본 연구의 목적은 우리나라 Jersey 암소 56두로부터 조사된 체고 데이터에 대해 성장 모형을 추정하고, 추정된 체고 성장 모형의 모수를 활용하여 우리나라 Jersey 암소의 체고 성장 기초 자료를 제공하고자 실시하였다. 추정된 Gompertz, von Bertalanffy, Logistic 및 Brody 모형의 체고 성장 곡선 함수식은 각각      ,         ,          및       이었다. 추정된 Gompertz, von Bertalanffy 및 Logistic 모형의 모수를 이용하여 성장 특성을 분석한 결과 변곡점 월령이 각각 -0.3880, -5.235 및 -0.426월로 성장 기간 중 존재하지 않았다. Gompertz, von Bertalanffy, Logistic 및 Brody 모형에 대한 오차 평균 제곱합은 각각 14.189, 14.083, 14.730 및 14.011로 추정되었으며, 모형 결정 계수는 각각 0.971, 0.972, 0.970 및 0.972로 추정되었 다. 각 모형의 오차 평균 제곱합과 모형 결정 계수의 결과를 종합해보면 Brody 모형이 Jersey 암소의 체고 성장 곡선에 적합도가 좋은 것으로 판단된다.

본 연구는 우리나라 Jersey 암소 41두로부터 측정된 체중 데이터를 이용해 Gompertz, von Bertalanffy 및 Logistic 모형의 성장 곡선을 추정하고, 추정된 성장 곡선의 모수를 활용하여 Jersey 암소의 성장 특성에 대해 알아보고자 실시하였다. 추정된 Gompertz, von Bertalanffy 및 Logistic 모형의 성장 곡선 함수식은 각각    ,         및          이었다. Gompertz, von Bertalanffy 및 Logistic 모형에 대해 변곡점은 각각 10.719, 8.4292 및 14.618 개월로 추정되었고, 변곡점 체중은 각각 208.514, 211.347 및 203.548kg으로 추정되었으며, 최대 증체율은 각각 20.851, 21.192 및 21.993 (kg/월)로 추정되었다. 오차 평균 제곱합과 모형 결정 계수의 결과를 종합해보면 von Bertalanffy, Gompertz 그리고 Logistic 모형 순으로 Jersey 암소 성장 곡선에 적합도가 높은 것으로 판단된다.

본 연구는 우리나라 Holstein의 번식형질에 대한 유전모수를 추정하기 위하여, 2009년부터 2013년까지 분만한 농협 젖소개량사업소의 검정자료 경산우 144,793두의 211,899개의 번식기록을 이용하였다. 7가지 형질의 유전 및 오차 (공)분산을 WOMBAT 패키지를 이용하여 분석하였다. CTFS, GL, NRR, NS, FSTC, DO 및 CI의 유전력은 각각 0.064, 0.060, 0.005, 0.014, 0.012, 0.021 및 0.021로 추정되었다. 형질들 간의 유전상관은 –0.910에서 0.995로 나타났다. NRR과 NS, NRR과 FSTC 간에는 부의 유전상관이 나타났으나, DC와 CI는 강한 양의 유전상관을 나타냈다. CTFS와 FSTC는 DO 및 CI와 유의하게 양의 유전상관관계를 나타냈다(0.479~0.862). CTFS와 FSTC 사이의 낮은 유전상관은 두 형질이 서로 다른 유전적 측면에 있다는 것을 의미한다. 본 연구는 번식능력 개량을 위한 기초 자료를 제공할 수 있을 것이라 판단한다.

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.

An experiment was carried out to assess the effect of feed selenium-lysine (Se-Lys) supplementation on milk compositions and serum biochemical indices in Saanen dairy goats in Korea. A total of twelve 36 months old Saanen lactating dairy goats (47±6.21 kg) fed the similar dry matter intake twice a day at 2% of BW (DMI) (10.9% moisture of concentrate and 19% moisture of roughage), milk yield (2.5 kg/d) and parity (2) were randomly selected and subjected for the present study, divided into two groups with six goats in each group. The goats in the control group received rice hulls (10 g/ day) only, and did not receive Se-Lys; goats in the treatment group were fed 0.06 g of Se-Lys with 10 g of rice hulls every day before feeding roughage for six weeks. The milk sample was collected every week, and its compositions were analyzed. The results of the present study showed that there is no significantly increased milk production in Se-Lys treated group goats when compared with control group goats. But, Se-Lys treatment significantly increased the milk protein content (3.98±0.16%), fat (3.72±0.27%), lactose (4.07±0.14%), total solids (12.51±0.28%) and urea (14.42±1.45 mg/dl) content as compared to the control group goats (p<0.05). The somatic cell counts (207,740±28.81 cells/ml) were significantly lower in the Se-Lys treated group than in the control group (p<0.05). Also, the results of the current study showed that supplementation of Se-Lys were significantly decreased the blood biochemical indices of IL-6 (34.34±6.04 pg/ml), TNT-α (0.56±0.22 ng/ml), MDA (5.07±1.03 ng/ml), GPx-1 (9.07±5.17 ng/ml), sCD4 (2.64±1.02 ng/ml) and sCD8 (5.08±2.08 ng/ml) level when compared with without addition of Se-Lys group dairy goats (p<0.05). On the other hand, the selenoprotein P (1,580.18±127.62 ng/ml) level was significantly higher in Se-Lys supplemented group than in the control group (p<0.05). Based on the study results, it was concluded that feed Se-Lys supplementation may improve milk yield with positively improved protein, fat, lactose, total solids, urea content, and biochemical indices without negative effects on milk production traits.

Although some factors, including season, age, type of estrus (natural estrus vs. induced estrus) and semen type (conventional vs. sexed), affect the conception rate following artificial insemination (AI) in dairy cattle, there is little information about the influence of ovarian characteristics, such as preovulatory follicle (PF) location at estrus, on fertility in dairy cattle. In most breeds of cattle the right ovary appears to function more actively than the left and about sixty percent of pregnancies in dairy cattle occur in the right horn of uterus (Reece and Tuner, 1938). Our study aimed to compare conception rates in dairy cattle between PFs that developed in the left ovary and those that developed in the right ovary at estrus. In this study, we examined the locational effect (left or right ovary) of the preovulatory follicle (PF) on fertility in dairy cattle. In total, 955 artificial inseminations (AI) were analyzed. At AI, PF locations were examined using rectal palpation, and dairy cattle were divided into two groups on their PF locations: (i) the PF located in the left ovary (L-PF); and (ii) the PF located in the right ovary (R-PF). Pregnancy was diagnosed by rectal palpation or ultrasonographic examination 60 days after AI. The conception rate was 38.1% in all dairy cattle. Conception rate was higher in the R-PF (40.8%) than in the L-PF (33.2%). In summary, PF development in the right ovary was associated with increased conception rates in dairy cattle.

The objective of this study is to investigate the immobilization properties of arsenic in solidification process using geopolymer binder. Metakaolin and fly ash were used as prime materials for geopolymer that was also called as activated metakaolin cement (or Si + Al cement). The immobilization of As in geopolymer was found to be very limited regardless of the oxidation state of As and the mixing ratio of As to the binders. These results may be ascribed to the low Ca contents in prime materials used and the structural property of geopolymer formed. It was generally accepted that As was immobilized into C-S-H (calcium silicate hydrates) via precipitation and sorption, when it was solidified with ordinary portland cement and/or lime. When Ca(II) or Fe(III) was used as stimulating agents, the As leaching was reduced by15 ~ 25% than that of control experiment. These limited improvements of As immobilization might be resulted from the extremely high pH in geopolymer reaction.