• Korean Chemical Engineering Research
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• 제60권3호
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• pp.392-397
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• 2022

Methane is one of the major greenhouse gases, recently, the biotechnological conversion from methane to high-value added chemicals have emerged as an effort to reduce methane gas emission. In this study, we optimized ectoine bio-milking conditions in which cells were repeatedly used to improve intracellular and extracellular ectoine yield from methane by using Methylomicrobium alcaliphilum 20ZDP2. First, the cultivation and intracellular ectoine accumulation conditions were optimized with respect to the growth phase and medium salinity to achieve the highest yield of synthesis. Second, ectoine excretion was optimized by determining the ectoine secretion time (15 min) in appropriate medium salinity under hypoosmotic conditions (1% NaCl). Finally, bio-milking of ectoine was successfully repeated more than 10 times using M. alcaliphilum 20ZDP2, and the ectoine yield was improved up to 129.29 mg/ DCW g.

• 한국축산시설환경학회지
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• 제21권2호
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• pp.65-70
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• 2015

Total three hundred and fourteen dairy cows were used in this study to analysis of correlation between milking levels and automatic milking system (AMS). Cows were divided into five groups according to their milking levels (over 50 kg/day, 49~40 kg/day, 39~30 kg/day, 29~20 kg/day, 19~10 kg/day). All groups were compared with daily milking number, rejected number by AMS, residence time at AMS, milking time, flow rate of milk. Daily milking number and milking time were higher in the group of over 50 kg and 49~40 kg than that of other groups (p<0.05). There are no correlation on rejected number by AMS, residence time at AMS and flow rate of milk between milking levels and AMS. In addition, we found that the milk yield affected to feed intake and rumination of dairy cows. In conclusion, present results indicated that installation of AMS on dairy farms with high milk producing cows might be affected positively.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.475-480
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• 1992

The effect of mechanical factors and season of the year on milking characteristics (milk yield, time of milking, rate of milk flow, stripping time and tripping milk) were studied on 26 Holstein Friesian cows, raised under Saudi Arabia environmental conditions. Cows were in the third and fourth lactation and reached the peak. Cows milked twice a day with equal intervals. Three vacuum levels (34, 38 and 42 cfm) and two pulsation ratios were used to form six vacuum-pulsation combinations. The study was carried during two seasons Autumn-Winter (S1) and Spring-Summer (S2). After absorbing the cow equations least square analysis was used to analyze the data. Vacuum level 38 cfm and pulsation ratio 70:30 was the best among all combinations of vacuum level-pulsation ratio. No significant effect (p < .01) for season, up to the seventh half minute, on the rate of milk flow. However, season of the year has a significant effect on total milk yield, stripping time and stripping milk.

• Journal of Animal Science and Technology
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• 제56권4호
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• pp.13.1-13.5
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• 2014

The production performance of multiparous lactating Sahiwal cows (n = 24) was evaluated according to both milking frequency and method. Selected animals were randomly divided into four groups containing six animals each under a completely randomized design. Cows in groups A & B were milked by the hand milking method three times per day, respectively. Similarly, cows in groups C & D were milked by the machine milking method two and three times per day, respectively. All animals were maintained under uniform feeding and management conditions. Dry matter intake was high in animal groups milked three times per day, and it remained unchanged between the hand and machine milking methods. Milk yield was higher (P < 0.05) in cows milked three times compared to those milked twice per day, and it did not differ between hand and machine milking methods. Milk fat percentage was higher (P < 0.05) in cows milked twice per day compared to those milked three times using both machine and hand milking methods. The percentage of total solids showed a similar pattern as the fat percentage. However, percentages of protein, lactose, and non-fat solids in milk were not significantly different (P > 0.05) among the treatment groups. Collectively, the results show that milking three times per day instead of twice at 8-hour intervals can enhance milk yield in Sahiwal cows using both hand and machine milking methods.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.315-320
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• 2002

