Postpartum Anestrus Research Articles

A deterministic, dynamic systems model of cow-calf production: The effects of the duration of postpartum anestrus on production parameters over a 10-year horizon

A deterministic, dynamic systems model of cow-calf production: The effects of the duration of postpartum anestrus on production parameters over a 10-year horizon

Estrus induction and fertility response following different treatment protocols in Murrah buffaloes under field conditions.

Aim:The aim of this study was to evaluate the efficacy of three different treatment protocols for estrus induction and conception rate in postpartum anestrus buffaloes during breeding season under field conditions.Materials and Methods:The 47 postpartum anestrus buffaloes of the 2nd to 6th parity were divided into three groups. Group 1 (n=16): Buffaloes received cosynch treatment, that is, buserelin acetate 10 µg on day 0 and 9, cloprostenol 500 µg on day 7 followed by fixed-time artificial insemination (FTAI) at the time of second buserelin acetate and 24 h later. Group 2 (n=15): Buffaloes received norgestomet ear implant subcutaneously for 9 days, estradiol benzoate 2 mg on the day of implant insertion (day 0), pregnant mare serum gonadotropin (PMSG) 400 IU and cloprostenol 500 µg on day 9 followed by AI at 48 and 72 h after implant removal. Group 3 (Cosynch-plus, n=16): Buffaloes received Cosynch protocol as per Group 1 except an additional injection of PMSG 400 IU (i.m.) was given 3 days before the start of protocol and FTAI done at the same time of Group 1. Pregnancy diagnosis was performed after 45 days of AI.Results:The estrus induction response following the treatment was 81.3%, 100%, and 93.7% in Group 1, 2, and 3, respectively. The buffaloes of Group 1, 2, and 3 expressed intense (38.4%, 60% and 46.6%, respectively) and moderate estrus (46.1%, 26.6%, and 40%, respectively). The conception rates in Group 1, 2, and 3, at FTAI and overall including subsequent estrus were 37.5% and 62.5%, 53.3%, and 66.6%, 56.3%, and 75%, respectively.Conclusion:All the three treatment protocols can be effectively used for induction of estrus with acceptable conception rate in postpartum anestrus buffaloes during breeding season under field conditions. However, Cosynch-plus (similar to Cosynch protocol except addition of PMSG, 400 IU 3 days before the start of first buserelin acetate administration) protocol results comparatively better pregnancy rate.

Seasonal Influence on Efficacy of Ovsynch, Heatsynch and Triu-B Protocols in Terms of Estrus Response, Conception Rate and Biochemical Profile in Postpartum Anoestrus Buffaloes

This study was undertaken on 48 postpartum (>90 days) anoestrus buffaloes each in winter and summer seasons with the object to know the seasonal influence on efficacy of three estrus induction/ synchronization protocols towards fertility response and blood biochemical profiles. Twelve buffaloes each in treatment group I, II and III were subjected to Ovsynch, Heatsynch and Triu-B hormone protocols, respectively, while group IV served as untreated control. The estrus induction response varied from 75.00 to 83.33% during summer and 83.33 to 91.66% during winter season with these protocols. The conception rates obtained at induced estrus and overall of 3 cycles in anoestrus buffaloes were comparatively lower under all three protocols during summer than winter season (16.27 vs 41.67 and 25.00 vs 58.33% for Ovsynch; 16.27 vs 25.00 and 25.00 vs 50.00% for Heatsynch, and 16.27 vs 41.67 and 33.33 vs 58.33%, respectively), and obviously higher than control group (overall CR 8.33 and 25.00%) in both the seasons. The overall mean plasma protein values were significantly higher (pis less than 0.01) in winter season than summer season in all three groups, while inverse results were found with respect to seasons for total cholesterol under Ovsynch and Triu-B protocols. The effect of period and pregnancy status was non-significant within the protocol for both the traits in both the seasons, except the total protein under Ovsynch protocol in winter season was significantly higher in conceived than non-conceived group (7.96 ± 0.09 vs. 7.54 ± 0.11 g/dl; pis less than 0.05). There was no influence of days or conceived and non-conceived status on the calcium, phosphorus and magnesium profile in any of the groups studied during both the seasons. However, significantly higher (pis less than 0.05) overall mean plasma values for calcium and magnesium were observed in winter as compared to summer season in buffaloes of all three protocols. It was concluded that all three protocols can be used successfully during winter and Triu-B only during summer season to induce estrus and improve fertility in postpartum anoestrus buffaloes, and that the plasma metabolite profile was significantly altered by season, but not by the hormonal treatments or pregnancy status

