Onset Of Estrus Research Articles

Does a single fixed-time insemination in weaned sows affect gestation and lactation length, and piglet performance during lactation compared with multiple insemination protocols in a commercial production setting?

This study evaluated the effect of different single fixed-time artificial insemination (FTAI) protocols on gestation length, farrowing distribution (synchrony), and piglet performance. In Study 1, 866 sows were assigned to two groups: Multiple AI (n = 484) – multiple artificial insemination (AI) at 24 h intervals during estrus; and FTAI+MultAI (n = 382) – OvuGel® 96 h post-weaning and single FTAI 22–24 h later. In Study 2, FTAI protocols were retrospectively analyzed: pLH – sows received 2.5 mg (Exp.1, n = 184) or 5 mg (Exp.2, n = 362) of porcine luteinizing hormone (pLH) at estrus onset, and single FTAI 24 h later. The FTAI+MultAI resulted in shorter gestation length (P < 0.01) and greater synchrony of farrowing on days 114–115 of gestation (P < 0.01) than Multiple AI. Longer lactation length (21.2 vs. 20.9 d; P = 0.02) and greater piglet weaning weight (5378.9 ± 73.1 vs. 5153.2 ± 74.4 g; P = 0.03) for FTAI+MultAI compared to Multiple AI were observed. In Study 2, the gestation length based on the first AI record was shorter for FTAI and resulted in greater synchrony of farrowing on days 114–115 of gestation, compared with Multiple AI (P ≤ 0.05). Gestation length did not differ between groups (P > 0.05) when measured based on most probable AI responsible for fertilization (ultrasound evaluation). In conclusion, FTAI resulted in shorter gestation length and greater farrowing synchrony compared with Multiple AI. Longer lactation length and greater piglet weaning weight were observed for FTAI compared with multiple insemination protocols.

Redox Status and Hematological Variables in Melatonin-Treated Ewes during Early Pregnancy under Heat Stress.

Simple SummaryHeat stress induces oxidative stress that negatively affects the fertility rate in farm animals, as it may disrupt normal follicular development and preimplantation embryogenesis. Although indigenous sheep breeds may exhibit adaptation to a certain level in high summer temperatures, their reproductive competence is still compromised under extreme severe heat stress conditions. Thus, the administration of melatonin is suggested, as an antioxidant regime, for improving the fertility rate and redox balance in heat-stressed ewes. The influence of environmental thermal stress in conjunction with melatonin treatment on hematological variables and cortisol secretion was also investigated. In this respect, melatonin seems to enhance the progressive adaptation of indigenous-breed ewes to environmental heat stress.The preovulatory follicles and preimplantation stage embryos are found to be rather sensitive to heat stress due to their low potential for scavenging reactive oxygen species (ROS). The aim of the present study was to assess the impact of melatonin administration on redox status and hematological variables during the preovulatory period and early stages of embryogenesis in heat-stressed ewes in vivo. Forty Karagouniko-breed ewes were divided in two groups, the melatonin (M, n = 20) group and control (C, n = 20) one. All animals were subjected to heat stress throughout the study, which lasted forty days (D0 to D40). In M group, melatonin implants were administered on D0. Then, oestrous synchronization was applied (D19-D33). On D34, six rams were introduced into the ewe flock for mating. Ultrasonographic examination was conducted on D73 for pregnancy diagnosis. The temperature humidity index (THI), the rectal temperature (RT), and the number of breaths per minute (BR) were evaluated twice daily. Redox biomarkers, namely total antioxidant capacity (TAC), reduced glutathione (GSH), and thiobarbituric acid reactive substances (TBARS), were assayed in blood samples collected on D0, D33, and D40. In addition, packed cell volume (PCV), white blood cells (WBCs), leukocyte differential count, and cortisol assessment were conducted in blood samples on D33 and D40. The results indicated improved fertility rate and mean number of lambs born per ewe due to improved redox status (p < 0.05) in ewes that received melatonin implants 34 days approximately before the onset of oestrus. The PCV decreased in both groups between the two time-points (p < 0.05). However, the NEU/LYMPH ratio decreased (p < 0.05) only in group M. The low cortisol levels and the decreased NEU/LYMPH ratio in both groups support the hypothesis that ewes of the indigenous Karagouniko breed may exhibit adaptation to environmental thermal stress. The administration of melatonin as an antioxidant regime may improve the reproductive competence of heat stressed ewes and may also enhance their ability to adapt at high ambient temperatures.

