scholarly journals Short-term nutritional supplementation of ewes in low body condition affects follicle development due to an increase in glucose and metabolic hormones

Reproduction ◽  
2005 ◽  
Vol 129 (3) ◽  
pp. 299-309 ◽  
Author(s):  
C Viñoles ◽  
M Forsberg ◽  
G B Martin ◽  
C Cajarville ◽  
J Repetto ◽  
...  
Keyword(s):  
Body Condition ◽  
Oestrous Cycle ◽  
Nutritional Supplementation ◽  
Ovulation Rate ◽  
Follicle Development ◽  
Short Term ◽  
Metabolic Hormones ◽  
The Third ◽  
Short Period ◽  
Igf I

This study tested whether the effects of a short period of nutritional supplementation given to ewes during the luteal phase on follicle development and ovulation rate is associated with an increase in circulating concentrations of FSH, glucose or metabolic hormones. Oestrus was synchronised with two prostaglandin injections given 9 days apart and the supplement consisted of corn grain and soybean meal. Corriedale ewes with low body condition were randomly assigned to 2 groups: the control group (C; n = 10) received a maintenance diet while the short-term supplemented group (STS; n = 10) received double the maintenance diet over days 9 to 14 of the oestrous cycle (day 0 = ovulation). Ovaries were examined daily by ultrasound and blood was sampled three times a day during the inter-ovulatory interval for measuring reproductive and metabolic hormones. On days 9, 11 and 14 of the oestrous cycle, half of the ewes from each group (n = 5) were bled intensively to determine the concentrations of glucose, insulin, IGF-I and leptin. Plasma FSH, progesterone, oestradiol and androstenedione concentrations were similar among groups. Dietary supplementation increased plasma insulin concentrations from the first to the sixth day of supplementation and increased glucose concentrations on the third day, compared with control ewes. Plasma leptin concentrations were higher in STS ewes from the second to the fifth day of supplementation. The pattern of IGF-I concentrations was similar among groups. In STS ewes, the nutritional treatment prolonged the lifespan of the last non-ovulatory follicle, so fewer follicular waves developed during the cycle. In STS ewes, increased concentrations of glucose, insulin and leptin one day before ovulatory wave emergence were associated with increased numbers of follicles growing from 2 to 3 mm and with stimulation of the dominant follicle to grow for a longer period. We suggest that the mechanism by which short-term nutritional supplementation affects follicle development does not involve an increase in FSH concentrations, but may involve responses to increased concentrations of glucose, insulin and leptin, acting directly at the ovarian level. This effect is acute, since concentrations of all three substances decrease after reaching peak values on the third day of supplementation. The status of follicle development at the time of maximum concentrations of glucose and metabolic hormones may be one of the factors that determines whether ovulation rate increases or not.

scholarly journals The use of a ‘first-wave’ model to study the effect of nutrition on ovarian follicular dynamics and ovulation rate in the sheep

Reproduction ◽  
2010 ◽  
Vol 140 (6) ◽  
pp. 865-874 ◽  
Author(s):  
C Viñoles ◽  
B Paganoni ◽  
K M M Glover ◽  
J T B Milton ◽  
D Blache ◽  
...  
Keyword(s):  
Body Condition ◽  
Wave Model ◽  
Ovulation Rate ◽  
Short Term ◽  
Metabolic Hormones ◽  
Follicular Waves ◽  
Follicular Wave ◽  
The Third ◽  
High Concentrations ◽  
Follicular Dynamics

We have developed an experimental model in which groups of ewes are simultaneously experiencing the first ovarian follicular wave of their oestrous cycle. We used this ‘first-wave model’ in a 2×2 factorial experiment (ten ewes per group) to study the effect of body condition (BC) and a short-term supplement on follicular dynamics and ovulation rate. The ‘first-wave’ was established by giving ewes three injections of prostaglandin (PG), 7 days apart. The 6-day supplement (lupin grain) began 2 days after the second PG injection and continued until the third. Follicles were studied by ultrasound, and blood was sampled to measure glucose and hormones. The supplement increased (P<0.01) the concentrations of glucose, insulin and leptin, decreased FSH concentrations (P<0.01) and tended to increase oestradiol concentrations (P=0.06). The supplement tended to increase the number of 3 mm follicles (P=0.06). Compared with low-BC ewes, high-BC ewes had more follicular waves (P<0.05), higher concentrations of insulin, leptin and IGF1 (P<0.05) and tended to have higher FSH concentrations (P=0.09). Leptin and insulin concentrations remained high until the end of supplementation in high-BC ewes, whereas they decreased after the third day of supplementation in low-BC ewes. In conclusion, high concentrations of metabolic hormones in fat ewes are associated with the development of more follicular waves. When a supplement is superimposed on this situation, changes in glucose and metabolic hormones allow more follicles to be selected to ovulate.

