Number Of Artificial Inseminations Research Articles

Evaluation of the Relationship of Some Environmental Factors and Number of Inseminations per Pregnancy with Milk Yield in Holstein Cows

In order to investigate the relationship between some environmental factors and the number of artificial inseminations per pregnancy with milk yield, data of 90 healthy Holstein breed dairy cows in a private dairy farm in Karapınar district of Konya province were taken. For the utilization of the data, age, number of artificial inseminations, lactation yield, calving season and sequence of lactation records were taken from the herd management program in the enterprise and analysed. As a result of the analysis, the number of artificial inseminations per pregnancy in 2016 was 1.79 and lactation milk yield was 10079,41 kg; the number of artificial inseminations per pregnancy in 2017 was 2.16 and lactation milk yield was 9767.94 kg. There was a statistically significant relationship between the number of artificial inseminations per pregnancy and milk yield during lactation period in both years. As a result, the increase in the number of artificial inseminations per pregnancy negatively affected the average milk yield of lactation period. Genetic and environmental factors are thought to play a major role in this effect.

Relation between body condition score and conception rate of Japanese Black cows.

This study analyzes interactions of body condition score (BCS) with other factors and the effect of BCS on estimates of genetic paremeters of conception rate (CR) in Japanese Black cows. Factors affecting CR were analyzed through the linear mixed model, and genetic parameters of CR were estimated through the threshold animal model. The interactions between BCS and each season and the number of artificial inseminations (AI) was significant (p<0.05), but that between BCS and parity showed no significance for CR. High CR was observed with BCS 3 in autumn (0.56±0.01) and BCS 4 in summer (0.56±0.02). The highest CR with BCS 3 (0.56±0.02) and BCS 4 (0.55±0.01) was observed at first AI. With BCS 5, however, the highest CR (0.55±0.08) was observed at second AI. The model with BCS was notably conducive to the estimation of genetic parameters because of a low deviance information criterion of heritability that, nevertheless, was slightly lower than the model without BCS.

Effect of Timing of Artificial Insemination on Fertility of Cows and Calf Sex Ratio in Arsi Cows

An on-station study was conducted to investigate the effect of the interval between artificial insemination (AI) and the beginning of estrus on the fertility and sex ratio of offspring in Arsi cows. Standing to be mounted was considered the beginning of estrus, and artificial inseminations were made 6 h (Group 1), 12 h (Group 2), 18 h (Group 3) and 24 h (Group 4) after the onset of estrus in the cows. Overall, 50 cows with parity between 2 and 4, body weight ranging from 250 to 300 kg were used for the purpose of this study. Ovulation was synchronized by administration of PGF2α hormone. Pregnancy diagnosis was performed by rectal palpation at 90 to 120 days post AI. Pregnancy rates were 60%, in each of the Groups 1, 2, 3 and 50% in group 4. The highest female to male ratio (P=0.041) of calves was obtained in Group 1. Whereas the highest male to female ratio was recorded in group 4. The number of artificial inseminations per pregnancy was within the economical limits in all groups. In conclusion, the results of this study indicated that the variation in time interval between the onset of estrus and artificial insemination alters the sex ratio of offspring in Arsi cows without affecting fertility parameters.

Mastitis causes negative reproduction performance similar to genital diseases

The economic efficiency of dairy farms is directly influenced by reproductive performance. Reproductive performance is affected by postpartum health; however, it is unknown which diseases reduce reproductive performance or how often these diseases occur in tie-stall dairy farms. In this study, the 15 most frequent diseases in tie-stalls and their impact on reproduction were determined by logistic analysis. Data from reproductive and veterinary records of 814 cows (473 Holstein) calving between April 2016 and March 2018 reared in 9 tie-stall commercial dairy farms were used. The 15 most frequent diseases were identified by medical records. The odds ratio (OR) of the diseases reducing reproductive performance (days open, number of artificial insemination, and first artificial insemination days in milk) was measured by logistic regression analysis. We focused on mastitis, and factors (inflammation grade, causative bacteria) having a negative effect on reproduction were measured similarly. Of the 15 most frequent diseases, endometritis (OR: 5.45, p<0.001), ovarian quiescence (OR: 3.95, p<0.001), mastitis (OR: 2.49, p<0.001), and follicular cyst (OR: 2.33, p=0.006) significantly prolonged days open after adjusting for environmental factors (farm, parity, and calving season). Focusing on mastitis, mastitis with mild inflammation significantly prolonged days open. Mastitis and genital diseases were frequent diseases that reduced reproductive performance. Strategies to reduce the incidence of these diseases are considered effective for the economics of tie-stall dairy farms.