Certain hormonal profiles of postpartum anestrus jersey crossbred cows treated with controlled internal drug release and ovsynch protocol.

Aim:The study was conducted to determine the serum levels of certain hormones in post-partum anestrus cows following treatment with controlled internal drug release (CIDR) and Ovsynch protocol.Materials and Methods:A total of 30 postpartum anestrus cows were divided into three equal groups after thorough gynecoclinical examination. The Group 1 animals received an intravaginal progesterone device on day 0 and 2 ml of prostaglandin F2α (PGF2α) on day of CIDR removal (7th day), Group 2 cows were treated with ovsynch protocol (gonadotropin-releasing hormone [GnRH]-PGF2α-GnRH) on day 0, 7 and 9, respectively, and Group 3 cows were supplemented with mineral mixture and treated as control. The serum estrogen, progesterone, triiodothyronine, and thyroxine concentration were estimated using enzyme-linked immunosorbent assay kit and absorbance was read at 450 nm with Perkin Elmer Wallac 1420 Microplate Reader.Results:There was a significant increase in progesterone level in Group 1 after withdrawal of CIDR as compared to other two groups. However, the estrogen assay revealed a greater concentration in Group 2 against Group 1 on day 7 of sampling. However, there was no significant difference for serum triiodothyronine (T3) and thyroxine (T4) irrespective of treatment protocols and days of sampling.Conclusion:Treatment with CIDR based progesterone therapy and drug combinations may affect the reproductive hormonal balance like estrogen and progesterone, which is inevitable for successful return to cyclicity and subsequent fertilization and conception. However, as far as serum T3 and T4 concentration concerned it may not give an astounding result.

Using a deterministic systems model to examine the effects of the postpartum period on cow-calf productivity over 10 years

The duration of postpartum anestrus is important to consider for reproductive momentum and efficiency in cow~calf operations. It is challenging to fully understand the long-term impacts that the average duration of postpartum anestrus has on production. We developed a deterministic model of cow-calf production over 10 years using the software program Stella Professional to model the effects that various postpartum anestrus lengths have on measures of herd productivity, including the percent of cows pregnant at pregnancy diagnosis and the pounds of calf weaned per cow exposed.

Postpartum anoestrus in five seasonally-calving dairy farms in Victoria, Australia.

A cross-sectional study of seasonally-calving dairy cows in south-western Victoria to quantify the prevalence of anoestrus and to assess the effect of body condition score (BCS), days in milk (DIM) at mating start date (MSD) and age on the likelihood of being diagnosed as anoestrus. Age, DIM and BCS details were collected from 1795 cycling and 1399 cows diagnosed as anoestrus in five seasonally-calving dairy herds in Victoria. Multivariable logistic regression was used to quantify the association between BCS, DIM and age and the probability of being diagnosed as anoestrus. The apparent prevalence of anoestrus in cows that took part in the study was 44% (95% confidence interval (CI) 42-46%). The risk of anoestrus increased with decreases in DIM and BCS. There was a significant interaction between BCS and DIM. For cows >90 DIM at MSD (the reference category) the odds of anoestrus in cows with BCS <4.00 was 8.05-fold (95% CI 3.2-20.2) that of cows of BCS ≥4.50. The risk of anoestrus decreased with increases in cow age. Cows aged 2 and 3-5 years had 2.4-fold (95% CI 1.79-3.22) and 1.4 (95% CI 1.11-1.77) odds of anoestrus, respectively, compared with cows aged ≥6 years. Reproductive management to maximise the number of days calved at MSD and nutritional management to ensure cows are in BCS >4.5 at mating will reduce the prevalence of anoestrus in Victorian dairy herds.