scholarly journals Follicle development, endocrine profiles and ovulation rate in adult Merino ewes: effects of early nutrition (pre- and post-natal) and supplementation with lupin grain

Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. 101-110 ◽  
Author(s):  
C Viñoles ◽  
B L Paganoni ◽  
K P McNatty ◽  
D A Heath ◽  
A N Thompson ◽  
...  
Keyword(s):  
Early Life ◽  
Ovarian Function ◽  
Ovulation Rate ◽  
Aromatase Activity ◽  
Follicle Development ◽  
Short Term ◽  
Antral Follicles ◽  
Cell Numbers ◽  
Metabolic Hormones ◽  
The Third

In adult ewes, we tested whether ovarian function, including the response to short-term supplementation, was affected by the nutrition of their mothers during the pre-/post-natal period. A 2×2 factorial design was used with nutrition in early life (low or high) and a 6-day supplement (with or without) as factors. All ewes received three prostaglandin (PG) injections 7 days apart, and the supplement (lupin grain) was fed for 6 days from 2 days after the second until the third PG injection. We measured reproductive and metabolic hormones, studied follicle dynamics (ultrasonography), and evaluated granulosa cell numbers, aromatase activity and oestradiol (E2) concentrations in follicular fluid in healthy follicles at days 3 and 7 of supplementation. Ovulation rate was increased by 25% by exposure to high pre-/post-natal nutrition (1.5 vs 1.2; P<0.05), in association with a small decrease in FSH concentrations (P=0.06) and a small increase in insulin concentrations (P=0.07). The number of healthy antral follicles was not affected. Acute supplementation increased the number of granulosa cells (3.7±0.2 vs 3.0±0.2 million; P<0.05) in the largest follicle, and the circulating concentrations of E2 (4.6±0.3 vs 3.9±0.3 pmol/l; P<0.05) and glucose (3.4±0.03 vs 3.3±0.03 mmol/l; P<0.01). Both early life nutrition and acute supplementation appear to affect ovulation rate through changes in glucose–insulin homoeostasis that alter follicular responsiveness to FSH and therefore E2–FSH balance.

Embryo losses in sheep during short-term nutritional supplementation

2012 ◽  
Vol 24 (8) ◽  
pp. 1040 ◽  
Author(s):  
C. Viñoles ◽  
K. M. M. Glover ◽  
B. L. Paganoni ◽  
J. T. B. Milton ◽  
G. B. Martin
Keyword(s):  
Nutritional Supplement ◽  
Nutritional Supplementation ◽  
Short Term ◽  
Embryo Survival ◽  
Embryo Mortality ◽  
Treatment Groups ◽  
Metabolic Hormones ◽  
Igf I ◽  
And Control

To test whether a nutritional supplement fed from 6 days before until 15 days after insemination reduces progesterone concentrations and increases embryo losses, Merino ewes were artificially inseminated (Day 0). Control ewes (n = 116) were not supplemented whereas Lupin6 ewes (n = 112) were supplemented with 500 g lupin grain daily for 6 days before insemination, and Lupin6+15 ewes (n = 122) from 6 days before until 15 days after insemination. There were no major differences between treatment groups in progesterone concentrations over the first 17 days of pregnancy. Embryo losses over Days 10–17 were lower in the Lupin6+15 than in the Control and Lupin6 groups, but the opposite occurred from Day 17–30. The concentrations of insulin and IGF-I were higher in Lupin6+15 ewes on Days 5, 12 and 17, compared with Lupin6 and Control ewes, while leptin concentrations decreased by Day 17 in the Lupin6+15 group. We conclude that feeding ewes for 15 days after mating improved embryo survival, which was associated with an increase in the concentrations of metabolic hormones and lower progesterone concentrations. However, the decrease in leptin concentrations promoted by the interruption of supplementation seems be linked to increased embryo mortality up to Day 30.

