Research Rept.
Biotechnical Fac. University of Ljubljana
Agricultural Issue. Zootechnica
74(October 1999)1
PROTEIN METABOLISM AND INVOLVEMENT OF DIFFERENT FACTORS *
a), Jasna
M. A. STEKAR and Etiennette COMBE a) Univ. of Ljubljana, Biotechnical Fac., Zootechnical Dept., Groblje
3, SI-1230 Dom¾ale, Slovenia, M.Sc.
Review paper
Language: Slovene
ABSTRACT The balance between protein synthesis and breakdown (protein turnover)
regulates whole - body protein mass. Synthesis of new proteins is achieved by
complex series of reactions. Protein breakdown plays a major role in muscle
growth and atrophy and in different tissues in body three major proteolytic
systems are known. Most methods for quantifying protein synthesis and breakdown
are based on isotopic techniques. The most important factors of the regulation
of protein metabolism are presented: hormones, substrates, nutrients of the
diet, genetic constitution and age of the animal. The highest protein synthesis
rate achieve tissues of gastrointestinal tract: small intestine 103.4 % day-1
and large intestine 62.1 % day-1, and liver, 105.4 % day-1
followed by the peripheral tissues (skeletal muscles). Skeletal muscles contain
the highest amount of protein. Whole body protein synthesis rate of the young
rats is around 30 % day-1
and decreases with age.
Kay words: protein / metabolism / synthesis /
degradation / regulation / rats
____________________
*
The article is a
part of a master of science thesis (justification 17. 12. 1996), supervisor
Prof. Jasna M. A. Stekar, Ph.D., co-advisor Etiennette Combe, senior
scientist.
CINNAMIC ACID DERIVATIVES AND LIGNIN: CONTENT, STRUCTURE AND PROPERTIES
a)
and Vekoslava STIBILJ a) Univ. of Ljubljana, Biotechnical Fac., Zootechnical Dept.,
Groblje 3, SI-1230 Dom¾ale, Slovenia, Ass.Prof., Ph.D.
Review paper
Language: Slovene
ABSTRACT This review article deals with the descriptions of contents, chemical
coposition and structure of cinnamic acid derivatives, especially p-coumaric
(PCA) and ferulic acid (FA) and lignin, together with their distribution within
plants and cell walls. Furthermore, chemical linkages between lignin and
cinnamic acid derivatives with structural carbohydrates are also described and
basic characteristics of structurally and chemically altered lignins of brown
midrib (BMR) and brittle culm mutants are mentioned.
Brigitte MICHALET DOREAUa)
and Christelle PHILIPPEAU a) INRA, Herbivore
Research Unit, Center Clermont-Ferrand - Theix, F-63122 Saint-Genčs Champanelle,
France, Ph.D.
Review paper
Language: English
ABSTRACT Maize breeding objectives have for a long time been limited to agronomic
criteria, but a high variability in nutritive value for ruminants is also
observed among hybrids. Nowadays breeding takes into account the effect of
chemical composition in the modification of maize nutritional value. The amount
and composition of whole plant cell walls, especially their lignification,
influences both digestibility and voluntary intake when maize is given as
silage. Starch, the main constituent of grain, is degraded slowly in the rumen,
and differences among genotypes exist. Among normal maize hybrids, the
differences are mainly related to grain vitreousness.
IMPROVING THE HONEYBEE PRODUCTION CHARACTERISTICS BY SELECTION INDEX
a)
a) Agricultural Institute of Slovenia, Hacquetova
17, SI-1001 Ljubljana, Slovenia, Ass.Prof., Ph.D.
Original scientific paper
Language: Slovene
ABSTRACT Honey bee selection index was created to simultaneously select bees for
colony honey yield, non - swarming behaviour and non - aggressive behaviour of
bee colonies. The population of 2,494 queens reared at 18 queen breeders and
tested at 199 various places between 1994-1998 was used to construct the index.