Effect of Serum Calcium, Magnesium, and Phosphorus Levels in Cyclic and Postpartum Anestrus Jersey Cross Cows

Effect of Serum Calcium, Magnesium, and Phosphorus Levels in Cyclic and Postpartum Anestrus Jersey Cross Cows

Administration of Leptin Increases the Level of Follicle Stimulating Hormone (FSH) and Development of Ovarian Follicles in Postpartum Anestrus of Bali Cattle

Background: Leptin is a metabolic signal that plays a role in reproduction through the Hypothalamic-PituitaryOvarian axis. The aim of this study is to determine the effect of leptin on the levels of FSH and development of ovarian follicles of post-partum anestrus in Bali cattle. Method: Postpartum anestrus in Bali cattle were divided into three groups of nine; group 1 (control) was injected with physiological saline, group 2 (treatment I) and group 3 (treatment II) were injected with recombinant o-leptin 100 µg and 200 µg/head respectively. Injection was done twice with an interval of 12 hours. Blood sample was collected via the jugular vein at intervals of 12 hours before the start of treatment until signs of estrus had appeared. Follicle diameter was measured using ultrasonography before treatment and during estrus. Results: The average levels of FSH before treatment for group 1, group 2, and group 3 were 11.3 + 0.36 mIU/ml, 11.6 + 0.40 mIU/ml, and 11.4 + 0.28 mIU/ml respectively. While at the end of the research, the levels of FSH were 11:02 + 0.39 mIU/ml, 13.0 + 0.48 mIU/ml, and 13.47 + 1.05 mIU/ml respectively. Ovarian follicle diameter for group 1, group 2, and group 3 before treatment were 5.10 + 0.41 mm, 5.21 + 0.36 mm, and 5.00 + 0.37 mm respectively. Whereas at the end of the research, the ovarian follicle diameters were 4.92 + 0.40 mm, 8.37 + 0.43 mm, and 8.45 + 0.38 mm respectively. Conclusion: administration of o-leptin in postpartum anestrus of Bali cattle increases the level of FSH and ovarian follicle development.

The effect of GnRH analogue on the fertility of Prostaglandin F2-? induced- oestrus cows

The effect of GnRH analogue (gonadorelin) was studied on the fertility of 35 postpartum anoestrus zebu cows and their crosses (Friesian, Sahiwal, Sindhi). Age (4-15 years), body weight (125-375 kg), body condition score (1.5-3; 1-5 scale), parity (1-9), postpartum intervals (4-12 months) of the cows were recorded. Oestrus was synchronized with two injections of PGF2-? analogue (Luprostinol, 15 mg) intramuscularly (i.m.) 10 days apart. The cows were divided into Group I (n = 11), Group II (n = 12) and Group III (n = 12). In Group I, 8 cows with oestrus were inseminated without gonadorelin treatment. In group II, 6 cows in oestrus were treated with gonadorelin (0.25 mg) i.m. just prior to insemination. In group III, 3 days after the second injection of luprostinol, cows with smooth ovaries were treated with gonadorelin followed by luprostinol injection 9 days later, which resulted in oestrus in 8 of the 12 cows, which were inseminated. Cows without oestrus signs were inseminated at fixed-time (72 and 96 hours after the last luprostinol injection). In group I, II and III, 5, 6 and 8 cows became pregnant, respectively (P&gt;0.05). More cows became pregnant at observed oestrus (68.2%) than at fixed-time insemination (30.8%; P&lt;0.05). Insemination in observed oestrus is more effective than at fixed-time. GnRH analogue may have favourable effect on the induction of oestrus by PGF2-? analogue.Bangl. vet. 2014. Vol. 31, No. 2, 60-69

