The Effect of Mineral on Reproductive Performance of Dairy Cattle in Summer

Hyun-Joo Lim,Jun-Kyu Son,Ho-Beak Yoon,Kwang-Soo Baek,Chang-Yong Choe,Goung-Suk Lee,Eung-Gi Kwon 한국동물번식학회 2012 Reproductive & Developmental Biology(Supplement) Vol.36 No.2s

today's dairy production management systems, reproductive efficiency affects the income of any farm by influencing overall milk production, genetic gain, amount of replacement heifers, and wise cullling decisions. Nutrition, management, and genetics play a major role achieving this maximum herd-reproductive performance. Several reports using trace minerals on the diet of cattle have shown reproductive effects. The main justification for using blocks, to provide deficient nutrients is, therefore, their convenience for packaging, storage, transport and ease of feeding. Dairy cattle are annually exposed to prolonged periods of elevated humidity and heat which reduce feed intake and reproductive performance. The objectives of the present study were to evaluate the effects of mineral on reproductive performance of dairy cows during Summer. The experimental group of cows had access ad libitum to the mineral lick in the following composition : Zn, Fe, Mn, Cu, I, Co, Se. Environmental heat load was described using the THI (temperature humidity index) because thermoregulation in cows is affected by both Temp and RH. The THI was calculated: THI=(0.8xTemp)+[RHx(Temp- 14.4)]+ 46.4. All cows were monitored for estrus twice daily in the morning and late afternoon. And any animal found in estrus was artificially inseminated. Pregnancy diagnosis was performed via ultrasonography at 45 to 70 d after insemination. The visitation and intake of mineral were higher with the maximum THI. The mean intake of mineral block was 23.1 kg in Summer and 17.7 kg in other seasons. The reproductive performance was considerably improved by mineral supplementation. The factors influencing consumption of mineral mixtures include: soil fertility and forage type, available energy and protein, individual requirements, salt content of the water, palatability of mineral mixture, availability of fresh minerals and physical form of minerals. These results show that minerals have a great impact on animal's reproductive physiology.

Relationship between serum magnesium concentration during the transition period, peri‑ and postpartum disorders, and reproductive performance in dairy cows

Jeong, J.K.,Choi, I.S.,Moon, S.H.,Kang, H.G.,Kim, I.H. Elsevier 2018 LIVESTOCK SCIENCE Vol.213 No.-

<P><B>Abstract</B></P> <P>This study evaluated the relationship between serum magnesium concentration, peri‑ and postpartum disorders, and reproductive performance in dairy cows. Blood samples were collected from 198 Holstein cows 4 weeks prepartum, after calving, and 1, 2, 4, 6, and 8 weeks postpartum to measure serum magnesium and/or progesterone concentrations. To determine the relationship between serum magnesium concentration and peri‑ or postpartum disorders, cows were divided into two groups based on their mean serum magnesium concentration 4 weeks prepartum and just after calving: a Low-Mg group (1.45–2.65 mg/dL, <I>n</I> = 110) and a High-Mg group (2.70–5.40 mg/dL, <I>n</I> = 88). Analysis of these groups showed that the incidences of dystocia, retained placenta, endometritis, and lameness were lower (<I>P</I> < 0.05–0.01) in the High-Mg than in the Low-Mg groups. To determine the relationship between serum magnesium concentration during the transition period and reproductive performance, cows were divided into two groups based on their mean serum magnesium concentration from 4 weeks prepartum to 4 weeks postpartum: a Low-Mg group (1.80–2.59 mg/dL, <I>n</I> = 116) and a High-Mg group (2.60–4.17 mg/dL, <I>n</I> = 82). The probability of cyclicity resuming (shown by a progesterone concentration ≥ 1 ng/mL) by 8 weeks postpartum was higher in the High-Mg group (hazard ratio [HR]: 1.70; <I>P</I> < 0.01) than that in the Low-Mg group. Moreover, the probabilities of first insemination by 150 days and pregnancy by 210 days postpartum were higher (HRs: 2.16 and 2.36, respectively; <I>P</I> ≤ 0.0001) in the High-Mg than in the Low-Mg groups, resulting in the mean calving-to-conception interval being 25 days shorter in the High-Mg group. In conclusion, high serum magnesium concentration during the transition period is associated with lower incidences of peri‑ and postpartum disorders and improved reproductive performance in dairy cows.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The relationship between serum magnesium and reproductive performance was studied. </LI> <LI> High serum magnesium is associated with a lower incidence of peripartum disorders. </LI> <LI> High serum magnesium is associated with improved reproductive performance. </LI> <LI> Serum magnesium may be useful for predicting health and reproductive performance. </LI> </UL> </P>

