scholarly journals Influence of suckling and continuous cow-calf association on the resumption of post-partum ovarian function in Bos indicus cows monitored by plasma progesterone profiles

1991 ◽  
Vol 31 (3) ◽  
pp. 241-247 ◽  
Author(s):  
E. Mukasa-Mugerwa ◽  
A. Tegegne ◽  
R. Franceschini
Keyword(s):  
Ovarian Function ◽  
Post Partum ◽  
Bos Indicus ◽  
Plasma Progesterone ◽  
Cow Calf

The use of salivary progesterone assays in the assessment of ovarian function in postmenarcheal girls

1984 ◽  
Vol 102 (2) ◽  
pp. 265-268 ◽  
Author(s):  
G. F. Read ◽  
D. W. Wilson ◽  
I. A. Hughes ◽  
K. Griffiths
Keyword(s):  
Luteal Phase ◽  
Ovarian Function ◽  
Age Groups ◽  
Premenopausal Women ◽  
Chronological Age ◽  
First Year ◽  
Published Data ◽  
Sufficient Data ◽  
Plasma Progesterone ◽  
Probable Occurrence

ABSTRACT Menstrual cycle profiles of salivary progesterone were derived from daily samples obtained from 75 postmenarcheal girls aged between 12 and 17 years. Data were analysed to establish the proportion of girls exhibiting ovulatory cycles in each of several age groups following menarche or in groups based solely on chronological age. 'Luteal'-phase profiles of salivary progesterone, which were similar in shape to those characteristic of mature premenopausal women, were taken to indicate the probable occurrence of ovulation. The percentage of cycles in those subjects judged to be ovulatory, grouped according to gynaecological age, rose from 14% in the first year to 56% in the fourth year. Those classified according to chronological age, and where sufficient data permitted reliable estimates of the percentage of subjects ovulating, rose from 11% at 12 years of age to 64% for girls aged 16. These data are in reasonable concordance with published data using plasma progesterone and urinary methods for establishing ovulatory incidence, and indicate the value of salivary progesterone measurements in studies of ovarian function in adolescence. J. Endocr. (1984) 102, 265–268

Effect of body condition score at calving and suckling frequency on post-partum interval in suckler cows

1992 ◽  
Vol 1992 ◽  
pp. 67-67
Author(s):  
M. G. Diskin ◽  
M. Grealy ◽  
J. M. Sreenan
Keyword(s):  
Body Condition ◽  
Nutrient Intake ◽  
Important Determinant ◽  
Body Condition Score ◽  
Post Partum ◽  
Reproductive Efficiency ◽  
Early Lactation ◽  
Preliminary Results ◽  
Condition Score ◽  
Cow Calf

The interval from calving to first oestrus (post-partum interval) is an important determinant of reproductive efficiency in suckler cows. While this interval is influenced by a range of factors including cow age, breed, presence of bull, cow-calf interactions and disease, the most important factors are suckling (frequency / number of calves) and nutrition (pre- and post-partum nutrient intake, body condition at calving and during early lactation). The mechanisms by which these factors, either independently or interactively, affect the length of the anoestrous period are unclear. Similarly, the time post-partum at which suckling exerts its effect on resumption of cyclicity is unknown. The effects of body condition score at calving and of changing the frequency of suckling on the length of the post-partum interval were determined. Preliminary results are presented.

Opioid involvement in LH release during the negative feedback effects of oestradiol and progesterone in dairy cows

1991 ◽  
Vol 3 (6) ◽  
pp. 709 ◽  
Author(s):  
AS Nanda ◽  
WR Ward ◽  
H Dobson
Keyword(s):  
Negative Feedback ◽  
Post Partum ◽  
Opioid Peptide ◽  
Endogenous Opioid ◽  
Endogenous Opioid Peptide ◽  
Plasma Progesterone ◽  
Lh Surge ◽  
Transient Rise ◽  
Lh Release ◽  
Feedback Phase

To create a clearly defined and uniform feedback phase of oestradiol, 1 mg oestradiol benzoate (OE2) was injected i.m. either 15-43 days post partum in 7 cows (Expt 1), or 12 h after prostaglandin oestrus synchronization of 4 cyclic cows (Expt 2 and 3). An endogenous opioid peptide (EOP) antagonist (250 mg naloxone), an EOP agonist (300 mg morphine), or a combination of the two was given in Expt 1, 2 and 3 respectively as a single i.v. injection in cows 16-18 h after OE2, i.e. in the negative feedback phase and before the expected onset of an induced luteinizing hormone (LH) surge. Blood samples were collected every 15 min for 1 h before and 2 h after each treatment. In Expt 1, naloxone failed to increase LH release when given during the negative feedback phase, but caused excessive release in one cow in which the LH surge had just begun. In all cows in Expt 2, morphine suppressed LH release (P less than 0.05). In Expt 3, naloxone prevented the suppressive effects of morphine for the first hour after treatment; a transient rise in LH occurred in one cow in which treatment was given 1 h before the start of the LH surge. In Expt 4, 250 mg naloxone was injected i.v. into 4 cows that had a plasma progesterone concentration of 1.5-3.1 ng mL-1 in the luteal phase of the oestrous cycle: naloxone failed to increase LH concentrations. It is concluded that LH can be further suppressed by opiates given to cows during the negative feedback phase of oestradiol.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of bromocriptine at parturition in the tammar wallaby, Macropus eugenii

