Conception Rates In Dairy Cattle Research Articles

The Effectiveness of Intrauterine Treatment with Momordica charantia L. on Some Hormone Parameters in Repeat Breeder Cattle

Background: Repeated breeding is a substantial problem in dairy cattle affecting reproductive efficiency. The goal of the current study was to see how intrauterine treatment of phytotherapeutic plant extract affected some hormonal indicators and conception rates in dairy cattle with fertility issues. Methods: In the study, 40 repeat breeder (RB) cattle were randomly divided into two groups. Forty ml (0.25 g/mL) Momordica charantia L. (MC) extract was administered intrauterine to cattle in group I (n=20) and 40 ml of pure olive oil was administered intrauterine to cattle in group II (n=20) at a time. The control group, group III (n=20), was composed of healthy heifers. Endometrial smear samples were taken from all RB cattle for cytological examination before the treatment and all were stained with Giemsa. Estradiol (E2), progesterone (P4) and insulin-like growth factor (IGF-1) levels were assessed by collecting blood samples starting from intrauterine treatment on days 0, 7 and 14. After the last blood sample was collected, the estrus cycles of all cattle were synchronized through a double dose of PGF2α administration at 14-day intervals. GnRH was administered with single insemination at the 60th hour following the second PGF2α treatment. Result: Subclinical endometritis was determined in 82.5% (33/40) of RB cattle. Pregnancy rates in group I, group II and group III were determined as 55%, 35% and 35%.respectively.(P greater than 0.05). There was no significant difference in E2 values according to time and between groups. For P4, there were also no significant differences between three time-dependent measurements, but there was a difference in the 7th and 14th days of the groups (P less than 0.01). For IGF-1, significant differences were found between the three time-dependent measurements of the groups (P less than 0.001). In conclusion, it was observed that the MC extract treatment, especially in RB with SCE, can improve the pregnancy rate by positively affecting the increase in IGF-1 which is a key element of the extremely complex endocrine system.

Factors affecting conception rate in dairy cattle using sorted semen in Uttarakhand

Factors affecting conception rate in dairy cattle using sorted semen in Uttarakhand

The effect of various administration routs of D-cloprostenol at the time of artificial insemination on conception rate in dairy cattle

The aim of the present study was to evaluate the effect of various administration routes of PGF2α analogue, D-cloprostenol, at the time of artificial insemination (AI) on conception rate in a large dairy herd. A total number of 659 lactating dairy cows (101 heifers and 558 cows) were enrolled in the study. Following heat detection, the cows were artificially inseminated according to the AM-PM rule. The animals were divided into a control (29 heifers and178 cows) and three experimental groups; IM (53 heifers and 110 cows), IV (155 cows) and IU (19 heifers and115 cows) groups that received intramuscular 150 µg, intravenous 150 µg and intrauterine 5 µg of D-cloprostenol, respectively, at the time of AI. The control group did not receive any treatment at the time of AI. To measure serum progesterone concentration, blood samples were obtained from 15 cows in each group at the time of insemination and on days 4 and 15 post-insemination. Pregnancy was diagnosed by rectal ultrasound examination between days 35-40 post-insemination. The effects of treatments, parity, milk production, and days in milk (DIM) on conception rate of adult cows were evaluated using the multivariate logistic regression model. Intramuscular administration of D-cloprostenol at the time of AI significantly increased conception rate in dairy cows compared to the control group (60.1% vs. 40.6%; p = .005). However, intravenous and intrauterine administration of D-cloprostenol did not alter the conception rate (32.3%; p = .29 and 50%; p = .11, respectively). D-cloprostenol treatment at AI could not significantly increase the conception rate of heifers followingboth (IM & IU) administration routes. In conclusion, this study showed that intramuscular administration of D-cloprostenol at the time of insemination might improve the conception rate in adult cows, while its intravenous and intrauterine administration did not induce any positive effects on reproductive efficiency of dairy cows. HIGHLIGHTS Intramuscular administration of D-cloprostenol at the time of insemination might improve the conception rate in adult cows. Intravenous administration of D-cloprostenol did not induce any positive effects on reproductive efficiency of dairy cows. Intrauterine administration of D-cloprostenol did not induce any positive effects on conception rate of dairy cows.