육성기 에너지 급여 차이에 따른 젖소 번식능력 평가

이원영,김종남,조광현,여준모,Lee, W.Y.,Kim, J.N.,Cho, K.H.,Yeo, J.M. 국립한국농수산대학교 교육개발센터 2018 현장농업연구지 = Journal of practical agricultural resear Vol.20 No.2

Recently, attempts have been made by dairy farms to shorten the time until the first estrus by feeding animals a high-energy diet during the heifer period. Energy consumption during the heifer period has been shown to be related to milk yield and reproductive performance. The present study was conducted to analyze the relationship between reproductive performance and energy intake in heifers. There were no differences in height or body weight between animals that were fed the Korean standard diet versus a high energy diet (110% of the Korean standard). However, there was a difference in the timing of the first estrus: 329.3 days under normal energy conditions versus 311 days under high energy conditions. There was no difference in the number of artificial insemination per gestation, but both the rate of female calf production and the weight of individual female calves increased in response to the high energy diet. Based on these results, it may be predicted that the reproductive performance of dairy cows will increase when the animals are fed a high energy diet (110% of the Korean standard). These results demonstrate a correlation between the amount of energy consumed and reproductive performance, and will be of great value to the dairy farming industry.

Effects of Milk Yield on the Postpartum Health and Reproductive Performance of Dairy Cows

김상곤,정재관,허태영,강현구,김일화 한국임상수의학회 2013 한국임상수의학회지 Vol.30 No.3

This study evaluated the effects of milk yield on the postpartum health and reproductive performance of dairy cows. In total, data were collected from 1,060 cows on six dairy farms, including their milk production, body condition score (BCS), postpartum disorders, and reproductive performance. The lactation data were grouped based on the 305-day milk yield into control (< 10,000 kg, n = 445) and high milk yield (≥ 10,000 kg, n = 615) groups. The milk fat and protein, and BCS were lower during the first 5 months postpartum in the high milk yield group compared with the control group (p < 0.01). Ovarian cysts were more frequent (p < 0.0001) in the high milk yield group (28.6%)than in the control group (15.3%), whereas endometritis tended to be less frequent in the high milk yield group (29.6%)than in the control group (35.1%, p = 0.06). A higher proportion of cows tended to receive reproductive hormones (p = 0.06) in the high milk yield group (62.4%) than in the control group (56.6%). The probability of a pregnancy after first insemination tended to be lower (odds ratio = 0.78, p = 0.07) in the high milk yield group (30.2%) than in the control group (35.2%). Furthermore, the hazard of pregnancy by 210 days in milk was lower in the high milk yield group (hazard ratio = 0.84, p = 0.04) than in the control group, which resulted in a 20-day increase in the median interval to pregnancy. In conclusion, high milk yield was related to lower milk fat and protein, lower BCS, an increased incidence of ovarian cysts, and increased use of reproductive hormones, which resulted in decreased reproductive performance of dairy cows.

