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1.
Wampler, Susan Anderson.
Preference and acceptability of four protein sources by ruminating Holstein calves.
Degree: MS, Dairy Science, 1988, Virginia Tech
URL: http://hdl.handle.net/10919/44093 
► Four successive groups of four calves each (~ 4 mo old) were individually penned and observed during a 14 d trial period for choice of…
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▼ Four successive groups of four calves each (~ 4 mo old) were individually penned and observed
during a 14 d trial period for choice of concentrate. Prior calf diets contained soybean meal (SBM)
(for two groups and distillers grains in place of SBM for two groups. Concentrates contained approximately equal amounts of corn with either SBM, peanut meal (PNM), fish meal (FSM), or
corn gluten meal (CGM). Each day of four trials, .45 kg of each concentrate was randomly assigned
to one of four equal feed box sections. Calf feeding position was recorded every 30 sec for no more
than 50 min or until calves stopped eating. In addition, 1.36 kg of first cutting orchardgrass hay
was offered twice per day. Measurements of amount of each feed consumed, order of consumption
and length of time spent eating each feed were analyzed statistically to determine preference.
Overall preference was for SBM, closely followed by PNM, both over FSM and CGM, with the
l preference status of FSM showing the most change over time by decreasing throughout the trial
periods. Neither section in which feed was offered nor previous experience with SBM significantly
influenced preference. In addition, twenty calves ranging in age from 4 mo to 7 mo were divided
and housed in four groups of five and observed during a 30 d trial period for acceptability of the
protein feeds tested for preference. Acceptability, measured subjectively as length of time required
by calves to eat each feed, was greatest for SBM, closely followed by PNM and CGM, and least
for FSM. Analysis of calf weight gain showed no differences between feeds.
Advisors/Committee Members: Polan, Carl E. (committeechair), Barnes, Michael A. (committee member), Siegel, Paul B. (committee member).
Subjects/Keywords: Cattle; LD5655.V855 1988.W356
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APA (6th Edition):
Wampler, S. A. (1988). Preference and acceptability of four protein sources by ruminating Holstein calves. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/44093
Chicago Manual of Style (16th Edition):
Wampler, Susan Anderson. “Preference and acceptability of four protein sources by ruminating Holstein calves.” 1988. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/44093.
MLA Handbook (7th Edition):
Wampler, Susan Anderson. “Preference and acceptability of four protein sources by ruminating Holstein calves.” 1988. Web. 06 Mar 2021.
Vancouver:
Wampler SA. Preference and acceptability of four protein sources by ruminating Holstein calves. [Internet] [Masters thesis]. Virginia Tech; 1988. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/44093.
Council of Science Editors:
Wampler SA. Preference and acceptability of four protein sources by ruminating Holstein calves. [Masters Thesis]. Virginia Tech; 1988. Available from: http://hdl.handle.net/10919/44093
Virginia Tech
2.
Matson, Kimberly Monica.
The effect of weekly handling on the temperament of peri-puberal crossbred beef heifers.
Degree: MS, Animal and Poultry Sciences, 2004, Virginia Tech
URL: http://hdl.handle.net/10919/33186
► The objectives of this study were to determine the effects of handling peri-puberal heifers for 2 h each week on in-chute behavior, isolation behavior, and…
(more)
▼ The objectives of this study were to determine the effects of handling peri-puberal heifers for 2 h each week on in-chute behavior, isolation behavior, and the time required for each heifer to leave the testing area; and to determine if the location of the facial hair whorl was associated with any of the behavior scores or social dominance order. Crossbred beef heifers (n = 146) were assigned to be walked through, sorted and moved through a chute for 2 hr each wk for 20 wk (HANDLED) or allowed to remain on pasture unless handling was required to treat an injury or disease (CONTROL). In-chute behavior, isolation behavior and exit times were observed and scored at the beginning (0 wk), middle (10 wk) and end of the experiment (20 wk). The facial hair whorl on each heifer was classified as being high (above the eyes), middle (between the eyes), or low (below the eyes). At the end of the experiment pairs of heifers in the HANDLED group competed for a feed source and a social dominance order was estimated. Weekly handling decreased in-chute behavior scores of heifers with facial hair whorl positions classified as medium or low, but not in heifers that exhibited a hair whorl high on their face. Cattle in the HANDLED treatment group which had an initial isolation score of 2 or 3 had the greatest improvement in temperament over the entire experiment when compared to CONTROL animals with the same initial isolation score. The calmest heifers were not negatively affected by the handling, while the most agitated animals in the HANDLED had a similar overall change in isolation score as those animals in the
CONTROL group. This indicates that while weekly handling improved the temperament and behavior of heifers with intermediate temperament rating at the outset of the experiment, weekly handling seemed unnecessary for the calmest heifers and did not have a beneficial effect on the heifers rated as the most nervous and agitated at the beginning of the experiment. Social dominance rankings were positively correlated (P < 0.10) with final in-chute behavior scores, but not with the other behavior scores or heifer body weight. Cattle with the hair whorls in the middle of the forehead had higher mean social dominant rank than those with hair whorls higher or lower on the face (P < 0.03). Overall, the results of this experiment indicate that behavior testing can reveal differences in the temperament of heifers and that, other than the most nervous and agitated heifers; repeated handling could serve to improve the temperament of the animals.