Prediction of energy balance from milk traits of Holsteins in Japan.

We predicted the energy balance (EB) of Holstein cows in Japan from milk traits obtained by herd testing. Records covered 156 lactations of 102 cows. The number of artificial inseminations was highest, and the first conception rate was lowest in the low-EB group. Four prediction models were developed-for the whole lactation and for the early, middle, and late stages of lactation-with 20 variables, covering days in milk (DIM), milk yield, and milk composition traits. The actual and predicted EB means agreed well within DIM classes; the means of the residuals were smaller in the lactation stage models than in the all-lactation model, but the standard deviations (SDs) of the residuals were similar among models. After data reduction, the SDs of the residuals for 100 iterations were <1 throughout lactation in both types of models when n = 100. After model reduction, including the daily change of milk yield as a variable minimized the SDs of the residuals. Our equations for herd-level EB prediction have potential for use in genetic evaluation.

Hyperketonemia Predictions Provide an On-Farm Management Tool with Epidemiological Insights.

Simple SummaryIn dairy cows, the transition to lactation period is metabolically challenging. Elevated blood ketone bodies, known as hyperketonemia or ketosis, is a postpartum metabolic disorder that is associated with negative energy balance, greater comorbidity risk, and decreased milk production. Research to understand the etiology of hyperketonemia has highlighted risk factors and unfavorable outcomes; however, analysis of real-world data is valuable for determining the outcomes across a region. Dairy herd improvement data from herds with diverse size and production were analyzed to determine potential risk factors for and production outcomes of hyperketonemia in the Midwest region (US). Cows predicted to have hyperketonemia had greater previous lactation dry period length, somatic cell count, and dystocia, which may represent risk factors for ketosis. Cows with predicted hyperketonemia had lower milk yield and milk protein but greater milk fat and somatic cell count in the current lactation. Culling rate within 60d of calving, days open, and artificial inseminations were all greater in cows predicted to have hyperketonemia. Prevalence of hyperketonemia decreased linearly in herds with greater rolling herd average milk yield. This work demonstrates the impact of hyperketonemia on production variables which underscores the importance on continued work to reduce hyperketonemia prevalence.Prediction of hyperketonemia (HYK), a postpartum metabolic disorder in dairy cows, through use of cow and milk data has allowed for high-throughput detection and monitoring during monthly milk sampling. The objective of this study was to determine associations between predicted HYK (pHYK) and production parameters in a dataset generated from routine milk analysis samples. Data from 240,714 lactations across 335 farms were analyzed with multiple linear regression models to determine HYK status. Data on HYK or disease treatment was not solicited. Consistent with past research, pHYK cows had greater previous lactation dry period length, somatic cell count, and dystocia. Cows identified as pHYK had lower milk yield and protein percent but greater milk fat, specifically greater mixed and preformed fatty acids (FA), and greater somatic cell count (SCC). Differential somatic cell count was greater in second and fourth parity pHYK cows. Culling (60d), days open, and number of artificial inseminations were greater in pHYK cows. Hyperketonemia prevalence decreased linearly in herds with greater rolling herd average milk yield. This research confirms previously identified risk factors and negative outcomes associated with pHYK and highlights novel associations with differential SCC, mixed FA, and preformed FA across farm sizes and production levels.

The economic value of days open in Holstein cows in Japan based on simulated changes in conception rate.