Resumption of cyclic ovarian activity in postpartum ewes: a review

The reproduction rate is considered a crucial factor that affects the ability of producers to meet the growing demand for ovines meat, and optimizing this factor will maximize the production rate and increase the efficiency of livestock. A reduction in the length of the postpartum anestrus period results in a shorter interval between lambing and conception and enables more lambs to be produced throughout the life of a ewe. This review discusses the current knowledge of several factors associated with the resumption of cyclic ovarian function in postpartum ewes and how the suckling management of ewes may affect this process. Factors that influence the resumption of cyclic ovarian activity include uterine involution, follicular development, occurrence of silent ovulation and short estrous cycles, breed, reproductive seasonality, nutrition and lactation. Controlled suckling and early weaning are management practices that may be used to obtain three lambings in a 24-month period. In the majority of the studies the interval between lambing and first estrus was reduced when a controlled suckling management strategy was used, therefore the controlled suckling appears to be the best alternative because it has produced good results and is easy to implement. Currently, however, this practice is still not widely used.

Effect of Various Ovulation Synchronization Protocols on Estrus Response, Conception Rate and Blood Biochemical Profile in Anoestrus Buffaloes

This study evaluated the fertility response and plasma profile of biochemical and mineral constituents in 46 postpartum anoestrus (>90 days) buffaloes treated under field conditions with TriU-B/PRID, Ovsynch and Heatsynch protocols (n=12 each), keeping untreated anoestrus control (n=10) and normal cyclic control (n=10) groups. The estrus induction response with 3 treatment protocols was 83.33, 83.33 and 91.66 % respectively within 2-3 days of PGF 2 α injection. The conception rates (CRs) obtained at induced estrus in buffaloes under TriU-B, Ovsynch and Heatsynch protocols were 25.00, 33.33 and 25.00 %, and those of overall three cycles’ 50.00, 58.33 and 50.00 %, respectively, which were at par with normal cyclic control group (CR at first cycle 30.00 & overall of 3 cycles 50.00 %). Among untreated anoestrus control group, only two buffaloes (20%) exhibited estrus and conceived over 90 days follow up. The overall pooled mean plasma total cholesterol concentrations (mg/dl) in anoestrus buffaloes under TriU-B and in normal cyclic control group were the same (166.70±5.28 and 165.18±6.37) and significantly (P<0.01) higher than in Ovsynch (131.54±3.71) and lower than in Heatsynch (186.14±5.69) group. The value for total protein (g/dl) was significantly (P<0.05) lower in TriU-B (7.27±0.08) followed by other two groups (7.62±0.07 & 7.44±0.07) and highest in normal control group (7.98±0.10). The calcium was significantly higher (P<0.05) in Ovsynch (10.41±0.07 mg/dl) than other 3 groups (8.82±0.11 to 9.09±0.09 mg/dl), while inorganic phosphorus (3.99±0.10 to 4.29±0.13 mg/dl) did not vary between groups. Normal cyclic control buffaloes had significantly higher protein and lower calcium levels than in most treatment groups. The conceived buffaloes had apparently higher values of total cholesterol and protein as compared to non-conceived ones in all groups. In general, Ovsynch protocol was the best followed by TriU-B and Heatsynch for induction of estrus and improvement of fertility in anoestrus buffaloes.

Effect of the length of the suckling period and dietary energy intake in lactation on the duration of postpartum anestrus in Creole goats

The objective of this study was to determine the effect of the length of the suckling period and the dietary energy level on the duration of postpartum anestrus in Creole goats. Twenty-eight multiparous pregnant goats (bodyweight BW 39.9±6.4kg; mean±SEM) each bearing a single fetus were used in a 2 suckling period (30 vs. 60 d)×2 levels of energy intake (low (L) vs. high (H)) factorial design. Kids were separated from their dams 3 d after birth and then suckled twice per day until weaned at 30 or 60 d postpartum. Dams weaned at 30 d postpartum were hand milked for the next 30 d. Goats were individually fed chopped alfalfa hay+balanced concentrates (45:55 DM basis) at 3% of BW in the last month of pregnancy and at the same level to the L goats in the postpartum period when the H goats were fed at 4% of BW. Energy balance was estimated by difference between energy intake and calculated energy requirements. Duration of postpartum anestrus was estimated by determining the occurrence of ovulation from changes in blood progesterone concentrations. There were no significant lengths of suckling x energy intake level interactions. Goats on all treatments lost weight until 45 d postpartum with more weight loss on the low than the high energy intake level (L 4.06±0.43 vs. H 1.99±0.64kg; P<0.05). The daily 4% FCM production was similar for all treatments (overall mean 1.10±0.01kg). The difference between the postpartum anestrus period between low (129 d) and high (128 d) dietary energy levels was not significant but no goat ovulated while in negative energy balance. The effect of suckling on the resumption of ovarian activity was highly significant (P<0.001) with goats weaned 30 d postpartum resuming ovulation 102 d after parturition compared to 155 d for those weaned 60 d postpartum. This study illustrates the importance of the bond between the doe and its kid in the prolongation of the anestrus period in goats.

