• Journal of agriculture & life science
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• v.50 no.5
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• pp.183-188
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• 2016

This experiment was conducted to investigate the effects of artificial insemination(AI) frequency on reproductive performance of sows. A total of 48 F1 sows(Yorkshire×Landrace) were allocated to 1 of 4 treatments using completely randomized design(CRD). Four experimental treatments were AI frequency from one to four times(AI1, AI2, AI3, AI4) respectively. Estrus detection was done at approximately 09:00 and 21:00 daily by applying back pressure to females with the presence of a mature boar and the weaning to estrus interval(WEI) of all sows were 5~6 day. Sows detected in estrus were mated at 12 hour after and mating interval was 12 hour by treatments. This experiment demonstrated that the lowest farrowing rate was observed AI3 treatment. Frequency of AI did not influence on reproductive performance when WEI was 5-6 day. No significant differences were observed on litter size, born alive and litter birth weight. Consequently, decreased AI frequency did not have any detrimental effect on reproductive performance when estrus detection was adequate. Decreased AI frequency could reduce cost of production of pigs when sows showed normal reproductive performance.

• Journal of Embryo Transfer
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• v.28 no.3
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• pp.177-184
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• 2013

The objective of this study was to analyze the accuracy of estrus detection of heat detector and analysis of estrus behavior (mounting and mounted), and the evaluation of conditions required for improving reproductive efficiency in Holstein dairy cows fitted with a estrous detector. The heat detection system consists of estrous detector based on wireless sensor and an electric bulletin board displayed estrus behavior data. When cow mounting other cows, the accuracy of estrus behavior displayed an electric bulletin board were 87.5% (mounting other cows only), 100% (mounting other cows but not standing), 80.0% (mounting other cows with standing for 1~4 seconds), 90.0% (mounting other cows but not standing for 1~4 seconds), 80% (mounting other cows with standing for more than 5 seconds) and 90.0% (mounting other cows but not standing for more than 5 seconds). When cow mounted other cows, the accuracy of estrus behavior displayed an electric bulletin board were 100% (mounted other cows but not standing), 100% (mounted other cows with standing for 1~4 seconds), 100% (mounted other cows but not standing for 1~4 seconds) and 100% (mounted other cows with standing for more than 5 seconds). Circadian distribution of first observed in estrus were 59.1% (am 8~pm 6) and 40.9% (pm 6~am 8). Distribution for the number of estrus behavior were 40.9% (less than 3 times), 36.4% (4~6 times) and 22.7% (more than 4 times). The conception rates relative to interval from first estrus behavior to insemination for estrus periods were 23.1% (less than 11 hours) and 55.6% (12~20 hours).

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.6
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• pp.851-856
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• 2011

This study was conducted to evaluate the effects of flavor supplementation on pre- and post-weaning performance and behavior of piglets and sows. A total of 30 sows (Landrace${\times}$Yorkshire) and their litters were employed in this study. Sows were randomly assigned to 3 dietary treatments (10 replications per treatment). Dietary treatments included: i) CON, basal diet; ii) TRT1, CON+0.1% vanilla supplement; iii) TRT2, CON+0.1% cheese supplement. The behavior of sows (nursery, eating and standing) and piglets (eating, sleeping and fighting) in each treatment was monitored throughout experiment. Each piglet was weighted at 5, 10, 15 and 21 d after birth to evaluate the average daily gain. Sows and piglets were bled on the weaning d to evaluate the blood characteristics. Back fat and estrus interval were investigated. In this study, there were no differences (p>0.05) in diarrhea score and blood characteristics among treatments. Likewise, the behavior was not influenced (p>0.05) by the dietary flavor supplementation. However, administration of flavor increased (p<0.05) the pre-weaning feed intake, post-weaning average daily gain (ADG) and gain/feed (G/F) ratio. No significant difference was observed (p>0.05) on the blood characteristics, behavior, backfat loss and estrus interval among treatments. In conclusion, administration of flavor could increase creep feed intake pre-weaning and piglet ADG post-weaning, whereas inclusion of flavor had no influence on blood characteristics and performance in sow and piglets.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.230-238
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• 2021