Test-day records (n=13677) sampled from 896 ewes in 5-9 (${\mu}$=7.5) monthly test-days were used to estimate genetic and phenotypic parameters of test-day yields, lactation milk yield (TMY), length of the milking period (DAYS) and three measures of persistency of milk yield in Boutsico dairy sheep. Τhe measures of persistency were the slope of the regression line (${\beta}$), the coefficient of variation (CV) of the test-day milk yields and the maximum to average daily milk yield ratio (MA). The estimates of variance components were obtained under a linear mixed model by restricted maximum likelihood. The heritability of test-day yields ranged from 0.15 to 0.24. DAYS were found to be heritable ($h^2$=0.11). Heritability estimates of ${\beta}$, CV and MA were 0.15, 0.13, 0.10, respectively. Selection for maximum lactation yields is expected to result in prolonged milking periods, high rates of decline of yields after peak production, variable test-day yields and higher litter sizes. Selection for flatter lactation curves would reduce lactation yields, increase slightly the length of the milking period and decrease yield variation as well as litter size. The most accurate prediction of TMY was obtained with a linear regression model with the first five test-day records.

• Journal of Animal Science and Technology
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• 제46권5호
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• pp.707-718
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• 2004

오전(AM) 및 오후(PM)의 단얼 착유기록에 의한 유우의 1일 생산량 추청을 위한 통계적 모형에 대한 연구를 실시하였다. 본 연구에서 조사한 모형들 가운데， Model 7은 각 요인 조합 구간별로 개별적인 회귀식을 추정함으로써 산차， 착유시간 간격， 비유 단계에 따른 이분산성을 고려할 수 있기 때문에 평균 오차 제곱 합， 추정치와 실제 1일 유 생산량간의 상관계수 및 추정치의 분산을 고려할 때 가장 적합도가 높은 것으로 사료된다. 오후 착유 기록을 이용한 1일 유 생산량 추정치는 오전 착유 기록을 이용한 것보다는 정확도가 낮은 것을 나타났으며， Model 7의 경우 l일 유 생산량 추정을 위한 제반 요인이 추가되어 정확도가 높일수 있으면서도 모형이 간단하기 때문에 적용이 간펀한 장점이 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권7호
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• pp.1044-1052
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• 2015

The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as 'moderate'; optimum pasture utilisation of 19.7 t DM/ha, termed as 'high') and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary return trip from parlour to paddock) and every one hour increase in MI, respectively. The high pasture utilisation combined with 30% of the farm in CFR in the farm increased milk yield by up to 1.5 kg/cow/d, thereby reducing loss by up to $0.5/cow/d (c.f. the moderate pasture and 800 cow herd scenario). Thus, it was concluded that the successful integration of grazeable CFS with pasture has the potential to improve financial performance compared to the pasture only, large herd, AMS.

• 한국축산시설환경학회지
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• 제13권1호
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• pp.21-28
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• 2007

본 실험은 우리나라에서 사육되고 있는 홀스타인 젖소 착유우의 사료 섭취량과 음수량이 산유량과 분뇨 배설량에 미치는 영향을 구명하기 위하여 수행하였다. 실험은 착유우 10두를 공시하여 수원의 축산연구소 낙농우사에서 봄, 여름, 가을, 겨울 등 4계절에 걸처 실시하였으며 그 결과는 다음과 같다. 1. 시험에 공시된 착유우의 건물섭취량은 평균 19.5kg으로 봄과 가을이 각각 23.9, 22.1kg으로 높았고, 여름과 겨울이 각각 17.0, 15.3 kg으로 낮은 섭취량을 보였다. 2. 착유우의 음수량은 평균 $77.2\ell$로, 여름이 $85.5\ell$로 가장 많았고 겨울이 $62.2\ell$로 가장 낮았으나 계절별 유의차는 보이지 않았다. 3. 착유우의 산유량은 평균 26.0kg으로 봄, 여름, 가을 및 겨울이 각각 30.8, 24.0, 25.4, 23.7kg으로 봄의 산유량이 가장 높았다(p<0.05). 4. 착유우의 분뇨 배설량을 계절별로 조사한 결과, 봄 64.4kg, 여름 63.5kg, 가을 60.4kg, 겨울 51.0kg으로 계절 간에 차이를 보였으며(p<0.05), 전체 평균 분뇨 배설량은 59.8kg이었다. 5. 착유우의 사료섭취량, 음수량, 산유량 및 분뇨 배설량과의 상관관계를 분석한 결과, 산유량과 음수량$(R^2=0.7742)$, 산유량과 사료 섭취량$(R^2=0.7459)$, 음수량과 뇨 배설량 $(R^2=0.7422)$, 사료 섭취량과 분 배설량$(R^2=0.6044)$, 산유량과 분 배설량$(R^2=0.692)$의 상관관계가 비교적 높았으나, 음수량과 분 배설량$(R^2=0.2950)$, 사료 섭취량과 뇨 배설량$(R^2=0.1985)$, 산유량과 뇨 배설량$(R^2=0.2335)$의 상관관계는 낮게 나타났다. 6. 따라서 산유량과 음수량, 산유량과 사료 섭취량의 상관관계식은 $Y=0.1919X_1+11.181(R^2=0.7742),\;Y=0.8568X_2+9.3067(R^2=0.7459)$(Y=milk yield $X_1=water$ consumption, $X_2=feed$ intake)로 추정할 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1239-1241
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• 2003

