Form of Supplemental Selenium in Vitamin-Mineral Premixes Differentially Affects Early Luteal and Gestational Concentrations of Progesterone, and Postpartum Concentrations of Prolactin in Beef Cows

Soils with marginal to deficient levels of selenium (Se) are widespread in the northwest, northeast, and southeast US. Supplementation to the diet of forage-grazing beef cattle with a vitamin-mineral mix containing additional Se is recommended in these geographic regions. We have reported that the form of supplemental Se provided to Angus-cross beef cows can affect circulating levels of progesterone (P4) on day 6 of the estrous cycle, a time when increased P4 is known to promote fertility. The objectives of this study were to (1) confirm and expand upon our initial report that the form of Se provided to cows affects early luteal-phase concentrations of systemic P4, (2) determine the effects of the form of Se on concentrations of P4 during gestation, and (3) determine the effects of the form of Se on concentrations of prolactin (PRL) during lactation. Throughout this study, Angus-cross beef cows had ad libitum access to a vitamin-mineral mix containing 35 ppm of Se in either an inorganic form (ISe) or a 1:1 mix of inorganic and organic forms (MIX). We observed a MIX-induced increase (p = 0.006) in systemic concentrations of P4 on day 7 but not on days 4 or 10 of the estrous cycle, consistent with our earlier report. We observed a MIX-induced increase (p = 0.02) in the systemic concentration of P4 at months 1, 3, 5, and 7 of gestation, and a MIX-induced decrease (p < 0.05) in systemic concentrations of PRL at months 5 and 6 of lactation. In summary, the form of Se provided to cows can be manipulated to affect the early luteal phase and gestational concentrations of P4, and postpartum concentrations of PRL.

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VOLUNTARY ROUGHAGE INTAKE BY NONPREGNANT AND PREGNANT OR LACTATING BEEF COWS

Canadian Journal of Animal Science ◽

10.4141/cjas73-115 ◽

1973 ◽

Vol 53 (4) ◽

pp. 733-738 ◽

Cited By ~ 7

Author(s):

W. A. JORDAN ◽

E. E. LISTER ◽

J. M. WAUTHY ◽

J. E. COMEAU

Keyword(s):

Beef Cattle ◽

Beef Cows ◽

Energy Requirements ◽

Early Lactation ◽

Full Energy ◽

Grass Silage ◽

Ad Libitum

Pregnant and nonpregnant Shorthorns were group-fed either hay or grass silage ad libitum from December until midsummer in 2 successive yr. Stage of gestation at the start of feeding each year averaged 120 days. In the 1st yr the cows were housed and in the 2nd they were confined to outside paved lots. Until the start of calving, the pregnant groups tended to consume less than their nonpregnant counterparts. During the 2 wk before the start of calving this difference in intake between pregnant and nonpregnant cows increased up to 12%. However, it was only for the silage-fed, pregnant cows wintered outside that intake was clearly insufficient for maintenance up to 48 h postcalving. Depsite a rapid increase in postcalving intake, all lactating groups lost weight. Results indicated that pregnancy in beef cattle may reduce intake below that expected from nonpregnant animals and may result in insufficient forage consumption for maintenance. During early lactation, beef cows were unable to consume enough stored forage to meet their full energy requirements.

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Serum mineral concentrations in relation to estrus and conception in beef heifers and cows fed conserved forage

Canadian Journal of Animal Science ◽

10.4141/a96-042 ◽

1997 ◽

Vol 77 (1) ◽

pp. 55-62 ◽

Cited By ~ 14

Author(s):

Julie A. Small ◽

E. Charmley ◽

A. V. Rodd ◽

A. H. Fredeen

Keyword(s):

