Anna Nogalska

The Effect of Slaughter Weight and Fattening Intensity on Changes in Carcass Fatness in Young Holstein-Friesian Bulls

The objective of this study was to determine the effect of body weight (BW) at slaughter and fattening intensity on carcass fatness and meat fatty acid profile in young Holstein-Friesian bulls. One-hundred bulls fattened on two levels of intensity a semi-intensive (SI) and an intensive (I) were used. Fattening was carried out to BW of 500, 550, 600, 650 and 700 kg. Live ultrasound measurements were performed to determine back fat thickness. Carcass dressing percentage, carcass conformation and fatness, intramuscular fat content of m. longissimus dorsi and fatty acid profile (by gas chromatography) were determined after slaughter. Intensively fattened bulls were characterised by a greater carcass dressing percentage – by 1.17% on average, greater carcass conformation scores, greater external fat thickness and a greater intramuscular fat content than bulls SI fattened. Fat from intensively fattened bulls contained higher levels of polyunsaturated fatty acids (PUFAs) – by 0.96/100 g on average. Semi-intensive fattening contributed to a decrease in the n-6/n-3 PUFA ratio and to a significant increase in the concentrations of C18:2 and C20:4 fatty acids. Regardless of the fattening intensity, the n-6/n-3 ratio was greater in heavier animals. The best results were achieved when young Holstein-Friesian bulls were fattened intensively to BW of 650 kg.

Phytoextraction potential of sunflower and white mustard plants in zinc-contaminated soil

Phytoextraction relies on plants with a high capacity to absorb heavy metals and remove them from the soil. The objective of this study was to analyze the potential of sunflower (Helianthus annuus L.) and white mustard (Sinapis alba L.) for phytoextraction of Zn-contaminated soil. Research was based on a strict pot experiment conducted in a greenhouse. Seven treatments were established with increasing Zn concentrations: 0, 25, 50, 100, 200, 400, and 600 mg Zn kg-1 air-dry soil. The first tested plant was fodder sunflower. In the following year, white mustard was sown in the same pots. Plants were harvested at the end of the flowering stage. The toxic effect of Zn on sunflower yields occurred at the contamination level of 200 mg Zn kg-1 soil. In the second year of the experiment, a significant decrease in mustard biomass took place in response to 400 mg Zn kg-1 soil. The contamination level of 600 mg Zn kg-1 soil resulted in complete plant death. Plant growth was not inhibited even at high tissue Zn concentrations of 515 mg Zn kg-1 sunflower DM and 422 mg Zn kg-1 mustard DM. The 2-yr cropping system did not contribute to a significant decrease in soil Zn content. Despite high concentrations of Zn in sunflower and mustard plants, total Zn uptake accounted for only 1% to 8% of the Zn rate introduced into the soil. However, in the long run, the growing of crops could reduce Zn contamination levels in the soil. The relatively high tolerance of sunflower and white mustard for Zn contamination and rapid growth of these species are possible alternatives for phytoextraction and phytostabilization of Zn-contaminated soil.

Carcass characteristics and meat quality of bulls and steers slaughtered at two different ages

Abstract 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 increasing doses of meat and bone meal (MBM) applied every second year on maize grown for grain

Recently, due to the detection of cases of Bovine Spongiform Encephalopathy (BSE) in cattle, it has become necessary to use animal meals differently. The EU Council Decision of 4 December 2000 forbade use of processed animal protein to make feeds for cattle, swine, and poultry. Meat and bone meal (MBM) is rich in macro- and microelements as well as in organic substance, and hence it can be a viable alternative to mineral fertilizers containing N and P. The objective of this study was to determine the effect of increasing doses of MBM applied every second year as an organic fertilizer on maize ( Zea mays L.) grown for grain. A two-factorial field experiment with a randomized block design was carried out in 2010-2011, in north-eastern Poland. Experimental factor I was MBM dose (2.0, 3.0, 4.0, and 5.0 Mg ha-1 applied every second year), and experimental factor II was the year of the study (two consecutive years). Increasing MBM doses applied every second year increased maize grain yield and improved grain plumpness, in comparison with mineral fertilization. The highest yield-forming effect was observed when MBM was applied at 3 Mg ha-1. Macronutrient uptake by maize plants and macronutrient concentrations in maize grain were affected by the year of the study rather than MBM dose. The results of a 2-yr experiment indicate that MBM is a valuable source of N and P for maize grown for grain, and that it is equally or more effective when compared with mineral fertilizers.

UTILIZATION OF ANIMAL MEAL FOR GROWING OF WILLOW DEDICATED FOR ENERGY

The aim of the study was to evaluate the effects of increased rates of meat and bone meal (MBM) to the soil on biomass yield, nitrogen (N) and phosphorus (P) content, and their accumulation in above ground biomass Salix viminalis, as well as the content of mineral N and available P forms in the soil. A two-year pot experiment was conducted at Warmia and Mazury University in Olsztyn (north-eastern Poland). Average biomass yield from two seasons of the studies was three higher from MBM treatments comparing to unfertilized control. Higher rates of MBM particularly in the second year showed higher yielding potential compared with mineral fertilizers. Willow biomass harvested from MBM treatments generally showed lower content of studied nutrients than willow from control treatment. It was found that in relation to the control accumulation of N in willow above ground biomass was significantly lower for 0.5% MBM treatment and significantly higher for the treatment with the highest rate (2.0%). The higher accumulation of P was found in the second year after MBM application, except treatment with the lowest MBM rate. Correlation coefficients values indicated that there is a relation between MBM rate and content of mineral N and available P in soil.