Increasing herd-life length and culling parity with increasing conception rate (CR) is necessary to increase lifetime profit from dairy cow production. Economic values of days open (DO) were determined by calculating changes in fertility traits, herd-life length, and milk yield when the simulated CR were changed in increments of 1% from -5% to 5% from the basal levels, which were obtained for Hokkaido and regions other than Hokkaido separately. When CR increased, number of artificial inseminations, DO, and milking length decreased. Furthermore, culling parity, and annual milk yield increased. Herd-life length increased in Hokkaido and decreased in the other regions. The economic values of CR were 1,623.8 to 946.8 yen and of DO were 857.4 to 399.0 yen. Relative economic values of milk yield to days open per genetic standard deviation were higher in the other regions than in Hokkaido where the economic effect of selection for DO was expected to be equal to selection for 305-day milk yield and herd life. If the survival rate of multipara cows in the other regions increases, then the economic value of DO would similarly increase in Hokkaido.

Analisis Pengetahuan Peternak dan Evaluasi Keberhasilan Program UPSUS SIWAB di Kecamatan Bayang, Kabupaten Pesisir Selatan

UPSUS SIWAB (Upaya Khusus Sapi Indukan Wajib Bunting) merupakan keberlanjutan proram pemerintah dari program swasembada daging. Tujuan dari kegiatan ini untuk menganalisa pengetahuan peternak dan evaluasi keberhasilan program UPSUS SIWAB di Kecamatan Bayang, Kabupaten Pesisir Selatan. Metode yang digunakan adalah metode survey dengan hasil wawancara langsung, dan kuisioner dengan masyarakat dan peternak. Analisis data menggunakan analisis deskriptif. Hasil kegiatan menunjukkan bahwa pelaksanaan program UPSUS SIWAB tahun 2018 di Kecamatan Bayang, Kabupaten Pesisir Selatan belum 100% terlaksana, namun informasi program UPSUS SIWAB ini diketahui peternak sebanyak 80% dari penyuluhan Dinas Peternakan dan 20% lainnya dari sesama peternak. Hal ini menunjukkan bahwa penyuluhan atau sosialisasi yang dilakukan pemerintah belum menjangkau semua peternak yang ada di Kecamatan Bayang. Sementara itu, Hasil capaian kinerja program ini yaitu jumlah akseptor yang telah di IB pada tahun 2017 (1.213 ekor) dan meningkat sebesar 73% pada tahun 2018 (2.100 ekor), jumlah Inseminasi Buatan pada tahun 2017 (1.314 kali) dan meningkat sebesar 92% pada tahun 2018 (2.526 kali), jumlah akseptor yang bunting pada tahun 2017 (1.158 ekor) dan menurun sebesar 2 % pada tahun 2018 (1.136 ekor), jumlah kelahiran pada tahun 2017 (766 ekor) dan menurun sebesar 80% pada tahun 2018 (151 ekor).

Relationship between management factors with days open in crossbred cattle and constraints faced by dairy farmers of Karnataka

The present study on relationship between management factors in crossbred cattle and days openas well as the constraints faced by dairy farmers was purposively conducted in Bengaluru rural district of Karnataka.The data were collected using a structured pretested interview schedule from 120 respondents selected randomly from four taluks viz; Devanahalli, Doddaballapur, Hoskote and Nelamangala. The study revealed that number of artificial insemination (AI) in relation to conception and voluntary waiting period had a positive significant correlation to days open in dairy cattle. Lack of awareness on deworming of cattle was the major constraint among the respondents. Hence, the authors conclude that extension activities like meetings, discussions, mass media, etc. are to be planned and conducted by extension agencies to increase knowledge and thereby adoption of recommended practices leading to increase production and income generation.

Effect of Single Nucleotide Polymorphisms of Toll-Like Receptor 4 (TLR 4) on Reproductive Performance and Immune Function in Dairy Cows.