Symposium review: Immunological detection of the bovine conceptus during early pregnancy

Infertility and subfertility reduce the economic viability of dairy production. Inflammation reduces conception rates in dairy cattle, but surprisingly little information exists about the populations and the functions of immune cells at the conceptus-maternal interface during the periattachment period in dairy cattle. Early pregnancy is accompanied by immune stimulation at insemination and conceptus secretion of IFN-τ, pregnancy-associated glycoproteins, prostaglandins, and other molecules whose effects on immune function during early pregnancy have not been determined. Our working hypothesis is that pregnancy induces changes in immune cell populations and functions that are biased toward immunological tolerance, tissue remodeling, and angiogenesis. This review summarizes current knowledge, starting with insemination and proceeding through early pregnancy, as this is the period of maximal embryo loss. Results indicated that early pregnancy is accompanied by a marked increase in the proportion of endometrial immune cells expressing markers for natural killer (CD335) cells and cytotoxic T cells (CD8) along with an increase in cells expressing major histocompatibility class II antigens (macrophages and dendritic cells). This is accompanied by increased abundance of mRNA for IL-15, a natural killer growth factor, and IL-10 in the endometrium during early pregnancy. Furthermore, expression of indoleamine 2,3 dioxygenase was 15-fold greater in pregnant compared with cyclic heifers at d 17, but then declined by d 20. This enzyme converts tryptophan to kynurenine, which alters immune function by creating a localized tryptophan deficiency and by activation of the aryl hydrocarbon receptor and induction of downstream tolerogenic mediators. Expression of the aryl hydrocarbon receptor is abundant in the bovine uterus, but its temporal and spatial regulation during early pregnancy have not been characterized. Pregnancy is also associated with increased expression of proteins known to inhibit immune activation, including programed cell death ligand-1 (CD274), lymphocyte activation gene-3 (CD223), and cytotoxic T-lymphocyte associated protein-4 (CD152). These molecules interact with receptors on antigen-presenting cells and induce lymphocyte tolerance. Current results support the hypothesis that early pregnancy signaling in dairy heifers involves changes in the proportions of immune cells in the endometrium as well as induction of molecules known to mediate tolerance. These changes are likely essential for uterine wall remodeling, placentation, and successful pregnancy.

Investigation of Relation between the Ovulation Confirmation and Conception Rate in Dairy Cattle

Investigation of Relation between the Ovulation Confirmation and Conception Rate in Dairy Cattle

Designing of an artificial neural network model to evaluate the association of three combined Y-specific microsatellite loci on the actual and predicted postthaw motility in crossbred bull semen

The freezing of bull semen significantly hamper the motility of sperm which reduces the conception rate in dairy cattle. The prediction of postthaw motility (PTM) before freezing will be useful to take the decision on discarding or freezing of the germplasm. The artificial neural network (ANN) methodology found to be useful in prediction and classification problems related to animal science, and hence, the present study was undertaken to compare the efficiency of ANN in prediction of PTM on the basis of the number of ejaculates, volume, and concentration of sperms. The combined effect of Y-specific microsatellite alleles on the actual and predicted PTM was also studied. The results revealed that the prediction accuracy of PTM based on the semen quality parameters was comparatively lower because of higher variability in the data set. The ANN gave better prediction accuracy (34.88%) than the multiple regression analysis models (32.04%). The root mean square error was lower for ANN (8.4353) than that in the multiple regression analysis (8.6168). The haplotype or combined effect of microsatellite alleles on actual and predicted PTM was found to be highly significant (P < 0.01). On the basis of results, it was concluded that the ANN methodology can be used for prediction of PTM in crossbred bulls.