농악 전승집단의 새로운 생태계 구축과 예능 복원․ 재현의 가치 -고창농악보존회의를 주목하며-

송기태 남도민속학회 2019 남도민속연구 Vol.39 No.-

With the weakening of the traditional foundations for inheriting Nongak, traditional instrumental music of peasants, preservation societies began to be formed to conserve the performing art of Nongak. Villages that still have active Nongak tradition have formed preservation societies, and villages with no active tradition left have formed local preservation societies to establish the system of Nongak and carry out education and performance. Most preservation societies, however, have systems considerably different from those in the traditional environment to pass down Nongak because they were formed for the ‘purpose of preserving Nongak in a state where the community basis had disappeared’. This paper proposes OS 2.0/2.1 to examine the environment for transmitting Nongak tradition that was built by preservation societies, and discusses the art of Nongak according to the division of Nongak Ver.2.0/2.1. The process up to Nongak OS 2.1 focused on expanding the boundary of Nongak. Due to the decline of communities and the sense of duty to preserve Nongak on the brink of extinction, the first step was to establish the prototype of Nongak and increase the number of people to engage in Nongak. This was the reason for the performer-centered transmission of Nongak. As the preservation societies proceeded up to the operating system OS 2.1, there arose the problem of a pyramid structure of transmission system, with its tendency toward centralization of cultural power and standardization of performance. It has been verified that in the performance, various existing forms were recombined to form performance repertories that acquired a prototypical character. Therefore, this paper defines the style of Nongak in the traditional period as Nongak Ver.1.0, and the new types of Nongak performance established by preservation societies as Nongak Ver.2.0. The reason for this classification is that the traditional Nongak and professional Geolgungpae Nongak establish local brands of Nongak, based on the designation as intangible cultural properties and formation of preservation societies in each of the administrative districts. Regarding the establishment of the Nongak Ver.2.0 version of Nongak, this paper pays attention to the constant efforts of the Gochang Nongkak Preservation Society to restore and reproduce Nongak performance. Lastly, this paper discusses the various attempts of the society at transmission and creation of Nongak. The society has been trying to create new forms of Nongak since the 2010, in an effort to move further than the traditional genre of Nongak that was handed down to modern times. New creations have considerable repercussion in Nongak today, and it has been confirmed that the performance regained through reproduction and restoration plays a key role. New creations did not start by forgetting the past; rather, the tradition retrieved by restoration and reproduction was the key to the future. 본고에서는 농악보존회가 구축한 전승생태계를 주목하고, 새롭게 구축된 보존회가 복원과 재현을 거듭하여 전승에 그치지 않고 창작의 단계까지 진행하고 있음을 논의하였다. 고창농악보존회의 사례가 무형문화재의 전반적인 상황을 대표하는 것은 아니지만, 무형문화재 중에서 농악 분야의 보존회 활동이 왕성하고 그들이 전승생태계를 새롭게 구축하는 데 앞서가고 있기 때문에 현 단계에서 농악보존회를 주목할 필요가 있다. 고창농악보존회는 그동안 농악의 외연을 확장하는 데 초점이 있었다. 공동체의 쇠락과 함께 존폐의 위기에서 농악을 보존해야 하는 사명감 때문에 우선 농악의 원형을 정립하고 농악인구를 늘리는 데 힘을 쏟을 수밖에 없었다. 그래서 농악의 전승이 연행자 중심의 구도에 머물러 있었다. 보존회는 변화를 거듭하면서 피라미드식 전승시스템을 구축하였는데, 그것이 문화권력의 집중화, 예능의 획일화 등의 문제를 발생시키고 있음을 파악하였다. 예능에 있어서는 기존의 다양한 형태가 재조합되어 원형성을 획득한 예능물이 형성되기에 이른 것으로 파악하였다. 그래서 본고에서는 전통시대에 전승되던 농악의 형태를 Ver.1.0으로 설정하고, 보존회가 구축한 새로운 원형의 예능을 Ver. 2.0으로 규정하였다. 전통시대의 마을농악과 전문 걸궁패 농악이 행정구역 단위의 무형문화재 지정과 보존회의 결성을 기반으로 지역 브랜드 농악을 성립시키기 때문에 버전을 다르게 규정한 것이다. Ver. 2.0의 농악 성립과 관련하여 고창농악보존회에서 예능의 복원과 재현을 위해 끊임없이 노력해 온 과정을 주목하였다. 끝으로 보존회에서 다양하게 시도하고 있는 농악 전승과 창작과 관련해 논의하였다. 보존회에서는 2010년대 이후 농악의 전승에 머물지 않고, 새로운 창작을 시도하고 있다. 새로운 창작물이 농악계에 작은 반향을 일으키고 있는데, 재현과 복원으로 되찾은 예능이 핵심적 역할을 하고 있음을 확인하였다. 이와 관련하여 새로운 창작의 세계가 과거를 잊는 데에서 출발하는 것이 아니고, 오히려 복원․재현으로 찾아낸 전통이 미래를 밝히는 열쇠가 되고 있음을 논의하였다.