In dairy cows, inflammatory diseases caused by infection with pathogenic bacteria post calving affect ovarian functions. This study examined the relationship between single-nucleotide polymorphisms (SNPs) of Toll-like receptor 4 (TLR4), reproductive performances [the number of artificial insemination (AI) application and days open], and immune cell functions (apoptosis and migration). Two hundred Holstein cows from the Obihiro University farm were included. The SNPs of TLR4 were genotyped by PCR-restriction fragment length polymorphism (PCR-RFLP) method. Polymorphonuclear leukocytes (PMNs) and peripheral blood mononuclear cells (PBMCs) were isolated from whole blood. The number of AI application in the animals with T/C genotype in the TLR4 exon3 was lower than that in animals with C/C genotype (1.6±0.2 and 2.2±0.2, respectively). Among the animals with TLR4 exon3 polymorphisms, the days open was shorter for the T/C cows than that for C/C cows (100.7±6.9days and 136.6±9.0days, respectively). The SNPs in the TLR4 intron did not affect the number of AI and days open. The apoptosis percentage of PMNs treated with lipopolysaccharide (LPS; 0.001 and 1μg/ml) tended to be lower in the T/C genotype compared to that in the C/C genotype. The transmigration rates of PMNs, and IL-1β production in PBMCs were tended to be higher for the animals with the T/C genotype compared to those for animals with the C/C genotype. Taken together, these results suggest that TLR4 polymorphisms offer a meaningful tool to judge the reproductive potential and immune activity in individual cows.

An Investigation of Livestock Infrastructural Facilities and its Impact on Milk Output in Rajasthan

The present investigation was carried out to investigate the livestock infrastructural facilities and its impact on milk output in Rajasthan in the year 2016. The study is based on secondary data collected from different sources for different years since, 1982 onwards. Tabular analysis and functional analysis were employed to analyse the data of study. The results of study indicated that major contributing factor in milk output was population effect of the milch animal followed by the yield effect and interaction effect. Considering the infrastructural facilities in Rajasthan, it was found that the number of veterinary hospitals and artificial insemination centres have increased during the study period, while the numbers of dispensaries and mobile veterinary clinics have been constant and declining. The facilities made available in terms of number of adult cattle units served and area covered per veterinary institute have decreased during the study period. The number of artificial insemination, castration and treatment done have declined. The area under fodder cultivation had increased, while the area under range land had decreased, thus an increase in grazing pressure and decrease in grazing intensity. The numbers of DCS and their members have increased and milk procured per day per DCS has decreased during study period. The numbers of animals brought to the fairs and selling of animals in fairs have decreased during study period. In-milk animal and rainfall have positive and significant impact on milk output, while the area under permanent pasture have significant and negative impact on milk output.

The Effect of PGF2α, GnRH, E2 or Antibiotics on the Intrauterine Environment and Reproduction in Holstein Dairy Cows with Retained Placentas

PGF2α, GnRH, estradiol (E2), or antibiotics were given to dairy cows with retained placenta after parturition to establish the most suitable treatment to prevent the development of endometritis. One hundred and seventy five parous Holstein cows with retained placenta were allocated to into six treatment groups, and groups were given PGF2α, GnRH, E2, or antibiotics at 30 or 45 days after parturition. The intrauterine perfusion fluid was collected at 60 days after parturition, and a bacteriological and cytological examination was conducted. Reproductive performance was also investigated. The detection rate for Trueperella pyogenes in the intrauterine perfusion fluid in each group ranged from 0% to 16%, and T. pyogenes was not isolated in cows that were given PGF2α or E2. The percentage of neutrophils observed in the intrauterine perfusion fluid ranged from 37.8 ± 5.3 to 56.3 ± 4.7, and it was lowest in cows given PGF2α and highest in cows given GnRH. The mean number of days from parturition to initial insemination, the mean number of days from parturition to conception and the mean number of artificial inseminations required for conception ranged from 85.9 ± 5.5 to 102.7 ± 8.0, 103.8 ± 9.0 to 162.3 ± 18.6 and 1.5 ± 0.2 to 2.6 ± 0.3, respectively. All three parameters were best in cows that were given a combination of PGF2α and E2. The results suggest that administration of PGF2α or E2, or ideally both, might be a suitable treatment for cows with retained placenta. However, treatment with GnRH might delay the cleansing of the uterus.

