Results 221 to 230 of about 464,037 (262)

Fine mapping of a quantitative trait locus on chromosome 9 affecting non‐return rate in Swedish dairy cattle

Journal of Animal Breeding and Genetics, 2007
SummaryWe previously mapped a quantitative trait locus (QTL) affecting the trait non‐return rate at 56 days in heifers to bovine chromosome 9. The purpose of this study was to confirm and refine the position of the QTL by using a denser marker map and fine mapping methods.
M, Holmberg, G, Sahana, L, Andersson-Eklund   +2 more
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Estimation of the potential fertility based upon non-return rates of bulls

2007
In the present study, we aimed to develop a polyacrylamide gel that could be used instead of bovine cervical mucus in the cervical mucus penetration test (CMPT) to obtain coherent and replicable results in bulls. The frozen semen samples of six Holstein bulls, which were divided into two fertility groups as low and high according to their non-return ...
Tas, M., Bacinoglu, S., Cirit, Ue., Oezguemues, S., Kasgoez, H., Pabuccuoglu, S.   +5 more
openaire   +1 more source

Estimation of genetic parameters for non‐return rate (NRR) in German herdbook Pietrain and Landrace AI boars

Journal of Animal Breeding and Genetics, 2002
SummaryBetween January 1993 and May 2000, 95 136 artificial insemination (AI) records of 445 Bavarian boars were recorded by three Bavarian AI stations. The analysis of the non‐return rate (NRR) was based on AI matings performed by AI technicians. The animal models applied for estimation of variance components for NRR included the fixed effects of AI ...
R. Steinheuer, H. Hamann, O. Distl
openaire   +1 more source

Linear model evaluations of non-return rates for dairy and beef bulls in Canadian AI

Canadian Journal of Animal Science, 1993
Québec artificial insemination data from 518 609 first inseminations performed by 304 AI technicians in 15 488 herds using semen from 1750 dairy and beef AI bulls were analyzed using a mixed linear model. The effects of month of insemination, age of cow, semen price, breed of service sire, technician and herd were included in an evaluation of service ...
openaire   +1 more source

Mixed data rate and format transmission (40-Gbit/s non-return-to-zero, 40-Gbit/s duobinary, and 10-Gbit/s non-return-to-zero) by mid-link spectral inversion

Optics Letters, 2004
A polarization-diverse subsystem based on periodically poled lithium niobate waveguides is used as an optical phase conjugator for compensation for linear and nonlinear distortion. We show successful transmission formats of 13 x 40 Gbit/s non-return-to-zero mixed with 6 x 10 Gbit/s non-return-to-zero and 40-Gbit/s duobinary over 8 x 100 km of standard ...
S L, Jansen, G D, Khoe, H, de Waardt, S, Spälter, C J, Weiske, A, Schöpflin, S J, Field, H E, Escobar, M H, Sher   +8 more
openaire   +2 more sources

Higher non-return rate associated with Mycobacterium avium subspecies paratuberculosis infection at early stage in Holstein dairy cows

Theriogenology, 2009
The effects of infection by Mycobacterium avium paratuberculosis (Map) on dairy cows are poorly documented and quite controversial. This retrospective study aimed at quantifying the variation in non-return to service of Holstein dairy cows according to their Map-infection status.
Marcé, Clara, Beaudeau, François, Bareille, Nathalie, Seegers, Henri, Fourichon, Christine   +4 more
openaire   +4 more sources

The Relationship Between Post‐Thaw Sperm DNA Integrity and Non‐Return Rate Among Norwegian Cross‐Bred Rams

Reproduction in Domestic Animals, 2012
ContentsWith the aim of investigating the relationship between sperm DNA integrity and non‐return rate (NRR) among Norwegian cross‐bred rams, semen from 15 individuals was examined by flow cytometry. Sperm Chromatin Structure Assay (SCSA) quantifies the proportion of spermatozoa with denatured DNA after in situ acid treatment, and the four parameters %
A B, Nordstoga, A, Krogenæs, A, Nødtvedt, W, Farstad, K, Waterhouse   +4 more
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Genetic studies on fertility in AI bulls. II. Environmental and genetic effects on non-return rates of young bulls

Animal Reproduction Science, 1994
Abstract Since male fertility is vitally important for cattle breeders, bull studs require means to select bulls efficiently for this trait and to cull those found below par. The present study was undertaken to investigate possible causes of variation in male fertility, measured as non-return rate (NRR), and to estimate genetic parameters for ...
Eva-Marie Stålhammar, Lennart Janson, Jan Philipsson   +2 more
openaire   +1 more source

Effect of time of artificial insemination after oestrus detection on non-return rate of lactating dairy cows on pasture

New Zealand Veterinary Journal, 2016
To determine the difference in reproductive performance between cows detected in oestrus during morning or afternoon milking when artificial insemination (AI) was carried out once daily, either after the morning or afternoon milking.The study used 20,816 records for cows in 30 spring calving dairy herds that used a camera-based system for oestrus ...
openaire   +2 more sources

Expectations of Heritability Estimates for Non-Return Rate of Bulls and Conception Rate of Cows

Journal of Animal Science, 1988
S. M. Azzam, J. W. Keele, M. K. Nielsen
openaire   +1 more source