Advisors/Committee Members: Beal, Wilfred E. (committeechair), Hall, John B. (committee member), Barnes, Michael A. (committee member).
Subjects/Keywords: facial hair whorl; behavior; temperament; beef heifer; social dominance
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APA (6th Edition):
Matson, K. M. (2004). The effect of weekly handling on the temperament of peri-puberal crossbred beef heifers. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/33186
Chicago Manual of Style (16th Edition):
Matson, Kimberly Monica. “The effect of weekly handling on the temperament of peri-puberal crossbred beef heifers.” 2004. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/33186.
MLA Handbook (7th Edition):
Matson, Kimberly Monica. “The effect of weekly handling on the temperament of peri-puberal crossbred beef heifers.” 2004. Web. 06 Mar 2021.
Vancouver:
Matson KM. The effect of weekly handling on the temperament of peri-puberal crossbred beef heifers. [Internet] [Masters thesis]. Virginia Tech; 2004. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/33186.
Council of Science Editors:
Matson KM. The effect of weekly handling on the temperament of peri-puberal crossbred beef heifers. [Masters Thesis]. Virginia Tech; 2004. Available from: http://hdl.handle.net/10919/33186
Virginia Tech
3.
Ahmadzadeh, Amin.
Effect of naloxone on serum luteinizing hormone concentrations during the early postpartum period and the estrous cycle in primiparous and multiparous holstein cows.
Degree: MS, Dairy Science, 1994, Virginia Tech
URL: http://hdl.handle.net/10919/42551
► Four experiments were conducted to investigate the effect of naloxone, an opioid receptor antagonist, on pituitary LH secretion in Holstein cows during two periods…
(more)
▼ Four experiments were conducted to investigate the effect of naloxone, an opioid
receptor antagonist, on pituitary LH secretion in Holstein cows during two periods after
parturition and two phases of the estrous cycle. In experiment 1, 24 cows (12
primiparous; 12 multiparous) received either saline (n = 12) or 1 mg/kg naloxone (n = 12)
i. v. at 14 1 days postpartum. Blood samples were collected at 15-minute intervals for
2 hours before and 2.5 hours after naloxone or saline. Serum LH concentrations
increased (P < .05) in response to naloxone injection in both primi- and multiparous
cows. Saline injection did not affect LH concentrations. In experiment 2, 27 cows (13
primiparous; 14 multiparous) received either saline (n=14) or 1 mg/kg naloxone (n=13)
i. v. at 28 ± 1 days postpartum. Blood samples were collected as in the previous
experiment. Naloxone did not affect serum LH concentrations in either primi- or
mUltiparous cows at 28 days postpartum. In experiment 3, estrous cycles were
synchronized via prostaglandin administration (25 mg) in 22 cows (10 primiparous; 12
multiparous). Cows received either saline (n=11) or 1 mg/kg naloxone (n=11) Lv.
during the luteal phase of the estrous cycle. Blood samples were collected as in the previous experiments. Luteinizing hormone concentrations were not affected by naloxone
in either primi- or mUltiparous cows during the luteal phase of the estrous cycle. In
experiment 4, the same cows used in experiment 3 received a second dose of
prostaglandin (25 mg). Thirty-six hours later, during the follicular phase of the estrous
cycle, the cows received either saline (n =9) or 1 mg/kg naloxone (n = 11) i. v. Naloxone
increased (P < .05) serum LH concentrations in both primi- and mUltiparous cows in
the follicular phase. These results suggest that LH release in the early postpartum dairy
cow is regulated, at least in part, by endogenous opioid pep tides , and the ability of
naloxone to affect LH secretion may change as days postpartum increases, perhaps due
to changes in degree of inhibition by endogenous opioid peptides, and (or) changes in
serum progesterone concentration due to onset of ovarian activity during postpartum
period. It appears that the modulation of LH secretion may be mediated via opioids
during the follicular phase of the estrous cycle. However, an opioid-mediated mechanism
for modulation of LH secretion was absent or overridden by progesterone feedback
during the luteal phase of the estrous cycle.
Advisors/Committee Members: Barnes, Michael A. (committeechair), Denbow, D. Michael (committee member), Pearson, Ronald E. (committee member), Vinson, William E. (committee member).
Subjects/Keywords: Holstein-Friesian cattle.; LD5655.V855 1994.A363
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APA (6th Edition):
Ahmadzadeh, A. (1994). Effect of naloxone on serum luteinizing hormone concentrations during the early postpartum period and the estrous cycle in primiparous and multiparous holstein cows. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/42551
Chicago Manual of Style (16th Edition):
Ahmadzadeh, Amin. “Effect of naloxone on serum luteinizing hormone concentrations during the early postpartum period and the estrous cycle in primiparous and multiparous holstein cows.” 1994. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/42551.
MLA Handbook (7th Edition):
Ahmadzadeh, Amin. “Effect of naloxone on serum luteinizing hormone concentrations during the early postpartum period and the estrous cycle in primiparous and multiparous holstein cows.” 1994. Web. 06 Mar 2021.
