bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Nitrogen Fertilization and Date of Utilization on the Quality and Yield of Tall Fescue in Winter
Authors: Wolf D. , Opitz von Boberfeld W. 
Published: March 2003

AbstractThere is no information available on the influence of nitrogen (N) fertilization on autumn‐accumulated forage under Central European conditions. In this context, the metabolizable energy and the degree of fungal infection have never been examined before. In this study, the effects of the amount of N fertilizer (0, 50, 100 and 150 kg N ha−1), the date of N application (July and August) and the date of winter harvest (December, January and February) on the quality and dry matter (DM) yield of Festuca arundinacea stands in winter were investigated. DM yield, the metabolizable energy and digestibility of organic matter (= in vitro rumen fermentation technique), crude protein, ADL (acid detergent lignin), and for the first time ergosterol were determined. Disregarding the 0 variant, no interactions of any relevance were present. DM yield, crude protein and values of ADL increased with increasing amounts of N, but the concentration of energy decreased. The late N application resulted mostly in lower DM yields but kept the forage physiologically younger, which brought about higher levels of metabolizable energy and lower concentrations of ADL. With later date of harvest, losses of mass and quality occurred. The degree of fungal infection rose as the amount of N fertilizer increased. Three years of investigation under different weather conditions, including interactions with the effects of N fertilization, provide a good base for generalization.
Lactation length in Venezuelan dual‐purpose cows
Authors: Vaccaro By L. , Velázquez E. , P A. , érez . , Mejías H. 
Published: March 2003

IntroductionShort lactations are frequently excluded from the analyses of milk records of tropical cattle. The practice leads to overestimates of milk yield and lactation length and decreases the accuracy of selection procedures. The objectives of this paper are to quantify lactation length using unselected records from a sample of Venezuelan dual‐purpose cows, evaluate some of the sources of variation and discuss suitable editing procedures for milk production records in these populations.
Identification of the variant C of β‐lactoglobulin in sheep using a polymerase chain reaction‐restriction fragment length polymorphism method
Authors: Anton By I. , Zsolnai A. , F L. , ésüs . 
Published: March 2003

Introductionβ‐Lactoglobulin (β‐LG) is the major whey protein in the milk of ruminants and is able to bind and transport small hydrophobic molecules. However, its biological role is mainly unknown (G odovac‐Z
immermann 1988). Previously three genetic variants have been found in sheep: A, B and C. The genetic variants A and B differ at amino acid position 20, where variant A has a His and variant B has a Thr (K
olde and B
raunitzer 1983). The variant C is a subtype of variant A with a single amino acid exchange of Arg→Glu at position 148 (E
rhardt et al. 1989). The genotype β‐LG BB was found to be associated with higher milk yield, whereas genotypes AA and AB had a higher milk protein and casein content as well as yielding more curd (G
arzon and M
artinez 1992). No data is available concerning the relationship between the β‐LG C allele and production traits or milk properties. Since DNA‐based genotyping has already been performed for alleles A and B (S
chlee et al. 1993), the aim of the present study was to develop a DNA‐based method for identifying the β‐LG C variant. However polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) typing has been established (P
rinzenberg and E
rhardt 1999) recently, and this study shows an alternative method to detect β‐LG C.
Inbreeding in populations with incomplete pedigrees
Authors: Lutaaya By E. , Misztal I. , Bertrand J. K. , Mabry J. W. 
Published: March 2003

