by N uptake by plants rather than the proportion of mineral N in the total N rate. Nitrogen utilization by plants was highest in the NPK treatment (58%) and in the treatment where mineral N accounted for 50% of the total N rate (48%).

The aim of a six-year field experiment conducted in north-eastern (NE) Poland was to determine the effect of meat and bone meal (MBM) on phosphorus (P) content and uptake by different crops, soil available P balance, and soil pH. Five treatments were established: (1) zero-fert; (2) inorganic NPK; (3) 1.0 t ha⁻¹ MBM; (4) 1.5 t ha⁻¹ MBM; and (5) 2.0 t ha⁻¹ MBM. Constant nitrogen (N) and potassium (K) rates and increasing P rates (0.0; 45; 68 and 90 kg ha⁻¹) were applied. The lowest dose of MBM, which supplied 45 kg P ha⁻¹ each year, was sufficient to meet the P requirements of silage maize, winter wheat, and winter oilseed rape to the same extent as mineral P fertilizer at the equivalent rate. The uptake, balance, and utilization of P by plants were comparable in both treatments. Phosphorus applied each year at high rates (68 and 90 kg ha⁻¹) with two higher MBM doses contributed to excessive P accumulation in soil; therefore, MBM should not be applied at doses exceeding 1.5 t ha⁻¹ to crops grown in acidic soils. Soil pH was not significantly affected by MBM. MBM can replace conventional mineral P fertilizers in crop cultivation.

The aim of this study was to determine the effect of meat and bone meal (MBM) used as an organic fertilizer on maize grown for grain. A two-factorial field experiment in a randomized block design was carried out in 2010 and 2011, in north-eastern Poland. Experimental factor I was MBM dose (1.0, 1.5, 2.0 and 2.5 t ha-1 year-1), and experimental factor II was the year of the study (two consecutive years). Increasing MBM doses contributed to an increase in maize grain yield and 1000-grain weight. The yield-forming effect of MBM applied at 1.5 t ha-1 year-1 was comparable with that of nitrogen and phosphorus contained in mineral fertilizers. A dose of 2.5 t ha-1 MBM led to a significant increase in maize grain yield. The P and K content of maize grain was determined by MBM dose, whereas the concentrations of N, Mg and Ca in grain were not affected by MBM dose. Significantly higher N, P, K and Mg uptake by maize plants was observed in treatments with the highest MBM dose, compared with the control treatment. Nitrogen and phosphorus uptake per 1 t MBM reached 101 kg and 26 kg, respectively. The results of a two-year study show that the maximum MBM dose (2.5 t ha-1 year-1) met the fertilizer requirements of maize with respect to nitrogen and phosphorus.