Insulin resistance: the link between metabolic disorders and cystic ovarian disease in high yielding dairy cows?

A preliminary investigation was performed to examine whether insulin resistance is a factor in the pathogenesis of cystic ovarian disease (COD) in high-yielding dairy cows. In total 30 cows, of which 15 were diagnosed as suffering from COD based on the anamnesis and clinical examination, and the other 15 served as matched controls, were subjected to an intravenous glucose tolerance test (IVGTT). The aim of the study was to investigate whether insulin activity was altered in COD cows. Differences in glucose clearance between the COD cows and their controls were analyzed comparing the fractional turnover rate (k), the glucose half-time (T1/2), and the area under the curve (AUC) 60 and 120 min after infusion. Differences in insulin response were analyzed comparing the insulin increment, the insulin peak concentration, and the AUC 60 and 120 min after glucose infusion. Although insulin resistance, attended by a secondary hyperinsulinemia, is stated to directly contribute to the ovarian abnormalities that characterize the polycystic ovary syndrome (PCOS) in human medicine, this was not observed in COD cows. On the contrary, COD cows appeared to have a low insulin response following an intravenous glucose load as compared with their matched controls. This was illustrated by significantly lower insulin increments (P = 0.04) and lower insulin peak concentrations (P = 0.04). As COD cows had a significantly lower insulin response to a standard glucose load, it was concluded that insulin could be a factor in the pathogenesis of COD in dairy cows.     

Effects of calving-related disorders on prostaglandin, calcium, ovarian activity and uterine involution in postrartum dairy cows

Postpartum ovarian activity, uterine involution and plasma concentrations of calcium and 15-keto-13, 14 dihydro-prostaglandin F2alpha (PGFM) were assessed in dairy cows with retained fetal membranes (n=10) and milk fever (n=10) at parturition. In addition, calcium and PGFM were evaluated in dairy cows affected with uterine prolapse (n=10) and pyometra (n=14). Cows with retained fetal membrane averaged 24.2+/-3.7 d until their first postpartum ovulation, while controls averaged 29.0+/-3.7 d (P>0.10). In cows with retained fetal membranes, the difference in follicular activity between the contralateral and ipsilateral ovaries in relation to the previously gravid uterine horn was appreciably greater post partum when compared with that of the controls. Cows with milk fever had an average of 30.8+/-3.1 d until their first postpartum ovulation, while control cows had an average of 20.4+/-3.3 d (P<0.05). The mean diameter of the uterine horns in cows with milk fever was greater (P<0.05) compared with that of the controls between Days 15-32 post partum. Concentrations of plasma calcium were lower in cows with retained fetal membranes within 24 h after parturition and during the first week post partum than in the controls (6.27+/-0.18 vs 7.40+/-0.18 mg/100ml, P<0.05). Concentration of calcium was lower (P<0.05) in cows with milk fever on Day 1 prior to treatment (4.68+/-0.40 < 5.8+/-0.45 mg/100ml) than in control cows; however, the calcium (Ca) level was not different during the subsequent 7 d post partum after treatment. Cows with uterine prolapse had lower concentrations of Ca during the first 7 d post partum than the controls (6.10+/-0.15 vs 7.33+/-0.12mg/100ml; P<0.01). Cows with pyometra had higher (P<0.05) concentrations of plasma PGFM than the controls (208.+/-13.2 > 138.1+/-15.2).     

Seasonal variation in the ovarian activity of beef cows assessed by monitoring progesterone concentrations

Ovarian activity was assessed for over a year in 16 beef cows, 10 of the Alentejano and 6 of the Mirandes breed, by measuring plasma progesterone twice weekly. It was observed that there were acyclic cows from January to the end of May and from the end of August to the end of September. The greatest number of acyclic cows (3 out of 16) was observed in April. Progesterone determinations showed that after the period of acyclia there was a small short-lasting increase in progesterone, then a cycle with a short dioestrus followed by cycles of normal duration. Oestrous cycles were on average 23.16 ± 0.16 days long; the difference between breeds was not significant. The duration of cycles throughout the year was statistically different (P < 0.01) between months. Minimum and maximum values were observed in March (21.5 ± 0.6 days) and December (25.05 = 0.58 days) respectively.     