1990 ◽  
Vol 2 (1) ◽  
pp. 79 ◽  
Author(s):  
TP Fletcher ◽  
G Shaw ◽  
MB Renfree
Keyword(s):  
Post Partum ◽  
Tammar Wallaby ◽  
Plasma Prolactin ◽  
Plasma Progesterone ◽  
Macropus Eugenii ◽  
Sequence Of Events ◽  
Prostaglandin Release ◽  
Peripartum Period ◽  
And Control ◽  
Subsequent Onset

Female tammar wallabies were treated with the dopamine agonist bromocriptine at the end of pregnancy to suppress the peripartum pulse of plasma prolactin. The animals were subsequently observed, and a series of blood samples taken to define the hormonal profiles before and immediately after parturition. Birth was observed in 4/5 control animals and occurred in 8/9 bromocriptine-treated animals. The peripartum peak in plasma PGFM concentrations was not affected by bromocriptine although the pulse of prolactin normally seen at parturition was completely abolished. The timing of luteolysis was apparently unaffected, as plasma progesterone concentrations fell similarly in both treated and control animals immediately after parturition. However, all of the neonates of the bromocriptine-treated animals died within 24 h, possibly because of a failure to establish lactation. Subsequent onset of post-partum oestrus was delayed or absent both in control and in bromocriptine-treated animals, suggesting that the frequent blood sampling and disturbances in the peripartum period interfered with these endocrine processes. It is concluded that both prolactin and prostaglandin can induce luteolysis in the pregnant wallaby, but that the normal sequence of events results from a signal of fetal origin inducing a prostaglandin release from the uterus, which in turn releases a pulse of prolactin that induces a progesterone decline.

Physiological Adaptations to Milk Production that Affect the Fertility of High Yielding Dairy Cows

2004 ◽  
Vol 29 ◽  
pp. 37-71 ◽  
Author(s):  
V. J. Taylor ◽  
D. E. Beever ◽  
D. C. Wathes
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Ovarian Function ◽  
Post Partum ◽  
Reproductive Function ◽  
Influential Factors ◽  
Corpora Lutea ◽  
Expected Time ◽  
Physiological Adaptations ◽  
Igf I

SummaryThe high yielding dairy cow is expected to produce a substantial milk output every year and at the same time to conceive and maintain a pregnancy to term. To fulfil lifetime production potential a balance between yield, fertility and other influential factors has to be achieved. Any inability on the part of the management system to identify and rectify problems or on the part of the cow to cope with metabolic demands invariably results in economic or welfare issues. Our studies of high yielding dairy cows have revealed that some animals are capable of normal reproductive function whilst others are classic repeat breeders (requiring 3+ services per conception) or simply fail to rebreed. It is well established that the somatotrophic axis (growth hormone and insulin-like growth factors) drives lactation in ruminants but it is also intimately involved in reproductive processes. An awareness of metabolic adaptations to lactation that impact on reproduction in dairy cows is needed for appropriate management.The objective of our studies was to explore the metabolic profiles of high yielding dairy cows to identify factors influencing their ovarian function and fertility, hence to characterise the physiological adaptations involved. Our studies revealed different relationships between progesterone profile categories and metabolic status post partum. Delayed ovulation (DOV) or persistent corpora lutea (PCL) may be an appropriate response to a nutritional state or physiological situation and it may therefore be inaccurate to refer to these as ‘abnormal’. Whilst associated with high milk yields, not all profile categories detrimentally affected fertility parameters. Delayed ovulation postcalving (DOV1) was identified as the most prevalent abnormal profile encountered in first lactation high yielding cows. This may have occurred because the cows were not yet physically mature and unable to sustain both milk production and growth. The condition lasted long enough (71 ± 8.3 days from calving) to have a detrimental impact on their overall fertility parameters and was associated with significant physiological changes, representative of tissue mobilisation. Although the incidence of persistent luteal phases (PCL1 and PCL2) in dairy cows is increasing, this condition was not found to have any substantial detrimental effects on fertility or production parameters of the primiparous or multiparous cows in these studies. The main reproductive problems in our high yielding primiparous and multiparous cows appeared to be a failure to ovulate and conceive at the expected time or to maintain a pregnancy. These situations were associated predominantly with high milk yields and low concentrations of plasma IGF-I. A failure to ovulate appears to occur when body reserves are mobilised to maintain milk yield at the expense of reproduction and seems most likely to occur in primiparous high yielding cows or those experiencing GH-resistance (low IGF-I) due to excessive body condition loss, reduced feed intakes and factors such as stress and disease. More detailed investigations of dietary means of increasing IGF-I and optimising insulin concentrations, targeted at important reproductive times, are required in high yielding dairy cows, to aid in their management.