IntroductionInbreeding has detrimental effects on a number of economically important traits. W iggans et al. (1995) estimated inbreeding depression of −29 kg, −1.08 kg and −0.97 kg for each 1% increase of inbreeding for the traits milk, fat and protein yield, respectively, across several dairy cattle breeds. For post‐weaning gain in Hereford cattle, the depression was −0.24 kg (G
engler et al. 1998). For the number of piglets born alive, 21‐day litter weight, and days to 104.5 kg, it was −0.023, −0.052 and 0.21, respectively (C
ulbertson et al. 1998). Inbreeding also adversely impacts reproductive traits, such as delayed puberty, reduced conception rates, higher likelihood of losing established pregnancies, increased mortality of calves and lowered bull fertility (Y
oung et al. 1969).National genetic evaluations involve animals with incomplete pedigrees. Regular inbreeding algorithms (RA) based on the definition of W right (1922), such as those by Q
uaas (1976), calculate the inbreeding of animals with at least one parent missing as zero. Even if an animal has both parents known, its inbreeding will be underestimated if some of its ancestors are unidentified. If the proportion of missing parents is large, the inbreeding trend in a population could be seriously underestimated. Subsequently, losses from inbreeding would be underestimated, and steps to slow the increase of inbreeding, such as using sires that are less related to the general population or mating less‐related animals (T
oro and P
erez‐E
nciso, 1990; G
rundy et al. 1994; M
euwissen and S
onneson 1998; V
anR
aden and S
mith 1999), may be delayed. In particular, use of a mating system can result in matings adjusted for both inbreeding and dominance (M
isztal et al. 1999).In populations that use AI substantially, unidentified parents may not differ genetically from identified parents, on average. Therefore the real average inbreeding in animals with unidentified parent(s) may be similar to their contemporaries with both parents known. V anR
aden (1992) proposed an algorithm (VRA), where the inbreeding of animals whose parent(s) are unknown is equal to the mean inbreeding of their contemporaries with known parents. Contemporaries are stratified along unknown parent groups (UPG).VRA has been applied to a few US dairy breeds (V anR
aden 1992; W
iggans et al. 1995). The calculated inbreeding for the youngest Holstein animals was 3.7% with RA and increased to 4.2% with VRA (V
anR
aden 1992). The increase was small because the number of unidentified animals was small. However, the performance of VRA in recovering inbreeding lost for a range of incomplete pedigrees has not been evaluated. The objectives of this study were (i) to determine average inbreeding coefficients when pedigrees are increasingly more incomplete; (ii) to assess the efficacy of VRA in recovering these inbreeding coefficients; and (iii) to determine the mean inbreeding using the two inbreeding algorithms in a large beef population.
Effect of more stringent convergence criterion of estimated breeding values on response to selection
Authors: Mehrabani‐Yeganeh By H. , Gibson J. P. , Schaeffer L. R. 
Published: March 2003

1 IntroductionIn the analysis of large amounts of data to obtain BLUP, large sets of mixed model equations must be solved iteratively, which can involve considerable computing time. In real life, solutions are required only periodically for breeders to choose the best individuals, so that computing time is not usually a limiting factor. In simulation studies involving evaluation of individuals by BLUP, many rounds of evaluation are required for each simulated population. Since several or many replicates are usually required to obtain an accurate result from stochastic simulations, computing time can become a limiting factor.  One of the factors that can drastically affect computing time in iterative methods is the criterion for ceasing iteration, or convergence criterion (CC). With iterative methods, a disadvantage can be that the rate of convergence can be slow, or under certain circumstances not converge at all. Nevertheless, when the system converges, the more stringent the CC, the more accurate the solutions. The more stringent the CC the more iterations and hence more computing time is required.  The objectives of this study were to investigate how much response to selection is affected by the stringency of the CC and how much reranking occurs among selected individuals at different levels of the convergence criteria. These explorations provided a profile analysis of the computing time spent for each of the major subroutines in the BBSIM program.
High frequency of M307a mutation at FUT1 locus, causing resistance to oedema disease, in an autochtonous polish pig breed, the zlotnicka spotted
Authors: Klukowska By J. , Urbaniak B. , Świtoński M. 
Published: March 2003