Body Weight ◽

Beef Cattle ◽

Free Choice ◽

Beef Cows ◽

Dietary Factors ◽

Beef Heifers ◽

Service Conception ◽

Ad Libitum ◽

Mineral Concentrations ◽

Body Condition Scores

A study was undertaken to examine serum mineral concentrations in relation to estrus and first service conception (FSC) in beef cattle fed conserved forage. Blood samples were taken from yearling nulliparous heifers, and suckled 2-yr-old primiparous heifers and multiparous cows at first service which occurred within 12 h of observed standing heat and 21 d after. Serum was analyzed for calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sulfur (S), sodium (Na), iron (Fe), copper (Cu), manganese (Mn), zinc (Zn) and boron (B) concentrations by ICAP. Heifers were fed in four groups based on parity and given 3.0 and 2.5 kg hd d–1 of a grain supplement, respectively, plus free-choice grass hay (1.71% K; 0.20% P; 8% protein; 41% ADF). Cows were individually fed ad libitum (21 g kg–1 body weight) grass-legume silage (2.82% K; 0.35% P; 14% protein, 34% ADF). Heifers and cows gained body weight over the breeding season and at turnout had body condition scores of 5 to 6 for heifers and 6 to 7 for cows. Rates of FSC were 53% (10/19), 48% (10/21) and 64% (18/28) for nulli-, primi- and multiparous groups, respectively. Serum Ca, Na, S, Cu, Fe, Zn and Mn did not differ (P > 0.05) between FSC groups, but Na and Cu were higher (P < 0.05) at estrus than at day 21, especially in nulliparous heifers. Concentrations of serum Mg were low (<0.74 mmol L–1) and K high (>4.5 mmol L–1) in heifers and cows but in nulliparous heifers only, serum Mg and K were lowest (P < 0.05) at estrus for those that conceived. Serum B concentrations were generally higher (P < 0.05) in animals that conceived especially on day 21 when B concentrations were higher (P < 0.05) than at estrus. Serum P concentrations were high (>3.5 mmol L–1), but highest in animals that conceived especially on day 21. It is concluded that P and B may be dietary factors limiting first service conception in beef cows fed conserved forage. Key words: Beef cattle, estrus, conception, minerals, boron, phosphorus

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Does breed affect nursing and reproductive behaviour in beef cattle?

Canadian Journal of Animal Science ◽

10.4141/cjas09033 ◽

2010 ◽

Vol 90 (2) ◽

pp. 137-143 ◽

Cited By ~ 2

Author(s):

J. Álvarez-Rodríguez ◽

J. Palacio ◽

I. Casasús ◽

A. Sanz

Keyword(s):

Beef Cattle ◽

Post Partum ◽

Beef Cows ◽

Reproductive Behaviour ◽

Similar Amount ◽

Similar Time ◽

Once Daily ◽

Ad Libitum ◽

Ovarian Cyclicity

This experiment was designed to assess the role of genetic differences in nursing behaviour and the resumption of post-partum ovarian cyclicity of beef cows with different types of calf management. Twenty-four multiparous winter-calving cows, 12 Parda de Montaña (PA) and 12 Pirenaica (PI), were randomly assigned to once-daily restricted nursing during 30 min (RESTR) or ad libitum nursing (ADLIB). Cow-calf behaviour was recorded at weeks 3, 8 and 13 of lactation. Results were compared within suckling system. Twice-weekly blood samples were drawn throughout lactation to analyse progesterone as an indicator of ovulation. Within each type of calf management, both breeds nursed their calves for a similar amount of time (23.0 and 57.2 min in PA vs. 25.9 and 59.0 min in PI, when nursing once daily or ad libitum, respectively; P > 0.10). Furthermore, ovarian cyclicity was initiated at a similar time after calving between breeds (70 vs. 73 d in PA and PI, respectively), although it was shorter in RESTR than in ADLIB (54 vs. 89 d; P < 0.001). Key words: Beef cattle, calf management, restricted nursing, post-partum anoestrus

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Dynamics of oxytocin, estrogen and progestin receptors in the bovine endometrium during the estrous cycle

Acta Endocrinologica ◽

10.1530/acta.0.1180096 ◽

1988 ◽

Vol 118 (1) ◽

pp. 96-104 ◽

Cited By ~ 55

Author(s):