Plasma progesterone and gonadotrophin concentrations and ovarian activity in post-partum dairy cows

Plasma progesterone concentrations in jugular vein blood samples collected every other day after calving from 13 Friesian dairy cows indicated that ovarian cyclic activity was initiated by 16.6 +/- 1.1 (s.e.m.) days post partum, except for 1 cow which did not resume cyclic activity until Day 98 post partum. Rectal palpation of the ovaries indicated that a developing follicle was recognizable at a mean time of 15.7 +/- 2.0 days after calving. During the first oestrous cycle after parturition there was a significantly shorter period when plasma progesterone levels were elevated than during the next 2 cycles. Concentrations of progesterone, LH, FSH and prolactin were determined for 4 cows, in blood samples taken every 6 h from 2 to 36 days post partum. Tonic LH release was lower during the first 10 days than subsequently, but the lack of change in pattern for FSH suggests dissimilar control mechanisms for these hormones during this time. Three cows showed evidence of a resumption of ovarian cyclicity during the sampling period: in 2 there was an initial LH surge of a magnitude which would normally give rise to ovulation, followed 4 days later by an increase in plasma progesterone lasting only 5 and 9 days. This progesterone was considered to be of follicular origin. A second LH surge was followed by the presence of a corpus luteum.     

Environmental constrains on post-partum ovarian activity in Tanzanian Zebu cows

Milk progesterone measurements were used to study post-partum ovarian activity and risk factors for ovarian dysfunction in Zebu cows reared under a traditional pastoral management system in three villages in Morogoro region, Tanzania. Milk samples for progesterone analysis were collected twice per week from a total of 98 lactations. The most prevalent ovarian dysfunction detected was delayed onset of post-partum ovarian activity and cessation of cyclical ovarian activity after a period of normal ovarian function. Prolonged luteal phases were not observed. Resumption of post-partum ovarian activity was observed in 61 (62.2%) cows. Pregnancy was diagnosed in 43 (43.8%) out of 98 cows and was terminated by abortion in 7 (16.3%) cows. The median number of days from calving to resumption of ovarian activity was lower in cows that calved during the dry season (167 days) as compared with those that calved in the rainy season (200 days, P=0.03), probably because ovarian function was stimulated in cows entering the rainy season first after the puerperal phase had ended. Cyclical ovarian activity ceased in seven (11.5%) cows, and all but one case of cessation of ovarian activity took place during the dry season. Cows in their first and second parities experienced prolonged intervals (244 days) between calving and onset of ovarian activity compared with cows in their third or later parity (172 days, P=0.03). Cows with marked losses in body condition experienced prolonged intervals between calving and onset of ovarian activity (229 days) as compared with cows that lost <1 body condition unit (172 days, P=0.03). The time interval from calving to resumption of ovarian activity varied between the three villages of the study (142, 192 and 229 days, P=0.05), indicating local differences in management practices.     

Effects of bull exposure on postpartum ovarian activity of dairy cows

The effects of bull exposure on postpartum reproduction have been previously studied in beef, but not in dairy cattle. The objective of this experiment was to investigate effects of bull exposure on postpartum reproductive characteristics during early lactation in high-producing Holstein dairy cattle. Forty-five multiparous dairy cows (9764 +/- 140 kg milk/lactation) were randomly grouped at the time of calving. Treatment 1 (NBE) was never exposed to the bull, treatment 2 (2 x BE) experienced fenceline contact with a mature Holstein bull twice daily during routine detection of oestrus, and treatment 3 (CBE) was in continuous proximity to the bull. All cows were observed for oestrous behaviour twice daily for 1/2 h following milking. Blood samples were collected every other day for progesterone (P4) assay. Postpartum ovarian reactivation, indicated by the occurrence of the first sustained rise in P4, was later (P = 0.02) during the postpartum period in both bull-exposed (2 x BE, CBE) treatments compared to the NBE treatment. Time postpartum until completion of the first ovarian cycle tended (P = 0.08) to be shorter in NBE cows compared to bull-exposed cows. Peak P4 concentrations were higher (P = 0.05) in NBE cows compared to bull-exposed cows prior to the second postpartum ovulation. Results indicate an extended period to ovarian reactivation in dairy cattle exposed to a bull, but bull exposure had no effect on long-term reproductive performance of exposed cows.     