Short communication: Development of the first follicular wave dominant follicle on the ovary ipsilateral to the corpus luteum is associated with decreased conception rate in dairy cattle

In this study, we examined the effect of the locations of the first-wave dominant follicle (DF) and corpus luteum (CL) on fertility. In total, 350 artificial insemination (AI) procedures were conducted (lactating dairy cows: n=238, dairy heifers: n=112). Ovulation was confirmed 24 h after AI. The locations of the first-wave DF and CL were examined 5 to 9d after AI using rectal palpation or transrectal ultrasonography. Lactating dairy cows and dairy heifers were divided into 2 groups: (1) the ipsilateral group (IG), in which the DF was ipsilateral to the CL; and (2) the contralateral group (CG), in which the DF was contralateral to the CL. Pregnancy was diagnosed using transrectal ultrasonography 40d after AI. Conception rates were 54.0% in all cattle: 48.9% in lactating dairy cows, and 58.9% in dairy heifers. The incidence of the first-wave DF location did not differ between IG and CG (all cattle: 184 vs. 166; lactating cows: 129 vs. 109; heifers: 55 vs. 57 for IG vs. CG). Conception rates were lower in IG than in CG (all cattle: 40.2 vs. 69.3%; lactating dairy cows: 38.0 vs. 67.0%; dairy heifers: 45.5 vs. 73.7%, for IG vs. CG). Conception rate was not affected by season or live weight in heifers and lactating cows. In addition, days in milk at AI, milk production, body condition score, and parity did not affect conception in lactating cows. In summary, development of the first-wave DF in the ovary ipsilateral to the CL was associated with reduced conception rates in both lactating cows and heifers.

Low-dose natural prostaglandin F2α (dinoprost) at timed insemination improves conception rate in dairy cattle

The primary objective was to determine if low doses of PGF2α (dinoprost) given intramuscularly (im) concurrent with timed artificial insemination (TAI) would improve conception rates in dairy cattle. A secondary objective was to determine if body condition score (BCS) and parity would influence conception rates, either independently or in interaction with PGF2α treatment. In experiment I, 307 lactating Holstein cows were randomly assigned to receive either 5-mg PGF2α im (PGF2α treated, n = 154) or 0-mg PGF2α (control, n = 153) at TAI (Day 0). Blood samples were obtained on Days −10, −3, 0, and 7 to determine plasma progesterone (P4) concentrations. Pregnancy was confirmed 30 to 32 days after insemination by transrectal ultrasonography. In experiment II, 451 cows were randomly assigned to receive either 10-mg PGF2α im (PGF2α treated, n = 226) or 0-mg PGF2α (control, n = 225) at TAI, and pregnancy was confirmed 45 to 50 days after TAI by palpation per rectum. Pregnancy data were analyzed by CATMOD (SAS). In experiment I, PGF2α treatment, BCS, and parity did not affect conception rate (35.7% vs. 37.0% for PGF2α treated vs. control; P > 0.05). However, in experiment II, conception rates were higher in cows given 10-mg PGF2α than those in control cows (45.8% vs. 36.0%; P < 0.05), in cows with high BCS than in cows with low BCS (52.1% vs. 30.4%; P < 0.01), and in primiparous than in multiparous cows (47.6% vs. 34.4%; P < 0.01), but their interaction with PGF2α treatment did not affect conception rates. In summary, 5 mg of PGF2α given im concurrent with TAI failed to enhance conception rate in lactating dairy cows, whereas 10 mg of PGF2α significantly increased conception rate.

Physical Properties of Estrus Mucus in Relation to Conception Rates in Dairy Cattle

Physical Properties of Estrus Mucus in Relation to Conception Rates in Dairy Cattle

Evaluation of the Effect of Muscular Injection of Progesterone on Days 2-5 Following Insemination on Pregnancy Rate in Dairy Cows

It was hypothesized that suboptimal progesterone concentrations during the late embryo and early fetal period may act to compromise conceptus development in dairy cattle. The importance of progesterone during early pregnancy in cows is well established. Adequate secretion of progesterone is clearly the major requirement for success of early pregnancy. The aim of this study was to evaluate the efficacy of exogenous progesterone injection from day 2 to 5 following AI on conception rate in dairy cattle. At 48 h after the AI the cows were alternately assigned to treatment group (n = 40), received 4 consecutive day, from Day 2 to 5, i.m. injection of 100 mg progesterone (Vetagesterone, Aburaihan, Iran, Each mL contains: 2.5 mg progesterone) and control group (n = 68), received no treatment. The study population was stratified by parity, milk yield production, number of AI and days in milk. Pregnancy proportion in treatment and control groups were 30.88 and 35%, respectively. The results demonstrated that there was no significant differences between two groups (p < 0.05).