Vancouver:
Ahmadzadeh A. Effect of naloxone on serum luteinizing hormone concentrations during the early postpartum period and the estrous cycle in primiparous and multiparous holstein cows. [Internet] [Masters thesis]. Virginia Tech; 1994. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/42551.
Council of Science Editors:
Ahmadzadeh A. Effect of naloxone on serum luteinizing hormone concentrations during the early postpartum period and the estrous cycle in primiparous and multiparous holstein cows. [Masters Thesis]. Virginia Tech; 1994. Available from: http://hdl.handle.net/10919/42551
Virginia Tech
4.
Sedano, Rodolfo Canseco.
Effect of immunoglobulins on early bovine embryo development in vitro.
Degree: MS, Dairy Science, 1985, Virginia Tech
URL: http://hdl.handle.net/10919/41575
► Bovine morulae (day 6: n=257) were obtained to evaluate the [effect of immunoglobulins (Ig) on early bovine embryo development in vitro. Fifty-four cows superovulations were…
(more)
▼ Bovine morulae (day 6: n=257) were obtained to evaluate
the [effect of immunoglobulins (Ig) on early bovine embryo
development in vitro. Fifty-four cows superovulations were
conducted in 36 cows with follicle stimulating hormone.
Embryos were collected by non-surgical procedures and
morphologically evaluated and randomly assigned to culture.
Embryos were cultured in Ham's F-10 containing 10%
(6.4 mg/ml) steer serum (SS), 1% (.64 mg/ml) bovine gamma .
globulins (GG), 1% (.64 mg/ml) bovine IgG, 1% (.64 mg/ml)
bovine 1gM, 10% SS plus 1% GG, 10% SS plus 1% 1gG, or 10% SS
plus 1% 1gM. Embryos were cultured to the hatched blastocyst stage or degeneration and evaluated at 12 h intervals.
Advisors/Committee Members: Gwazdauskas, Francis C. (committeechair), Vinson, William E. (committee member), Barnes, Michael A. (committee member), White, John M. (committee member).
Subjects/Keywords: Veterinary embryology; LD5655.V855 1985.S432
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APA (6th Edition):
Sedano, R. C. (1985). Effect of immunoglobulins on early bovine embryo development in vitro. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/41575
Chicago Manual of Style (16th Edition):
Sedano, Rodolfo Canseco. “Effect of immunoglobulins on early bovine embryo development in vitro.” 1985. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/41575.
MLA Handbook (7th Edition):
Sedano, Rodolfo Canseco. “Effect of immunoglobulins on early bovine embryo development in vitro.” 1985. Web. 06 Mar 2021.
Vancouver:
Sedano RC. Effect of immunoglobulins on early bovine embryo development in vitro. [Internet] [Masters thesis]. Virginia Tech; 1985. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/41575.
Council of Science Editors:
Sedano RC. Effect of immunoglobulins on early bovine embryo development in vitro. [Masters Thesis]. Virginia Tech; 1985. Available from: http://hdl.handle.net/10919/41575
Virginia Tech
5.
Grove, Tina Moler.
Effects of using an enzyme-linked immunosorbent assay to monitor the control of Staphylococcus aureus mastitis in dairy herds.
Degree: MS, Dairy Science, 1990, Virginia Tech
URL: http://hdl.handle.net/10919/42101
► Bovine mastitis is the most important economic disease to the dairy industry with losses estimated at 2 billion dollars per year in the United…
(more)
▼ Bovine mastitis is the most important economic disease to the dairy
industry with losses estimated at 2 billion dollars per year in the United
States. Staphylococcus aureus (.§.. aureus) is the primary cause of
contagious mastitis. Conventional culture methods (National Mastitis
Council) were used as a basis for comparing the ability of the enzyme linked
immunosorbent assay. ProStaph Iâ ¢, to identify s. aureus. The test
had an accuracy of 96%, with a sensitivity of 90% and a specificity of
97%. Results indicated that rinsing teat-cup liners with a 25 ppm
iodophor or 100 ppm chlorine solution reduced the presence of S. aureus on
the liners by 97%. ProStaph I was used to rapidly screen DHIA preserved
milk samples in 10
Virginia cooperator herds. Herds were classified as
high (>10% infected) or low prevalence (<10% infected). There were six
high prevalence herds after the first test. Average prevalence of cows
scoring Ab +2 and +3 was 11.9% ± 7.9. Over the seven month study,
prevalence of positive cows declined significantly (P<.OI), but somatic
cell count remained relatively unchanged (P>.lO). Four herds continued to
have >10% of the animals infected. Incidence of new infection averaged
3.6% ± 2.8 from the first to the last test. Chronic cows averaged 6.9% ±
4.8 over the seven month study. Analysis of variance showed significant
(P<.Ol) effects of herd on ProStaph I score J milk yield, and see.
Elevated ProStaph I scores were highly correlated (P <.01) with increases
in lactation number. ProStaph I changed quadratically (P<.Ol) with
increasing SCC. Somatic cell count increased (P<.OI) as ProStaph I score
increased.
Advisors/Committee Members: Jones, Gerald M. (committeechair), Barnes, Michael A. (committee member), Bishop, J. Russell (committee member), Vinson, William E. (committee member).