Inducción de ciclos estrales en vacas lecheras con anestro posparto utilizando progesterona y hormonas gonadotróficas

Kizur, A.; Garrido, M.J.; Konrad, J.L.; Crudeli, G.A.; Gatica-García, R.: Inducción de ciclos estrales en vacas lecheras con anestro posparto utilizando progesterona y hormonas gonadotróficas. Rev. vet. 26: 1, 13-16, 2015

Saliva ferning, an unorthodox estrus detection method in water buffaloes (Bubalus bubalis)

Estrus detection is a major problem in buffalo husbandry because of inconsistent expression of estrous signs at different seasons, and a high prevalence of the silent heat and postpartum anestrus in this species. Around 50% of the estrus events in buffaloes are currently undetected in the field conditions, resulting in a huge economic loss. Although the cervicovaginal fluid fern patterns confirm the estrus for a breeding decision, the fluid discharge is absent during the silent-heat condition. Therefore, the present study focused on the crystallization patterns of the saliva as an alternative method for estrus detection in buffaloes. Saliva is a body fluid available regularly, and its ferning ability before ovulation was established in women. In this study, eight female nonpregnant Murrah buffaloes (Bubalus bubalis) were considered during two experimental periods of 3 months each. One period was in summer with five animals, and another period was in rainy season with three animals. Estrus was determined by the estrus symptoms, ovarian ultrasonography, and salivary estradiol (E2) to progesterone (P4) ratio. A total of 450 saliva samples were collected from these animals on the daily basis. The salivary smear was prepared with 20 μL of the cell-free saliva on a clean glass slide, and its microscopic images were captured at a magnification of × 200. The images were used for fractal analysis as the salivary crystallization or fern patterns follow the fractal geometry. Saliva at estrus showed a typical symmetrical fern-like crystallization patterns with significantly (P < 0.05) lower fractal dimension values. Salivary estradiol levels and E2/P4 ratio were significantly (P < 0.05) higher at the estrus stage than those at the diestrus stage. An average period of an estrous cycle was 21.7 ± 2.7 days (n = 18 estrous cycles) in buffaloes on the basis of distinct salivary crystallization patterns. The proportion of estrus detection by the salivary fern patterns was very significantly (P < 0.01) higher (0.84) than the proportion of estrus detection (0.5) in the field conditions. Altogether, salivary fern patterns along with the current methods can help reduce estrus detection problem in buffaloes.

Effect of Vitamin-E and Selenium Supplementation on Oxidative Stress Parameters in Postpartum Anestrus Buffaloes

The present experiment was conducted to evaluate the effect of vitamin-E-Selenium on stress parameters in anestrus Murrah buffaloes located at R.S. Pura, Jammu. Twelve animals with similar age and reproductive status were selected for experiment. The selected animals were divided in two groups, each comprising six animals. Group I was given used CIDR protocol while in group II animals along with used CIDR protocol, were administered two injections of vitamin-E-care-Se (50 mg α-tocopheryl acetate and 1.5 mg selenium per ml) at the dose rate of 1ml/50 kg b. wt. on day 0 and day 7 through intramuscular route. The blood samples were collected on day 0, day 7 and day 9 during the experiment. The collected samples were stored at-20°C and later evaluated for oxidative stress parameters. A significant decrease (P<0.05) in lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activity along with non-significant increase in glutathione peroxidase (GPx) level was observed when postpartum anestrus buffaloes were treated with used CIDR protocol either alone or in combination with vitamin-E and Selenium. The with used CIDR protocol in combination with vitamin-E and Selenium resulted in significant reduction in oxidative stress parameters (except MDA) at day 7 and day 9. However, with respect to MDA, there was no significant difference between two groups at start of treatment and after treatment.

