The cause of the inherently high variation in number of folliclesand oocytes in ovaries of mammals is unknown. However, nutritionduring gestation has a significant impact on postnatal health,but little is known about the role of maternal nutrition onovarian development in offspring. Our previous results showthat number of follicles growing during follicular waves reflectssize of the ovarian reserve (total number of healthy folliclesand oocytes in ovaries) in cattle. Therefore, the aim of thepresent study was to use the bovine model to examine the effectof maternal nutritional restriction from shortly before conceptionto the end of the first trimester of pregnancy (period encompassingthe peak in oocyte numbers in fetus) on the number of antralfollicles during follicular waves in female offspring. Cross-bredbeef heifers (n = 60), of similar age and weight, were randomlyassigned to one of two nutritional treatments: control (C; n= 25) or restricted (R; n = 35) and were individually fed at1.2 or 0.6 of their maintenance (M) energy requirements, respectively,starting 11 days before artificial insemination. Estrous cycleswere synchronized and heifers were artificially inseminatedwith sex-sorted semen from a single sire to increase the proportionof female calves born. Pregnancy diagnosis was carried out onDay 28 using ultrasonography and pregnant heifers (n=28) continuedto receive their respective diets up to Day 110 of gestation.From Day 110 to calving all animals received a 1.4 M diet. Twenty-ninecalves were born (C = 13; R = 16): 23 single female calves,one set of female twins and 4 males. Single female calves bornto mothers in the two groups (C, n=13; R, n=10) were weighedat birth and thereafter every fortnight. Daily transrectal ovarianultrasonography was performed for 10-14 days to count numberof antral follicles ≥ 3mm in diameter during a follicular wavestarting at 7 and 18 weeks of age. Maternal nutrition did notinfluence pregnancy rate on Day 28, gestation length, calf weightat birth, at 7 or 18 weeks of age, or diameter of the largestfollicle in each follicular wave. However, the peak, minimumand mean number of antral follicles ≥ 3mm in diameter in follicularwaves were 60% lower in calves born to heifers in the Restrictedcompared with the Control group. In conclusion, maternal nutritionalrestriction during the first trimester of pregnancy has a significantnegative impact on number of follicles growing during follicularwaves and correspondingly size of the ovarian reserve in calves.Funded by the Irish Department of Agriculture, Fisheries andFood (RSF 06-328) and NRI Competitive Grant nos. 2004-35203-14781& 2007-35203-18178 from CSREES to JJI.
Evidence That Undernutrition During the First Trimester of Pregnancy Influences Development and Function of the Cardiovascular System in Female Offspring in Cattle / Mossa, Francesca; Walsh, Sw; Hildebrandt, Tb; Kenny, Da; Lonergan, P; Smith, Gw; Ireland, Jj; Evans, Aco. - In: BIOLOGY OF REPRODUCTION. - ISSN 0006-3363. - 85:(2011), pp. 281-281.
Evidence That Undernutrition During the First Trimester of Pregnancy Influences Development and Function of the Cardiovascular System in Female Offspring in Cattle
MOSSA, Francesca;
2011-01-01
Abstract
The cause of the inherently high variation in number of folliclesand oocytes in ovaries of mammals is unknown. However, nutritionduring gestation has a significant impact on postnatal health,but little is known about the role of maternal nutrition onovarian development in offspring. Our previous results showthat number of follicles growing during follicular waves reflectssize of the ovarian reserve (total number of healthy folliclesand oocytes in ovaries) in cattle. Therefore, the aim of thepresent study was to use the bovine model to examine the effectof maternal nutritional restriction from shortly before conceptionto the end of the first trimester of pregnancy (period encompassingthe peak in oocyte numbers in fetus) on the number of antralfollicles during follicular waves in female offspring. Cross-bredbeef heifers (n = 60), of similar age and weight, were randomlyassigned to one of two nutritional treatments: control (C; n= 25) or restricted (R; n = 35) and were individually fed at1.2 or 0.6 of their maintenance (M) energy requirements, respectively,starting 11 days before artificial insemination. Estrous cycleswere synchronized and heifers were artificially inseminatedwith sex-sorted semen from a single sire to increase the proportionof female calves born. Pregnancy diagnosis was carried out onDay 28 using ultrasonography and pregnant heifers (n=28) continuedto receive their respective diets up to Day 110 of gestation.From Day 110 to calving all animals received a 1.4 M diet. Twenty-ninecalves were born (C = 13; R = 16): 23 single female calves,one set of female twins and 4 males. Single female calves bornto mothers in the two groups (C, n=13; R, n=10) were weighedat birth and thereafter every fortnight. Daily transrectal ovarianultrasonography was performed for 10-14 days to count numberof antral follicles ≥ 3mm in diameter during a follicular wavestarting at 7 and 18 weeks of age. Maternal nutrition did notinfluence pregnancy rate on Day 28, gestation length, calf weightat birth, at 7 or 18 weeks of age, or diameter of the largestfollicle in each follicular wave. However, the peak, minimumand mean number of antral follicles ≥ 3mm in diameter in follicularwaves were 60% lower in calves born to heifers in the Restrictedcompared with the Control group. In conclusion, maternal nutritionalrestriction during the first trimester of pregnancy has a significantnegative impact on number of follicles growing during follicularwaves and correspondingly size of the ovarian reserve in calves.Funded by the Irish Department of Agriculture, Fisheries andFood (RSF 06-328) and NRI Competitive Grant nos. 2004-35203-14781& 2007-35203-18178 from CSREES to JJI.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
