Search

We evaluated the influence of diets differing in non-fiber carbohydrates and rumendegradable protein (RDP) levels on changes in the ruminal bacterial populations in lactating Holstein cows. In all, 12 ruminally cannulated cows were assigned to diets with high or low RDP levels. Within each RDP level, molasses was substituted for corn grain at a concentration of 0%, 5.25%, or 10.5% of diet drymatter in a replicated 3 × 3 Latin square design with 28-day periods. Liquid and solid rumen digesta fractions collected at the end of each period underwent 16S rRNA gene sequencing to identify operational taxonomic units andwere analyzed for short-chain fatty acids. Protein degradability affected 6 bacterial genera, whereas carbohydrate alteration impacted 13 genera (p < 0.05). Of the 30 genera with the highest relative abundance, 26 differed by digesta fraction (p < 0.05), with Bacteroidetes genera showing a greater abundance in solids and Firmicutes genera demonstrating a greater prevalence in liquids. Regarding relative abundances, with increasing molasses, Succiniclasticum decreased in liquid (p < 0.05), and CF231, YRC22, Clostridium, Desulfovibrio, BF311, and Oscillospira increased in solids (p < 0.05). In contrast, at higher RDP levels, Succiniclasticum increased while YRC22 and Pseudobutyrivibrio decreased in solids (p < 0.05). Genera with abundances found to be correlated with fermentation products in the liquid included Shuttleworthia, Treponema, Lachnospira, and Schwartzia, which typically have lower relative abundances, showing strong positive correlations with molar proportions (mol%) of propionate, butyrate, and valerate (p < 0.05), and negative correlationswith pH and acetate mol% (p<0.05). Fibrobacter was positively correlatedwith lactate mol% (p<0.05). Butyrate mol% exhibited a quadratic increase as molasses increased (p = 0.017), and lactate mol% rose with increased RDP levels (p = 0.042). No treatment effects were detected for pH propionate and valerate mol%; however, we observed a tendency (p = 0.075) for a quadratic effect of molasses treatment on the mol% of acetate. These findings substantiate the pivotal role of diet in shaping rumen microbiota and metabolism, elucidating a nuanced relationship between dietary components, bacterial community structure, and metabolic output. This offers a more detailed understanding of rumen function and the potential for high-precision dietary management in lactating cows. [ABSTRACT FROM AUTHOR]

A previous genome-wide search with a moderate-density 10,000-SNP set identified many marker associations with twinning rate on BTA14 through either single-marker analysis or combined linkage-linkage disequilibrium (LLD; haplotype) analysis. The objective of the current study was to fine-map putative QTL using a more densely populated marker map and both a larger and an independent set of phenotypic data. Holstein bulls (n = 921) from 100 paternal half-sib families were genotyped for 129 SNP markers that included both original and additionally selected markers for increasing marker density in the targeted 34 megabase region. Twinning rate predicted transmitting abilities were calculated using calving records from 1994 to 1998 (data I) and 1999 to 2006 (data II), and the underlying liability scores from threshold model analysis were used as the trait in marker association analyses. The previous analysis used 201 bulls with daughter records in data I. In the current analysis, this was increased to 434, providing a revised estimate of effect and significance. Bulls with daughter records in data II totaled 851, and analysis of these data provided an opportunity for an independent analysis separate from data I. Single-marker association and LLD analyses were performed. Fifteen significant single-marker associations were found (minimally exceeding P < 8.74 x [10.sup.-3]) to concur between data sets. Three and 12 regions in data I and data II, respectively, showed positive results for the presence of QTL from LLD analysis (P < 0.001) within the respective data sets. After combining results from single-marker association, LLD analysis, and model-building strategies, 3 QTL were identified on BTA14. Based on single-marker results from data II, BTA14 harbors QTL responsible for approximately 24% of the variation in twinning rate predicted transmitting ability. Key words: Holstein, linkage disequilibrium, single nucleotide polymorphism, twin, twinning rate doi: 10.2527/jas.2010-2808