H. H. D. Meyer ◽

Th. Mittermeier ◽

D. Schams

Keyword(s):

Estrous Cycle ◽

Luteal Phase ◽

Oxytocin Receptor ◽

Minor Importance ◽

Progestin Receptors ◽

Progestin Receptor ◽

Nuclear Estrogen Receptor ◽

Low Sensitivity ◽

A Minor ◽

Estradiol Levels

Abstract. The levels of oxytocin receptor (OTR), cytosolic progestin receptor (cPR), cytosolic and nuclear estrogen receptor (cER, nER) were measured in the endometrium of 28 heifers that had been slaughtered on a defined day of the estrous cycle, In an additional, trial endometrial tissue obtained from 78 heifers or cows at the abattoir was analyed for OTR. OTR was absent during the luteal phase (after day 6), but a minor elevation was observed after day 15. OTR increased rapidly after luteolysis on days 17–18 reaching a maximum during estrous on day 21, and decreased again during days 1–6. cER and cPR were different to OTR but followed a similar pattern with maximal levels during days 1–8 of the estrous cycle. At day 12 both receptors were minimal and increased again towards day 21. nER was maximal at day 19–21 coinciding with maximal estradiol levels and estrous. Our data indicate that owing to an increasing sensitivity of the endometrium to progesterone and estradiol after day 12, these steroids may be mainly responsible for the initiation of first PGF2α surges and luteolysis. Oxytocin seems to be of minor importance at this stage owing to low sensitivity of the endometrium for oxytocin.

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Response of beef heifers and non-suckling beef cows to different oestrous synchronization protocols

Animal Science ◽

10.1017/s135772980005270x ◽

2002 ◽

Vol 74 (3) ◽

pp. 547-552 ◽

Cited By ~ 3

Author(s):

D. Cavestany ◽

N. Negrin ◽

R. Negrin ◽

J. F. Groth

Keyword(s):

Beef Cattle ◽

Medroxyprogesterone Acetate ◽

Artificial Insemination ◽

Experimental Period ◽

Fixed Time ◽

Beef Cows ◽

Pregnancy Rates ◽

Gnrh Analogue ◽

Beef Heifers

AbstractThe objective was to evaluate different oestrous synchronization schemes in beef cattle under range conditions. In experiment 1, 202 heifers averaging 26 months of age were assigned randomly to three treatments: (a) GnRH-PG. (no. = 44) day 0 (D0): injection of GnRH; D7: injection of PGF2α; D0 to D25 oestrous detection (OD) and artificial insemination (AI); (b) OD-PG. (no. = 45) D0 to D4; OD + AI; D5: injection of PGF2α; D5 to D25 OD + AI; and (c)Ovsynch. (no. = 113) D0: injection of GnRH; D7: injection of PGF2α; D9: injection of GnRH and 16 h later AI at fixed time. In experiment 2, 318 non-suckling cows were assigned randomly to three treatments: (a) GnRH-PG. (no. = 106) D0: injection of GnRH; D7: injection of PGF2α; D0 to D25 OD + AI; (b) GnRH-MAP-PG. (no. = 106) D0: injection of a GnRH analogue and insertion of an intravaginal sponge impregnated with 250 mg of medroxyprogesterone acetate; D7: injection of PGF2α and sponge withdrawal; D0 to D25 OD + AI; (c) controls. (no. = 106) OD and AI. The experimental period lasted 25 days and, with exception of the Ovsynch treatment, oestrous detection was carried out twice a day (a.m./p.m.) and inseminations performed 12 h later. The pregnancy rates assessed by ultrasonography 30 days after AI were: experiment 1: (a) 30·0%; (b) 28·6% and (c) 62·3% (P < 0·05); experiment 2: (a) 60·2%; (b) 57·8% and (c) 45·5% (P < 0·05). It is concluded that in heifers and non-suckling cows, oestrous synchronization treatments result in higher pregnancy rates. In non-suckling cows, the addition of a progestagen did not improve the response.