Subjects/Keywords: Enzyme-linked immunosorbent assay; LD5655.V855 1990.G775
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APA (6th Edition):
Grove, T. M. (1990). Effects of using an enzyme-linked immunosorbent assay to monitor the control of Staphylococcus aureus mastitis in dairy herds. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/42101
Chicago Manual of Style (16th Edition):
Grove, Tina Moler. “Effects of using an enzyme-linked immunosorbent assay to monitor the control of Staphylococcus aureus mastitis in dairy herds.” 1990. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/42101.
MLA Handbook (7th Edition):
Grove, Tina Moler. “Effects of using an enzyme-linked immunosorbent assay to monitor the control of Staphylococcus aureus mastitis in dairy herds.” 1990. Web. 06 Mar 2021.
Vancouver:
Grove TM. Effects of using an enzyme-linked immunosorbent assay to monitor the control of Staphylococcus aureus mastitis in dairy herds. [Internet] [Masters thesis]. Virginia Tech; 1990. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/42101.
Council of Science Editors:
Grove TM. Effects of using an enzyme-linked immunosorbent assay to monitor the control of Staphylococcus aureus mastitis in dairy herds. [Masters Thesis]. Virginia Tech; 1990. Available from: http://hdl.handle.net/10919/42101
Virginia Tech
6.
Liles, Amanda Gail.
The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers.
Degree: MS, Animal and Poultry Sciences, 2008, Virginia Tech
URL: http://hdl.handle.net/10919/34684
► Recent efforts have improved synchronization systems that facilitate timed insemination in beef cattle. However, synchronization systems utilizing a single fixed-time artificial insemination (FTAI) frequently result…
(more)
▼ Recent efforts have improved synchronization systems that facilitate timed insemination in beef cattle. However, synchronization systems utilizing a single fixed-time artificial insemination (FTAI) frequently result in 25-40% non-pregnant heifers. The purpose of this study was to determine the effectiveness and define economic parameters of a FTAI resynchronization protocol in beef heifers after synchronization using a 5d CO-Synch + CIDR system. Estrus was synchronized in crossbred heifers (n=176) using 5 d CO-Synch + CIDR with FTAI at 72 h. After the initial AI, open heifers received either resynchronization (RS) or natural service (NS) return service treatments. The RS treatment was diagnosed for pregnancy 29 d after the initial AI, and all open heifers were resynchronized using the 5 d CO-Synch + CIDR with FTAI at 72 h. Heifers diagnosed pregnant following initial AI received no further treatment. Heifers in the NS treatment were exposed to fertile bulls from d 14 to d 66 following initial AI. Return to estrus data were collected using the Heat Watch Estrus Alert System. Total AI pregnancies tended to be higher (P=0.07) for RS (69.7%) than NS (56.5%) heifers. Overall pregnancy rate was greater for NS (89.4%) than for RS (69.7%) at the end of the breeding season (P < 0.01). The cost of RS was 128.63 and for NS was 82.50 per pregnancy. The expected average calf value per heifer exposed was 195.84 for RS treatment and 357.62 for NS treatment. This difference was attributed to the increased number of open heifers in the RS treatment. The resynchronization of estrus after the initial FTAI yielded a limited number of pregnancies in the breeding season in this study. However, the resynchronization program also cost more per pregnancy. Further investigation into resynchronization should focus on both biological and economic impacts.
Advisors/Committee Members: Greiner, Scott P. (committeechair), Barnes, Michael A. (committee member), Beal, Wilfred E. (committee member), Hall, John B. (committee member).
Subjects/Keywords: Beef; Heifer; Reproduction; Resynchronization; Economics
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APA (6th Edition):
Liles, A. G. (2008). The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/34684
Chicago Manual of Style (16th Edition):
Liles, Amanda Gail. “The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers.” 2008. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/34684.
MLA Handbook (7th Edition):
Liles, Amanda Gail. “The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers.” 2008. Web. 06 Mar 2021.
Vancouver:
Liles AG. The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers. [Internet] [Masters thesis]. Virginia Tech; 2008. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/34684.
Council of Science Editors:
Liles AG. The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers. [Masters Thesis]. Virginia Tech; 2008. Available from: http://hdl.handle.net/10919/34684
Virginia Tech
7.
Johnson, David W.
Regulation and site of action of exogenous and endogenous opioids on growth hormone and prolactin secretion in Holstein calves.
Degree: PhD, Animal Science, 1990, Virginia Tech
URL: http://hdl.handle.net/10919/39812
► Four studies were conducted to investigate the effect and site of action of exogenous and endogenous opioids on pituitary growth hormone (GH) and prolactin (PRL)…
(more)
▼ Four studies were conducted to investigate the effect and site of action of exogenous and endogenous opioids on pituitary growth hormone (GH) and prolactin (PRL) secretion in Holstein calves. In the first study, the effect of the opioid agonist DAMME (D-Ala²⁺,N-Me-Phe⁴,Met(O)⁵-01 enkephalin) on plasma GH and PRL secretion was measured in Holstein calves in fall season. Plasma concentrations of both GH and PRL increased in response to DAM ME injection. Pretreatment with either the lipid soluble opioid antagonist naloxone (NAL), which readily penetrates the blood brain barrier (BBB), or the peripherally acting antagonist methyl levallorphan mesiltate (MLM), blocked the PRL response to DAMME. Naloxone, but not MLM, negated the GH response to DAMME. In spring, the experiment was repeated with similar results.