Effect of Season, Parity and Lactation on Reproductive Performance of Sows in a Tropical Humid Climate

Gourdine, J.L.,Quesnel, H.,Bidanel, J.-P.,Renaudeau, D. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.8

The aim of this study was to analyze post-weaning reproductive performance of Large White sows in relation to season, parity and their lactation performance under tropical conditions in Guadeloupe (French West Indies, $16^{\circ}$ Lat. N, $61^{\circ}$ Long. W.). This work was based on data recorded in the experimental unit of INRA from January 1993 to December 2003. Two seasons were determined a posteriori from climatic parameters recorded continuously in a station close to the experimental unit. Mean ambient temperature was higher during the hot season than the warm season ($26^{\circ}C$ vs. $24^{\circ}C$) but relative humidity was comparable for both seasons (i.e. 87% on average). Season had a significant effect on all reproductive parameters analyzed. Primiparous sows weaned in the hot season had a higher probability of a prolonged weaning to estrus interval, WEI (odds ratio was 4.1; p<0.01) but multiparous sows were not affected. A higher probability of a prolonged weaning to conception interval, WCI (odds ratio >2.5, p<0.01) and a lower subsequent farrowing rate (-10%, p<0.01) were found for sows weaned in the hot season. A higher daily feed intake during lactation reduced the probability of a prolonged WEI (p<0.05). Body weight and average back-fat thickness at farrowing affected WEI and WCI (p<0.05), whereas body weight and average backfat thickness change in lactation did not. This study confirms the negative effects of the hot season on primiparous reproductive performance. It also indicates that lactation performance influences sow non-productive period.

모돈 사료 내 Portulaca oleracea L.의 첨가가 번식성적, 혈액성상, 면역반응 및 분 중 미생물에 미치는 영향

오승민,최요한,정현정,전세민,김진수 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.7

This study was undertaken to determine the effects of dietary supplementation with herbal extracts of Portulaca oleracea L. (POL), on the reproductive performance, blood profiles, immune response, and fecal microbial population in multiparous sows. On the basis of initial body weight, a total of 20 multiparous sows (Landrace×Yorkshire; 229.2±1.15 kg) were randomly allotted to 2 treatment groups, each including 10 replicates. The dietary treatments were administered during the lactation period, and included a corn-soybean meal-based diet (control group) and diet supplemented with 0.05% POL. Throughout the experimental period, no significant differences were observed between the two diet groups for body weight, backfat thickness, and reproductive performance. Blood profile analysis revealed significantly decreased lymphocyte concentrations and IL-1β levels (p<0.05), and increased serum IgG levels (p=0.051), of sows consuming the POL supplemented diet. Furthermore, coliform counts tended to decrease in sows consuming diet supplemented with POL (p=0.063). Taken together, our results indicate that POL supplemented diets exert beneficial effects on blood profiles, immune response, and fecal microflora of multiparous sows, without any negative effect on the reproductive performance. 본 실험은 모돈 사료 내 Portulaca oleracea L.(POL)의 첨가가 번식성적, 혈액성상, 면역반응 및 분 중 미생물에 미치는 영향을 구명하기 위해 수행하였다. 본 실험을 위해 총 20두의 모돈(Landrace×Yorkshire; 229.2±1.15 kg)을 공시하였으며, 개시체중에 기반하여, 2처리 10반복, 반복당 1두씩 완전임의 배치하였다. 실험 처리구는 옥수수-대두박 기초사료를 대조구로 하여 기초사료 내 POL을 0.05% 첨가한 처리구가 포함되었으며, 분만직후부터 포유기간 동안 수행하였다. 사료 내 POL을 첨가하였을 때, 모돈의 체중, 등지방두께 및 번식성적에서는 유의적인 차이가 나타나지 않았다(p>0.05). 혈액성상에서 사료 내 POL의 첨가하였을 때, 모돈의 림프구가 유의적으로 감소하는 것으로 나타났다(p<0.05). 또한, 면역반응에서 사료 내 POL을 첨가하였을 때 포유모돈의 혈 중 IL-1β의 수치는 유의적으로 감소하였으며(p<0.05), IgG는 증가하는 경향이 관찰되었다(p=0.051). 분 중 미생물에서는 POL 처리구에서 포유모돈의 coliforms이 감소하는 경향을 확인하였다(p=0.063). 본 실험의 결과들을 종합해보면, 사료 내 POL의 첨가는 번식성적에 부정적인 영향을 미치지 않으며, 모돈의 혈액성상, 면역반응 및 분 중 미생물에 긍정적인 효과를 미치는 것을 시사한다.