IntroductionOedema disease and post‐weaning diarrhoea (enteric colibacillosis) occur in pigs aged 4–12 weeks, and are responsible for considerable economic losses (B ertschinger et al. 1992). The typical clinical symptoms of oedema disease are neurological signs such as ataxia, convulsions and paralysis. At post‐mortem examination, oedema is typically present at characteristic sites such as eyelids and forehead, stomach wall and mesocolon. The occurrence of these illnesses in the whole population is quite high, about 15%, and the mortality among the sick animals is about 90% (N
ielsen 1986). The disease is associated with the colonization of the small intestine with toxigenic Escherichia coli strains of a limited number of serotypes: O138, O139, O141, O147, O157, O16, O108 (B
ertschinger et al. 1990; W
ittig et al. 1994; R
ippinger et al. 1995). It was revealed that E. coli strain 107/86 (serotype: O139:K12), forms fimbriae which adhere in vitro to cells isolated from small intestine epithelium (B
ertschinger et al. 1990). Genetic studies revealed that susceptibility to colonization by an Escherichia coli strain with fimbriae F18 is controlled by a dominant allele, and the resistance to colonization by a recessive allele (B
ertschinger et al. 1993). The gene locus for E. coli F18 receptor (ECF18R) has been mapped to the porcine chromosome 6 (V&
ouml;
geli et al. 1996). Following this finding, M
eijerink et al. (1997) have cloned the α(1,2)‐fucosyltransferase genes FUT1, FUT2 and the pseudogene FUT2P. Sequencing of the FUT1 gene in swine resistant to adhesion by F18 fimbriated E. coli revealed a transition (G → A) at 307 bp position (M307). Thus, the M307A allele was considered as a good marker for the selection of resistant animals (M
eijerink et al. 1997; V&
ouml;
geli et al. 1997).The main purpose of this paper was the recognition of the mutation in four Polish pig breeds, namely Polish Large White, Polish Landrace, Zlotnicka White and autochtonous Zlotnicka Spotted.
Risk ratio as parameter for the genetic characterization of complex binary traits in cattle. A simulation study under various genetic models using halfsib families
Authors: Thaler‐Neto A. , Fries R. , Thaller G. 
Published: March 2003

SummaryThe risk ratio (λR) is defined as ‘the recurrence risk for a relative of an affected individual divided by the prevalence in the general population’ and is considered as the most important parameter when designing mapping experiments for diseases in humans. In this paper, the risk ratio was introduced as a parameter to genetically characterize complex binary traits such as mastitis in cattle. Simulations were applied to evaluate the properties of λR under different genetic models (monogenic, digenic, polygenic and mixed models) and in dependency of their parameters for a design consisting of unbalanced halfsib families typically found in dairy cattle. Population prevalences of the simulated data ranged from 5 to 40% and λR was estimated on a phenotypic level. In the discrete loci models complexity of the traits was introduced through different levels of penetrance and the proportions of phenocopies within each genetic background. The risk ratio and the power to reject the null hypothesis of independent halfsibs (λR=1) were influenced by the prevalence in all genetic models chosen. Absolute values for λR were higher for lower prevalences, for example, λR=2.77 and 1.62 for a pure monogenic recessive model with 5 and 20% prevalence, respectively, whereas the power decreases in the case of lower prevalences. For all the prevalences investigated, higher risk ratios were found for discrete loci models compared with the polygenic models, with higher values for the monogenic relative to the digenic models in general. For the mixed models, λR was intermediate between the polygenic and discrete loci models. Genes with dominant relative to recessive inheritance for susceptibility caused higher risk ratios in monogenic and mixed models, for example, λR=5.16 and 2.77 for a pure monogenic model with 5% prevalence. In the discrete loci models, λR decreased with lower penetrance and a higher proportion of phenocopies. Risk ratios increased with the heritability in the polygenic and in addition with the effect of the major gene in mixed models. Consistent patterns of risk ratios were observed under the analysed genetic models and parameters, which indicate that the risk ratio is a parameter well suited to genetically characterize binary traits in unbalanced halfsib families.
Assessment of carcass composition based on ultrasonic measurements and EUROP conformation class of live lambs
Authors: Puntila M‐L. , Mäki K. , Rintala O. 
Published: March 2003

Summary The aim of this study was to investigate the accuracy of ultrasound muscle (UMD) and fat depth (UFD) measurements as well as live EUROP conformation class (LEUROP) in predicting carcass composition and conformation in lambs. Measurements of 5993 lambs were analysed applying a multi‐trait animal model and the Restricted Maximum Likelihood (REML) method to obtain variance components for scanning live weight (SLW), UMD, UFD and LEUROP. The data were field records of Finnsheep and a small number of lambs from other breeds, from over 30 flocks between 1997 and 1999. The lambs were measured close to 120 days of age. Scanning was behind the last rib and at the third lumbar vertebra. Just before slaughter, scanning was repeated with a subset of lambs, whose half carcasses (n = 224) were dissected for lean, fat and bone. The UMD (third lumbar) and SLW together accounted for 51% of the variance in lean weight in the model in Finnsheep. The UFD alone explained 21% of the variance in lean percentage, UMD was a better predictor for carcass conformation than LEUROP. The estimates of heritability for SLW, UMD, UFD and LEUROP were 0.44, 0.46, 0.39 and 0.27 (with standard errors of 0.03 each), respectively. High positive genetic correlations, ranging from 0.49 to 0.69, were obtained between the four traits. Selection for UMD has resulted in genetic improvement of 0.06 mm/year (1%) in a Finnsheep nucleus flock. Conformation score of live animals could be considered to be included in the breeding programme if uniformity of assessment is assured by continued training.
Candidate genes for growth traits in beef cattle crosses Bos taurus × Bos indicus
Authors: Tambasco D. D. , Paz C. C. P. , Tambasco‐Studart M. , Pereira A. P. , Alencar M. M. , Freitas A. R. , Coutinho L. L. , Packer I. U. , Regitano L. C. A. 
Published: March 2003