Twinning in cattle is a complex trait that is associated with economic loss and health issues such as abortion, dystocia, and reduced calf survival. Twinning-rate QTL have been detected previously on BTA5 in the North American Holstein and Norwegian dairy cattle populations and in a USDA herd selected for high twinning rate. In previous work with the North American Holstein population, the strongest evidence for a QTL was obtained from analysis of an extended, multiple-generation family. Using additional animals, an increased density of SNP marker association tests, and a combined linkage and linkage disequilibrium mapping method, we refined the position of this QTL in the North American Holstein population. Two sets of twinning-rate predicted transmitting abilities estimated during 2 different time periods in the North American dairy cattle population were used to provide validation of results. A total of 106 SNP and 3 microsatellites were used to scan the genomic region between 5 and 80 Mb on BTA5. Combined linkage-linkage disequilibrium analysis identified significant evidence for QTL within the 25- to 35-Mb and 64- to 70-Mb regions of BTA5. The IGF-1 gene (IGF1) was examined as a positional candidate gene and an SNP in intron 2 of IGF1 was significantly associated with twinning rate by using both data sets (P = 0.003 and P = 1.05 x [10.sup.-6]). Replication of this association in other cattle populations will be required to examine the extent of linkage disequilibrium with the underlying quantitative trait nucleotide across breeds. Key words: bovine, cattle, insulin-like growth factor-1, ovulation, twin

In the early 1900s, breed society herdbooks had been established and milk-recording programs were in their infancy. Farmers wanted to improve the productivity of their cattle, but the foundations of population genetics, quantitative genetics, and animal breeding had not been laid. Early animal breeders struggled to identify genetically superior families using performance records that were influenced by local environmental conditions and herd-specific management practices. Daughter– dam comparisons were used for more than 30 yr and, although genetic progress was minimal, the attention given to performance recording, genetic theory, and statistical methods paid off in future years. Contemporary (herdmate) comparison methods allowed more accurate accounting for environmental factors and genetic progress began to accelerate when these methods were coupled with artificial insemination and progeny testing. Advances in computing facilitated the implementation of mixed linear models that used pedigree and performance data optimally and enabled accurate selection decisions. Sequencing of the bovine genome led to a revolution in dairy cattle breeding, and the pace of scientific discovery and genetic progress accelerated rapidly. Pedigree-based models have given way to whole-genome prediction, and Bayesian regression models and machine learning algorithms have joined mixed linear models in the toolbox of modern animal breeders. Future developments will likely include elucidation of the mechanisms of genetic inheritance and epigenetic modification in key biological pathways, and genomic data will be used with data from on-farm sensors to facilitate precision management on modern dairy farms. [ABSTRACT FROM AUTHOR]

Bovine leukosis virus is an oncogenic virus that infects B cells, causing bovine leukosis disease. This disease is known to have a negative impact on dairy cattle production and, because no treatment or vaccine is available, finding a possible genetic solution is important. Our objective was to perform a comprehensive genetic analysis of leukosis incidence in dairy cattle. Data on leukosis occurrence, pedigree and molecular information were combined into multitrait GBLUP models with milk yield (MY) and somatic cell score (SCS) to estimate genetic parameters and to perform whole-genome scans and pathway analysis. Leukosis data were available for 11 554 Holsteins daughters of 3002 sires from 112 herds in 16 US states. Genotypes from a 60K SNP panel were available for 961 of those bulls as well as for 2039 additional bulls. Heritability for leukosis incidence was estimated at about 8%, and the genetic correlations of leukosis disease incidence with MY and SCS were moderate at 0.18 and 0.20 respectively. The genome-wide scan indicated that leukosis is a complex trait, possibly modulated by many genes. The gene set analysis identified many functional terms that showed significant enrichment of genes associated with leukosis. Many of these terms, such as G-Protein Coupled Receptor Signaling Pathway, Regulation of Nucleotide Metabolic Process and different calcium-related processes, are known to be related to retrovirus infection. Overall, our findings contribute to a better understanding of the genetic architecture of this complex disease. The functional categories associated with leukosis may be useful in future studies on fine mapping of genes and development of dairy cattle breeding strategies. [ABSTRACT FROM AUTHOR]