Gilt reproductive performance in a tropical environment after oestrus synchronization and fixed-time artificial insemination

The present study was performed to evaluate the reproductive performance of gilts inseminated using fixed-time artificial insemination (FTAI) protocol. A total of 408 Landrace × Yorkshire crossbred gilts were included in the experiment. Gilts at 8 months of age were randomly allocated into three groups: control AI (n = 192), treatment 1–TAI (n = 117) and treatment 2–FTAI (n = 99). Gilts in the control AI group were inseminated 2–3 times during standing oestrus at 0, 12 and 24 h after the onset of oestrus. Gilts in the treatment 1–TAI group were orally administered 20 mg per day of altrenogest for 18 days and then inseminated 2–3 times during standing oestrus by conventional AI. Gilts in the treatment 2–FTAI group were synchronized like gilts in treatment 1–TAI group but then GnRH (10 μg of buserelin) was administered 120 h after the end of altrenogest treatment and fixed time artificial inseminated twice at 24 and 32 h after GnRH irrespective of the presence of oestrus or not. Conception rate of gilts in treatment 2–FTAI (87.9%) was similar to the treatment 1–TAI (94.9%) and control AI (83.3%) (P > 0.05). Conception rate in treatment 1–TAI (94.9%) was higher compared to control AI group (83.3%, P = 0.040). Farrowing rate of gilts in treatment 2–FTAI (83.8%) was similar to treatment 1–TAI (89.7%) and control AI (76.0%) (P > 0.05). Farrowing rate of treatment 1–TAI (89.7%) was higher than control AI gilts (76.0%, P = 0.033). In treatment 2–FTAI, the conception and farrowing rate of the nine gilts that were inseminated even if they were not detected in oestrus (all during warm season) was 44.4% and 44.4%, respectively. Regular return to oestrus was similar between groups (9.4%, 0.9% and 4.1% for control AI, treatment 1–TAI and treatment 2–FTAI, respectively, P > 0.05). The total number of piglets born per litter in treatment 1–TAI group was higher than control AI (13.1 ± 0.2 versus 11.6 ± 0.2, respectively, P < 0.001) and treatment 2–FTAI groups (12.2 ± 0.3, P = 0.019). The number of piglets born alive was higher in treatment 1–TAI (12.1 ± 0.3) compared to treatment 2–FTAI (11.3 ± 0.2) and control AI group (11.2 ± 0.3). The percentage of stillbirth and mummified foetus were not different between groups (P > 0.05). The present study indicated that fixed-time AI in gilts can be successfully performed by administration of altrenogest for 18 days, GnRH at 120 h after altrenogest withdrawal and then double fixed-time AI at 24 and 32 h after the administration of GnRH. Fertility metrics such as conception rate, farrowing rate and litter performances using this method were similar to gilts inseminated at oestrus with conventional AI.

The efficiency of estrus synchronization protocols and artificial insemination in the Abergelle goat on-station and on-farm conditions of Northern Ethiopia

ABSTRACT This study was conducted to investigate the effect of different estrus synchronization protocols followed by artificial insemination on estrus response and the conception rate of Abergelle goats. Three estrus synchronization protocols: (i) the standard protocol associating progestogens, gonadotropins and prostaglandins (P4 + eCG + PGF2α), (ii) single injection of prostaglandin (PGFS), (iii) double injection of prostaglandin (PGFD) were evaluated and compared to a control group that did not receive a hormonal treatment. Estrus behaviour was monitored in all does and those in estrus were inseminated. The estrous response was significantly higher in P4 + eCG + PGF2α does than in counterparts in PGFS and PGFD groups (p < 0.001). Results also revealed an earlier onset of estrus in the PGFD-treated group, a longer duration of estrus for second- and third- parity -does and an earlier onset of estrus in animals having a 3.5 body condition score. Even if the conception rate (CR) was highest when using the PGFD protocol, the lowest kidding rate (KR) was obtained when using this same treatment. The P4 + eCG + PGF protocol yielded the highest litter size. Farmers’ perception surveys revealed that a higher proportion of goat keepers used a controlled mating system and had culling practices and farmers selected PGFD as a preferred protocol.

