Influence of Rough Hair Coats and Steroid Implants on the Performance and Physiology of Steers Grazing Endophyte-Infected Tall Fescue in the Summer

doi:10.1532/S1080-7446(15)30851-2

The Professional Animal Scientist

Volume 24, Issue 3, June 2008, Pages 269-276

https://doi.org/10.1532/S1080-7446(15)30851-2 Get rights and content

Abstract

Sixty-two steers were assigned to six 3- ha pastures of toxic tall fescue to study the effects of steroid implants and winter hair coat retention on weight gain and body heat dissipation. Either 10 clipped or 10 unclipped steers were assigned to pastures as the main plot treatment. Groups of steers in each pasture were implanted with either Synovex-S (200 mg progesterone, 20 mg estradiol) or Compudose (25 mg estradiol) and evaluated as subplot treatments. An area approximately 41cm2 was clipped over the shoulder to measure hair length growth (mm/d) and sweating rate (g/m2 per h). Responses were measured at 28, 56, 84, and 104 d of grazing. Frequency of grazing behavior was periodically measured during the experiment. Hair growth rate averaged 0.28 mm/d and was unaffected (P > 0.10) by implant treatments. Sweating rate declined (P < 0.001) over the grazing period and was less (P < 0.10) with the progesterone-estradiol implant. Rectal temperatures were lower (P < 0.05) in clipped cattle (39.3°C) compared with unclipped cattle (39.5°C) on d 84 when the highest ambient temperature (33°C) of the study was recorded. At increased ambient temperatures, percentage of steers actively grazing was negatively correlated (-0.82, P < 0.10) with ambient temperature. Cumulative ADG declined (P < 0.05) over the last 2 weigh dates when there were higher ambient temperatures. Results indicated that rough hair coat retention and continuous hair growth into the summer caused impaired thermoregulatory ability at higher ambient temperatures and that heat stress was exacerbated by reduced sweating.

Refrence (37)

A. Gudmundsson et al.
Effects of estrogen replacement therapy on the circadian rhythms of serum cortisol and body temperature in post-menopausal women
Exp. Gerontol.
(1999)
S.A. Samaan et al.
Es-trogen and cardiovascular function after meno-pause
J. Am. Coll. Cardiol.
(1995)
S.P. Schmidt et al.
Effects of endophyte-infected tall fescue on animal performance
Agric. Ecosyst. Environ.
(1993)
M. Tarazon-Herrera et al.
Effects of bovine somatotropin and evaporative cooling plus shade on lactation performance of cows during summer heat stress
J. Dairy Sci.
(1999)
G.E. Aiken et al.
Influence of stocking rate and steroidal implants on growth rate of steers grazing toxic tall fescue and subsequent physiological responses
J. Anim. Sci.
(2006)
C.G. Aldrich et al.
The effects of endophyte- infected tall fescue consumption on diet utilization and thermal regulation in cattle
J. Anim. Sci.
(1993)
A. Al-Haidary et al.
Ther-moregulatory ability of beef heifers following intake of endophyte-infected tall fescue during controlled heat challenge
J. Anim. Sci.
(2001)
AllenT.E.
Responses of Zebu, Jersey and Zebu x Jersey crossbred heifers to rising temperature, with particular reference to sweating. Aust
J. Agric. Res.
(1962)
C.W. Bacon et al.
Endo- phyte parasitism of tall fescue
J. Prod. Agric.
(1988)
BermanA.
Influence of some factors on the relative evaporation rate from the skin of cattle
Nature
(1957)

BermanA.

Estimates of heat stress relief needs for Holstein dairy cows

J. Anim. Sci.

(2005)

J. Bond et al.

For-age composition and growth and physiological characteristics of cattle grazing several varieties of tall fescue during summer conditions

J. Anim. Sci.

(1984)

D.I. Bransby et al.

Disk meter for rapid estimation of herbage yield in grazing trials

Agron. J.

(1977)

R. Browning et al.

Effect of ergotamine and ergonovine on thermal regulation and cardiovascular function in cattle

J. Anim. Sci.

(1997)

N.N. Chan et al.

Changes in endothelium-dependent vasodilation and α-adrenergic responses in resistance vessels during the menstrual cycle in healthy women

J. Clin. Endocrinol. Metab.

(2001)

EdwardsD.P.

Regulation of signal transduction pathways by estrogen and proges-terone

Annu. Rev. Physiol.

