509 research outputs found
Palynology and Paleoecology of the Fossil Butte Member of the Eocene Green River Formation in Fossil Basin, Lincoln County, Wyoming
The palynoflora of the Fossil Butte Member of Green River Formation was studied to enhance our understanding of the depositional environment of ancient Fossil Lake. Forty-nine outcrop samples were collected from three measured sections representing the center, the margin, and intermediate areas of Fossil Lake. Of the 49 samples, 12 yielded a fairly well preserved palynomorph assemblage.
A late early Eocene to early middle Eocene age for the Fossil Butte palynoflora is indicated by the presence of Bombacaceae, Eucommia, Ilex, Juglans, Pistillipollenites, Platycarya, Pterocarya, Tilia, and Taxodium. Additional evidence for the early to middle Eocene age of the Fossil Butte Member was from a potassium-argon age determination of a potassium-feldspar tuff of 49.1 ± 1.8 m.y. These data indicate that the major portion of the Fossil Butte Member was contemporaneous with the deposition of the Wilkins Peak Member in the Green River Basin.
Evidence from the palynoflora suggests that the climate during deposition of the Fossil Butte Member was in transition between a humid, subtropical and a cooler, drier, warm temperate one with moderate fluctuations during various episodes of deposition.
Other evidence from the palynoflora indicates that moist lowlands and floodplains existed around Fossil Lake with upland forests on the surrounding ridges and mountains. Streams originating in the highlands supplied water for Fossil Lake and the surrounding vegetation.
Kerogen analysis of rocks from the Fossil Butte Member showed no correlation between the kerogen type and either the lithology or preservation of palynomorphs
Effect of heifer calving date on longevity and lifetime productivity
Longevity and lifetime productivity are important factors in profitability of the beef cow herd. Therefore, a concern for many producers is the productivity and longevity of the individual cow in their herd. The 2007-08 survey from National Animal Health Monitoring System (NAHMS) reported that the largest percentages of cows (33%) are culled because they do not become pregnant during the breeding season. It also reported that 15.6% of all culled cows leave the herd before 5 years of age, and an additional 31.8% leave the herd between 5 and 9 years of age. Research has reported that it takes 5 calves to pay for the development costs and annual maintenance of a replacement heifer (E.M. Mousel, Unpublished data). Therefore, to be sustainable, producers need to manage their herd to reduce the number of cows that are culled at a young age
Proteomic analyses identify differences between bovine epididymal and ejaculated spermatozoa that contribute to longevity
Sperm are stored for extended periods of time in the epididymis, but upon ejaculation motility is increased and lifespan is decreased. The objective of this study was to identify differences in proteins between epididymis and ejaculated samples that are associated with longevity. Ejaculated semen was collected from mature Angus bulls (n = 9); bulls were slaughtered and epididymal semen was collected. Epididymal and ejaculated semen were centrifuged to separate sperm and fluid. Fluids were removed and sperm pellets were resuspended in a high ionic solution and vortexed to remove loosely attached proteins. Sperm samples were centrifuged, and the supernatant was removed; both fluid and sperm samples were snap frozen in liquid nitrogen and stored at -80 oC. Protein analysis was performed by LCMS/MS. A different group of yearling Angus cross bulls (n = 40) were used for sperm cultures. Ejaculated (n = 20) and epididymal (n = 20) semen were diluted and cultured in a commercial media at pH 5.8, 6.8 and 7.3, at 4 oC. Sperm were evaluated for motility and viability every 24 h until motility was lower than 20%. There was an effect of pH, time and pH by time interaction for motility and viability for both ejaculated and epididymal sperm (P ≤ 0.05). At 216 h of incubation epididymal sperm at pH 7.3 and ejaculated sperm at pH 6.8 reached motility below 20%. A total of 458 unique proteins were identified; 178, 298, 311, and 344 proteins were identified in ejaculated fluid, ejaculated sperm, epididymal fluid and epididymal sperm, respectively. There were 8, 24, 10, and 18 significant KEGG pathways (FDR \u3c0.05) for ejaculated fluid, epididymal fluid, ejaculated sperm, and epididymal sperm, respectively. The metabolic pathway was identified as the most important KEGG pathway; glycolysis/gluconeogenesis, pentose phosphate, and glutathione metabolism pathways were significant among proteins only present in epididymal samples within the metabolic pathway. Other proteins identified that may be related to epididymal sperm\u27s increased longevity were peroxidases and glutathione peroxidases for their antioxidant properties. In summary, energy metabolism in the epididymis appears to be more glycolytic compared to ejaculated and epididymis sperm have a larger number of antioxidants available which may be helping to maintain sperm in a quiescent state. Epididymal sperm remained viable (membrane integrity) longer than ejaculated sperm when cultured at the same pH
Proteomic Analysis of Epididymal and Ejaculated Sperm and Respective Fluids
Study Description:
Ejaculated and epididymal semen was collected from mature Angus bulls (n = 9), and then centrifuged to separate sperm and fluid. Fluids were collected and sperm pellets were resuspended in a high ionic solution and vortexed to remove loosely attached proteins. Sperm samples were centrifuged, and the supernatant was collected. Samples collected for protein analysis were snap frozen in liquid nitrogen and stored at -80 ºC. Protein analysis was performed by liquid chromatography with tandem mass spectrometry (LCMS/MS). Yearling Angus cross bulls (n = 40) were used for sperm cultures. Ejaculated (n = 20) and epididymal (n = 20) sperm were collected, diluted and cultured in a commercial media at pH 5.8, 6.8 and 7.3, at 4 ºC and evaluated for motility and viability every 24 h until motility was below 20%. There was an effect of pH, time and pH by time interaction for motility and viability for both ejaculated and epididymal sperm (P ≤ 0.05). At 216 h of incubation epididymal sperm at pH 7.3 and ejaculated sperm at pH 6.8 dropped below 20% motility. Overall, in all samples, a total of 458 unique proteins were identified. It was identified that ejaculated fluid and ejaculated sperm had 178 and 298 proteins, respectively. Also, it was identified that epididymal fluid and epididymal sperm had 311 and 344 proteins, respectively. There were Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways significantly enriched (FDR \u3c 0.05) for ejaculated fluid (n = 8), epididymal fluid (n = 24), ejaculated sperm (n = 10), and epididymal sperm (n = 18). The most important KEGG pathway identified was the metabolic pathway. Within the metabolic pathway the glycolysis/gluconeogenesis, pentose phosphate, and glutathione metabolism pathways were significantly enriched among proteins only present in epididymal samples. Other proteins identified that may be related to epididymal sperm’s increased longevity were peroxidases and glutathione peroxidases for their antioxidant properties
Influence of estradiol on bovine trophectoderm and uterine gene transcripts around maternal recognition of pregnancy
Embryo survival and pregnancy success is increased among animals that exhibit estrus prior to fixed time-artificial insemination, but there are no differences in conceptus survival to d16. The objective of this study was to determine effects of preovulatory estradiol on uterine transcriptomes, select trophectoderm (TE) transcripts, and uterine luminal fluid proteins. Beef cows/heifers were synchronized, artificially inseminated (d0), and grouped into either high (highE2) or low (lowE2) preovulatory estradiol. Uteri were flushed (d16); conceptuses and endometrial biopsies (n = 29) were collected. RNA sequencing was performed on endometrium. Real-time polymerase chain reaction (RT-PCR) was performed on TE (n = 21) RNA to measure relative abundance of IFNT, PTGS2, TM4SF1, C3, FGFR2, and GAPDH. Uterine fluid was analyzed using 2D Liquid Chromatography with tandem mass spectrometry-based Isobaric tags for relative and absolute quantitation (iTRAQ) method. RT-PCR data were analyzed using the MIXED procedure in SAS. There were no differences in messenger RNA (mRNA) abundances in TE, but there were 432 differentially expressed genes (253 downregulated, 179 upregulated) in highE2/conceptus versus lowE2/conceptus groups. There were also 48 differentially expressed proteins (19 upregulated, 29 downregulated); 6 of these were differentially expressed (FDR \u3c 0.10) at the mRNA level. Similar pathways for mRNA and proteins included: calcium signaling, protein kinase A signaling, and corticotropin-releasing hormone signaling. These differences in uterine function may be preparing the conceptus for improved likelihood of survival after d16 among highE2 animals