Bovine leukosis (BL) is a retroviral disease caused by the bovine leukosis virus (BLV), which affects only cattle. Dairy cows positive for BL produce less milk and have more days open than cows negative for BL. In addition, the virus also affects the immune system and causes weaker response to vaccines. Heritability estimates of BL incidence have been reported for Jersey and Holstein populations at about 0.08, indicating an important genetic component that can potentially be exploited to reduce the prevalence of the disease. However, before BL is used in selection programs, it is important to study its genetic associations with other economically important traits such that correlated responses to selection can be predicted. Hence, this study aimed to estimate the genetic correlations of BL with milk yield (MY) and with somatic cell score (SCS). Data of a commercial assay (ELISA) used to detect BLV antibodies in milk samples were obtained from Antel BioSystems (Lansing, MI). The data included continuous milk ELISA scores and binary milk ELISA results for 11,554 cows from 112 dairy herds across 16 US states. Continuous and binary milk ELISA were analyzed with linear and threshold models, respectively, together with MY and SCS using multitrait animal models. Genetic correlations (posterior means ± standard deviations) between BL incidence and MY were 0.17 ± 0.077 and 0.14 ± 0.076 using ELISA scores and results, respectively; with SCS, such estimates were 0.20 ± 0.081 and 0.17 ± 0.079, respectively. In summary, the results indicate that selection for higher MY may lead to increased BLV prevalence in dairy herds, but that the inclusion of BL (or SCS as an indicator trait) in selection indexes may help attenuate this problem. [ABSTRACT FROM AUTHOR]

The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) aboard the Envisat satellite provided measurements from August 2002 until April 2012. SCIAMACHY measured the scattered or direct sunlight using different observation geometries. The limb viewing geometry allows the retrieval of water vapour at about 10-25 km height from the near-infrared spectral range (1353-1410 nm). These data cover the upper troposphere and lower stratosphere (UTLS), a region in the atmosphere which is of special interest for a variety of dynamical and chemical processes as well as for the radiative forcing. Here, the latest data version of water vapour (V3.01) from SCIAMACHY limb measurements is presented and validated by comparisons with data sets from other satellite and in situ measurements. Considering retrieval tests and the results of these comparisons, the V3.01 data are reliable from about 11 to 23 km and the best results are found in the middle of the profiles between about 14 and 20 km. Above 20 km in the extra tropics V3.01 is drier than all other data sets. Additionally, for altitudes above about 19 km, the vertical resolution of the retrieved profile is not sufficient to resolve signals with a short vertical structure like the tape recorder. Below 14 km, SCIAMACHY water vapour V3.01 is wetter than most collocated data sets, but the high variability of water vapour in the troposphere complicates the comparison. For 14-20 km height, the expected errors from the retrieval and simulations and the mean differences to collocated data sets are usually smaller than 10 % when the resolution of the SCIAMACHY data is taken into account. In general, the temporal changes agree well with collocated data sets except for the Northern Hemisphere extratropical stratosphere, where larger differences are observed. This indicates a possible drift in V3.01 most probably caused by the incomplete treatment of volcanic aerosols in the retrieval. In all other regions a good temporal stability is shown. In the tropical stratosphere an increase in water vapour is found between 2002 and 2012, which is in agreement with other satellite data sets for overlapping time periods. [ABSTRACT FROM AUTHOR]

More than a decade ago it was suggested that a cooling of stratospheric temperatures by 1K or an increase of 1 ppmv of stratospheric water vapour could promote denitrification, the permanent removal of nitrogen species from the stratosphere by solid polar stratospheric cloud (PSC) particles. In fact, during the two Arctic winters 2009/10 and 2010/11 the strongest denitrification in the recent decade was observed. Sensitivity studies along air parcel trajectories are performed to test how a future stratospheric water vapour (H2O) increase of 1 ppmv or a temperature decrease of 1K would affect PSC formation. We perform our study based on measurements made during the Arctic winter 2010/11. Air parcel trajectories were calculated 6 days backward in time based on PSCs detected by CALIPSO (Cloud Aerosol Lidar and Infrared Pathfinder satellite observations). The sensitivity study was performed on single trajectories as well as on a trajectory ensemble. The sensitivity study shows a clear prolongation of the potential for PSC formation and PSC existence when the temperature in the stratosphere is decreased by 1K and water vapour is increased by 1 ppmv. Based on 15 years of satellite measurements (2000- 2014) from UARS/HALOE, Envisat/MIPAS, Odin/SMR, Aura/MLS, Envisat/SCIAMACHY and SCISAT/ACE-FTS it is further investigated if there is a decrease in temperature and/or increase of water vapour (H2O) observed in the polar regions similar to that observed at midlatitudes and in the tropics. Performing linear regression analyses we derive from the Envisat/MIPAS (2002-2012) and Aura/MLS (2004-2014) observations predominantly positive changes in the potential temperature range 350 to 1000 K. The linear changes in water vapour derived from Envisat/MIPAS observations are largely insignificant, while those from Aura/MLS are mostly significant. For the temperature neither of the two instruments indicate any significant changes. Given the strong inter-annual variation observed in water vapour and particular temperature the severe denitrification observed in 2010/11 cannot be directly related to any changes in water vapour and temperature since the millennium. However, the observations indicate a clear correlation between cold winters and enhanced water vapour mixing ratios. This indicates a connection between dynamical and radiative processes that govern water vapour and temperature in the Arctic lower stratosphere. [ABSTRACT FROM AUTHOR]