In the second experiment, the opioid antagonists NAL and MLM were administered alone to detennine whether endogenous opioids mediate basal GH and PRL secretion, and the site of action of any of opioid-mediation of basal GH and PRL. In fall, NAL administration increased both plasma GH and PRL secretion. Methyl levallorphan mesilate did not affect PRL, but increased plasma GH concentrations. In spring, a second trial using 5 different doses of each antagonist was conducted. Naloxone did not affect GH levels at any dose in spring, but decreased plasma PRL at the same dose which increased plasma PRL in fall. Plasma PRL was again unaffected by MLM, but plasma GH was increased by 3 separate doses of MLM.
The third experiment was designed to determine if the increases in plasma PRL seen after DAMME administration were mediated via dopaminergic mechanisms. Plasma PRL in calves again increased in response to DAMME injection alone. In calves pre-treated with the long-acting dopamine agonist 2-Br-&alp. ergocryptine (CB 154), plasma PRL was unresponsive to DAMME injection. The pituitaries of calves treated with CB 154 in this experiment were able to respond to thyrotropin-releasing hormone (TRH) injection with increased PRL secretion.
In the final experiment, the role of growth hormone-releasing hormone (GRH) in facilitating GH release after DAMME injection was investigated, and whether endogenous opioidergic mechanisms play a role in mediating the effects of exogenous GRH on GH secretion. Plasma GH concentrations increased in calves receiving either DAMME or D-ala²⁺, fragment 1- 29 amide, a synthetic GRH. The immediate increase in plasma GH concentrations after GRH injection in calves pre-treated with DAMME was approximately 5 fold less than that in calves not pre- treated with DAMME. Calves receiving DAMME and GRH in combination also produced a GH response curve with greater area under it than either compound alone, indicating possible synergism between the synthetic GRH and a DAMME-sustained release of endogenous GRH. Naloxone administration concomitantly with synthetic GRH did not alter the ability of the synthetic GRH to increase GH secretion overall, compared to synthetic GRH alone.
In conclusion, these studies are…
Advisors/Committee Members: Barnes, Michael A. (committeechair), Akers, Robert Michael (committee member), Pearson, Ronald E. (committee member), Gwazdauskas, Francis C. (committee member), Denbow, D. Michael (committee member).
Subjects/Keywords: Mammary glands; Holstein-Friesian cattle; LD5655.V856 1990.J6465
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APA (6th Edition):
Johnson, D. W. (1990). Regulation and site of action of exogenous and endogenous opioids on growth hormone and prolactin secretion in Holstein calves. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/39812
Chicago Manual of Style (16th Edition):
Johnson, David W. “Regulation and site of action of exogenous and endogenous opioids on growth hormone and prolactin secretion in Holstein calves.” 1990. Doctoral Dissertation, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/39812.
MLA Handbook (7th Edition):
Johnson, David W. “Regulation and site of action of exogenous and endogenous opioids on growth hormone and prolactin secretion in Holstein calves.” 1990. Web. 06 Mar 2021.
Vancouver:
Johnson DW. Regulation and site of action of exogenous and endogenous opioids on growth hormone and prolactin secretion in Holstein calves. [Internet] [Doctoral dissertation]. Virginia Tech; 1990. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/39812.
Council of Science Editors:
Johnson DW. Regulation and site of action of exogenous and endogenous opioids on growth hormone and prolactin secretion in Holstein calves. [Doctoral Dissertation]. Virginia Tech; 1990. Available from: http://hdl.handle.net/10919/39812
Virginia Tech
8.
Daniel, Thomas Earl.
Histological evaluation of ovine mammary tissue xenografted into cyclosporine treated mice.
Degree: MS, Dairy Science, 1988, Virginia Tech
URL: http://hdl.handle.net/10919/43398
Subjects/Keywords: Mammary glands; LD5655.V855 1988.D365
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APA (6th Edition):
Daniel, T. E. (1988). Histological evaluation of ovine mammary tissue xenografted into cyclosporine treated mice. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/43398
Chicago Manual of Style (16th Edition):
Daniel, Thomas Earl. “Histological evaluation of ovine mammary tissue xenografted into cyclosporine treated mice.” 1988. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/43398.
MLA Handbook (7th Edition):
Daniel, Thomas Earl. “Histological evaluation of ovine mammary tissue xenografted into cyclosporine treated mice.” 1988. Web. 06 Mar 2021.
Vancouver:
Daniel TE. Histological evaluation of ovine mammary tissue xenografted into cyclosporine treated mice. [Internet] [Masters thesis]. Virginia Tech; 1988. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/43398.
Council of Science Editors:
Daniel TE. Histological evaluation of ovine mammary tissue xenografted into cyclosporine treated mice. [Masters Thesis]. Virginia Tech; 1988. Available from: http://hdl.handle.net/10919/43398
Virginia Tech
9.