Inhibition of Vascular Endothelial Growth Factor Manipulates Follicles in Beef Females
Vascular Endothelial Growth Factor (VEGF) is produced by cells surrounding the egg in the follicle. If VEGF is inhibited, ovulation does not occur. Understanding how VEGF regulates follicle development may allow for manipulation of estrous cycles. In previous studies in our laboratory, blocking the actions of VEGF decreased activation of early stage follicles in neonatal rat ovary cultures. Therefore, we hypothesized inhibition of VEGF actions would also inhibit follicle activation in bovine ovarian cortical cultures. Inhibition of VEGF did inhibit follicle progression, thus regulation of VEGF may be a way to manipulate follicle development and more accurately time ovulation
Inhibition of Vascular Endothelial Growth Factor Manipulates Follicles in Beef Females
Vascular Endothelial Growth Factor (VEGF) is produced by cells surrounding the egg in the follicle. If VEGF is inhibited, ovulation does not occur. Understanding how VEGF regulates follicle development may allow for manipulation of estrous cycles. In previous studies in our laboratory, blocking the actions of VEGF decreased activation of early stage follicles in neonatal rat ovary cultures. Therefore, we hypothesized inhibition of VEGF actions would also inhibit follicle activation in bovine ovarian cortical cultures. Inhibition of VEGF did inhibit follicle progression, thus regulation of VEGF may be a way to manipulate follicle development and more accurately time ovulation
Effect of beef heifer development systems utilizing corn residue and late summer planted cover crops on growth, reproductive performance, and economics
The objective of this study was to evaluate growth and reproductive performance of heifers developed using 3 different winter systems in the midwestern U.S. Spring-born heifers (n = 1,156; 214 d of age; SD ± 17 d) were used in a 3-yr study to evaluate performance in winter development systems, which utilized cover crop (CC) and corn residue grazing. Heifers were assigned to 1 of 3 treatments: grazing corn residue with 0.77 kg/d dried distillers grains (CD) or 1.69 kg/d wheat midds (CW) supplementation followed by a grower ration in the drylot, or grazing late summer planted oat-brassica CC followed by corn residue grazing with 0.35 kg/d dried distillers grains supplementation (CC). Supplementation during the corn residue phase was targeted to result in a common body weight (BW) (276 kg; ~45% of mature BW) by the end of the winter development period. Grazing of corn residue (CD and CW) and CC began in early November. After 63 d, heifers assigned to CC were moved to corn residue; on day 77 heifers assigned to CD and CW began receiving a grower ration in the drylot. In mid-February (day 98), heifers were comingled and managed in a single group. Breeding season began in June and lasted for 29 d. The ADG of heifers assigned to CC when grazing CC (days 1 to 63) was greater (0.76 kg/d; P \u3c 0.01) than those assigned to CD or CW (0.58 kg/d and 0.49 kg/d, respectively). Gain during the last 35 d of the winter period for heifers assigned to CC (0.36 kg/d) was less (P \u3c 0.01) than those assigned to CW (0.49 kg/d) but not different from CD heifers (0.41 kg/d). Overall (days 1 to 98), winter ADG was greater (P \u3c 0.05) for heifers assigned to CC (0.62 kg/d) than CD (0.53 kg/d) or CW (0.50 kg/d), which did not differ (P = 0.42). Percent of mature BW in May (27 d pre-breeding) was greater (P \u3c 0.01) for heifers assigned to CC (52%) than for those on CD and CW (50%), which did not differ (P = 0.64). Pregnancy rates were affected by treatment (P \u3c 0.03), with heifers assigned to CC (76%) being greater than CW (64%) and CD heifers being intermediate (70%). When accounting for the differences in cost and the value of open and bred heifers, the economic return tended to differ (P = 0.07) among treatments, with CC and CW not differing (P ≥ 0.20) from CD but return for CC being $73 greater than CW (P = 0.02). Utilizing oat-brassica CCs early in the winter followed by a slower rate of gain while grazing corn residue with distillers supplementation appears to be as effective for developing beef heifers in the midwestern U.S. as supplementing distillers grains