Conception rates and serum progesterone concentration in dairy cattle administered gonadotropin releasing hormone 5 days after artificial insemination

The objectives of this study were to determine the effect of administration of exogenous GnRH 5 days after artificial insemination (AI) on ovarian structures, serum progesterone concentration, and conception rates in lactating dairy cows. In experiment 1, 23 Holstein cows were synchronized using the Ovsynch protocol. Five days after AI (day 0) cows were assigned randomly to receive either saline (saline; n = 11) or 100 μg GnRH (GnRH; n = 12). To examine ovarian structures, ultrasonography was performed on day 1 and every other day beginning on day 5 until day 13. On days 5 and 13 blood samples were obtained to measure serum progesterone concentrations. All cows in the GnRH-treated group developed an accessory corpus luteum (CL), whereas cows in the saline group did not. Mean serum progesterone concentrations did not differ between GnRH and saline groups on day 5 (1.64 ± 0.46 ng/ml versus 2.04 ± 0.48 ng/ml). On day 13 serum progesterone concentrations were greater ( P < 0.05) in the GnRH group compared with saline (5.22 ± 0.46 ng/ml versus 3.36 ± 0.48 ng/ml). In experiment 2, 542 lactating cows, at two different commercial dairies, were used to test the effect of administering GnRH 5 days after AI on conception rates. Cows were synchronized and detected for estrus according to tail chalk removal. Cows detected in estrus received AI within 1 h after detection of estrus. Five days after AI, cows were assigned randomly to receive either GnRH ( n = 266) or saline ( n = 276). Pregnancy status was determined by palpation per rectum of uterine contents approximately 40 days after AI. There was no effect of farm on conception rate. There was no effect of treatment as conception rates did not differ between GnRH and saline groups (26.7% GnRH versus 24.3% saline). Regardless of treatment, days in milk, parity, milk yield, and number of services had no effect on the odds ratio of pregnancy. In summary, the results of this study indicated that GnRH administered 5 days after AI increased serum progesterone by developing an accessory CL but did not improve conception rates in dairy cattle.

Effect of simultaneous thawing of multiple 0.5-mL straws of semen and sequence of insemination on conception rate in dairy cattle.

The objectives of this study were to determine 1) the effect of simultaneous thawing of multiple 0.5-mL straws of semen and sequence of insemination (first, second, third, or fourth) on conception rates in dairy cattle, 2) whether the conception rates achieved following AI by professional AI (PAI) technicians and herdsman-inseminators (HI) differed, and 3) the effect of elapsed time from initiation of thawing straws of semen to seminal deposition on conception rates in dairy cattle. Four dairies with PAI and four with HI participated in the study. Initial data recorded included beginning thaw time, cow identification number, and time of seminal deposition. Herd records were retrieved following pregnancy diagnosis. Conception rates of dairy cows (n = 1025) were not affected by sequence of insemination (first, second, third, or fourth). Conception rates for herds using PAI were 40, 47, 41, and 50%. Conception rates for herds using HI were 24, 20, 33, and 30%. Average conception rates of dairy cows differed between PAI and HI (45 vs. 27%, respectively). The difference in mean conception rate achieved by PAI and HI was not attributable to milk production, parity, service number or stage of lactation. The elapsed time from initial thaw to completion of fourth AI was shorter for PAI than for HI, 7.6 vs. 10.9 min, respectively. Although the average conception rate differed between PAI and HI, elapsed time from initial thaw to completion of fourth AI and sequence of insemination (first, second, third, or fourth) had no effect on conception rate within inseminator group.