Degelos, Suzanne Denise.
Separation of abnormal spermatozoa from semen produced by bulls with impaired testicular thermoregulation.
Degree: PhD, Animal Sciences, Dairy, 1995, Virginia Tech
URL: http://hdl.handle.net/10919/38205
Subjects/Keywords: spermatogenesis; LD5655.V856 1995.D444
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APA (6th Edition):
Degelos, S. D. (1995). Separation of abnormal spermatozoa from semen produced by bulls with impaired testicular thermoregulation. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/38205
Chicago Manual of Style (16th Edition):
Degelos, Suzanne Denise. “Separation of abnormal spermatozoa from semen produced by bulls with impaired testicular thermoregulation.” 1995. Doctoral Dissertation, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/38205.
MLA Handbook (7th Edition):
Degelos, Suzanne Denise. “Separation of abnormal spermatozoa from semen produced by bulls with impaired testicular thermoregulation.” 1995. Web. 06 Mar 2021.
Vancouver:
Degelos SD. Separation of abnormal spermatozoa from semen produced by bulls with impaired testicular thermoregulation. [Internet] [Doctoral dissertation]. Virginia Tech; 1995. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/38205.
Council of Science Editors:
Degelos SD. Separation of abnormal spermatozoa from semen produced by bulls with impaired testicular thermoregulation. [Doctoral Dissertation]. Virginia Tech; 1995. Available from: http://hdl.handle.net/10919/38205
Virginia Tech
10.
Jewell, Tracy Michelle.
Artificial Induction of Lactation in Nonbreeder Dairy Cows.
Degree: MS, Dairy Science, 2002, Virginia Tech
URL: http://hdl.handle.net/10919/33721
► Thirty-four cows (26 Holsteins and 8 Jerseys) were subjected to an estrous synchronization protocol administering 2 PGF2Æ Ã injections 11 d apart prior to beginning…
(more)
▼ Thirty-four cows (26 Holsteins and 8 Jerseys) were subjected to an estrous synchronization protocol administering 2 PGF2Æ Ã injections 11 d apart prior to beginning the lactation-induction protocol. Artificial induction of lactation yielded a 92% success rate for Holstein cows with success defined as achieving >9 kg milk/d, and a 88% success rate for Jersey cows with success defined as achieving > 5 kg milk/d. Mean accumulated milk yield for induced cows at 150 DIM was 65% of mean yield for nontreated cows. Mean peak milk yield for lactation- induced Holsteins and Jerseys was 32 kg/d and 20 kg/d, respectively. Mean serum and milk progesterone concentrations for samples collected during the first 6 d of lactation were not different between lactation-induced and nontreated cows. However, mean serum estradiol concentrations for induced cows were higher (P <0.05) in samples collected 3 and 5 DIM. Lactation-induced cows exhibited an increase in serum alpha-lactalbumin concentrations 2 d prior to initiation of milking, reaching values of ~260 ng/ml. Mean days-to-first service was greatly reduced in cows induced into lactation compared to nontreated cows, while mean services per conception was similar between induced and nontreated cows. Mean days to conception was lower for induced cows than for nontreated cows. By 150 DIM, pregnancy rate of induced cows was 70%, whereas nontreated cows averaged 56% pregnancy rate.
Advisors/Committee Members: Barnes, Michael A. (committeechair), Akers, Robert Michael (committee member), Pearson, Ronald E. (committee member), Nickerson, Stephen C. (committee member), Nebel, Raymond L. (committee member).
Subjects/Keywords: estrous cycle; dairy cattle; induction of lactation
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APA (6th Edition):
Jewell, T. M. (2002). Artificial Induction of Lactation in Nonbreeder Dairy Cows. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/33721
Chicago Manual of Style (16th Edition):
Jewell, Tracy Michelle. “Artificial Induction of Lactation in Nonbreeder Dairy Cows.” 2002. Masters Thesis, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/33721.
MLA Handbook (7th Edition):
Jewell, Tracy Michelle. “Artificial Induction of Lactation in Nonbreeder Dairy Cows.” 2002. Web. 06 Mar 2021.
Vancouver:
Jewell TM. Artificial Induction of Lactation in Nonbreeder Dairy Cows. [Internet] [Masters thesis]. Virginia Tech; 2002. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/33721.
Council of Science Editors:
Jewell TM. Artificial Induction of Lactation in Nonbreeder Dairy Cows. [Masters Thesis]. Virginia Tech; 2002. Available from: http://hdl.handle.net/10919/33721
Virginia Tech
11.
Ahmadzadeh, Amin.
Role of Endogenous Dopamine in Regulation of Anterior Pituitary Hormone Secretion During Early Postpartum and Various Stages of the Estrous Cycle in Holstein Cows.
