Oestrous Cycle Control and Fertility in Beef Cattle Following Short-Term Progestagen Treatments

Food intake was monitored continuously throughout the oestrous cycle of the rat by operant methods. On the night of oestrus the size of meals eaten was reduced and the average intermeal interval was shorter; and even after meals of the same size, oestrous animals returned to eat again more quickly than dioestrous animals. These results suggest that the way in which ovarian oestrogens reduce food intake is by intensifying processes responsible for the short-term satiation of hunger without affecting the motivational processes responsible for its arousal. Signs of motivational arousal at oestrus could thus be the result of a self-imposed nutritional deprivation, rather than a direct effect of ovarian hormones on sexual receptivity.

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Repeatability and variability of short-term spot measurement of methane and carbon dioxide emissions from beef cattle using GreenFeed Emissions Monitoring System

Canadian Journal of Animal Science ◽

10.1139/cjas-2015-0190 ◽

2016 ◽

Cited By ~ 7

Author(s):

Ghader Manafiazar ◽

Scott Zimmerman ◽

John Basarab

Keyword(s):

Carbon Dioxide ◽

Beef Cattle ◽

Monitoring System ◽

Carbon Dioxide Emissions ◽

Short Term

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The effect of season and the introduction of rams on oestrous activity in Somali, Nandi, Merino, Karakul and New Zealand Romney Marsh ewes in Kenya

Animal Science ◽

10.1017/s000335610000266x ◽

1986 ◽

Vol 43 (3) ◽

pp. 447-457 ◽

Cited By ~ 4

Author(s):

A. B. Carles ◽

W. A. K. Kipngeno

Keyword(s):

Time Series ◽

Seasonal Variation ◽

New Zealand ◽

Time Series Analysis ◽

Oestrous Cycle ◽

Significant Source ◽

Short Term ◽

Series Analysis ◽

The Mean

ABSTRACTA study was made of the levels of oestrous activity of two indigenous breeds of sheep (Somali and Nandi) and three exotic breeds of sheep (Merino, Karakul and New Zealand Romney Marsh) over a period of 3 years, in an equatorial environment. Breed was the only significant source of variation for the length of the oestrous cycle (P < 0·01). The mean lengths of the oestrous cycle were 17·2 (s.d. 3·21), 17·5 (s.d. 2·24), 17·9 (s.d. 2·99), 17·5 (s.d. 2·57) and 16·5 (s.d. 3·41) days for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively.The mean percentage of ewes of the different breeds showing oestrus in 20-day periods were 69·8 (s.d. 22·57), 49·9 (s.d. 18·67), 63·4 (s.d. 25·70), 79·2 (s.d. 20·30) and 33·2 (s.d. 23·50) % for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively. Time-series analysis did not detect any evidence of seasonal variation in oestrous activity, although there was an indication that the Merino and Romney Marsh breeds showed a marked increase in oestrous activity following, the introduction of rams. It was concluded that the variation in level of oestrous activity was short term and random.

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Association of Fertility with Numbers of Antral Follicles within a Follicular Wave During the Oestrous Cycle in Beef Cattle

Reproduction in Domestic Animals ◽

10.1111/j.1439-0531.2006.00786.x ◽

2007 ◽

Vol 42 (4) ◽

pp. 337-342 ◽

Cited By ~ 10

Author(s):

MJ Starbuck-Clemmer ◽

H Hernandez-Fonseca ◽

N Ahmad ◽

G Seidel ◽

EK Inskeep

Keyword(s):

Beef Cattle ◽

Oestrous Cycle ◽

Antral Follicles ◽

Follicular Wave

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Effects of Feeding Encapsulated Nitrate to Beef Cattle on Ammonia and Greenhouse Gas Emissions from Their Manure in a Short-Term Manure Storage System

Journal of Environmental Quality ◽

10.2134/jeq2016.02.0056 ◽

2016 ◽

Vol 45 (6) ◽

pp. 1979-1987 ◽

Cited By ~ 5

Author(s):

Chanhee Lee ◽

Rafael C. Araujo ◽

Karen M. Koenig ◽

Michael L. Hile ◽

Eileen E. Fabian-Wheeler ◽

...

Keyword(s):

Beef Cattle ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Storage System ◽

Short Term ◽

Gas Emissions ◽

Manure Storage

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Forty years of control of the oestrous cycle in ruminants: progress made, unresolved problems and the potential impact of sperm encapsulation technology

Reproduction Fertility and Development ◽

10.1071/rd9930587 ◽

1993 ◽

Vol 5 (6) ◽

pp. 587 ◽

Cited By ~ 17

Author(s):

W Jochle

Keyword(s):

Artificial Insemination ◽

Oestrous Cycle ◽

Regulatory Agencies ◽

Short Term ◽

Cattle Industry ◽

Prostaglandin F2 Alpha ◽

Effective Doses ◽

Potential Impact ◽

Pharmacological Control

Pharmacological control of the oestrous cycle may, with or without sperm encapsulation, remain an indispensable part of any attempt to make artificial insemination available to the ranch-cattle industry. Of the current methods, those most likely to remain acceptable with regulatory agencies and to gain acceptance with industry are those involving the short-term use (7-10 days) of minimal effective doses of progestins (preferably progesterone) and the subsequent use of an analogue of prostaglandin F2 alpha. The use of microencapsulated sperm with a long lifespan would allow artificial insemination to be achieved without reference to the time when heat and ovulation may occur.

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Dietary protein intake during the oestrous cycle does not alter the ovulation rate in gilts

Reproduction Fertility and Development ◽

10.1071/rd03100 ◽

2004 ◽

Vol 16 (6) ◽

pp. 589 ◽

Cited By ~ 1

Author(s):

César A. Mejia-Guadarrama ◽

Armelle Prunier ◽

Hélène Quesnel

Keyword(s):

Dietary Protein ◽

Protein Intake ◽

Plasma Concentrations ◽

Prostaglandin F2α ◽

Protein Restriction ◽

Oestrous Cycle ◽

Ovulation Rate ◽

Short Term ◽

Nutritional Treatment ◽

Digestible Energy

The effect of protein intake on ovulation rate was investigated in cross-bred gilts. On Day 14 of the third oestrous cycle, luteolysis was induced by injection of an analogue of prostaglandin F2α. The ovulation rate was recorded when gilts were killed on Day 27. In the first experiment, nutritional treatment was applied from Day 14 to Day 27. Gilts were fed diets providing the same amount of digestible energy, but containing either a low, medium or high amount of dietary protein. Protein restriction linearly decreased plasma concentrations of urea (P < 0.001) and had no effect on plasma concentrations of insulin-like growth factor-I and leptin measured at Day 27 (P > 0.1). Protein restriction did not influence ovulation rate (mean (± s.e.m.) 17.0 ± 0.4; P > 0.1). In the second experiment, the nutritional treatment was applied from Day 5 until Day 27. Gilts received the same amount of digestible energy and either a low or a high amount of protein, as in Experiment 1. A third group of gilts received the high amount of protein and also more digestible energy. The ovulation rate did not differ between the three groups of gilts. These data indicate no effect of short-term dietary protein restriction on ovulation rate in cyclic gilts.

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