Does buck stimulation affect the reproductive performance of goats synchronized with Medroxyprogesterone Acetate (MAP) sponges?

This investigation was executed to determine effect of buck exposure on estrus response, onset of standing estrus, ovulation rate, conception rate and pregnancy rate in goats synchronized with medroxyprogesterone acetate (MAP) sponges. Sponges were placed inside the vagina for fifteen days in buck exposed and isolated groups. Post sponge withdrawal, estrus activities were continuously observed. The interval between sponge withdrawal and the onset of standing estrus were 32.3±10 h (18-51 h) and 45.2±10.9 h (27-51h) in buck isolated and exposed group respectively (p&lt;0.05). Ovulation and conception rates were confirmed by serum progesterone level using radioimmunoassay. Ovulation rates were 100% in both groups and conception rates were 93% and 100% in buck exposed and in isolated group respectively (p&gt;0.05). Pregnancies were confirmed by ultrasound on day 35 post mating which were 93%, was and 69% in buck exposed and isolated group respectively (p&gt;0.05). Based upon the evidence, it was inference that post sponge removal sudden buck exposure cause markedly earlier estrus onset while the continuous buck exposure was unable to show significantly impact on conception and pregnancy rates compare to isolated group.

Effect of Breed and Risk Factors Affecting Conception Rate to Artificial Insemination in Dairy Cows of Tullo District Western Haraghe, Ethiopia

Aim This study was conducted using the questionnaire method to assess the effect of breed and factors affecting conception rate on artificial insemination in dairy cows in Tullo district, Western Haraghe, Ethiopia. Methods A follow-up study design was conducted from December 2018 to June 2019 to determine the effect of breed and factors affecting conception rate to artificial insemination in dairy cows, taking breed, age, parity, body condition and timing of insemination as risk factors. The demographic factors were recorded by interviewing the owners. Most of the cows were examined for pregnancy diagnosis by rectal palpation of the genital tract at 60-80-days post-artificial insemination. Results Out of 114 artificially inseminated cows/heifers, 59 became pregnant, giving an overall first service conception rate of 51.8%. Although the breed, age, parity and body condition score did not affect the conception rate significantly, the pregnancy rate was better in the cross-breed (62.5%), in cows of 5-7-years of age (54.6%), in cows of parity 2-3 (59.2%) and in cows of good body condition score (57.7%). The conception rate in cows inseminated at 12-18-hours after the onset of estrus was significantly higher (62.3%) than those inseminated after 18-hours (31.2%) and before 12-hours (52.4%) after the onset of estrus. Therefore, cows with good body condition score (BCS) and artificial insemination (AI) service at 12-18-hours after the onset of estrus are the best choice of selection for obtaining the best result in the first service conception rate to AI in dairy cows/heifers. Conclusion This study reveals that the conception rate was influenced by the time of AI, so awareness should be given to cattle owners, as they should give AI for their cattle at optimum time within 12-18-hours after onset of heat sign.