Effects of subclinical Mycobacterium avium ssp. paratuberculosis infection on some physiological parameters, health status and production in dairy cows

Milk yield, milk ingredients, health and other, production-related parameters of subclinically infected, Mycobacterium avium ssp. paratuberculosis (MAP-) shedding (positive faecal PCR, n = 20) and non-shedding (negative faecal PCR, n = 10) dairy cows were compared in the period from 10 days prepartum to 120 days postpartum. Body condition, rumen fill and faeces scores were lower in the MAP-shedding cows. There was no significant difference in plasma or urine metabolic parameters between the groups. Milk yield and lactose content tended to be lower (P = 0.074 and 0.077, respectively), somatic cell count tended to be higher (P = 0.097), while milk fat content was significantly higher (P = 0.006) in MAP-shedding cows than in the controls. Milk protein content did not differ between the groups. All other health and production parameters [number of reproductive tract treatments, number of udder treatments, number of artificial inseminations (AIs), calving interval, and service period] were significantly better in the control group. It is concluded that MAP infection, even in a subclinical form, has a significant impact on some production and health parameters of dairy cows.

Levantamento comparativo do desempenho reprodutivo de vacas com diferentes níveis de produção de leite

This study aimed at correlating reproductive rates with milk production based on the evaluation of cows in different milk production levels in a commercial dairy herd located at Triângulo Mineiro region. A total of 241 cows of the following breeds were monitored: Holstein, Girolando, Jersey crossing with Holstein and Jersey in full stabling system, subjected to three daily milking and treated with recombinant bovine somatotropin (rbST) from the second month of lacta­tion until 60 days before the subsequent delivery. Conception rates, number of artificial inseminations (NAI), days between calving and first AI (FAI) and calving interval to conception (ICC) were estimated. Cows were grouped according to three independent criteria, average daily production (10-19; 20-29; 30-39; >40 kg day -1 ), total production in lactation ( 10,000 L) and days in lactation (<150; 150-300; 300-450; 450-600 days). The results indicated that the days in lactation negatively influenced (P<0.001) the FAI, CIC and NAI. The number of inseminations was also influenced by total production during lactation. The maintenance of milk production through the use of rbST negatively influenced the reproductive rates.

Influence of hepatic load from far-off dry period to early postpartum period on the first postpartum ovulation and accompanying subsequent fertility in dairy cows.

The aim of the present study was to investigate nutritional and metabolic parameters during the dry and early postpartum periods of ovulatory and anovulatory cows, as well as their postpartum reproductive performance. Blood samples from 20 multiparous Holstein cows were collected once a week from the far-off dry period to 3 weeks postpartum. Early postpartum (0–3 weeks) ovulation was confirmed using plasma progesterone concentration profiles, and cows were considered ovulatory if they had resumed luteal activity by this point (n = 9), whereas cows that had not were considered anovulatory (n = 11). Data from the ovulatory and anovulatory cows were analyzed separately for the far-off dry period (7–4 weeks prepartum), the close-up dry period (3–1 weeks prepartum), and the early postpartum period (0–3 weeks). Serum gamma-glutamyl transpeptidase activity (far-off, P = 0.065; close-up, P = 0.051; and early postpartum, P = 0.030) and aspartate aminotransferase (close-up, P = 0.050 and early postpartum, P = 0.087) activities were higher in anovulatory than in ovulatory cows. The days open period was longer (P = 0.019) in anovulatory than in ovulatory cows, and the number of artificial inseminations per conception (P = 0.025) was greater. In conclusion, we found that continuously high gamma-glutamyl transpeptidase activities in serum, which may be induced by liver disorders, prevent subsequent ovulation and affect subsequent fertility, even if cows obtain sufficient ovulation-related energy and β-carotene.

Effect of intrauterine infusion of an organic-certified product on uterine health, survival, and fertility of dairy cows with toxic puerperal metritis