공연예술의 환경변화와 예술가의 대응: 판소리의 경우를 중심으로

유영대 이화여자대학교 음악연구소 2019 이화음악논집 Vol.23 No.1

This paper discusses the nature of performing arts, analyzing Pansori as its example, examining both characteristics of live performance and recorded performances. Performing arts exist as an ephemeral form of art, only existing at the moment it is performed. Nonetheless, performing arts also exist in form of memories of the audiences, and the works of the masters are re-performed in aural and visual recordings. Performing art of the traditional era remains only in memories. In traditional societies, we do not have formalized space for performances. Pansori were performed in living rooms, yards, or arbors. The aura of such performances can be re-created, based on the textual recordings of them. The records show that the performances of Pansori masters had overwhelming aura. On the twentieth century, we have gained access to modern theaters, and thus gained the chance to re-experience the memories of the traditional performances. Some performances were mostly similar to the traditional performances, and some were differentiated. Throughout the era of artistic reproduction, many different genres of performing arts including pansori are recorded with various means. With reproduced performing arts, we examine how the original performances were conducted, and we attempt to understand the underlying elements of them. However, reproduced art could never replicate the ‘aura’ of the original performance. Performing art is art of time. Being in the audience of live performance is at the core of understanding performing arts. Being at the moment of performance is an unparelled experience. Pansori as performing art has come to a great change of environment in the modern era. There have been many experiments, to show the authenticity and the aura of the original performances, out of the performance space itself. However, being in the audience of pansori in its live performance is essential in Pansori’s appreciation. Therefore, it is the mission of the modern artist to recreate Pansori in a live performance with exceptional quality. 이 논문은 판소리를 중심으로 삼아, 공연예술의 현장성과 기록으로 재현되는 특성에 관하여 점검한 것이다. 공연예술은 일회적이고 그 순간이 지나면 사라져버리는 특성을 가지고 있다. 그럼에도 공연예술은 관객에게 기억으로 존재하고 있다. 거장의 작품은 음반이나 영상자료를 통하여 재현된다. 전통사회의 공연예술은 그 실체를 확인할 수 없으며 단지 기억으로만 남아있다. 전통사회에서 판소리는 규격화된 공연공간을 갖지 못하고, 마당이나 사랑방에서 진행되었다. 당대 공연을 직접 체험하는 대신, 생생하게 그 현장을 기록한 자료를 기반으로 삼아 그 공연현장을 재구할 수 있다. 기록에 의하면 명창의 공연에는 그 주변을 압도하는 현장의 아우라가 있다는 사실을 확인할 수 있다. 20세기에 들어서서 서구식 극장을 확보하면서, 우리는 기억되거나 기록된 공연을 재현할 수 있는 기회를 갖게 되었다. 재현된 소리판은 전통사회에서 이루어졌던 공연현장과 유사한 부분이 있었고 차별화된 것도 있었다. 기계복제시대를 거치면서 판소리를 포함한 공연예술의 다양한 장르들이 음반이나 영상으로 기록되었다. 복제된 음반을 통하여 우리는 이전 시대에 이루어졌던 공연의 규모를 확인하고, 그 특징을 확인할 수 있게 되었다. 복제된 음반에는 원본공연예술이 가지고 있는 현장감이 없고, 따라서 아우라도 사라졌다. 음반에 아우라까지 담아내려는 노력이 없었던 것은 아니지만, 그럼에도 현장이 주는 긴밀함은 어느 경우에도 재생되지 못했다. 어느 시대를 막론하고 공연은 현장의 예술이다. 아무리 다양한 매체가 있다 해도 현장에서 직접 공연을 보는 것에 비견할만한 것은 없다. 현장에 있어야 생동감 있는 무대를 경험하고 열광한다. 현대에 와서 판소리라는 공연예술의 환경은 변화의 폭이 대단히 크다. 다양한 방식의 실험을 통하여 원본의 핍진함과 아우라를 공연현장 밖에서도 느낄 수 있는 방법에 대한 모색이 있어왔다. 그럼에도 판소리를 포함한 공연예술의 감상은 현장을 떠나서는 그 본질적 아우라가 발현되지 않는다. 공연예술의 변화된 환경에 대하여 명확하게 인식하고, 이에 대하여 적극적으로 대응할 방법을 적극적으로 모색하는 것이 예술가인 광대의 숙명이다.