Effect of Body Condition Score Limousine Crossbred Cow on Cattle Oestrus Response Synchronized using PGF2α Single Dose

One of the strategies to increase the cattle population in Indonesia is the AI (Artificial Insemination) method. The AI program's improvement of reproductive efficiency can use the oestrus synchronization method. The purpose of this study was to evaluate the effect of body weight and body condition score on the oestrus synchronization response with the brand "lutelyse." This research was conducted in Senggreng Village, Sumberpucung District, Malang Regency, This research method uses experimental field experiments with a sampling technique of purposive sampling. This study took a sample of 21, aged 1,5 –5 years, synchronized with PGF2α as much as 5 ml, which was then carried out by observing oestrus behavior for 24 hours after synchronization. The results showed that, the percentage of oestrus in cows with body condition score (BCS) 4, which is 76.92%, is lower than cows with BCS 5, which is 100%. For the synchronization distance with the onset of oestrus in BCS 4 cattle, namely 3802.92 ± 1007.80 (minutes) and BCS 5, namely 4081 ± 884.91 (minutes) with the results of the conception rate of BCS 4 cattle of 38.46% and BCS 5 of 50%. Based on the results of the study, it was concluded that BCS 5 has a higher success pregnancy rate than BCS 4.

Vaginal cytology and receptivity to mating behaviour of Kintamani bitch during the proestrus to estrus phase

The breeding and rearing of Kintamani Bali dogs have evolved from just keeping them as pets to a dog farming industry. Individual variation in female dog fertility must be detected to manage to breed successfully. Vaginal smear cytology is a low-cost and simple method of determining dog’s estrus cycle stages. This study aims to determine the vaginal cytology and receptivity to mating behavior in Kintamani Bali bitch during the proestrus to the estrus phase. The investigation started on the first day of proestrus and continued until the first day of receptivity of mating with a male naturally. The results of this study showed that from the beginning of serosanguinous discharge to early estrus, characterized by a gradual change from initially parabasal and intermediate cells (small then larger) and finally to superficial cells. The onset of estrus is characterized by a predominance of superficial cells and their nucleus disappears and is accompanied by a peak of fully cornified cells. In conclusion, was observed a significant difference in cornified cell identification between the proestrus and estrus phases.

4 Variation in Sow Body Temperature Following Weaning

Abstract There is limited data available on variation in sow temperature following weaning. The objective of this study was to determine variation (diurnal and with day post-weaning) in rectal (RT) and vulva surface (VT) temperature following weaning. A cross-sectional survey was carried out using 114 multi-parous sows weaned in 7 groups between September and December. Sows were housed in individual stalls and were checked daily for standing reflex from d 4 to 8 post-weaning. Sow RT (measured with a standard thermometer) and VT (measured with an infrared thermal camera) were measured daily [at 06:15 (feeding time), 07:00, 07:30 (heat checking time), 09:00, 11:00, 13:00, 15:00, 17:00, 19:00, 21:00, and 23:00]. A repeated-measures analysis was carried out using PROC MIXED of SAS; models included the fixed effect of either study day or measurement time, and random effect of group. The number of sows exhibiting standing reflex on d 4, 5, 6, 7, and 8 post-weaning was 1, 45, 45, 19, 1, respectively; 3 sows did not exhibit standing reflex. Average VT and RT over the study period were 30.8 ± 3.23 and 38.2 ± 0.60°C, respectively; the correlation between these measurements was 0.08 (P &amp;lt; 0.05). There was considerable day-to-day variation in average VT (range between day: 29.5 to 32.6°C) and to a lesser extent RT (range: 37.7 to 38.5°C). The VT was higher (P &amp;lt; 0.05) on d 3 to 5 post-weaning compared with other days. Also, VT was higher (P &amp;lt; 0.05) between 06:15 and 07:30 than at the other measurement times. There was no clear pattern for either day-to-day or diurnal variation in RT. In conclusion, this study described between-sow variation in RT and VT following weaning. Further research is needed to determine if any of this variation in temperature is associated with the onset of estrus.