Activity of alkaline phosphatase in uterine flushings of dairy cows affected with ovarian cysts or endometritis

Both uterine horns of 14 dairy cows with ovarian follicular cysts, and four animals affected with purulent endometritis were flushed via catheter using 30 ml phosphate buffered saline, following evisceration at a local abattori. Activity in the flushing media of alkaline phosphatase (ALP) and aspartate aminotransferase (GOT) were examined. Ovaries were prepared for light microscopy. Amount and morphological integrity of luteinized tissue found on the ovaries were reflected by correspondent levels in ALP activity, which was higher in the media taken from the ipsilateral to the luteal tissue situated uterine horns (651 +/- 228 vs 244 +/- 62 u/l, n = 3). Only cows having relatively large amounts of luteal tissue on the cystic ovaries (as in luteinized follicular cysts) exhibited very high ALP activity in uterine flushings (2693 +/- 1348 u/l, n = 2). Results suggest the existence of local relationships between luteal tissue in the ovary and the ipsilateral uterine horn in cows with ovarian follicular cysts.     

Effect of restricted suckling on ovarian activity and uterine involution in Brahman cows

Seventy-six Brahman cows and first-calf heifers ranging in age from three to five or more years were used to determine the effects of restricted suckling on postpartum ovarian activity and uterine involution. At 30 days postcalving, cows were randomly assigned to one of two groups: 1)normal suckling (34 cows) and 2)twice-daily suckling (42 cows). The cows were examined by rectal palpation weekly from parturition until the onset of the breeding season. The average interval from parturition to the presence of the first follicle larger than 10 mm (PPFI) was 36.0 +/- 1.0 days, and twice-daily suckling decreased PPFI length 8.1 days (P < 0.01); likewise, first- and second-calf heifers tended to have longer PPFI length (P < 0.05) than cows with three or more calvings. The average interval from parturition to first corpus luteum (PPCLI) was 59.0 +/- 2.0 days. PPCLI was affected by the age (P < 0.05) and weight of the cow at 30 days postpartum (P < 0.10). The average interval from parturition to first estrus (PPEI) was 68.0 +/- 5.0 days. PPEI was affected by suckling (P < 0.10) and month of parturition (P < 0.05). The average interval from parturition to uterine involution was 33.0 +/- 1.0 days. Uterine involution was influenced by month of calving (P < 0.01) and age of the cow (P < 0.05).     

The diagnosis and prevalence of subclinical endometritis in cows evaluated by different cytologic thresholds

The aims of our study were to determine (1) how the prevalence of cytologically determined subclinical endometritis varies when using three different cytological threshold ratios to categorize cows as either with or without endometritis, (2) how the number of animals categorized as having endometritis changes from the fourth to the sixth wk postpartum when using each threshold, (3) how subclinical endometritis influences the number of days open, and (4) how the results of cytological and bacterial examinations correlate. To answer these questions, 222 clinically healthy cows in two herds were examined in the fourth (Exam 1) and the sixth wk (Exam 2) postpartum, when endometrial surface scrapings for bacteriologic and cytologic examination were collected by cytobrush from their uterine horns. After each examination, all cows were categorized using three different thresholds: (1) > 18% polymorphonuclear leucocytes in Exam 1 and > 10% in Exam 2, (2) > 8% in both exams, and (3) > 5% in both exams. It was found that: (1) The number of cows categorized as having endometritis increased as the threshold was lowered, and ranged from 18.9% to 75.4% according to herd, time of examination, and the threshold used; (2) with all three thresholds and in both herds, the number of cows categorized as having endometritis in Exam 1 was approximately double that in Exam 2; whereas depending on the herd and the threshold used, 6.1% to 17.0% of the cows that were negative in the first exam were positive in the second, and 7.4% to 33.3% were positive in both exams; (3) cows were open for a significantly greater number of days if categorized as having endometritis with the first threshold in Exam 1 (mean ± SEM 151.5 ± 9.5 vs. 115.9 ± 7.8; P < 0.01), or with either the first or the second threshold in Exam 2 (mean ± SEM 155.0 ± 15.0 vs. 125.1 ± 6.6; P < 0.05); and (4) the most common bacteria were Streptococcus acidominimus and Escherichia coli, and the correlation between cytologic and bacteriologic findings was low (Φ = 0.08 to 0.17 for different tested thresholds). Subclinical endometritis seems to be associated more with the postpartum recovery of the endometrium than with bacterial infection.     