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127 Predicting Dry Matter Intake of Gestating and Lactating Beef Cows

Journal of Animal Science ◽

10.1093/jas/skz397.132 ◽

2020 ◽

Vol 98 (Supplement_2) ◽

pp. 58-58

Author(s):

Megan A Gross ◽

Claire Andresen ◽

Amanda Holder ◽

Alexi Moehlenpah ◽

Carla Goad ◽

...

Keyword(s):

Beef Cattle ◽

Milk Yield ◽

Feed Intake ◽

Beef Cows ◽

Multiple Regression Equation ◽

Validation Data ◽

Data Set ◽

Lactating Cows ◽

Downward Bias ◽

Protein Supply

Abstract In 1996, the NASEM beef cattle committee developed and published an equation to estimate cow feed intake using results from studies conducted or published between 1979 and 1993 (Nutrient Requirements of Beef Cattle). The same equation was recommended for use in the most recent version of this publication (2016). The equation is sensitive to cow weight, diet digestibility and milk yield. Our objective was to validate the accuracy of this equation using more recent published and unpublished data. Criteria for inclusion in the validation data set included projects conducted or published within the last ten years, direct measurement of forage intake, adequate protein supply, and pen feeding (no tie stall or metabolism crate data). The validation data set included 29 treatment means for gestating cows and 26 treatment means for lactating cows. Means for the gestating cow data set was 11.4 ± 1.9 kg DMI, 599 ± 77 kg BW, 1.24 ± 0.14 Mcal/kg NEm per kg of feed and lactating cow data set was 14.5 ± 2.0 kg DMI, 532 ± 116.3 kg BW, and 1.26 ± 0.24 Mcal NEm per kg feed, respectively. Non intercept models were used to determine equation accuracy in predicting validation data set DMI. The slope for linear bias in the NASEM gestation equation did not differ from 1 (P = 0.07) with a 3.5% positive bias. However, when the NASEM equation was used to predict DMI in lactating cows, the slope for linear bias significantly differed from 1 (P < 0.001) with a downward bias of 13.7%. Therefore, a new multiple regression equation was developed from the validation data set: DMI= (-4.336 + (0.086427 (BW^.75) + 0.3 (Milk yield)+6.005785(NEm)), (R-squared=0.84). The NASEM equation for gestating beef cows was reasonably accurate while the lactation equation underestimated feed intake.

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Circulating levels of anxiolytic steroids in the luteal phase in women with premenstrual syndrome and in control subjects.

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.79.5.7962316 ◽

1994 ◽

Vol 79 (5) ◽

pp. 1256-1260 ◽

Cited By ~ 3

Author(s):

P J Schmidt ◽

R H Purdy ◽

P H Moore ◽

S M Paul ◽

D R Rubinow

Keyword(s):

Premenstrual Syndrome ◽

Luteal Phase ◽

Control Subjects ◽

Circulating Levels

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Differential expression of cyclooxygenase 1 and cyclooxygenase 2 in the bovine oviduct

Journal of Endocrinology ◽

10.1677/joe.1.06761 ◽

2006 ◽

Vol 191 (1) ◽

pp. 263-274 ◽

Cited By ~ 29

Author(s):

Simone Odau ◽

Christoph Gabler ◽

Christoph Holder ◽

Ralf Einspanier

Keyword(s):