Heritability of honey production was 0.41 ± 0.22, heritability of colony
swarming behaviour 0.73 ± 0.28, and heritability of colony defense behaviour
0.49 ± 0.24. Index = 0.42 * (kg of honey a year) +1.94 * (points of swarming
behaviour) + 0.80 * (points of colony defense behaviour). Variability of index
was 29.45, variability of aggregate genotype was 62.39. R2 of index
was 0.47, which is for 14.5 % higher than the value of heritability of honey
production.
INFLUENCE OF QUEEN MOTHERS ON THE HONEYBEE HIVE VARROA MITE POPULATION IN THE
YEAR 1998
a)
a) Agricultural Institute of Slovenia, Hacquetova
17, SI-1001 Ljubljana, Slovenia, Ass.Prof., Ph.D.
Original scientific paper
Language: English
ABSTRACT Varroa mite population was studied in 317 hives located in 40 apiaries in
July 1998. Queens originated from 46 mother queens were reared at 16 different
rearing locations in Slovenia. Diagnostic treatment represented 10 ml of 85 %
formic acid applied on the bottom board. Fallen mites were counted 48 hours
after treatment. We found a highly significant effect of the apiary on the
varroa infestation by using the analysis of variance. Queen rearing locations
and mother queens nested within queen rearing locations did not affect a level
of varroa infestation significantly. LSMEAN estimate extracted two mother queens
with extremely small varroa population (Kropiv¹ek b/97 and Vozelj 1/97). There
was no evidence of a colony having a significantly higher level of varroa mite
infestation than tested population of bees. Highly infested colonies yielded
approximately 2 kg less honey than less infested bee colonies.
a)
a) Univ. of Ljubljana, Biotechnical Fac., Zootechnical Dept., Groblje
3, SI-1230 Dom¾ale, Slovenia, Prof., Ph.D.
Professional paper
Language: Slovene
ABSTRACT In the last twenty years causes and prevention of reproductive failure in
dairy cattle on Slovenian farms were the object of widely extended research
work. On most dairy farms fertility is a management rather than a physiological
problem. Efficient diagnostic and prevention methods in fertility management
were developed. In the review article characteristic measures of reproductive
efficiency are specified. Possible and typical causes of reproductive failures
are described (genetic variation in reproduction, influence of infectious
diseases and unspecific genital infections, artificial insemination procedures,
environmental factors affecting reproduction, calving season, age of cows,
management problems associated with reproduction, milk yield and nutritional
factors). Methods for detection of reproductive failure reasons based on our own
investigations are presented and some typical correlations among specific
fertility disturbance symptoms and failures in nutrition and in management are
illustrated.
INFLUENCE OF GROWTH INTENSITY AND SLAUGHTER MASS ON MEAT TRAITS IN BROWN BULLS
*
Evgen ZGUBIČa),
and Silvester ®GUR a) Ministry of Agriculture, Forestry and Nutrition, Inspectorate of
the Republic of Slovenia for Agriculture, Forestry, Hunting and Fisheries,
Parmova 33, SI-1000 Ljubljana, Slovenia, M.Sc.
Original scientific paper
Language: Slovene
ABSTRACT On 49 brown bulls we investigated the influence of slaughter mass and daily
gain from birth to slaughter on collagen traits, sensory traits, physical
traits, meat colour, percentage of intramuscular fat and diameter of muscle
fibre in m. longissimus dorsi. To exclude the influence of animal
genotype, we included percentage of American Brown Swiss genotype and sire as a
fixed effect in the analysis. Bulls were slaughtered at an interval from 501 to
658 kg live mass. Daily gain from birth to slaughter varied between 883 and 1256
g day-1, and was on average 1083 g day-1. Live mass at
slaughter had significant influence on meat colour (L* value) and percentage of
intramuscular fat. Meat became darker and percentage of intramuscular fat
increased with increased live mass. Tendency of brighter colour and lower
percentage of intramuscular fat with increased daily gain from birth to
slaughter was also noted.
Key words: cattle / bulls / breeds
/ brown breed / growth / growth rate / body mass / meat / quality
____________________
*
The article is a
part of master of science thesis (justification 23. 04. 1998), supervisor
Prof. Slavko Čepin, Ph.D., co-advisor, Ass. Prof. Silvester ®gur, Ph.D.
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