Lying patterns of high producing healthy dairy cows after calving in commercial herds as affected by age,environmental conditions and production

An animal expresses its physiological and well-being status by its behaviour. Changes in behaviour can be associated with health, production or well-being problems and therefore with the profitability of the farm. The objectives of the present study were to analyse lying patterns of healthy cows, collected with a commercial behaviour sensor, in early lactation in relation to environmental conditions, age of the cow and production performance. In future, these results may be used as a ‘baseline’ for detection of alterations in behaviour that indicate health problems. The study involved 210 healthy multiparous Israeli Holstein cows in three commercial dairy farms. Only healthy cows during the first 28 days after calving were included in this study. Data were analysed in relation to calving season, age of cows and correlation between milk production and lying time.The results show that lying time increased significantly with age and is significantly (P < 0.05) higher in winter than in summer (summer lactation 2: 491 ± 17 min/day (mean ± SD), summer lactation 3 and more: 520 ± 25 min/day, winter lactation 2: 531 ± 25 min/day, winter lactation 3 and more: 579 ± 38 min/day).The proportion of positively and negatively milk production and lying time correlated cows is affected by calving season.This study indicates that behaviour variables in early lactation are affected by calving season, lactation number and type of correlation between milk production and lying time.     

Influence of repeated dinoprost treatment on ovarian activity in cycling dairy cows

To study the ovarian response to the long-term effect of PGF_2α, 16 cows were treated with 25 mg tromethamine dinoprost (Pronalgon F; Pfizer, Tokyo, Japan) for 21 days after natural ovulation. Five control cows were treated with sterile physiological saline. The follicle and corpus luteum (CL) development were monitored using a real-time ultrasound instrument. In addition, the plasma concentration of progesterone (P₄) was determined. In nine of the 16 Pronalgon-treated cows, the first dominant follicle (1st DF), second dominant follicle (2nd DF), and third dominant follicle ovulated consecutively (group A). In five cows, the 1st and 2nd DFs ovulated consecutively (group B). The developing CL started to regress approximately 5 days after each ovulation without maturation in groups A and B. In the two remaining Pronalgon-treated cows, there was no further ovulation after natural ovulation (group C). In one cow in group C, the 1st DF became atretic and the 2nd DF became cystic with the diameter of the cystic follicle reaching 31.2 mm on Day 30. In another cow, the 1st DF became cystic with a diameter of 30.9 mm on Day 18. Although P₄ began to increase after each ovulation in all of the Pronalgon-treated cows, it decreased immediately after each ovulation without a large increase, peaking at approximately 1 ng/mL. Furthermore, the number of days when P₄ was >1 ng/mL from natural ovulation to Day 21 was 2.6 ± 0.7 days, which was significantly less than that in the control cows (16.0 ± 0.6 days). These results indicate that the long-term effect of PGF_2α has an important role in ovulation of all dominant follicles and might induce cystic ovaries in cows.     

The influence of ovarian activity and uterine involution determined by ultrasonography on subsequent reproductive performance of dairy cows

The objective of this study was to test the hypothesis that a follicle >8 mm diameter in the ovary ipsilateral to the previously gravid uterine horn (PGUH), between 14 and 28 days postpartum, improves subsequent reproductive performance. Lactating Holstein-Friesian cows (n=284) in 3 commercial herds were examined using transrectal ultrasonography once between 14 and 28 days postpartum to determine associations between uterine and ovarian measurements and subsequent fertility. There were fewer cows with a corpus luteum in the ovary ipsilateral to the PGUH compared with the contralateral ovary (16.9% vs. 37.0%; P<0.001). In addition, in the ovary ipsilateral to the PGUH there were fewer follicles >5 mm diameter (mean +/- SEM; 0.69 +/- 0.06 vs. 1.02 +/- 0.06; P<0.001) and fewer animals with a follicle >8 mm diameter (26.1% vs. 49.6%; P<0.001). These differences between the ovaries ipsilateral or contralateral to the PGUH declined with increasing time between 14 and 28 days postpartum. The presence of a purulent vaginal discharge decreased the number of animals with a corpus luteum in the ovary contralateral to the PGUH (45/143 vs. 60/141; P<0.05), but not in the ovary ipsilateral to the PGUH. The presence of a follicle >8 mm diameter in the ovary ipsilateral to the PGUH was associated with a shorter calving to conception interval compared with animals without such a follicle (99.0 +/- 5.6 days, n=74, vs. 112.8 +/- 4.4 days, n=210; P<0.05). These observations raise an intriguing issue: how does this follicle affect subsequent fertility--does the follicle exert a local influence on the uterus, or vice versa?     