Technology Adoption Using PGF2 Alpha for Breeding

The productivity and health level of goats kept are still relatively low. This is because the maintenance system carried out by farmers is still traditional and there is no touch and technology adoption. The limited scale of ownership coupled with the spread of cage locations makes it difficult to detect estrus/estrus, the absence of superior males also causes a decrease in the genetic quality of livestock. This study aims to find a method of breeding in sheep using reproductive engineering mating techniques to obtain an applicable goat breeding model. Research Design 10 ewes that are not pregnant, prepared for natural mating with the joint bull mating model. The treatment for the ewes was prepared for estrus synchronization reproductive technology using prostaglandins with two doses. The livestock group was induced by intramuscular estrus as much as 0.5; 1; 1.5; and 2 cc per head using the hormone PGF2 alpha (lutalyse). The injection is done with two injections (double injection) with an interval of 11-12 days. Two days after the application of the hormone, the goat showed estrus, then observed the percentage of estrus, estrus intensity and estrus strength. The results showed that all doses that had been given gave good results on the onset of estrus, standing heat, duration of estrus, intensity of estrus and after the second injection with a distance of 11 days all treatments showed 100 percent estrus. Days 14 to 18 after treatment were the peak period with the highest intensity of estrus and standing heat in goats. Giving a dose of prostaglandin 2 ml has been effective and more economical in estrus synchronization to produce quality estrus symptoms.

Reproductive Performance of Saanen Goats After PGF2α Intramuscular Injection in Correlation to Body Weight

An experiment was conducted at Kalikesur Farm, Kedung Banteng, Banyumas to investigate the reproductive performance of Saanen dairy goats after PGF2α injection on different body weights. This experiment included twenty female Saanen goats at 2-3 years of age, 2-3 kidding periods, and varying body weights of 30 to 55 kg. All goats were intramuscularly injected by 2 ml PGF2α (LutalyseTM, Pharmacia and Upjohn Company, Pfizer Inc) in a double injection pattern, with 11-day interval to perform estrous synchronization. The variables on reproductive performance such as estrus onset, length of estrus, and intensity of estrus were measured and monitored twice a day at 6-10 am and 3-5 pm. Descriptive statistics and correlation analysis were conducted. Results demonstrated that body weight performed strong correlations with estrus intensity (r = 0.66) while the time for the first estrus (onset) has a negative moderate correlation with body weight (r = -0.47), a negative weak correlation was recorded between body weight and length of estrus (r = -0.17). Based on the results obtained, it can be concluded that the body weight of goats in the estrus synchronization program can be used to be an indicator of reproductive performance, especially in estrus intensity. This can help farmers to predict estrus behavior after PGF2α synchronization.

27 Transcriptome Comparison of Parthenogenetic vs. Biparental Embryos in Beef Cattle

Abstract This experiment aimed to determine differences in circulating pregnancy-associated glycoprotein (PAG) concentrations, differentially expressed genes (DEGs), and comparative gene ontology profiles between parthenogenetic embryos (PA; absence of paternal genetics) and biparental control embryos (CON). PA embryos were produced in vitro using a validated chemical activation method, and CON embryos were produced in vitro using industry standard techniques. A blood sample was collected on day 31, and PAG concentrations were determined by an in-house ELISA. Transrectal ultrasonography was performed daily to monitor conceptus development. Cows (n = 30) were synchronized, underwent embryo transfer [ET; 7 days after onset of estrus (day 0)] and were euthanized at approximately day 31 of gestation. Tissues from endometrium (EM), trophectoderm (TE), and corpus luteum (CL) were collected and sequenced from both groups (3 PA; 3 CON). Average PAG concentrations between PA and CON on day 31 were 0.81±0.44 ng/mL and 5.23±0.44 ng/mL (P = 0.01), respectively. When comparing PA to CON, there were 969 DEG in the EM (599 genes upregulated; 269 genes downregulated; 101 nonannotated genes) and 250 DEG in the TE (163 genes upregulated; 47 downregulated; 40 nonannotated genes). Comparative gene ontology profiles between DEGs showed an upregulation in immune system-associated activities and extracellular matrix interactions and a downregulation in redox reactions and proteolytic activities involving PAGs for PA as compared to CON. Similarly, the TE comparisons showed an upregulation in prolactin (PRL) inhibiting pathways and a downregulation in structural molecule activity and signaling for PA as compared to CON. The DEGs observed in PAs show significant decreases in conceptus-derived products and gene ontology profiles associated with pregnancy. Overall, these findings demonstrate that uniparental embryos can be a useful model to better understand pregnancy development and loss in cattle.