EFFECTS OF DIETARY PROTEIN LEVEL UPON PERIPHERAL PLASMA PROGESTERONE CONCENTRATION AND CONCEPTION RATE IN DAIRY CATTLE

There have been concerns that high protein intake had a significant influence on blood components and uterine constituents in non-lactating dairy cows and on spcrmatozoal motility. There are study that show that as dietary crude protein (CP) is increased, there is a tendency of reduced fertility in dairy cows while other studies have suggested that there is no relationship between reproductive performance and dietary CP intake. The objective of the study was to investigate the effect of dietary CP intake on blood progesterone concentrations and conception rate in dairy cattle. Fourteen lactating Friesian cows were randomly divided into two equal groups, a control group - Low Protein (LP) and a treated - High Protein (HP) group. The cows’ oestrous cycles were synchronized and inseminated with frozen semen. Jugular blood samples were collected daily for at least 21 days after the first insemination starting on day of oestrus and then twice per week until they were 6-weeks of pregnant and then once per week until they were 12-weeks pregnant. The result showed that the progesterone concentrations in the control (LP) cows were significantly higher than in the treated (HP) cows during pre-conception oestrous cycles that did not result in pregnancy for 10 cows (5 in each group). Except on the last day of sampling (day 42), there were no differences in progesterone concentrations between the two groups of cows during first 6-weeks of pregnancy. The plasma progesterone concentrations were significantly lower in the HP group on days 45 and 52. However, dietary protein had no significant effect on overall group mean concentrations over this 6-week period (7 to 12 week) but the interaction, Group x time, was significant. The number of services per conception was lower for the cows fed the low CP diet. However, the median number of services per conception for the two groups was not statistically different. The results clearly indicated that cows fed the high CP rations had significantly reduced plasma progesterone concentrations when compared with those fed the low protein diet. The result also suggested that low progesterone concentrations particularly during the pre-conception oestrous cycle in the HP-fed groups were associated with a lower conception rate (32%) compared in the LP-fed group (54%).

Reduced conception rates in dairy cattle associated with serological evidence of Leptospira interrogans serovar hardjo infection.

Fertility data from 673 cows in five dairy herds with a moderate to high seroprevalence of microscopic agglutination titres (MAT) of > or = 1:10 against Leptospira interrogans serovar hardjo were collated to assess the relationship between pregnancy rates and antibody titres to serovar hardjo. A significant proportion of failures of conception (10 to 13 per cent, P < 0.001) were associated with MATs of 1:10 to 1:100; the overall pregnancy rate of the seronegative cows was 28.5 per cent higher (P < 0.001) than that of the cows with MATs of > or = 1:100. First service pregnancy rates showed a similar trend but the differences were significant (P < 0.05) only in cows with antibody titres > or = 1:30. An assessment of other possible risk factors for reduced pregnancy rates, such as lactation number and calving to first service interval, had no effect on the statistical results of the study or its conclusions.

The role of shelterbelts in protecting livestock: A review

Abstract Planting a shelterbelt is the only option open to some New Zealand livestock farmers for reducing the adverse effects of wind. Wind reduces pasture productivity by mechanically agitating the leaves and this results in inhibition of plant cell expansion. It causes greater evaporation and physical damage to the plants, which also reduce pasture yield. At any given temperature, wind raises the lower critical temperature for an animal, and this is potentially wasteful in terms of energy utilisation, and it increases the risk of hypothermia and mortality in particularly sensitive stock such as newborn lambs and recently shorn ewes. Ewes that are shorn pre‐lambing seek protection from the wind and there is a greater likelihood of them lambing within shelter if it is available. The tendency to lamb in isolation away from shelter depends on breed and weather conditions. For most purposes, the best shelterbelt is one which has between 40 and 60% porosity that is distributed evenly throughout its length and height and protects the maximum area of pasture from the wind. Under cold conditions shelter has been shown to improve pasture yield, and growth rate, ovulation rate, and wool growth rate in cattle and sheep, and to reduce lamb mortality and abortions that are induced by hypothermia. Providing shelter from the sun during hot conditions has been shown to improve milk yield, milkfat yield, freedom from mastitis, and conception rates in dairy cattle, and growth rate in fattening cattle. The welfare benefits from shelterbelts and shadebelts are implicit in their greater use during cold‐windy and hot‐sunny conditions and they relate to the thermal comfort of animals. The purpose of snow shelterbelts is to filter the wind and trap snow without forming snowdrifts in which stock are likely to be trapped. Their effectiveness depends largely on the amount of snow falling relative to the size and porosity of the shelterbelt. Trees‐on‐pasture systems provide protection from wind and raise the minimum grass temperature, but because of the competition introduced with the trees they are usually less productive in terms of livestock yield than pasture alone. There are a number of disadvantages in growing shelterbelts but many of them can be controlled with appropriate management procedures.