Degree: PhD, Dairy Science, 1998, Virginia Tech
URL: http://hdl.handle.net/10919/30764
► The role of endogenous dopamine, utilizing a dopamine antagonist (fluphenazine; FLU), in modulation of gonadotropin, growth hormone (GH) and prolactin (PRL) secretion during the early…
(more)
▼ The role of endogenous dopamine, utilizing a dopamine antagonist (fluphenazine; FLU), in modulation of gonadotropin, growth hormone (GH) and prolactin (PRL) secretion during the early postpartum period and various stages of the estrous cycle was investigated in Holstein cows. Experiment 1 was conducted in anovulatory early postpartum cows. Fluphenazine caused a decrease (P < .05) in mean serum LH concentration and LH pulse frequency. Likewise, FLU caused a (P < .05) decrease in mean GH concentration. These results suggest that endogenous dopamine, at least in part, is responsible for regulation of LH and GH secretion in anovulatory Holstein cows. Experiment 2 was conducted in cyclic lactating Holstein cows during the mid-luteal phase of the estrous cycle. Mean serum LH and FSH concentrations, pulse frequencies, and peak amplitudes did not change in response to FLU. FLU did not affect mean serum GH concentration. These results suggest that a dopamine-mediated mechanism for modulation of gonadotropin and GH secretion is absent or perhaps overridden by high progesterone concentration during the luteal phase of the estrous cycle in lactating dairy cows. Experiment 3 was conducted during the early follicular phase of the estrous cycle in Holstein cows. During the follicular phase, FLU caused a decrease (P < .05) in mean serum LH concentration and LH pulse frequency. However, FLU had no effect on mean serum FSH concentration or pulse frequency. Further, FLU increased (P < .05) GH concentrations during the follicular phase. Experiment 4 was conducted during the early
ii
metestrus phase of the estrous cycle. During the metestrus phase, FLU tended to decrease (P < .1) mean LH concentration and suppressed (P < .05) LH pulse frequency but had no effect on FSH secretion. Fluphenazine caused a transient increase (P < .05) in mean serum GH concentration. The results of the third and fourth experiments suggest that, during the early follicular and metestrus phases of the estrous cycle, when progesterone concentration is low, modulation of LH and GH secretion, at least in part, is modulated by endogenous dopamine. However, a dopamine mediated mechanism for FSH secretion is absent during both phases of the estrous cycle in lactating Holstein cows. In all experiments FLU increased (P < .01) PRL secretion indicating that endogenous dopamine suppresses PRL secretion in cattle regardless of ovarian status. It is concluded that: 1) endogenous dopamine plays a stimulatory role in LH secretion during the anovulatory postpartum period and during the estrous cycle only when serum progesterone is low. 2) FLU decreased GH secretion in anovulatory postpartum Holstein cows but it increased GH secretion during the follicular and metestrus phases of the estrous cycle. However FLU had no effect on GH secretion during the luteal phase of the estrous cycle. Thus it appears that, modulation of GH secretion is dependent upon reproductive status and ovarian hormones secretion.
Advisors/Committee Members: Barnes, Michael A. (committeechair), Gwazdauskas, Francis C. (committee member), Akers, Robert Michael (committee member), Vinson, William E. (committee member), Denbow, D. Michael (committee member), McGilliard, Michael L. (committee member).
Subjects/Keywords: follicle stimulating hormone; luteinizing hormone; dopamine antagonist; growth hormone; prolactin; cattle
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APA ·
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APA (6th Edition):
Ahmadzadeh, A. (1998). Role of Endogenous Dopamine in Regulation of Anterior Pituitary Hormone Secretion During Early Postpartum and Various Stages of the Estrous Cycle in Holstein Cows. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/30764
Chicago Manual of Style (16th Edition):
Ahmadzadeh, Amin. “Role of Endogenous Dopamine in Regulation of Anterior Pituitary Hormone Secretion During Early Postpartum and Various Stages of the Estrous Cycle in Holstein Cows.” 1998. Doctoral Dissertation, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/30764.
MLA Handbook (7th Edition):
Ahmadzadeh, Amin. “Role of Endogenous Dopamine in Regulation of Anterior Pituitary Hormone Secretion During Early Postpartum and Various Stages of the Estrous Cycle in Holstein Cows.” 1998. Web. 06 Mar 2021.
Vancouver:
Ahmadzadeh A. Role of Endogenous Dopamine in Regulation of Anterior Pituitary Hormone Secretion During Early Postpartum and Various Stages of the Estrous Cycle in Holstein Cows. [Internet] [Doctoral dissertation]. Virginia Tech; 1998. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/30764.
Council of Science Editors:
Ahmadzadeh A. Role of Endogenous Dopamine in Regulation of Anterior Pituitary Hormone Secretion During Early Postpartum and Various Stages of the Estrous Cycle in Holstein Cows. [Doctoral Dissertation]. Virginia Tech; 1998. Available from: http://hdl.handle.net/10919/30764
Virginia Tech
12.
Loor, Juan Jose.
Alterations in Mammary Gland Synthesis and Secretion of Fatty Acids in Response to Trans Isomers of Octadecenoic Acid or Conjugated Linoleic Acid Isomers.