Korean cattle breeders have shown interest in genetic improvement of milking ability because poor milking ability and short suckling period of Korean cattle is a hindrance to growth of calves. In this study, daily milk yields by period in Korean cattle were analyzed with an animal model. The milk yields were actually measured at sequential intervals from 1 to 4 months after calving: daily milk yields from delivery to 1 month (DMY1), from 1 to 2 months (DMY2), from 2 to 3 months (DMY3), and from 3 to 4 months (DMY4). Genetic variance estimates gradually increased by the periods while environmental variance estimates gradually decreased. This resulted in a dramatic increase in the heritability by periods: 0.02 for DMY1, 0.11 for DMY2, 0.16 for DMY3, and 0.42 for DMY4. In multi-trait analyses with daily milk yield and body weight of calf, genetic correlation estimates between milk yield and body weight were quite small (-0.08 to 0.02 for birth weight and -0.10 to 0.00 for weaning weight). The trends of the heritability estimated in this study showed that the genetic effects were more influential when the milking period was longer, suggesting genetic evaluations with daily milk yield collected at a longer period.

• Journal of Animal Science and Technology
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• 제46권4호
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• pp.517-524
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• 2004

본 연구는 유우의 착유 지속시간, 평균 유속 및 최대 유속에 영향하는 환경 요인을 추정하고 이들 형질들과 산유량간의 관련성을 규명하여 진공압에 의한 착유기를 이용한 여건에서 비유 특성에 대해 알아보고 또한 향후 진행될 수 있는 착유우의 유방관련 질병과의 관계에 대한 연구 기초자료를 제공하고자 실시하였다. 조사된 착유 지속 시간 및 유속에 대해 분석 모형에 고려한 분만계절, 산차, 비유 월수 및 착유 시간 간격의 환경 요인들이 대부분 유의적인 효과를 가지는 것으로 추정되었다. 착유 유량과 착유 지속 시간 및 유속간의 상관관계 조사를 통해 유속이 빠를수록 유량이 많아지고, 착유 지속 시간과 유속간의 부의 상관관계가 존재하여, 착유 시간에 대한 경제적 가치를 고려한 투입비용의 절감을 위해 착유시간이 짧은 착유우가 바람직하면서 동시에 착유 유속이 빠르고 착유 유량이 많아질 것으로 기대할 수 있으나, 착유 유속과 유성분내의 체세포 수 및 유방염의 발생 빈도에 대한 기존의 보고들을 고려할 때 질병 발생에 따른 치료비용 및 유질의 저하로 인한 손실을 주의해야 하며, 착유 유량과 착유 지속 시간간의 높은 상관으로 인해 형질간 상관 반응에 대하 해석에 주의가 필요한 것으로 생각되므로 본 연구에서 조사한 착유 유량, 착유 유속 및 착유 지속 시간 뿐만 아니라 체세포 수와 유방염 자료 조사를 통해 다각적인 경제 가중치가 고려된 종합적인 지수식으로 해석하는 것이 적절하며 이에 대한 추가적인 연구가 필요할 것으로 생각된다.