SummaryCandidate gene strategy has been proposed to direct the search for quantitative trait loci, and polymorphisms at these loci have been associated with several production traits in bovine. A total of 211 animals resulting from crosses between Nelore females with sires from either Aberdeen Angus, Canchim and Simmental breeds were analyzed for restriction fragment length polymorphisms (RFLPs) in the κ‐casein, β‐lactoglobulin (LGB) and growth hormone GH genes. Average daily gain from birth to weaning (GBW) and from weaning to yearling (GWY) were analyzed by a statistical model comprising RFLP genotypes and their interaction effects. Significant effects (p < 0.05) of growth hormone (GH) and of the interaction β‐lactoglobulin × GH were verified for the GWY. Animals with LL genotypes for GH had higher GBW than LV animals but lower GWY (p < 0.05).
Zum Einfluss des Reifestadiums von Maispflanzen und des Einsatzes von Milchsäurebakterien bei ihrer Einsilierung auf die Nährstoffumsetzungen im Verdauungstrakt von Milchkühen
Authors: Jochmann . von K. , Lebzien P. , Daenicke R. , Flachowsky G. 
Published: March 2003

EinleitungDer Einsatz qualitativ hochwertiger Grundfuttermittel ist eine wesentliche Voraussetzung für eine bedarfsgerechte Nährstoffversorgung hochleistender Milchkühe. Von besonderer Bedeutung ist hierbei Maissilage. Da diese einen relativ hohen Gehalt an Stärke aufweist, die zudem im Vergleich zu anderen Getreidestärken nur in geringerem Umfang im Pansen abgebaut wird (C hase 1993; H
untington 1997; L
oose et al. 1998), kann durch sie die Menge an Stärke, die das Duodenum erreicht, gesteigert und somit die Energieversorgung aus dem Grundfutter deutlich erhöht werden. Bisher ist jedoch weitgehend unklar, inwiefern die Maisreife und die damit verbundenen Änderungen im Stärke‐ und Rohfasergehalt der Maispflanze auch die ruminale Abbaubarkeit der Stärke und somit die postruminale Stärkeanflutung am Duodenum beeinflussen. Ebenso sind die Ergebnisse aus den bisher noch wenigen Untersuchungen zum Einfluß einer Beimpfung von Maispflanzen mit Milchsäurebakterien (MSB) vor der Silierung noch recht widersprüchlich. So beobachteten zum Beispiel C
leale et al. (1990) eine um 5,2%‐Punkte verbesserte Verdaulichkeit der organischen Substanz, wenn die Maispflanzen vor der Einsilierung beimpft worden waren gegenüber der unbeimpften Variante. L
eahy et al. (1988) konnten dagegen keine Effekte einer MSB‐Beimpfung auf den Futterwert von Maissilage feststellen. Deshalb sollte es das Ziel der vorliegenden Arbeit sein zu ermitteln, welchen Einfluß zum einen der Reifegrad der Maispflanzen und zum anderen die Beimpfung des Siliergutes mit lebenden Milchsäurebakterien auf den Futterwert der hieraus hergestellten Maissilage haben. Hierzu wurde in den durchgeführten Untersuchungen der Einfluß der Silagen auf pansenphysiologische Kenndaten, den ruminalen Stärke‐ und Rohfaserabbau, die postruminale Nährstoffanflutung sowie die Rohnährstoffverdaulichkeit bestimmt.
Untersuchungen zum Einfluß einer Xylanaseergänzung in Legehennenrationen auf Weizenbasis 1. Mitteilung: Auswirkungen auf die praecaecale und faecale Nährstoffverdaulichkeit sowie Umsetzbare Energie
Authors: Oloffs K. , Samli E. , Jeroch H. 
Published: March 2003