Genome-wide association for the outcome of fixed-time artificial insemination of Brahman heifers in northern Australia.

Fixed-time AI (FTAI) is a powerful tool for genetic improvement of extensively managed beef cattle. A genomewide association study (GWAS) was conducted to investigate genes and genetic markers associated with the outcome (pregnant or not pregnant) of FTAI in 614 commercial Brahman heifers genotyped for 18,895 SNP and imputed to 51,588 SNP. The likelihood of Brahman heifers becoming pregnant after hormonal treatment to synchronize ovulation followed by FTAI was influenced by the content of their genomes, as determined by a principal component analysis. The principal component analysis involved comparisons between the studied heifers and populations of known and ancestry. The heritability of FTAI outcome was = 0.18, which is higher than for most other reproductive outcome traits. The number of SNP associated with FTAI outcome was 101 ( < 0.001, false discovery rate = 0.53). Compared with all SNP tested, associated SNP had a tendency for highly divergent allelic frequencies between and . Associated SNP were located in nearly all chromosomes, a result that shows a complex genetic architecture that is typical of highly complex traits with low heritability. Considering this and previous GWAS that examined Brahman heifer puberty and postpartum anestrus interval, 3 genomic regions emerge as important for overall Brahman heifer fertility, which mapped to chromosomes 1, 7, and 9. Further analyses, including improved genome annotation, are required to elucidate the link between these regions and heifer fertility. Additional studies are needed to confirm SNP and gene associations reported herein and further elucidate the genetics of FTAI outcome. Future GWAS should target other Braham populations and additional cattle breeds with FTAI records, including breeds with higher ancestry.

Effect of an energy supplementation, weaning and oestrous synchronisation on ovarian activity and ovulation in early postpartum primiparous Bos indicus cows raised in the tropics of Costa Rica

To evaluate the effect of an energy supplementation, 26 postpartum Bos indicus cows were assigned either to receive an energy diet supplementation (n = 11, SSD) or no supplementation (n = 15, NSSD). Cows in the SSD treatment received a diet consisting of 5.5% crude protein, 2.85 Mcal digestible energy per head per day, at 1% ratio of the average bodyweight, started 23.5 ± 3.4 days after calving and continued for 44 days. In contrast, NSSD cows were grazing only native pastures during the experiment. All cows were synchronised at 65 days postpartum with a subcutaneous progestin ear implant (Norgestomet) for 9 days and an injection of oestradiol valerate and Norgestomet at the same time as implant placement. A random sample of six animals from each treatment was scanned with ultrasound every 6 h and the dominant follicle (s) was measured until ovulation occurred or after 114 h. The nadir of body condition score for the NSSD was observed at 37.5 ± 3.4 days postpartum, while SSD was at 22.3 ± 7.9 days (P &lt; 0.01); no differences (P &gt; 0.05) in dorsal backfat thickness or average bodyweight between treatments were observed. During the ultrasound-scanning period, four of six cows ovulated in the SSD treatment and five of six in the NSSD. No difference (P &gt; 0.05) was observed at the time of ovulation after progestin implant withdrawal (55.8 ± 7.8 h in NSSD vs 94.5 ± 21.7 h in SSD). The largest follicle diameter at the beginning of the scanning was in SSD treatment (7.25 ± 1.4 mm in SSD vs 5.0 ± 0.8 mm in NSSD), whereas at the time of ovulation, it was similar (15.2 ± 1.8 mm in SSD vs 11.0 ± 1.4 mm in NSSD) between the treatments (P &gt; 0.05). The resumption of ovarian activity was similar between SSD (69 ± 20.7 days, ranging from 42 to 83 days) and NSSD (69.8 ± 6.4 days, ranging from 59 to 73 days). The length of postpartum anoestrus was influenced by the onset of the nadir of body condition score. Energy diet supplementation did not influence the onset of ovarian activity.