Effects of restricted nutrition and flushing on reproductive performance and metabolic profiles in sheep

The aim of this study was to assess the impact of dietary restriction during the lactation period on flushing performance and metabolic profiles in sheep. The treatments were performed in a 2 × 2 factorial arrangement with (i) adequate and restricted feeding treatment during lactation and (ii) flushing and control feeding treatment during mating season. Eighty-four Karacabey Merino ewes were divided into two groups for adequate energy (100%) and restricted (70%) at energy requirements for three months of lactation. Each group was also divided into two sub-groups based on flushing diet (AL-F, RL-F; 150%) or control diet (AL-C, RL-C; 100%) during the mating season. Live weight (LW), body condition score (BCS), serum metabolites and hormone concentrations, ovulation rate, estrus performance and lambing performance of ewes were observed. Data from this study showed that average difference (P < 0.001) of LW and BCS between groups were 5.45 kg and 0.54 respectively at the end of lactation. No significant effects of nutritional treatments (P > 0.05) were observed; the average fecundity, litter size and ovulation rates of ewes were 1.30±0.07, 1.44±0.06 and 1.53±0.07 respectively. The onset of estrus was earlier (P = 0.021) in RL-F ewes (7.0 d) than for AL-F, AL-C and RL-C ewes (11.0, 12.2 and 10.9 d respectively). Mean PRG concentration of ewes was lower (P = 0.011) in RL-C group than ewes in AL-C group (1.859±0.266 and 3.143±0.272 ng/ml respectively) at the ram introduction day. Serum biochemical variables blood urea nitrogen (BUN), glucose (GLUC), triglycerides (TGL) and very low density lipoprotein cholesterol (VLDL-CHOL) concentrations- decreased (P < 0.05), while non-esterified fatty acid (NEFA), cholesterol (CHOL), high density lipoprotein cholesterol (HDL-CHOL) and low density lipoprotein cholesterol (LDL-CHOL) concentrations increased (P < 0.05) in the restricted ewes compared with adequate ewes in the different months. In conclusion, in addition to BCS, blood total protein, BUN, GLUC, NEFA and CHOL can be recommended for testing flock metabolic profiles as specific blood metabolites. Flushing did not cause significant differences in reproductive parameters including the ovulation rate. However, the time required for onset of estrus was found to be significantly shorter after the flushing treatment in restricted group of animals.

Comparison of GnRH and hCG effects on oestradiol, progesterone and premature luteolysis in Ovsynch-synchronized ewes.

The purpose of this study was to ascertain whether premature luteolysis can be alleviated by substituting the ovulation inducing agent hCG for GnRH. Seventy-two hours after the end of artificial insemination (AI), pluriparous Awassi ewes were randomly assigned to one of three treatment groups of 13 ewes each. First group received 37.5µg of the GnRH analog Lecirelin, the second 1000I.U hCG and the third group served as a control (received 1ml of physiological saline solution). Blood samples were collected at daily intervals after GnRH treatment and analysed for plasma oestradiol and progesterone concentrations. Ovarian follicles were monitored ultrasonically at the time of GnRH administration, 60hr and 84hr later. Pregnancy was diagnosed ultrasonically at Day 35 after AI. Number and size of ovarian follicles did not differ (p>.05) among treatment groups. Onset and duration of oestrus were not affected by treatment (p>.05). No significant differences (p>.05) were recorded in oestradiol and progesterone concentrations between the treatment groups during the inspection period. Premature luteolysis became evident in ewes with longer oestrous durations by Day 6.25 after AI and amounted to 7.69%, 18.18% and 23.07% in GnRH, hCG and Control groups respectively. Pregnancy rates increased to 92.31% and 81.82% in GnRH and hCG groups, compared to 76.92% in the Control group. The results indicate that GnRH was more effective in reducing premature luteolysis than hCG. Substituting hCG for GnRH as an ovulation inducing agent was of no avail.