Creep feeding and prepartum supplementation effects on growth and fertility of Brahman-cross cattle in the dry tropics

1996 ◽  
Vol 36 (4) ◽  
pp. 389 ◽  
Author(s):  
G Fordyce ◽  
NJ Cooper ◽  
IE Kendall ◽  
BM O'Leary ◽  
Jde Faveri ◽  
...  
Keyword(s):  
Post Partum ◽  
Bos Indicus ◽  
Weather Conditions ◽  
Wet Season ◽  
Short Term ◽  
Research Committee ◽  
Creep Feeding ◽  
Dry Tropics ◽  
Creep Feed ◽  
Short Period

Post-partum anoestrus is a primary contributor to low branding rates in Bos indicus cattle herds in the dry tropics of northern Australia [Entwistle, K. W. (1983). Australian Meat Research Committee Review No. 431. To increase branding rates, it was hypothesised that creep feeding for a short period in mid-late lactation during the latter half of the growing season may trigger an earlier onset of post-partum oestrus cycling, just as short-term, high-level, prepartum supplementation can achieve. Two experiments were conducted using Fn Brahman-cross cows (1/2, 5/8 and 3/4 crosses with Beef Shorthorn) which calved from late October to late Januarv. Cows were mated from mid-late Januarv to mid-April. Calves in one treatment in both experiments had ad libitum access to creep feed (calf pellets: 16% crude protein, 10 MJ ME/kg) for 4042 days from late February to early April. In experiment 2, the effects on cow growth and fertility due to supplementation with either cottonseed meal (1.5 kg/day) or molasses with 7.4% (w/w) urea for 49 days late in the dry season before calving ('spike' feeding) were also evaluated. Control cattle were unsupplemented. Creep feed was only consumed at 0.1 and 0.4 kg/day in experiments 1 and 2, respectively. Short-term creep feeding had no consistent effects on cow liveweights, condition, or fertility, or on calf growth and temperaments under extensive grazing conditions during the tropical wet season. Spike feeding reduced weight loss by 0.2-0.4 kg/day (P<0.01). The effects on liveweights did not persist into the wet season. There were no effects on cow fertility in this year of extreme weather conditions, when 4 months of nutritional and climatic stress followed supplementation.

scholarly journals Progesterone production in superovulated holstein heifers and in crossbred recipient of embryo supplemented with betacarotene and tocopherol

2011 ◽  
Vol 35 (4) ◽  
pp. 817-825
Author(s):  
José Nélio de Sousa Sales ◽  
Lilian Mara Kirsch Dias ◽  
Celso Rodrigues Franci ◽  
Alexandro Aluísio Rocha ◽  
Guilherme Gastão Cardoso ◽  
...  
Keyword(s):  
Intramuscular Injection ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Fixed Time ◽  
Corpora Lutea ◽  
Estrus Synchronization ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Implant Placement ◽  
Intravaginal Device

Two experiments were conducted to evaluate the effect of the intramuscular injection of betacarotene associated to tocopherol on the plasma concentration progesterone of superovulated Holstein heifers (experiment 1) and in crossbred (Bos taurus x Bos indicus) heifers submitted to fixed-time embryo transfer (FTET, experiment 2). In experiment 1, after estrus synchronization and superovulation animals were inseminated 12 and 24 hours after estrus onset and embryos flushed 7 days later. Heifers were allocated randomly to one of three treatments: Control; T800 (800 mg of betacarotene plus 500 mg of tocopherol) and T1200 (1,200 mg of betacarotene plus 750 mg of tocopherol). The treatments were given on the day of ear implant placement and repeated on the first day of superovulation. Blood samples were collected on D0, D5, D9, D12 and D16. In experiment 2, treatments were imposed at intravaginal device insertion (D0). The same experimental design, as in experiment 1, was used. Blood samples were collected on D17 (embryos implanted) for progesterone determination by radioimmunoassay. In experiment 1, average plasma progesterone concentrations after corpora lutea formation (D12 plus D16 means) were 13.7±1.8 ng/ml, 14.5±2.3 ng/ml and 10.8±2.3 ng/ml for control, T800 and T1200, respectively, and did not differ (P=0.44). In experiment 2, progesterone concentrations on D17 in Control (8.88±0.57 ng/ml), T800 (7.48±0.64 ng/ml) and T1200 (5.90±1.33 ng/ml) groups were similar (P=0.11). Results indicate that the supplemental betacarotene and tocopherol injections did not influence peripheral progesterone concentrations in superovulated Holstein donors and crossbreed recipients heifers.

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