Secretion of prostaglandins and leukotrienes by endometrial cells in cows with subclinical and clinical endometritis

The aims of this study were (1) to measure the secretion of prostaglandin F_2α (PGF_2α), prostaglandin E₂ (PGE₂), leukotriene B₄ (LTB₄), and leukotriene C₄ (LTC₄) by endometrial cells collected by a cytobrush from healthy cows and cows with subclinical and clinical endometritis in the fourth week postpartum, and (2) to evaluate the relationship between the mediators' levels of secretion and the number of polymorphonuclear neutrophils (PMNs) in the uterine smears of cows with subclinical endometritis. The study included cows without any signs of clinical endometritis (n = 63) and cows with clinical endometritis as a positive control (ENDOM, n = 12). Two different threshold ratios (>5% and >18% of PMNs) were used to categorize the cows without clinical signs as with or without cytologic endometritis (CE). Considering the first or second threshold, the animals with CE were included in group CE POS I or CE POS II, whereas the healthy cows were assigned to group CE NEG I or CE NEG II, respectively.     

Inverse association between BMI and prefrontal metabolic activity in healthy adults

Obesity has been associated with a higher risk for impaired cognitive function, which most likely reflects associated medical complications (i.e., cerebrovascular pathology). However, there is also evidence that in healthy individuals excess weight may adversely affect cognition (executive function, attention, and memory). Here, we measured regional brain glucose metabolism (using positron emission tomography (PET) and 2-deoxy-2[(18)F]fluoro-D-glucose (FDG)) to assess the relationship between BMI and brain metabolism (marker of brain function) in 21 healthy controls (BMI range 19-37 kg/m(2)) studied during baseline (no stimulation) and during cognitive stimulation (numerical calculations). Statistical parametric mapping (SPM) revealed a significant negative correlation between BMI and metabolic activity in prefrontal cortex (Brodmann areas 8, 9, 10, 11, 44) and cingulate gyrus (Brodmann area 32) but not in other regions. Moreover, baseline metabolism in these prefrontal regions was positively associated with performance on tests of memory (California Verbal Learning Test) and executive function (Stroop Interference and Symbol Digit Modality tests). In contrast, the regional brain changes during cognitive stimulation were not associated with BMI nor with neuropsychological performance. The observed association between higher BMI and lower baseline prefrontal metabolism may underlie the impaired performance reported in healthy obese individuals on some cognitive tests of executive function. On the other hand, the lack of an association between BMI and brain metabolic activation during cognitive stimulation indicates that BMI does not influence brain glucose utilization during cognitive performance. These results further highlight the urgency to institute public health interventions to prevent obesity.     

Pattern of follicular growth and resumption of ovarian activity in post-partum beef suckler cows

The ovaries of 18 post-partum beef suckler cows were examined daily, using ultrasound, from Day 5 post partum until a normal oestrous cycle was completed. Periods of growth and regression of medium-sized (5-9 mm) follicles were identified before one medium follicle became dominant (single large follicle greater than or equal to 10 mm). The mean (+/- s.e.m.) number of days from parturition to detection of the first post-partum dominant follicle was 10.2 +/- 0.5. The first post-partum dominant follicle ovulated in 2/18 (11%) cows. The interval from calving to first ovulation (mean +/- s.e.m. = 35.9 +/- 3.3 days) was characterized by the growth and regression of a variable number (mean = 3.2 +/- 0.2; range 1-6) of dominant follicles. The maximum diameter of the dominant follicle increased as the cows approached first ovulation (P less than 0.05). Behavioural oestrus was not detected in 16/18 (89%) cows at first ovulation. Following first ovulation, the length of the subsequent cycle was short (mean = 9.7 +/- 0.5 days; range 8-15 days) in 14/18 (78%) cows and was characterized by the development and ovulation of a single dominant follicle. During oestrous cycles of normal length (mean = 20.6 +/- 0.5 days; range 18-23 days) one (N = 2), two (N = 7) or three (N = 8) dominant follicles were identified. The growth rate, maximum diameter or persistence of non-ovulatory dominant follicles before first ovulation or during oestrous cycles were not different (P greater than 0.05). These data show that, in beef suckler cows, follicular development and formation of a dominant follicle occur early after parturition and the incidence of ovulation of the first dominant follicle is low. The number of dominant follicles that develop before first ovulation is variable; first ovulation is rarely associated with oestrus and short cycles are common after first ovulation. It is concluded that prolonged anoestrus in post-partum beef suckler cows is due to lack of ovulation of a dominant follicle rather than delayed development of dominant follicles.     