Efficiency of Copper and Selenium during Estrus Synchronization on Estrus Behaviour, Estradiol and Progesterone Concentration in Salem Black Goats

Background: Copper and selenium were proven modulaters of reproductive function in ruminants under dietary supplementation. Their effects under pareneral administraton during estrus synchronization are not clearly defined. On this background the present was aimed to evaluate the effect of copper and selenium on estrus associated responses in goats. Methods: Thirty adult female Salem black goats were selected. On day ten of the estrus cycle, 250 µg of cloprostenol injection was given intramuscularly to all the animals and assigned to five groups. GI: control, GII: 4 µg of Buserelin, GIII: 20 mg cupric chloride, GIV: 10 mg sodium selenite and GV: copper plus selenium injections were administrated. Whole blood was collected for seven days for hormone assay. Estrus was detected using aproned bucks. Result: There was no significant (p greater than 0.05) difference in estrus response, onset and duration of estrus between groups. The progesterone concentration decreased significantly (p less than 0.05) from day 0 (before PGF2α) to day 1 (after PGF2α) in all groups. There was a significant (p less than 0.05) increase in estradiol and progesterone concentration in the GnRH group compared to other groups. Parenteral administration of copper and selenium did not significantly improve estrus behavior, estradiol and progesterone concentration in Salem black goats. GnRH was once again proved to be effective in the improvement of estrus associated responses in goats.

Study of the factors affecting embryo yields and quality in superovulated Morada Nova ewes that underwent non-surgical uterine flushing.

The present study compared the outcomes of in vivo embryo production in Morada Nova ewes subjected to either 9-day (G-9SOV , n=21) or 12-day (G-12SOV , n=21) progesterone (P4 )-based estruses synchronization protocol coupled with superovulatory treatment with decreasing doses of porcine follicle-stimulating hormone (133mg of pFSH given over 3days). Non-surgical embryo recovery (NSER) was performed 6-7days after the onset of oestrus. Total antral follicle count doubled from the first to the sixth pFSH dose in both groups (p<.05). Oestrus responses did not vary between the two groups of animals (95.2%). Corpora lutea (CL) were detected in 85.0% and 60.0% of ewes that previously manifested oestrus behaviour in G-9SOV and G-12SOV respectively. NSER was successfully completed in 86.2% of ewes that had CL (p>.05). The mean number of CL per ewe/successfully flushed donor ewe was greater (p<.05) in G-12SOV (12.3±1.7/12.1±1.9) than in G-9SOV (7.9±1.4/8.2±1.6). Mean numbers of retrieved blastocysts and viable embryos were greater (p>.05) in G-12SOV (5.8±1.9 and 3.7±1.7) than G-9SOV (3.5±1.1 and 0.8±0.3 respectively). The total follicle count (all follicles ≥2mm in diameter) at the sixth pFSH dose (at P4 -device removal) was positively correlated (p<.05) with the number of CL (r=.95) and viable embryos (r=.91) in G-12SOV . The ewes with ≥10 Cl (48% of all flushed donors) yielded 80.5% of viable embryos. In summary: (a) Morada Nova ewes from G-12SOV group had better superovulatory responses compared with G-9SOV group; (b) total follicle count at the last pFSH dose was a good predictor of superovulatory responses only in the ewes primed with P4 for 12days; and (c) animals with ≥10 ovulations are main contributors to viable embryo production in Morada Nova ewes.

Using machine-learning technique for estrus onset detection in dairy cows from acceleration and location data acquired by a neck-tag