scholarly journals Relationships between changes in Holstein cow’s body condition, acetone and urea content in milk and cervical mucus and sperm survival

2012 ◽  
Vol 60 (5) ◽  
pp. 39-48 ◽  
Author(s):  
Jan Beran ◽  
Luděk Stádník ◽  
Jaromír Ducháček ◽  
Monika Okrouhlá
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
Cervical Mucus ◽  
Short Term ◽  
Data Set ◽  
The Third ◽  
Urea Content ◽  
Condition Score ◽  
Sperm Survival ◽  
The Relationship

The objectives of this study were to evaluate the relationship between changes in Holstein cow’s body condition score (BCS), acetone and urea content in the milk and cervical mucus (CM) and sperm survival in CM. At insemination, samples of milk and CM were collected from 64 Holstein cows. Content of acetone and urea were determined. Sperm motility was assessed subjectively at the beginning and after 30, 60 and 90 minutes of the short-term heat test in CM. Data about evaluation of cow’s BCS were taken from farm evidence. The data set was analyzed using SAS/STAT software. Effect of change in cow’s BCS one month before insemination was significant only in relation to the acetone content in milk (P < 0.05). Higher values of acetone and urea content were found in the CM compared to milk. Higher levels of both metabolites were detected in primiparous cows and in cows on the third and subsequent lactation, resp. in cows inseminated 3 times and more. The highest values of both metabolites negatively affected sperm survival during the short-term heat test, especially after 90 minutes (P < 0.05–0.01). Significant decreases (P < 0.05–0.01) were detected in cows with the highest level of acetone and urea.

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

2004 ◽  
Vol 16 (6) ◽  
pp. 589 ◽  
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.

The effect of energy intake level, body condition score, and leptin on ovulation rate in fat-tailed ewes

2003 ◽  
Vol 2003 ◽  
pp. 80-80 ◽  
Author(s):  
A. Towhidi ◽  
F. Rostami ◽  
H. Khazali ◽  
A.H. Ahadi
Keyword(s):  
Body Weight ◽  
Energy Intake ◽  
Body Condition ◽  
Body Condition Score ◽  
Ovulation Rate ◽  
Long Period ◽  
Intake Level ◽  
Short Period ◽  
Condition Score ◽  
Plasma Leptin

Ovulation rate (OR) is depended to energy intake level (EIL) and body condition score (BCS) in ewe (Gordon, 1997). There is a high correlation between BCS and plasma leptin concentration (PLC) in sheep (Blache et al, 2000). Corresponding to leptin is a metabolic stimulant for reproduction (Barb et al, 1999), it is possible that leptin is involved in the ovulation rate in ewe. Therefore, first experiment was conducted to study the effect of EIL on body weight (BW), BCS, OR and PLC in a long period, and second experiment was designed to investigate the effect of EIL and leptin administration on OR in a short period in fat-tailed Shal ewes.

The pattern of LH secretion and the ovarian response to the ‘ram effect’ in the anoestrous ewe is influenced by body condition but not by short-term nutritional supplementation

2014 ◽  
Vol 26 (8) ◽  
pp. 1154 ◽  
Author(s):  
R. J. Scaramuzzi ◽  
L. Oujagir ◽  
J-B. Menassol ◽  
S. Freret ◽  
A. Piezel ◽  
...  
Keyword(s):  
Body Condition ◽  
Ovarian Response ◽  
Nutritional Supplementation ◽  
Short Term ◽  
Blood Concentrations ◽  
Lh Surge ◽  
Lh Pulsatility ◽  
Lower Glucose ◽  
Good Nutrition ◽  
Ram Effect

