Browsing by Subject "ultraääni"

Residual feed intake (RFI) is a measurement method used in animals to determine feed efficiency. Improving feed efficiency has been found to be more cost-effective than maximizing daily gain. Determining the feed efficiency is laborious as the measurement periods are long and expensive. The problem is the limited capacity of the measuring devices in relation to the number of animals, because the animals daily dry matter intake (DMI), average daily gain (ADG) and metabolic body weight (MMBW) must be measured over a sufficiently long continuous period. The aim of the study was to optimize the measurement of residual feed intake to reduce workload. In this case, the costs of measurement would be lower, and the utilization rate of measuring equipment would be improved. The study sought a critical limit on the amount of data required. Measurements were removed from the data until it was found that the reliability of the results was affected. The hypothesis was that the fewer measurements and the shorter the measurement period, the greater the risk of error in the results. The study material included 105 dairy bulls and the experiment lasted 56 days. DMI was measured for each animal and the animals were weighed once a week during the experiment, a total of nine times (double weighings at the beginning, middle and end of the measurement period). The growth curves were used to calculate the ADG and MMBW of the animals. In addition, the area of the area of the cross-section of the longissimus muscle (M.longissimus dorsi) and the thickness of the back fat of each bull were measured with an ultrasound device at the end of the experiment. RFI was calculated for seven different measurement periods. The original 56-day period was shortened to seven days at a time until the period was 28 days. Ultrasound measurements were added to the 56-day measurement period model only. In addition, the number of weighing was reduced from nine to five and three times from the original 56-day model. The addition of ultrasound measurements weakened the statistical model compared to the initial 56-day measurement period. The animal RFI results changed the most in the 28-day and 35-day models. The reliability of the results decreased the least in the 49-day and five-weighing models. The ADG and MMBW averages remained almost the same in the models until 35 days. The shorter the measurement period, the more the DMI values changed. Based on the results, shortening length of the RFI measurement period to 42 days had no market effect on the results. A 42-day measurement period is enough for DMI, but a longer measurement period is recommended for ADG. Three weighings did not change the ADG as much as the 49-day measurement period and was more reliable than the 42-day measurement period. Adding longissimus muscle and back fat to the RFI model did not improve the reliability of the model and thus did not provide added value. Based on this study, ultrasonic measurements are not required to determine RFI, and the workload can also be reduced by shortening the measurement period or reducing weighing times.

The literature review examined structures and functionalities of two major canola proteins, cruciferin and napin. In addition, fundamental functional properties of proteins and the impact of high intensity ultrasound on functionality of other proteins were reviewed. Ultrasound treatment has been successfully used to improve several functional properties of other proteins such as soy, pea and egg white proteins. However, research on high intensity ultrasound treatment for improving canola protein functionality is limited. The aim of the experimental part was to improve solubility, rheological and emulsification properties of canola proteins using high intensity (20 kHz) ultrasound. The effects of ultrasound treatment on protein structures were also examined. Canola samples were first preheated (95 °C, 5 min) and then treated with ultrasound at different power intensity levels (200 and 400 W) and durations (10 and 30 min). Albumin fractions were obtained by water extraction (pH 7.3) and NaCl extraction (1 M, pH 6.3) was used to obtain globulin fractions. The soluble protein concentration was determined using DC Protein Assay (Bio-Rad, USA), free sulfhydryl content was measured according to Ellman’s procedure and electrophoresis (SDS-PAGE) was performed for the determination of protein composition. Emulsifying ability, creaming index, average particle size, viscosity, storage modulus (G’) and loss modulus (G’’) were determined from the heat-induced emulsion gels. Solubility and emulsion stability of ultrasound treated canola samples were improved compared to control samples. In addition, ultrasound treatment reduced the average particle size. However, the electrophoretic profiles of the control and ultrasound treated canola protein samples did not differ significantly. Based on the rheological measurements, all the emulsion gels were shear thinning and indicated elastic properties (G’>G’’). These results suggest that high intensity ultrasound treatment modified the structures of canola proteins enabling increased molecular interaction and enhancing particularly emulsion gel stability.