SummaryInvestigations of the influence of a xylanase‐containing enzyme preparation on precaecal and faecal digestibility as well as metabolizable energy of laying hens fed on wheat‐rich rationsThe influence of an enzyme additive containing xylanase on precaecal and faecal digestibility as well as on metabolizable energy were tested in laying hens fed with wheat‐rich rations. Eight diets were tested in groups of five hens and the balance was carried out in the 32th week of life. Two species of wheat with different viscosity were used. With regard to precaecal digestibility of crude protein and crude fat no significance difference could be seen between the eight test variations. A positive influence on the digestibility of crude fat could be observed in all variants which was statistically significant in some groups. Control groups fed wheat Alidos showed a significant difference in the content of AMEN. A 7.6% increase from 12.44 to 13.39 MJ/kg DM resulted from the application of the enzyme supplement. All measured viscosities (jejunum, ileum, excrements) were distinctly reduced by the xylanase additive.
Significance of parasitoids in the reduction of oak bark beetle Scolytus intricatus Ratzeburg (Col., Scolytidae) in Serbia
Authors: Marković Č. , Stojanović A. 
Published: March 2003

Abstract:
As the vector of vascular fungi of the genus Ophiostoma the oak bark beetle, Scolytus intricatus, is one of the significant links in the chain of agents of oak forest decline in Serbia. It is known that the adults of this bark beetle, which develop under the bark of the trees infected by fungi of the genus Ophiostoma, transport the spores of these fungi. During the maturation feeding, the spores are transmitted to healthy tree crowns, where they germinate and cause infection. In period 1992–96 at 27 localities in Serbia, the significance of parasitoids in the reduction of this bark beetle was examined, as the intensity of spore transmission depends upon the number of oak bark beetle adults in nature. In the research of parasitoids of S. intricatus 20 species were identified in five families of Hymenoptera: Braconidae (six species), Eurytomidae (one), Pteromalidae (10), Eupelmidae (one) and Eulophidae (two). Among these parasitoids the greatest influence on the abundance of oak bark beetle was the species Ecphylus silesiacus. It was identified in 90.91% of study samples, its domination was 39.15% and the percentage of oak bark beetle parasitism was 5.66%. In addition, the species Entendon ergias, Dendrosoter protuberans and Cheiropachus quadrum were significant in reduction of S. intricatus. The average percentage of parasitism of oak bark beetle by E. ergias was 2.74%, by D. protuberans it was 2.63% and by Ch. quadrum 1.63%. The significance of other parasitoids in the reduction of oak bark beetles was low. In the study period the total parasitism of oak bark beetle varied between a minimum of 8.64% in 1992 and a maximum of 19.64% in 1996. The average for the whole study period was 14.49%.
Bioecological characteristics of Bassus tumidulus (Nees) (Hym., Braconidae), a parasitoid of the poplar twig borer, Gypsonoma aceriana (Dup.) (Lep., Tortricidae) in Bulgaria
Authors: Georgiev G. , Delkov A. 
Published: March 2003

Abstract:Main aspects of biology and ecology of Bassus tumidulus (Nees), a parasitoid of Gypsonoma aceriana (Dup.), were studied during the period 1989–2000. Poplar tender shoots with G. aceriana larvae were collected at four localities in Bulgaria (Sofia, Svoge, Vardim and Pazardzhik) and examined in laboratory conditions. B. tumidulus was recovered in the Sofia and Svoge localities. It is a solitary internal parasitoid that attacks young larvae of G. aceriana (first–second instars) and kills host pre‐pupae. It develops two generations and overwinters as a larva in the host. Adult emergence of both overwintering and summer generation of B. tumidulus coincides with adult emergence of the host. In 1997, the first generation emergence of B. tumidulus was in relatively good synchrony with the first larval population of G. aceriana. However, the second generation B. tumidulus was not very well synchronized with the life cycle of G. aceriana because adult parasitoids appeared mostly in the beginning of the host larval population. The average mortality of G. aceriana, caused by this parasitoid in 1997 in Sofia, was 15.7 and 23.3% for the overwintering and summer generation, respectively. The highest level of parasitism by B. tumidulus, observed in individual study, was 61.5%, occurring during the summer generation in 1997.