The objective was to evaluate the effect of intrauterine infusion of an organic certified product (Optimum UterFlush, Van Beek Natural Science, Orange City, IA) on uterine health, survival, and fertility of cows affected with toxic puerperal metritis (TPM) in an organic dairy farm. Cows with TPM were defined as having an abnormally enlarged uterus and a fetid watery red-brown vaginal discharge, associated with systemic illness and fever (rectal temperature ≥39.5°C), within 12 d postpartum. Cows diagnosed with TPM (n=220; study d 0) were blocked by parity (1 and ≥2) and randomly assigned into 1 of 2 intrauterine treatments applied every other day for a total of 3 applications: (1) control (CON)=200mL of povidone iodine diluted in 2L of distilled water (n=113); (2) Optimum UterFlush (UF)=3.75mL diluted in 117mL of distilled water (n=107). All enrolled cows received hypertonic saline solution (500mL 7.2% i.v.), dextrose (500mL 50% i.v.), and oral aspirin (5 boluses/d). Outcome variables for treatment efficacy included fever and presence of fetid vaginal discharge at study d 6 and 14, survival at study d 6 and 14 and at 30 and 100 DIM, and reproductive performance. Control variables were parity, BCS at enrollment, calving season, and milk yield. Occurrence of fever at d 6 and 14 was not different between the 2 treatment groups. Presence of fetid vaginal discharge at d 6 and 14 was lower in cows treated with UF compared with cows in the CON group (10.7 vs. 28% and 1.1 vs. 9.1%). The odds (95% confidence interval) for survival and remaining in the farm at study d 6 and 14 and at 30 and 100 DIM for cows in the UF treatment were 4.67 (1.38–15.8), 2.77 (1.25–6.10), 3.13 (1.22–8.02), and 2.82 (1.38–5.71) times the odds of cows in the CON group, respectively. The odds of AI until 150 DIM and the interval from calving to first AI were not different between the 2 treatments. However, pregnancy was affected by treatment; the odds (95% confidence interval) of pregnancy at the first AI, 150 DIM, and 300 DIM for cows treated with UF were 2.15 (1.05–4.40), 1.81 (1.04–3.15), and 1.92 (1.09–3.38) times the odds of cows in the CON group, respectively. Days to pregnancy were similar in both treatment groups, but the number of artificial inseminations per pregnancy were different (2.69 vs. 2.02 for cows in the CON and UF treatments). Results indicate that cows with TPM administered intrauterine infusion of Optimum UterFlush had higher odds of recovering and improved reproductive performance compared with cows treated with povidone iodine.

Efeito do número de inseminações artificiais sobre a fertilidade de éguas inseminadas com sêmen asinino diluído e resfriado a 5ºC por 12 horas de armazenamento

Estudou-se o efeito do número de inseminações sobre a fertilidade de éguas inseminadas com sêmen asinino diluído, resfriado e armazenado. Os ciclos foram acompanhados por palpação retal e rufiação, sendo as inseminações realizadas às terças, quintas e sábados (três vezes por semana), a partir da detecção de um folículo de 3,0 a 3,5cm de diâmetro, em um dos ovários, até a ovulação. O sêmen de cinco jumentos da raça Pêga foi diluído nos diluidores de leite em pó desnatado-glicose ou glicina-gema de ovo, resfriado a 5ºC e armazenado por 12 horas, sendo a dose inseminante de aproximadamente 400x10(6) espermatozoides móveis (no momento da diluição final, pré-resfriamento). De acordo com o número de inseminações artificiais (IA)/ciclo, os resultados de 195 ciclos, referentes a 140 éguas, foram agrupados em 1IA, 2IA e 3 ou mais IA. As taxas de concepção, ao primeiro ciclo, foram de 50,0%, 62,1% e de 41,0% e, após quatro ciclos, de 47,7%, 55,6% e de 42,9% para 1IA, 2IA e 3 ou mais IA, respectivamente (P&gt;0,05). O número de IA/ciclo, utilizando sêmen asinino resfriado, não teve efeito sobre a fertilidade das éguas.

Association of the occurrence of some diseases with reproductive performance and milk production of dairy herds in southern Brazil

This study analyzed associations between the occurrence of mastitis, metritis and retained placenta with the reproductive performance and milk production of four Holstein dairy herds of southern Brazil. Calving-to-conception intervals (CCI) and daily milk production were compared across herds, number of artificial inseminations and clinical occurrences and occurrence of mastitis, metritis and retained placenta. The CCI of cows with three or more clinical occurrences was longer than for those with no occurrences, but shorter for cows with retained placenta than for those without it. Cows with clinical mastitis up to 60 days post-partum had shorter CCI than those with mastitis after 60 days. Cows with retained placenta also had higher frequency of metritis. The daily milk production was higher for cows with three or more clinical occurrences than for those with one or none and for those without retained placenta than for those with retained placenta. A high number of clinical occurrences was related to prolonged CCI and increased daily milk production.