(2005)

FinchV.A.

Body temperature in beef cattle: Its control and relevance to production in the tropics

J. Anim. Sci.

(1986)

S.P. Ford et al.

Role of estradiol-17/3 and progesterone in regulating constriction of ovine uterine arteries

Biol. Reprod.

(1977)

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Those findings are similar to Gray et al. (2011) who described a relationship between dam hair coat score and calf weaning weights. Elevated circulating prolactin concentrations during the summer months leads to winter hair coat shedding (McClanahan et al., 2008; Porter and Thompson, 1992). A low hair coat score in the summer months allows cattle to better dissipate heat and can reduce the effects of heat stress (Olson et al., 2003).
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Two experiments were conducted to characterize and evaluate rough hair-coats of cattle grazing endophyte (Neotyphodium coenophialum)-infected tall fescue (Lolium arundinaceum) during the summer and their effect on body temperature. In Exp. 1, hair was clipped in bleached areas over the rumps of 5 steers grazing endophyte-infected fescue in the summer to determine percentages in 5 length intervals for hair emerged during decreasing day lengths (fall and winter) and those emerged during increasing day lengths (spring and summer). In Exp. 2, rectal temperature data from 7 grazing experiments were compiled to compare linear relationships between rectal temperature and both ambient temperature and temperature-humidity indices, and between cattle with rough, transitional (i.e., some hair shedding), and sleek hair-coats. Frequency distributions of hair-length intervals in Exp. 1 differed (P < 0.001), with 31.3% of short-day emerged hairs and 19.5% of long-day emerged hairs having lengths > 20 mm; however, 80% of the hairs were emerged during long day lengths rather than short day lengths. For Exp. 2, linear increases in rectal temperatures as mean ambient temperature and temperature-humidity indices increased were greater for cattle with rough and transitional hair coats than for cattle with sleek hair coats. From these experiments, it was concluded that rough hair coats on cattle grazing endophyte-infected tall fescue are composed predominately of hair emerged during long-day lengths in the late spring and summer. Growing to excessive hair-lengths, these rough hair coats insulate elevated core body temperature to intensify hyperthermia triggered by ergot alkaloid-induced vasoconstriction.
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¹: Mention of trade names or commercial products in the article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA.

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Case StudyInfluence of Rough Hair Coats and Steroid Implants on the Performance and Physiology of Steers Grazing Endophyte-Infected Tall Fescue in the Summer1

Abstract

Exp. Gerontol.

J. Am. Coll. Cardiol.

Agric. Ecosyst. Environ.

J. Dairy Sci.

Influence of stocking rate and steroidal implants on growth rate of steers grazing toxic tall fescue and subsequent physiological responses

J. Anim. Sci.

The effects of endophyte- infected tall fescue consumption on diet utilization and thermal regulation in cattle

J. Anim. Sci.

Ther-moregulatory ability of beef heifers following intake of endophyte-infected tall fescue during controlled heat challenge

J. Anim. Sci.

Responses of Zebu, Jersey and Zebu x Jersey crossbred heifers to rising temperature, with particular reference to sweating. Aust

J. Agric. Res.

Endo- phyte parasitism of tall fescue

J. Prod. Agric.

Influence of some factors on the relative evaporation rate from the skin of cattle

Nature

Estimates of heat stress relief needs for Holstein dairy cows

J. Anim. Sci.

For-age composition and growth and physiological characteristics of cattle grazing several varieties of tall fescue during summer conditions

J. Anim. Sci.

Disk meter for rapid estimation of herbage yield in grazing trials

Agron. J.

Effect of ergotamine and ergonovine on thermal regulation and cardiovascular function in cattle

J. Anim. Sci.

Changes in endothelium-dependent vasodilation and α-adrenergic responses in resistance vessels during the menstrual cycle in healthy women

J. Clin. Endocrinol. Metab.

Regulation of signal transduction pathways by estrogen and proges-terone

Annu. Rev. Physiol.

Body temperature in beef cattle: Its control and relevance to production in the tropics

J. Anim. Sci.

Role of estradiol-17/3 and progesterone in regulating constriction of ovine uterine arteries

Biol. Reprod.

Case Study
Influence of Rough Hair Coats and Steroid Implants on the Performance and Physiology of Steers Grazing Endophyte-Infected Tall Fescue in the Summer1