To promote reproductive performance in dairy cows, the timely and accurate detection of estrus onset associated with ovulation time is necessary. However, poor heat detection by manual inspection and incompetent monitoring ability via the current automated estrus discrimination methods, lead to an unsatisfactory pregnancy rate. The aim of this study was to evaluate the potential of machine learning technique based on acceleration and location data to identify the onset of estrus in dairy cows. Measurements were obtained from 296 lactating cows housed in a free-stall barn for 8 months. A total of 325 estrus events were used for modelling and testing, consisting of 2768 1-h estrus time windows and 20,632 1-h non-estrus time windows. The backpropagation neural network (BPNN) algorithm with optimized parameter combination of the number of hidden layer neurons and learning rate were investigated to automatically detect estrus onset from seven behavioral metrics, which were: duration of standing, duration of lying, duration of walking, steps, displacement, switching times between standing and walking, and number of standing mounts. The study showed that the accuracy, precision, sensitivity, specificity and F1 score of the BPNN algorithm were up to 95.46%, 72.80%, 98.29%, 95.08%, 83.65%, respectively, enabling automated estrus identification. Compared to the support vector machine (SVM) and logistic regression (LR) algorithms, the perception capability of the proposed method of estrus onset was comparable in performance to manual inspection as assessed by mean, standard deviation, absolute value of the difference, and consistency, making it an excellent alternative to replace laborious visual observation.

Comparative study of short term and long term protocols for progesterone based estrus synchronization in ewes during breeding season

The study was designed to compare the effect of length of progesterone treatment (6 d vs 10 d vs 14 d) on synchronization efficiency and fertility response in multiparous ewes. The crossbred ewes (30) were equally allotted to three groups designated as short (6 days), medium (10 days) and long-term (14 days) treatment. All the ewes were injected PGF2α 250 μg, intramuscularly 24 h before sponge removal. After the sponge removal ewes were kept with breeding rams for tupping upto 72 h. Although the onset of estrus was more precise in short and long term groups, however overall estrus response rate was highest in short treatment group (90%) followed by long treatment group (70%) and medium treatment group (60%). The pregnancy rates were non-significantly higher for short and medium treatment groups than long treatment group. The progesterone values in pregnant ewes, decreased significantly from day pre-treatment to day 0 followed by significant increase from day 0 to day 10, 17 and 35. In conclusion, short term (6 d) intravaginal progesterone treatment may replace the traditional long term treatment (14 d) for induction of estrous during breeding season. However, the results should be validated in larger number of animals before recommending the protocol.

Relationship between the timing of insemination based on estrus detected by the automatic activity monitoring system and conception rates using sex-sorted semen in Holstein dairy cattle.

We investigated the optimal timing of artificial insemination (AI) for achieving pregnancy according to the onset/end of estrus detected by an accelerometer system in Holstein cattle. The conception rates of conventional semen were used as a reference. The conception rate from AI of sex-sorted semen was higher at −4 to 4 h (57.1%) from the end of estrus than those at −12 to −4 h (37.7%) and 12–20 h (30.3%), whereas AI at 4–12 h showed an intermediate conception rate (47.4%). Conversely, conception rates were similar in AI performed between 0 and 32 h from the onset of estrus. Regarding conventional semen, the interval from the onset and end of estrus did not affect conception rates. The present results suggest that the time of the end of estrus is the better indicator of optimal AI timing for sex-sorted semen than the onset of estrus.

Início do estro e sua correlação com os parâmetros ovarianos em cabras leiteiras

Abstract This study assessed the effects of social dominance on the behavioral estrus and ovarian parameters of dairy goats subjected to synchronous estrus induction during the non-breeding season. Synchronous estrus was induced in 23 dairy goats allocated to collective pens. Ovarian ultrasonography was performed at 12 h intervals from device removal to ovulation. Upon estrus onset (EO) detection, the goats were immediately removed from the pens. Dominance was scored according to EO in relation to device removal in each pen, with HD - high dominants (&lt;36 h; n = 8), MD - medium dominants (36 to 48 h; n = 10) and LD - low dominants (&gt;48 h; n = 5). Goats in estrus underwent flexible time artificial insemination (FxTAI) according to EO. The estrus response was 100.0%. The interval to estrus was longer (P&lt;0.05) in LD (53.7 ± 6.5 h) than in MD (37.9 ± 5.5 h) and HD goats (32.3 ± 6.6 h), while the interval from device removal to ovulation was similar (P&gt;0.05) among all groups. The interval from EO to FxTAI was longer in HD goats compared to the other groups (P&lt;0.05). In conclusion, although social hierarchy influenced the time of EO, the ovarian parameters, including ovulation, were not affected.