a)
Josip
Juraj Strossmayer University of Osijek, Faculty of Agriculture, Trg sv.
Trojstva 3, HR-31000 Osijek, Croatia
ABSTRACT
The present study was carried out on 47 barrows equally distributed into two
different feeding groups (intensive and restricted). MR tomography was used
to obtain the data needed for calculation of optimal slaughter weight.
Growth analyses and predictions were performed using asymmetric S-function.
Feeding regime had significant effect on the growth of live weight and fat
volume (P < 0.05); the influence on muscle volume growth was not detected
(P > 0.05). The optimal slaughter weight in the sense of maximal utilisation
of the muscle growth was 130 kg in the case of intensively fed pigs; and 114
kg in the case of restrictive feeding. The power of prediction of the
established models was satisfactory. The accuracy of live weight prediction
at the age of 154 days was lower in the intensively fed pigs (error ~6 days
on average) than in the restrictive group of pigs (error ~4 days on average).
Since average divergence from actual live weights was less than one week,
the models could be considered fairly accurate.
Agris category codes: Q04, U03
COBISS Code 1.08
Language:
English
THE EFFECT OF CARCASS TEMPERATURE AND TREATMENT ON THE COMPUTER TOMOGRAPH
BASED TISSUE SEPARATION
and László BABINSZKY
Kaposvár University, Faculty
of Animal Science, Department of Animal Nutrition, Kaposvar, Hungary
Corresponding author: Cs. Szabo, Guba S. ut 40., H-7400 Kaposvar, Hungary,
Tel/fax: +36-82313562
ABSTRACT Computer
tomography (CT) is a tool used to determine body composition in live
animals. However, only at limited numbers of institutions CT is available
for animal investigations. Long distance transport may alter the body
composition of animals. Therefore, scanning carcasses (chilled, frozen or
thawed) could be the solution to extend the possibilities. In two
experiments, pigs (at 60 and 105 kg live weight in exp. 1 and exp 2 resp.,
n = 10 and n = 12 resp., equal ratios of barrows and gilts) were CT scanned,
first alive in the evening. Next day pigs were slaughtered and left
carcasses were kept at +4
°C
for 36 hours. After CT scanning, the chilled carcasses were put into a
freezer for 48 hours, where the ultimate temperature was –12
°C.
Carcasses were CT scanned and put back into the cooling room at +4
°C
for 48 hours to thaw gently for the final CT scanning. Our results indicate
that both the tissue position in the body and the temperature affect the Hu
(Hounsfield unit) value of muscle and fatty tissue. However, in the case of
frozen tissues it is not systematic. The CT is applicable for the detection
in changes of fatty tissue volume at any stage of carcass (r = 0.95–0.99).
In the case of muscle, the correlation as high as 0.90–0.98 with live
measurements was found, while in frozen carcasses just r = 0.10 was achieved
for Hu value of weighed muscle volume. The results show that chilled or
thawed carcasses can be used for CT based tissue separation without losing
information. This could extend the number of potential users of computer
tomography.
Key words: pigs / computer tomography / CT / body composition
/ carcass / temperature
Agris category codes: L02, U10
COBISS Code
1.08 Language:
English
SPREADSHEET TOOL FOR LEAST-COST AND NUTRITION BALANCED BEEF RATION
FORMULATION
and Stane KAVČIČ
Univ. of
Ljubljana, Biotechnical Fac., Dept. of Animal Science, Groblje 3, SI-1230
Domžale, Slovenia
ABSTRACT This paper points out some facts that might improve
economic outcome of livestock production in the sense of diet formulation. A
spreadsheet tool from two linked modules based on MS Excel platform was
constructed, merging different mathematical deterministic programming
techniques. The first module utilizes linear program for least-cost ration
formulation, aiming to obtain rough estimate what magnitude of the costs
might be expected. Resulting value is then considered as target value of
cost goal in the second module. It is based on weighted goal programming
with penalty function. Obtained results confirm benefits of applied
approach. It enables formulation of least-cost ration not taking too much
risk of worsening the ration’s nutritive value and balance between
nutrients. This is especially important when improved economic and nutritive
efficiency is the primal and common aim of optimization tool.
Agris category codes: L01, Q04
COBISS Code
1.08 Language:
English
COMPARISON OF CALCULATION METHODS OF DAILY MILK YIELD, FAT AND PROTEIN
CONTENTS FROM AM/PM MILKINGS
a),
Tomaž PERPAR, Betka LOGAR, Jože VERBIČ and
Milena KOVAČ
a)
Agricultural Institute of Slovenia, Hacquetova 17, SI-1000
Ljubljana, Slovenia
ABSTRACT
For prediction of daily milk
yield (DMY), daily fat percentage (DFP), and daily protein percentage (DPP)
from alternate AM/PM recording scheme, three different methods were tested.
The data comprised information on 483 813 test-day records. Methods were
compared on the whole data set or just on the upper or the lower quartile of
the records according to DMY, DFP, DPP, and milking interval (MI). Method 1
included DMY, DFP or DPP as a dependent variable in regression analysis. In
Method 2 ratio of partial AM/PM to daily yield was included as a dependent
variable, whereas Method 3 is based on doubling milk yield from AM/PM
milking while DFP and DPP are expected to be the same as the AM or PM
milking. The bias on the whole data set was low. With respect to high DMY,
DFP, and DPP on the upper quartile of data set bias in underestimation of
records was noticed for Method 1 whereas with this method, data from the
lower quartile of data set were overestimated. With respect to the short MI
on the average DMY was underestimated whereas DFP and DPP were overestimated
with Method 3. DMY with long MI were overestimated on the average with
Method 3 while DFP and DPP were underestimated. That kind of bias was not
detected with Method 2.