Efficacy of CIDR - based Protocols for Treatment of Prolonged Postpartum Anoestrus in Jersey Crossbred Cattle on Smallholder Farms

Efficacy of CIDR - based Protocols for Treatment of Prolonged Postpartum Anoestrus in Jersey Crossbred Cattle on Smallholder Farms

Estimulación reproductiva en burras en posparto, bajo pastoreo controlado en región tropical seca

Este trabajo fue desarrollado para investigar el comportamiento reproductivo a nivel del trópico seco de las burras Criollas en anestro posparto. Veinticuatro hembras, mantenidas en pastoreo controlado fueron sometidas a tres tratamientos de sincronización: T1: día 0 implante auricular de 3 mg norgestomet (Crestar ®, Intervet Inc.) + 50 mg P4/IM (Progesterona ®, Erma), día 12 retiro del implante y 0,25 mg/IM de cloprostenol sódico (Lutaprost ®, Agrovetmarket S.A.); T2: día 0 se aplicó 250 µg de gonadorelin, GnRH /IM (Fertagyl ®, Intervet Inc.) y el día 12 vía IM 0,25 mg cloprostenol sódico (Lutaprost ®); T3: día 0 dispositivo vaginal 0,5 g P4 (DIB ®, Sintex), día 12 se retiró dispositivo + 0,25 mg/IM de cloprostenol sódico (Lutaprost ®). Los incrementos de progesterona en sangre (P4) en los tratamientos hormonales, el inicio, duración y comportamiento del celo sincronizado y la eficacia de los protocolos mediante el diagnóstico ecográfico de gestación al día 50 poscubrición con monta directa el día 2 y 3 de iniciado el celo, fueron evaluados. Los tres protocolos analizados provocaron un incremento en los niveles de P4 de 16,6 ± 8,8 ng/mL, no existiendo diferencia entre ellos; todas las burras presentaron un celo manifiesto que se inició a los 3,3 ± 0,4 días en los protocolos con implantes auriculares y dispositivos vaginales y a los 3,9 ± 0,5 días en el protocolo usando GnRH (p

Fertility response in postpartum anoestrus buffaloes (Bubalus bubalis) using modified Ovsynch based timed insemination protocols.

Background and Aim:Suboestrus constitutes the largest factor responsible for poor reproductive efficiency in buffaloes. Therefore, oestrus synchronization (OS) and fixed-time artificial insemination (AI) is considered an alternative approach to enhance reproductive efficiency in buffaloes. Thus, the present study was carried out to study the efficacy of modified Ovsynch protocol with fixed time insemination in post-partum anoestrus buffaloes.Materials and Methods:Total 50 post-partum anoestrus dairy buffaloes were selected and randomly divided into 5 Groups, each comprising ten animals (n=10). Animals of Group I received buserelin acetate 10 μg(GnRH) at day 0 and 9, and prostaglandin F2α (PGF2α) at day 7; in Group II similar to Group I except double dose of Gn RH (20 μg) at day 0; in Group III, similar to Group I plus additional administration of insulin on day 0, 1 and 2; in Group IV, similar to Group II plus additional administration of insulin on day 0,1 and 2; in Group V similar to Group I except replacement of first Gn RH with insulin on day 0,1 and 2. Animal of all groups were inseminated at fixed time using frozen semen at 60 h and 72 h after PGF2α administration and confirmed for pregnancy at day 60 post-insemination.Results:The results revealed satisfactory and comparable synchronization of oestrus (60-80%) and conception rate (20-40%) among the various treatment groups in the present study. The better synchronization was observed in modified protocols. However, non-significantly higher conception rate was recorded in modified Ovsynch protocol (40% each in Group II-V) as compared to 20% in Group-I (p>0.05).Conclusion:In this study comparatively higher OS and conception following insulin modified Ovsynch based timed AI protocols in post-partum anoestrus buffaloes was found satisfactory and comparable.