옛 동리정사[신재효(申在孝) 고택(古宅)] 재현과 공연학적 해석

이영일 ( Yeong Il Lee ) 판소리학회 2011 판소리연구 Vol.31 No.-

This thesis is aimed to reproduce past shape of Dongli-Jeongsa, and then to insquire the meaning and significance from view of performance study about that. Reproducing past shape of Dongli-Jeongsa is first problem, and when this is achieved successfully, second problem shall be solved easy and be useful to us. I analyzed a dozen of files about activities of shin Jaihyo, his poems (Danjapga), testimony, collections of Pansori museum, cadastral map and data of the Japanese Ruling Era, testimony of Lee kiwha, actual measurement data on Sarangchai(Shin Jaihyo`s old house). and then I submitted position and scale of Dongli-Jeongsa, and arrange Sarangchai(Shin Jaihyo`s old house), Seokgasan, loutus pond, a pavilion standing beside that, the main building and side building on it. This reappearance map will be important for reproducing real buildings. Based on this map, I interpret the meaning and signification from view of performance study on Dongli-Jeongsa. This community have the all processes of performance-training, workshops, rehearsals, warm-ups, performance, cooldown, aftermath in their cultural site. First, The site of Dongli-Jeongsa is used for training of Pansori. Second, A kind of workshop that Dongri correct sound and meaning of word for Pansori singers, and that let them correct their vulgar is held in this site. Third, Pansori performed centered Yeondang(pavillion standing beside lotus pond) and Sarangchai. This is very symbolic and meaningful science that let the legacy continue. fourth, Gisaeng and Gwangdai performed Pansori front of Shin Jaihyo, and received comment about the performances. Jeong Hyeonseok appraise Shin Jaihyo as a thoughtful man. He evaluate Shin know how to improve the dignity throughout art. In early days, Shin had great insight about poetry, calligraphy, paintings, and pursuit spiritual realm of Pungryu throughout Pansori, keeping himself in Seokgasan that symbolizes the Pungryudo Dongli-Jeongsa where community member trained, taught, performed, evaluated Pansori is not private house anymore. This site is Pansori private Institute and the Cradle of Pansori in korea. Therefore, Dongli-Jeongsa must be reproduced and preserved as educational property for Pansori. This is a way to preserve International Intangible Cultural Heritage, Pansori.

Effects of Days Open on the Subsequent Reproductive Performance Following to CIDR-Based Estrus Synchronization in Lactating Dairy Cows

강현구,김일화 사단법인 한국동물생명공학회 2011 한국동물생명공학회지 Vol.26 No.2

The purpose of this study was to evaluate the effects of days open on subsequent reproductive performance following to estrus synchronization in the 114 lactating dairy cows. The animals were divided into two groups according to the time of estrus synchronization; viz, ≤85 days, and > 85 days postpartum, respectively. The estrus synchronization protocol consisted of insertion of a controlled internal drug release (CIDR) device containing 1.9 g progesterone with an injection of 250 μg gonadorelin (Day 0), an injection of PGF2α and removal of the device on Day 7, an injection of 250 μg GnRH on Day 9, and TAI 17 h later. Pregnancy diagnosis was determined at 30to 60 days after TAI using both ultrasonography and rectal palpation. The body condition score (BCS) gradually increased over the postpartum period. In estrus synchronized cows until 85 days, conception rate on first service,number of service per conception, interval from estrus synchronization to conception, and interval from calving to conception were not significantly different among two farms (P>0.05). In estrus synchronized cows after 85 days postpartum, conception rate on first service, number of service per conception and interval from calving to conception were significantly different (P≤0.05) between herds A and B (26.8 vs 50.0%; 2.1±1.35 vs 1.37±0.54 times,237.3±97.8 vs 164.7±69.3 days, respectively). In estrus synchronized cows after 85 days postpartum interval from estrus synchronization to conception was greater (P<0.01) in herd B than in herd A (63.6±57.4 vs 26.1±24.9). These results indicate that the time of estrus synchronization for maximized the reproductive performance is before 85 days postpartum and feeding and management is important factor for high reproductive performance.