This study attempted to determine the characteristic features of postpartum dairy cows during their return to estrus. Moreover, it investigated the effects of abnormal ovarian cycles (AOC) on subsequent reproductive performance and the relationship between normal ovarian cycles (NOC) and the blood urea nitrogen (BUN) level postpartum. Incidentally, 56.3% of the Holstein cows and 66.7% of the Jersey cows had NOC, whereas the 43.7% and 33.3% of the Holstein and Jersey, respectively, had AOC. Within 100 days of calving, the cows with AOC had significantly lower rates of artificial insemination (AI) submission as well as pregnancy and a significantly longer interval to first AI, as compared to that in the cows with NOC. Additionally, the cows with NOC had a significantly higher first AI conception rate than that in the cows with AOC. In this study, of the 32 Holstein cows, 8 resumed their ovarian cycle within 20 days of calving, 10 resumed the cycle with 21-40 days of calving, 8 within 41-60 days of calving, while the remaining 6 did not resume their ovarian cycles until 60 days postpartum. Furthermore, the likelihood ratios of incidence of NOC are 0.93, 1.94, and 0.38, respectively, in the groups with BUN levels < 15, 15-19.9, and ≥ 20 mg/dl. In conclusion, AOC postpartum adversely affects reproductive performance such as AI submission rate, pregnancy rate, interval to first AI and first AI conception rate; moreover, an increase or decrease in the BUN levels beyond 15-19.9 mg/dL leads to the AOC postpartum.

• Animal Bioscience
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• v.36 no.4
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• pp.591-600
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• 2023

Objective: We aimed to evaluate the efficacy of a modified Double-Ovsynch protocol vs artificial insemination following estrus detection (AIED) for the enhancement of reproductive performance in Hanwoo cattle. Methods: Four hundred twelve Hanwoo cows were allocated to two treatment groups. The first group of cows were administered gonadotropin releasing hormone (GnRH) on Day 36 (±0.6), prostaglandin F_2α (PGF_2α) on Day 46 (8 to 12 days later), and GnRH on Day 49, which was followed by Ovsynch, consisting of an injection of GnRH on Day 56, PGF_2α on Day 63, and GnRH 56 h and timed AI (TAI) 16 h later (modified Double-Ovsynch group, n = 203). The second group of cows underwent AIED (AIED group, n = 209) and were designated as controls. Results: The pregnancy per AI 60 days after the first AI was higher in the modified Double-Ovsynch (68.5%) than in the AIED (56.5%) group, resulting in a higher probability of pregnancy per AI (odds ratio: 1.68, p<0.05). Moreover, cows in the modified Double-Ovsynch group were more likely (hazard ratio: 1.28, p<0.05) to be pregnant by 150 days after calving than cows in the AIED group, and this difference was associated with a lower mean number of AIs per conception (1.27 vs 1.39, p<0.05) and a shorter median interval between calving and pregnancy (72 vs 78 days, p<0.1). Conclusion: The modified Double-Ovsynch protocol, adjusted according to the herd visit schedule, can be readily used to increase the pregnancy per AI following the first AI and to shorten the interval between calving and pregnancy in beef herds.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.952-961
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• 2003