Mrna Expression ◽

Estrous Cycle ◽

Luteal Phase ◽

Cellular Level ◽

Differential Distribution ◽

Cyclooxygenase 1 ◽

Epithelial Cell Layer ◽

Cox 2 ◽

Cycle Dependent ◽

Cox 1

The aim of the present study was to investigate the enzymes for the local prostaglandin (PG) biosynthesis present in the bovine oviduct during the estrous cycle to influence early reproductive events. Bovine oviducts were classified into four phases: pre-ovulatory, post-ovulatory, early-to-mid luteal, and late luteal phase, subdivided further into ipsi- or contralateral site and separated into ampulla or isthmus. Oviductal cells were gained by flushing the oviductal regions. Quantitative real-time reverse transcriptase-PCR was performed for the secretory and cytosolic phospholipases A2 (sPLA2IB, cPLA2α, and cPLA2β) and cyclooxygenases (COX-1 and COX-2) as the first step enzymes of PG synthesis. COX-1 and cPLA2β showed significant highest mRNA expression around and before ovulation compared with the luteal phase respectively. sPLA2IB and cPLA2α mRNA expression was unregulated during the estrous cycle. Regional differences in mRNA content were found for sPLA2IB with higher mRNA expression in the ampulla than in the isthmus. Western blot analysis revealed the highest COX-1 protein content in the early-to-mid luteal phase. Immunohistochemistry demonstrated that COX-1 was localized in epithelial and smooth muscle cells, whereas COX-2 was only localized in epithelial cells. COX-2 showed a differential distribution within the epithelial cell layer suggesting a regulation on a cellular level, although the COX-2 mRNA and protein amounts did not vary throughout the estrous cycle. A COX activity assay of oviductal cells revealed that COX activity originated predominantly from COX-1 than from COX-2. Treatment of primary oviductal cells with 10 pg/ml 17β-estradiol or 10 ng/ml progesterone resulted in a higher expression of COX-2 and cPLA2α, but not of the other enzymes. The expression pattern of these enzymes suggests that an estrous-cycle dependent and region-specific PG synthesis in the bovine oviduct may be required for a successful reproduction.

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PSVII-13 Performance and environmental benefits from biochar supplementation in beef cattle grazing systems

Journal of Animal Science ◽

10.1093/jas/skab235.799 ◽

2021 ◽

Vol 99 (Supplement_3) ◽

pp. 448-449

Author(s):

Emily Conlin ◽

Herbert Lardner ◽

Jennifer L Ellis ◽

Ira B Mandell ◽

Katharine M Wood

Keyword(s):

Beef Cattle ◽

Production Systems ◽

Beef Cows ◽

Environmental Benefits ◽

Stable Form ◽

Primary Concern ◽

Ch4 Emissions ◽

Body Weights ◽

Cow Calf ◽

Rapid City

Abstract Worldwide, beef production systems represent a significant source of greenhouse gas (GHG), and enteric methane (CH4) emissions are the primary concern. The objective of this experiment was to determine whether biochar (Oregon Biochar Solution, White City, OR) supplementation can reduce CH4 emissions from grazing beef cows. Biochar is a stable form of carbon produced through the pyrolysis of organic matter (typically forestry waste). Sixty-four cows and their calves were blocked by cow body weight and calf age, and randomly allocated to 8 paddocks, each with 8 cow-calf pairs. Using a crossover design, each paddock was assigned to one of two treatments: (1) biochar supplemented at approximately 3% of estimated dry matter intake (DMI) or (2) control (no biochar). Biochar was incorporated into a pellet containing 45% biochar, 42.5% wheat midds, 10% canola oil, and 2.5% dry molasses and fed in a portable trough once daily. Each period consisted of 28 days: 21 days for biochar adaptation and 7 days for data collection. Enteric gas emissions from each paddock were measured using C-Lock GreenFeed trailers (C-Lock Inc., Rapid City, SD, USA) with pasture DMI estimated using paddock entry/exit quadrats during each sampling week. Enteric CH4 emissions expressed as g CH4/d were 249 and 260 ± 50.3 g (P ≥ 0.37) for control and biochar, respectively. Similarly, g CH4/kg DM and g CH4/kg BW were not affected (P ≥ 0.44) by biochar supplementation on pasture. Biochar supplementation did not affect estimated DMI or cow/calf body weights (P ≥ 0.15). Results suggest that biochar was ineffective for reducing methane emissions from grazing beef cows; however, measures of animal performance were not affected by biochar consumption. Further work is required to determine if type or higher inclusions of biochar can reduce CH4 emissions from beef cattle.

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