In sheep, the ‘ram effect’ induces out-of-season fertility and good nutrition increases prolificacy. This experiment determined if fatness or short-term nutritional supplementation modified the response to the ‘ram effect’. A group of 48 Île-de-France ewes were fed diets that produced groups with body-condition scores (BCS) of >3.0 and <2.0. Within each BCS group animals were supplemented daily with 500 g of lupins from Day –5 to Day 0 (ram introduction) resulting in four groups: low BCS, supplemented (n = 7) and non-supplemented (n = 8) and high BCS, supplemented (n = 12) and non-supplemented (n = 11). The blood concentrations of glucose and insulin and the LH response to gonadotrophin-releasing hormone (GnRH) were determined. After the ‘ram effect’ the pattern of LH pulsatility, the LH surge and ovarian responses were analysed. Low BCS ewes had lower glucose and insulin (P < 0.001) and supplementation increased both (P ≤ 0.001). The increase in LH induced by GnRH was reduced in low BCS ewes (P = 0.015) but it was not affected by supplementation. Similarly, LH pulsatility was reduced in low BCS ewes (P < 0.05). The LH surge and ovarian cyclicity were not affected but the follow-up cycle was delayed (P = 0.034) and progesterone was reduced (P = 0.029) in low BCS ewes. There was an effect of BCS on ovulation rate (P < 0.05). These results show that the BCS can modify the response to the ‘ram effect’ and that supplementation has little effect on this response.

scholarly journals The effect of a direct arterial infusion of insulin and glucose on the ovarian secretion rates of androstenedione and oestradiol in ewes with an autotransplanted ovary

1999 ◽  
Vol 163 (3) ◽  
pp. 531-541 ◽  
Author(s):  
JA Downing ◽  
J Joss ◽  
RJ Scaramuzzi
Keyword(s):  
Ovarian Function ◽  
Ovarian Follicle ◽  
Plasma Concentrations ◽  
Ovulation Rate ◽  
Follicle Development ◽  
Short Term ◽  
Arterial Infusion ◽  
Follicle Selection ◽  
Metabolic Hormone ◽  
Secretion Rates

Improving ewe nutrition even for short periods will increase ovulation rate. The increased nutrients must in some way affect the number of follicles that develop to the pre-ovulatory stage. One possible mechanism is that a nutrient or a metabolic hormone that responds to nutrition might act directly on the ovary to influence follicle development and/or follicle selection. In the study described here, insulin and glucose, alone or together, were infused directly into the ovarian artery of ewes with an autotransplanted ovary, for 13.5 h on day 11 of the oestrous cycle. The pattern of androstenedione and oestradiol secretion in response to a GnRH-stimulated LH pulse was measured 2.5 h before and 12.5 h and 24.5 h after the start of the infusion. Glucose or insulin infused alone had no effect on the secretion of androstenedione and oestradiol. However, when infused together, they decreased significantly the secretion of androstenedione and, to a lesser extent, oestradiol. We suggest that the sudden availability of additional glucose and insulin increases insulin-stimulated glucose uptake by the follicle. This leads to an inhibition of LH-stimulated steroidogenesis by the ovarian follicle which occurs in the absence of any detectable changes in circulating plasma concentrations of FSH. These results show that insulin and glucose act together to influence ovarian function directly and suggest that the effects of short-term nutrition on ovulation rate may be mediated by a direct ovarian action of insulin and glucose.

Effect of body condition on ovarian sensitivity to exogenous FSH in ewes in which endogenous gonadotrophin secretion is suppressed

1991 ◽  
Vol 1991 ◽  
pp. 172-172
Author(s):  
S.R. McMillen ◽  
S.M. Rhind ◽  
A.S. McNeilly
Keyword(s):  
Body Condition ◽  
Gnrh Agonist ◽  
Ovarian Follicles ◽  
Ovulation Rate ◽  
Follicle Development ◽  
Sample Collection ◽  
Gonadotrophin Secretion ◽  
Body Condition Scores

The results of previous experiments indicate that the effect of body condition (BC) on ovulation rate is mediated through changes in the number of large, potentially ovulatory, ovarian follicles. However, these differences in follicle populations were not associated with consistent differences in gonadotrophin profiles. It was therefore postulated that effects of level of BC on follicle development and ovulation rate are due to differential ovarian sensitivity of FSH.Two groups of 20 Scottish Blackface ewes were fed differentially so that they achieved mean (±s.e.m.) body condition scores of 1.78±0.017 (Low; L) and 2.94±0.031 (High; H) by 2 weeks before sample collection. They were then fed to maintain these body conditions throughout the remainder of the experiment. Four weeks before study, Alzet minipumps (Charles Rivers UK Ltd.) containing GnRH agonist (buserilin; Hoechst AG; Frankfurt, F.R.G.) were inserted, subcutaneously, in all ewes. This treatment partially suppresses FSH secretion and totally inhibits LH pulses so that growth of ovarian follicles >2.5 mm in diameter is inhibited.

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