Relationship of molecular breeding value for beef tenderness with heifer traits through weaning of their first calf
Polymorphisms in μ-calpain (CAPN1) that beneficially associate with beef tenderness are reported to antagonistically associate with calving day in beef heifers and post-partum interval to estrus in beef cows. We, therefore, hypothesized that a molecular breeding value for slice shear force, calculated based on CAPN1 and calpastatin (CAST) genotypes, would demonstrate an antagonistic relationship between genomically predicted slice shear force and ordinal calving date in replacement beef heifers. A secondary objective of this study was to evaluate the association of a polymorphism in diacylglycerol O-acyltransferase (DGAT1) with reproductive traits in beef heifers. One hundred eighty-seven MARC III heifers (¼ Angus, ¼ Hereford, ¼ Red Poll, and ¼ Pinzgauer) that had been selectively bred to increase the frequency of these polymorphisms were submitted for monthly ultrasound exams beginning at 333 d of age and continuing until the start of breeding to determine pubertal status. At the last exam before breeding, all antral follicles were counted, and the length and height of each ovary was measured to determine if genomic selection for slice shear force associated with ovarian follicle number. Calving date, calf gender, and calf birth weight were recorded at parturition. Regression analysis of the molecular breeding value for slice shear force of the heifers on ordinal calving date indicated no association between genomic prediction of tenderness and calving date (P = 0.16); however, there was a tendency for age at puberty to be delayed in heifers as genetic merit for tenderness improved (P = 0.09). The results of the present study indicate that within experimental precision, selecting for tenderness using genomic predictions had minimal or no antagonistic association with reproductive performance in heifers. Further analysis of reproductive performance as cows is needed within this population but applying these genetic markers to select for tenderness in steers does not antagonize reproductive traits influencing conception or first calf birth date and birth weight in replacement beef heifers
Extended Aging and Marbling Class Effects on Color Stability of Beef Longissimus lumborum, Gluteus medius, and Biceps femoris Steaks
Postmortem aging improves palatability of various muscles, especially those from lower quality grades. This study evaluated postmortem aging and marbling class effects on the color stability of longissimus lumborum, gluteus medius, and biceps femoris steaks. Carcasses were selected at grading to have Lower Small (Small00 to Small50; n = 50) or Upper Slight (Slight50 to Slight90; n = 50) marbling scores. Strip loin and top sirloin subprimals from each carcass side were assigned to aging treatments (14, 21, 28, or 35 d) in an incomplete block arrangement. After aging, subprimals were cut into longissimus lumborum, gluteus medius, and biceps femoris steaks, respectively. Steaks were placed in a simulated retail display for 11 d. Changes in redness (a* and hue angle) were much slower and less extensive (P < 0.001) in longissimus lumborum steaks than in gluteus medius steaks, which had slightly slower and less extensive (P < 0.01) redness changes than biceps femoris. Increasing aging time increased (P < 0.001) the rate and extent of overall color change (ΔE) during simulated retail display. Steaks from Lower Small carcasses had higher (P < 0.01) L* values than steaks from Upper Slight carcasses at 14, 28, and 35 d postmortem. In steaks from Upper Slight carcasses, L* values were lower (P < 0.01) in steaks aged for 28 d compared to other aging times. In steaks from Lower Small carcasses, L* values were highest (P < 0.001) when aged for 14 d. Increased aging time generally decreased (P < 0.05) a*, b*, and chroma values. However, within each aging time, only b* values of steaks aged for 35 d differed (P = 0.01) with regard to marbling class. Results indicate that increasing aging time decreased color life of beef muscles, and that marbling class had minimal impact on lean color stability
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