Gonadotrophin-releasing hormone treatment in cattle: a meta-analysis of the effects on conception at the time of insemination.

Data from 40 trials described in 27 published papers were analysed by meta-analysis (pooling of data from numerous trials into a single analysis) to evaluate the effects of injecting gonadotrophin-releasing hormone (GnRH) in cattle at the time of insemination on the risk of pregnancy. A total of 19,019 cows were involved in these studies. Analyses were stratified by trial and by the effects of dose of GnRH, type of GnRH and insemination number (first, second or third and greater). Mantel-Haenszel analysis revealed that use of GnRH at insemination significantly increased the overall risk of pregnancy by 12.5% in treated cows (P < 0.05). However, increases in risk of pregnancy were greatest (22.5%) when repeat breeders were tested. Results for use of GnRH or analogue at first service were similar, with increased risks of pregnancy in treated cows of 5.2 and 8.0%, respectively. The risk of pregnancy tended to be higher (11.1%) when the dose of GnRH was > or = 250 micrograms and when used at second insemination (9.9%). The analyses demonstrated that while treatment at insemination with GnRH and GnRH analogues increased conception rates in dairy cattle, some variation in study results was attributable to the number of inseminations after calving at which GnRH is administered. Further efforts should be made to determine characteristics of populations of cows that have good fertility responses to GnRH and to determine the mode of action of GnRH in increasing fertility.(ABSTRACT TRUNCATED AT 250 WORDS)

Estimation of the economic value of conception rate in dairy cattle

The economic value of fertility in dairy cattle was estimated using dynamic programming. The expected future cash flow of a cow, given the average conception rate of the herd, was determined and maximized with a model similar to that of van Arendonk, which was used to optimize the replacement policy. The marginal cost of a decrease in fertility in the herd was then estimated as the ratio of the difference between the expected cash flow of a heifer at calving to the difference of respective average conception rates in the herd. The estimated result was a minimum value but took into account all the consequences of a change in fertility, i.e. on culling rate, on the current and each subsequent lactation and on immediate costs. In the present French conditions, the marginal value of 1% absolute change in conception rate was estimated to be between 10 and 20 FF. This value decreased when the average fertility level increased or when the conditions for culling and replacement were more favourable, i.e. when the culling value was high or the replacement costs were low.

Conception rates in dairy cattle treated with cloprostenol and inseminated at observed oestrus.

Conception rates in dairy cattle treated with cloprostenol and inseminated at observed oestrus.

Ovarian findings in relation to the onset of oestrus and conception rates in dairy cattle.

Ovarian findings in relation to the onset of oestrus and conception rates in dairy cattle.

Estrus synchronization and conception rate in dairy cattle treated with progestin-impregnated vaginal sponges

Twelve Israeli-Friesian heifers and cows were treated for estrus synchronization with intravaginal sponges impregnated with 250 mg. medroxyprogesterone acetate (MAP) for a period of 14 days. All sponges were retained throughout the treatment period and 100% of the animals came into estrus 3–7 days after sponge removal. Conception rate from insemination at the synchronized estrus was 60%. It is concluded that further investigation is justified regarding the value of progestin-impregnated sponges as a practical means of estrus synchronization in cattle.