In the first part of the study, rates of estrus occurrence and success of A.I. service in the Thai-native and Friesian crossbred, and purebred Friesian cows fed in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand were traced monthly throughout a year. An electric fan and a water sprinkler cooled the stall for the purebred cows during the hot season (March-September). Both rates in pure Friesians were at their highest in the cold-dry season (October- February), but they decreased steadily during the hot-dry season (March-May) and were at their lowest in the hot-wet season (June-September). Seasonal change of a similar pattern was observed in the incidence of estrus, but not in the success rate of insemination in the crossbred cows. By the use of reproductive data, compiled in the same institute, on the 75 % cross- and purebred Friesian cows, and climatological data in Chiang Mai district, effects of ambient temperature and humidity on the reproductive traits of cows were examined by regression analysis in the second half of the study. Significant relationships in the crossbred, expressed by positive-linear and parabola regressions, were found between reproductive parameters such as days to the first estrus (DTFE), A.I. service (DTFAI), and conception, the number of A.I. services required for conception and some climatic factors. However, regarding this, no consistent or intelligible results were obtained in purebred cows, perhaps because electric fans and water sprinklers were used for this breed in the hot season. Among climatic factors examined, the minimum temperature (MINT) in early lactation affected reproductive activity most conspicuously. As the temperature during one or two months prior to the first estrus and A.I. service rose, DTFE and DTFAI steadily became longer, although, when MINT depleted below $17-18^{\circ}C$, the reproductive interval tended to be prolonged again on some occasions. The maximum temperature also affected DTFE and DTFAI, but only in limited conditions. The effect of humidity was not clear, although the inverse relationship between DTFE and minimum humidity during 2 months before the first estrus in the crossbred seemed to be significant. Failure to detect any definite effect of climate on the reproductive traits of pure Friesians seemed to indicate that forced ventilation by electric fans and water sprinklers were effective enough to protect the reproductive ability of this breed from the adverse effects of a hot climate.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.255-260
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• 2016

The aim of this study is to evaluate the effects of vitamin or mineral supplements on the conception rates of dairy heifers when replacing the last injection of GnRH with hCG in ovsynch protocol (experiment 1) and also to investigate whether the estrus synchronization treatment in the heifer stage affects the conception rates after $1^{st}$ parturition (experiment 2). In experiment 1, 50 heifers were randomly assigned into 3 groups: 20 heifers each in groups 1 and 2, and 10 in group 3. All three groups were treated with an intramuscular injection of GnRH on day 0 (day 0 = the day of program start), $PGF_{2{\alpha}}$ on day 7 and hCG on day 9, and were inseminated on day 10, 12~16h after hCG injection. In group 1 (vitamin group), the heifers were treated with an intramuscular injection of 5 ml of vitamin-ADE $500^{(R)}$, and group 2 (mineral group) was treated twice with an intramuscular injection of 30 ml of mineral supplement-LAPTOVET$^{(R)}$ on a one-week interval beginning on the day of hormone treatment (day 0 and day 7 respectively). Group 3 (control) was treated only with hormones. Pregnancy diagnosis was performed by ultrasonography through a rectal probe. First service conception rates (FSCR) and average services per conception (ASPC) were recorded for all subjects. Of the total 50 heifers, 6 (2 in group 1, 3 in group 2, and 1 in group 3) heifers were eliminated due to accidents during experiment 1. FSCRs were 58.8% (10/17), 66.7% (12/18) and 44.4% (4/9) in groups 1, 2 and 3, respectively. ASPCs were $1.53{\pm}0.72$, $1.27{\pm}0.59$ and $1.63{\pm}0.74$ in groups 1, 2 and 3, respectively. Although there were no significant difference between the groups, relatively good results (higher FSCR and lower ASPC) were obtained in both group 1 and 2. In experiment 2, 11 primiparous cows from group 2 of experiment 1 in heifer stage which had been treated both with the hormones for estrus synchronizing and mineral supplements (ES group), and 12 primiparous cows treated only with minerals (non-ES group) were compared to examine the effects of estrus synchronization program on conception rates after $1^{st}$ parturition. Following the examination, postpartum ASPCs were $1.55{\pm}0.82$ and $2.17{\pm}1.47$ in ES group and non-ES group, respectively. The postpartum average days open (ADO) were $116{\pm}56$ and $197{\pm}93$ in ES group and non-ES group, respectively. Although there were no significant difference between the two groups, desirable results (lower ASPC and shorter ADO) were found in ES group after $1^{st}$ parturiton. In conclusion, experiment 1 indicates that vitamin or mineral supplement with ovsynch protocol may have some positive effect on FSCR and ASPC of dairy heifers, and in experiment 2, ES program in heifer stage had a positive effect on ASPC and ADO following $1^{st}$ parturition.