Hesperidin methyl chalcone ameliorates lipid metabolic disorders by activating lipase activity and increasing energy metabolism

Obesity has become an increasingly serious health issue with the continuous improvement in living standards. Its prevalence has become an economic burden on health care systems worldwide. Flavonoids have been shown to be beneficial in the prevention and treatment of obesity. Here, we evaluated the therapeutic potential of the flavonoid hesperidin methyl chalcone (HMC) on mice with high-fat diet (HFD)-induced hepatic steatosis in vivo and in vitro. Treatment with HMC reduced oleic and palmitic acid-induced increases in intracellular triglyceride accumulation in HepG2, AML12 and LMH cells. HMC also enhanced energy metabolism and lowered oxidative stress. We used Discovery studio to dock key proteins associated with lipid metabolism disorders to HMC, and found that HMC interacted with lipase. Furthermore, we demonstrated that HMC improved lipase activity and lipolysis. In addition, we found that HMC promoted glucose absorption, alleviated lipid metabolic disorders, improved HFD-induced liver injury, and regulated HFD-induced changes in energy metabolism. In conclusion, our study demonstrated that HMC ameliorated HFD-induced obesity and its complications by promoting lipase activity, and provides a novel approach for the prevention and treatment of obesity and related diseases.     

Xylem sap flow as affected by metabolic inhibitors and girdling

The flow of sap in Populus tremuloides was studied by the thermoelectric method immediately prior to and at several periods of time after radical girdling. Similarly, the flow of sap in Betula papyrifera was studied before and after girdling or injection with metabolic inhibitors or a filtrate of a culture of Ceratocystis ulmi.     

Effect of eCG on early resumption of ovarian activity in postpartum dairy cows

The purpose of the present study was to hasten the resumption of ovarian activity early postpartum in lactating dairy cows, using equine chorionic gonadotropin (eCG), to enhance follicular growth, followed by hCG, to induce ovulation. Primiparous Holstein dairy cows (n=21) were assigned equally into eCG, eCG-hCG and Control groups. Cows in the eCG and eCG-hCG groups received an i.m. injection of eCG (500 IU Folligon?) on Day 6 postpartum. Cows in the eCG-hCG group were also given an i.m. injection of hCG (500 IU Chorulon?), once dominant follicle reached the diameter of 13-16 mm following eCG injection. Cows in Control group did not receive any treatment. Daily blood sampling and ultrasound examination were conducted, starting at Day 6 postpartum until confirming the third ovulation. Follicles ≥10 mm in diameter were detected on Day 11.5±1.48, 10.1±0.52 and 11.1±1.36 after calving in Control, eCG and eCG-hCG groups, respectively (P>0.05). The first wave dominant follicle ovulated in 71.4% of cows treated with eCG and eCG-hCG. In contrast, none of the first wave dominant follicles ovulated in Control cows. By Day 20 postpartum, all cows in eCG group, 6/7 cows in eCG-hCG group and none of the cows in Control group ovulated (P<0.05). Short estrous cycles (≤16 days) were detected in 2/7, 1/7 and 6/7 cows in eCG, eCG-hCG and control groups, respectively (P<0.05). In conclusion, injection of eCG on Day 6 postpartum could assist the early resumption of ovarian activity by enhancing ovarian follicle growth and early ovulation in postpartum cows. In this context, subsequent hCG injection may not provide any more beneficial effect.     

Genetic relationship between cyclic ovarian activity in heifers and cows and beef traits in males

Records were collected in an experimental herd over an 11-year period from purebred Charolais heifers (n = 351), cows (n = 615) and young entire bulls (n = 383). The objective of the study was to estimate the genetic relationship between the components of female ovarian activity (age at puberty and postpartum anoestrus length), their growth rate and body condition score and beef traits measured on related bulls. Two methods were used to estimate age at puberty and postpartum anoestrus length: the detection of oestrous behaviour and a test of cyclicity based on plasmatic progesterone assay. This study shows the existence of significant heritability estimates for the different cyclicity traits (h² between 0.11 and 0.38). Most of the genetic correlation coefficients between ovarian activity and growth rate of females and males are negative and favourable (r_g between -0.43 and 0.06). Cyclicity is also favourably related with body condition score in young or adult females (r_g between -0.65 and -0.22). The genetic relationship between female ovarian activity and proportion of adipose tissue in the male carcass is, however, close to zero. These results show that an antagonism between male beef traits measured in this study and female ovarian activity is unlikely to be a cause for concern in the short term.