Inflammatory breast cancer (IBC) is a rare and highly invasive type of breast cancer, and patients diagnosed with IBC often face a very poor prognosis. IBC is characterized by the lack of primary tumor formation and the rapid accumulation of cancerous epithelial cells in the dermal lymphatic vessels. Given that normal epithelial cells require attachment to the extracellular matrix (ECM) for survival, a comprehensive examination of the molecular mechanisms underlying IBC cell survival in the lymphatic vessels is of paramount importance to our understanding of IBC pathogenesis. Here we demonstrate that, in contrast to normal mammary epithelial cells, IBC cells evade ECM-detachment-induced apoptosis (anoikis). ErbB2 and EGFR knockdown in KPL-4 and SUM149 cells, respectively, causes decreased colony growth in soft agar and increased caspase activation following ECM detachment. ERK/MAPK signaling was found to operate downstream of ErbB2 and EGFR to protect cells from anoikis by facilitating the formation of a protein complex containing Bim-EL, LC8, and Beclin-1. This complex forms as a result of Bim-EL phosphorylation on serine 59, and thus Bim-EL cannot localize to the mitochondria and cause anoikis. These results reveal a novel mechanism that could be targeted with innovative therapeutics to induce anoikis in IBC cells. [ABSTRACT FROM AUTHOR]

Recent evidence has suggested that some of the decline in reproductive ability in dairy cattle has been caused by embryonic death. The current study compared expected genomic inbreeding from sire-dam mating pairs to genomic inbreeding from live progeny in an attempt to determine how embryonic inbreeding may affect fertility. A total of 11,484 Holstein cattle with 43,485 SNP markers and pedigree information were available for analysis. A total of 412 sire-dam-progeny trios in which all animals had reliable genotypes were discovered. After removal of trios because of parentage errors, 374 remained for analysis. Additionally, a total of 3,031 animals comprising 3,906 genotyped full-sibling pairs were available for comparison. Expected genomic inbreeding measures were calculated by predicting homozygosity independently per SNP (FPHE) in sire-dam mating pairs and by simulating progeny using phased haplotype information (FROHE and FPHE). Actual genomic inbreeding measures were calculated using the percent homozygosity of all SNP (FPH) and using runs of homozygosity (FROH). Average FPHE values (62.8 ± 0.78%) were slightly lower than FPH (63.1 ± 1.12%), when considering each SNP independently. After phasing haplotypes, FPHE (62.5 ± 0.83%) was again slightly lower than FPH (62.7 ± 1.16%), and FROHE (3.46 ± 1.54%) was slightly lower than FROH (3.53 ± 2.17%). Results suggest increases in expected genomic inbreeding do not explain a large effect on embryo viability at average levels of expected inbreeding. Higher variation in FROH values was present with sire-dam mating pairs exhibiting high FROHE, which may suggest high levels of genomic inbreeding are required for a noticeable effect on overall embryo viability. Genomic inbreeding between full siblings was also compared with moderate correlations (0.47-0.52) present. Overall, expected genomic inbreeding measures were calculated, but results did not suggest a large effect of expected inbreeding on embryo viability. [ABSTRACT FROM AUTHOR]

As part of ESA's climate change initiative high vertical resolution ozone profiles from three instruments all aboard ESA's Envisat (GOMOS, MIPAS, SCIAMACHY) in combination with ESA's third party missions (OSIRIS, SMR, ACE-FTS) are to be combined in order to create an essential climate variable data record for the last decade. A prerequisite before combining data is the examination of differences and drifts between the datasets. In this paper, we present a detailed analysis of ozone profile differences based on pairwise collocated measuerements, including the evolution of the differences with time. Such a diagnosis is helpful to identify strengths and weaknesses of each data set that may vary in time and introduce uncertainties in long-term trend estimates. Main results of this paper indicate that the 6 instruments perform well in the stratosphere particularly between 20 and 40 km with a mean relative difference of ±5% (middle latitudes) to ±10% (tropics). Larger differences and variability in the differences are found in the upper troposphere lower stratosphere region and in the mesosphere. The analysis reveals that the relative drift between the sensors is not statistically significant for most pairs of instruments. [ABSTRACT FROM AUTHOR]