Flushing em vacas de corte no pós-parto, submetidas ao desmame precoce: desempenho reprodutivo

The objective of this experiment was to evaluate the effects of short-time fat supple-mentation (flushing) on the reproductive performance (postpartum estrus, postpartum anestrus, postpartum estrus interval, calving interval, number of artificial insemination, artificial insemination interval, and pregnancy rate) of postpartum beef cows, submitted to the early weaning. Two hundred and fifty eight beef cows were used from the following genetic groups: Aberdeen Angus (n= 21), Aberdeen Angus x Canchim (n= 20), Canchim x Aberdeen Angus (n= 52), Charoles x Caracu (n= 29), Charolais (n= 18), Cachim (n= 34), Caracu (n= 35), Caracu x Charoles (n= 26) an Puruna (n= 23), with 418.1 kg of body weight and all pregnant. These animals were split into two types of treatments: flushing (30% soybean full + 70% corn) and no supplementation. There was no flushing effect on postpartum estrus percentage (82.9%), anestrus percentage (17.0%), postpartum estrus interval (100.5 days), calf birth weight (34.2 kg), number of artificial insemination (1.4), interval between the 1st and the 2nd artificial insemination (19.2 days), interval between the 1st and the 2nd artificial insemination (19.9 days), and pregnancy percentage (54.6%). The flushing reduced calving interval (391.14 vs. 399.31 days). The November period had lower postpartum estrus percentage (70.6%), anestrus percentage (29.4%), postpartum estrus interval (90.3 days), calving interval (378.3 days), number of artificial insemination (1.2), interval between the 1st and the 2nd artificial insemination (11.5 days), and pregnancy percentage (27.5%).

Effects of a single administration of prostaglandin F2alpha, or a combination of prostaglandin F2alpha and prostaglandin E2, or placebo on fertility variables in dairy cows 3–5 weeks post partum, a randomized, double-blind clinical trial

BackgroundDelayed uterine involution has negative effects on the fertility of cows; use of prostaglandin F2alpha alone as a single treatment has not been shown to consistently improve fertility. Combined administration of PGF2alpha and PGE2 increased uterine pressure in healthy cows. We hypothesized, that the combination of both prostaglandins would accelerate uterine involution and have, therefore, a positive effect on fertility variables. In commercial dairy farming, the benefit of a single post partum combined prostaglandin treatment should be demonstrated.Methods383 cows from commercial dairy farms were included in this study. Uterine size and secretion were evaluated at treatment 21–35 days post partum and 14 days later. Cows were randomly allocated to one of three treatment groups: PGF2alpha and PGE2, PGF2alpha or placebo. For every animal participating in the study, the following reproduction variables were recorded: Interval from calving to first insemination, days open, number of artificial inseminations (AI) to conception; subsequent treatment of uterus, subsequent treatment of ovaries. Plasma progesterone level at time of treatment was used as a covariable. For continuous measurements, analysis of variance was performed. Fisher's exact test for categorical non-ordered data and exact Kruskal-Wallis test for ordered data were used; pairwise group comparisons with Bonferroni adjustment of significance level were performed.ResultsThere was no significant difference among treatment groups in uterine size. Furthermore, there was no significant difference among treatments concerning days open, number of AI, and subsequent treatment of uterus and ovaries. Days from calving to first insemination tended to be shorter for cows with low progesterone level given PGF2alpha and PGE2 in combination than for the placebo-group (P = 0.024).ConclusionThe results of this study indicate that the administration of PGF2alpha or a combination of PGF2alpha and PGE2 21 to 35 days post partum had no beneficial effect upon measured fertility variables. The exception was a tendency for a shorter interval from calving to first insemination after administration of the combination of PGF2alpha and PGE2, as compared to the placebo group. Further research should be done in herds with reduced fertility and/or an increased incidence of postpartum vaginal discharge.