Degree: PhD, Dairy Science, 2001, Virginia Tech
URL: http://hdl.handle.net/10919/27187
► Experiments were conducted to investigate: 1) production of trans-18:1 and cis/trans-18:2 isomers due to input of forage and corn grain in continuous culture fermenters, 2)…
(more)
▼ Experiments were conducted to investigate: 1) production of trans-18:1 and cis/trans-18:2 isomers due to input of forage and corn grain in continuous culture fermenters, 2) concentrations of trans-18:1 and cis/trans-18:2 isomers in blood and milk fat of grazing cows fed a grain supplement containing solvent- or mechanically-extracted soybean meal, 3) plasma and milk fatty acid profiles of lactating cows in response to a conjugated linoleic acid (CLA) mixture infused into the rumen, and 4) effects of cis9,trans11-18:2 (9/11CLA) or trans10,cis12-18:2 (10/12CLA) on de novo synthesis and desaturation of milk fatty acids in lactating cows fed unsaturated oils. In the first study, rumen fermenters were fed (50 g DM/d) orchardgrass or red clover with 0, 8, or 16 g/d corn replacing equal portions of forage DM. Outflow of trans11,cis15-18:2 (11/15LA) in effluents was greater when DM input was clover or grass only. With each increment of corn, output of 9/11CLA increased until it was 205% greater compared with forage alone. Trans11-18:1 (TVA), an intermediate in 18:2n6 (LA) and 18:3n3 (LN) hydrogenation, output increased by 28% with corn addition. Outputs of trans10-18:1 and 10/12CLA nearly doubled as corn increment increased. In the second experiment, Holstein cows grazing mixed clover-grass pastures were fed a grain supplement (6.7 kg/d) containing 1.7 kg solvent-extracted soybean meal (SES, 15 mg LA/g of DM), 1.9 kg mechanically-extracted soybean meal (MES, 24 mg LA/g of DM), or 1.9 kg MES plus 30 g of liquid methionine hydroxy analog (MESM). Cows fed MES or MESM had greater concentrations of LA, TVA, 9/11CLA, and 11/15LA in blood compared with cows fed SES. Daily yields of 18:0 (SA), LA, LN, TVA, and 9/11CLA in milk fat also were greater for cows fed MES or MESM compared with SES. In experiment 3, four Holstein cows were used in a 4 x 4 Latin square to determine plasma and milk fatty acid profiles during infusion of a CLA mixture at 0, 45, 90, or 180 g/d for 48 h into the rumen. Relative to the control, infusion of 180 g CLA/d decreased milk fat percentage and yield. Lower milk fat yield resulted from depressed concentrations of saturated 6:0 to 16:0 medium-chain fatty acids (MCFA). Concentrations of TVA, trans10-18:1, and 10/12CLA in blood plasma, and yields in milk fat increased in response to each dose of CLA. Stearic acid yield also increased as dose of CLA increased. Yield of cis9-18:1 (OA) in milk fat, however, was lower at 180 g CLA/d. In experiment 4, four cows were fed high-oleic (HO) or high-linoleic (HL) (2.5% of DM) oil for 11 d prior to abomasal infusion (15 g/d) of 9/11CLA or 10/12CLA for 48 h (2 x 2 factorial). Milk fat percentage and yield decreased 25% due to infusion of 10/12CLA compared with 9/11CLA, regardless of diet. Lower fat yields resulted from lower MCFA concentrations and yields. Regardless of diet, concentration (but not yield) of SA increased 40% when 10/12CLA was infused compared with 9/11CLA. Concentrations and yields of OA, 9/11CLA, and 20:4n6 also were reduced by infusing…
Advisors/Committee Members: Herbein, Joseph H. Jr. (committeechair), Keenan, Thomas W. (committee member), Stallings, Charles C. (committee member), Polan, Carl E. (committee member), Barnes, Michael A. (committee member), Kronfeld, David S. (committee member).
Subjects/Keywords: trans10cis12-18:2; rumenic acid; trans10-18:1; trans-vaccenic acid; grazing; milk fat
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Loor, J. J. (2001). Alterations in Mammary Gland Synthesis and Secretion of Fatty Acids in Response to Trans Isomers of Octadecenoic Acid or Conjugated Linoleic Acid Isomers. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/27187
Chicago Manual of Style (16th Edition):
Loor, Juan Jose. “Alterations in Mammary Gland Synthesis and Secretion of Fatty Acids in Response to Trans Isomers of Octadecenoic Acid or Conjugated Linoleic Acid Isomers.” 2001. Doctoral Dissertation, Virginia Tech. Accessed March 06, 2021.
http://hdl.handle.net/10919/27187.
MLA Handbook (7th Edition):
Loor, Juan Jose. “Alterations in Mammary Gland Synthesis and Secretion of Fatty Acids in Response to Trans Isomers of Octadecenoic Acid or Conjugated Linoleic Acid Isomers.” 2001. Web. 06 Mar 2021.
Vancouver:
Loor JJ. Alterations in Mammary Gland Synthesis and Secretion of Fatty Acids in Response to Trans Isomers of Octadecenoic Acid or Conjugated Linoleic Acid Isomers. [Internet] [Doctoral dissertation]. Virginia Tech; 2001. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10919/27187.
Council of Science Editors:
Loor JJ. Alterations in Mammary Gland Synthesis and Secretion of Fatty Acids in Response to Trans Isomers of Octadecenoic Acid or Conjugated Linoleic Acid Isomers. [Doctoral Dissertation]. Virginia Tech; 2001. Available from: http://hdl.handle.net/10919/27187
. 
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