• Korean Journal of Animal Reproduction
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• v.15 no.2
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• pp.109-115
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• 1991

This experiment was conducted to find out the time to farrowing induction after PGF2$\alpha$ treatment, the rate of farrowing induction, the effect of kids born by the induced farrowing on birth weight and development with study on artificial control of parturition in Korean native goats. A total of 24 pluriparous goats were offered for this experiment. The animals were divided into 4 goats per treatment by administration time(142, 145 or 148 day of pregnancy) and dosage (5 or 7.5mg). The results obtained in this experiments were as follows : 1. The effect of synchronization of estrus was induced 23 goats(95.1%), 16 goats(66.6%) in the 1st treatment and 7 goats(28.5%) in the 2nd treatment PGF2$\alpha$ and exhibited estrus at a mean interval of 75$\pm$5 hours after PGF2$\alpha$ injection. 2. The time to farrowing induction after PGF2$\alpha$ treatment on day 145 or 148 was significantly(P<0.01) shorter than that of the 5mg treatment, but there was no significant difference(P>0.01). 3. Parturition was induced in all goats(100%) treated 5 or 7.5mg of PGF2$\alpha$ on day 148 and 7.5mg of PGF2$\alpha$ on day 145, but was induced 75% in treatment with 5mg of PGF2$\alpha$ on day 145 and 5 or 7.5mg of F2$\alpha$ on day 142. 4. The birth weight and development of kids induced farrowing was heaviest (P<0.01) on days 148 among treatment, but there was no significant difference in dosage.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1025-1030
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• 1999

Fifth one Nili-Ravi dairy buffaloes in their last two months of gestation, were selected in NWFP Pakistan. Rectal palpation was carried out fortnightly, until the occurrence of first estrus. Ovulation was confirmed per rectum and milk progesterone levels (MPL). Body condition score (BCS)was recorded weekly. Milk samples were collected weekly for MPL and blood samples fortnightly for metabolites analysis. Milk yield was recorded and samples were collected for milk fat. The buffaloes calving during the normal breeding season (NBS, August to January)had short (p<0.01) postpartum estrus interval of $55.95{\pm}4.90$ days versus $91.15{\pm}11.61 $ days in the buffaloes calving during the low breeding season (LBS, February to July). MPL in the LBS calvers remained lower than NBS calves (p<0.01). The incidence of silent ovulation was higher during LBS as compared to NBS (70.6% versus 29.4%). MPL showed a pattern opposite to atmospheric temperature. In NBS calvers serum glucose levels were higher (p<0.01) and magnesium levels were lower (p<0.01) than LBS calvers. Higher serum urea was found in summer and spring than that autumn and winter (p<0.05). The reproductive performance in buffaloes calving in the LBS coincided with a low BCS (p<0.01). Fat corrected milk production (FCM) was higher in NBS than LBS (p<0.01) calvers.

• Korean Journal of Veterinary Research
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• v.21 no.1
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• pp.59-64
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• 1981

Holstein-Friesian cows(n=284) were given $100{\mu}g$ of gonadotropin-releasing hormone(GnRH) or saline solution by intramuscular injection at 10 to 22 days after parturition, and were investigated their reproductive performance and frequency of ovarian cysts. Among them 28 cystic cows were injected with $150{\mu}g$ of GnRH intramuscularly and examined the recovery rate. The results obtained in this study were summarized as follows: 1. The interval from calving to 1st ovulation was reduced from 28.2 days in controls to 16.5 days for cows given GnRH (p<0.01). 2. The intervals from calving to 1st estrus and from calving to conception were extended significantly in control group (p<0.05). 3. Inseminations per conception and conception rate at 1st insemination did not reveal difference between two groups. 4. Frequency of ovarian cysts was reduced from 14.0% in control to 4.20% for cows given GnRH (p<0.05). 5. Of the 28 cystic cows receiving $150{\mu}g$ of GnRH, 23(82.1%) responded to 1st treatment and returned to estrus $24.2{\pm}4.3$ days after treatment. 6. These data provide evidence for reduction in infertility and reproductive disorders in early postpartum dairy cows given GnRH as a prophylactic.