• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.26-30
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• 2006

The study was undertaken to investigate the validity of milk urea concentration as an index of the reproductive performances in crossbred Karan-Fries (Holstein Friesian${\times}$Tharparkar) cows under farm condition. Milk urea was analysed in noon milk samples (1200 to 1300 h) to interrelate with the interval from parturition to first service, number of insemination per conception, first service conception rate and service period. Milk progesterone (P4) was analysed in noon milk samples on the day 1, 10, 20 and 30 post insemination to study the effect of milk urea concentration on early embryonic mortality. The interval from parturition to first service was found significantly (p<0.01) higher ($77.2{\pm}5.5$ days) when milk urea concentration was ${\geq}63.4mg/dl$. The average milk urea concentrations (mg/dl) were found $42.1{\pm}2.5$, $47.9{\pm}1.5$ and $50.3{\pm}3.1$, respectively in cows that conceived at $1^{st}$, $2^{nd}$ and $3^{rd}$ insemination. However, the variation was not statistically significant. The first insemination conception rate was found significantly (p<0.05) higher (68.8%) when milk urea level was ${\leq}32.4mg/dl$. The service period was found significantly (p<0.05) higher ($125.4{\pm}8.8$ days) when milk urea concentration was ${\geq}45.1mg/dl$. The milk P4 level indicated that the cows, those were detected as non-pregnant on day 60 post insemination were initially pregnant but the pregnancy was terminated sometime during the day 30 to 60 post insemination. The study indicates that the milk urea values may be used as an index of reproductive performances in dairy herd when individual animals are not being monitored for nutritional status. The altered milk urea values may be utilised by the farmers as ready reference to rectify the protein and energy nutrition in cows to achieve the better reproductive performances in herd.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1285-1290
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• 2003

The present study was carried out to investigate the effect of test day milk yield, test day evening milk yield, parity, stage of lactation and body weight on milk urea and milk protein concentration. A total of 319 milk samples was collected from buffaloes over four month's period and subjected to urea and protein analysis. Milk urea concentration (mg/dl) was significantly (p<0.01) increased with increasing test day milk yield. The lowest value ($57.03{\pm}1.13$) was observed in the milk yield group ${\leq}4.5kg/day$ and the highest value ($64.15{\pm}1.13$) in the group 7.7-10.7 kg/day. However, test day evening milk yield had no significant effect on milk urea concentration. Milk protein did not vary significantly with the test day milk yield as well as test day evening milk yield. A clear decreasing trend of milk urea concentration (mg/dl) was found with the increasing parity. The highest MU concentration ($64.03{\pm}1.14$) was found in the first parity and the lowest ($55.67{\pm}1.22$) was found in the sixth and above parity. Whereas, stage of lactation had no effect on milk urea concentration. Moreover, parity and stage of lactation did not have any significant effect on milk protein concentration. Body weight (kg) was also found negatively (p<0.05) related with urea content (mg/dl) in milk. The highest mean MU concentration ($64.34{\pm}0.88$) was found when body weight was between 532 and 598 kg and lower mean values ($59.24{\pm}0.94$ and $59.33{\pm}1.23$) were observed in 599 to 665 kg and ${\geq}666kg$ group. Body weight also had significant (p<0.05) effect on milk protein content. The highest milk protein content (%) was found in ${\geq}666kg$ group and the lowest in <531 kg group. In conclusion, for proper interpretation of milk urea values to monitor protein nutrition status of the buffaloes parity, milk yield and body weight should be considered.

• 대한수의학회지
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• 제41권2호
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• pp.243-252
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• 2001

Milk constituents and somatic cell count (SCC) were analysed for 4,059 milk samples from 178 dairy farms from April to December in 1999. Correlations among each milk constituents, milk urea (MU) concentration and SCC in association with lactation stage, milk yield and parity, and balancing status of nutrients' supplies were analysed, and the results are summarized as follows; Averages of milk fat percent, total solids percent and milk yield were $3.72{\pm}0.91%$, $12.50{\pm}1.31%$ and $23.80{\pm}8.54kg$, respectively, whereas those were significantly lower during the summer season. In contrast, average of MU concentration was $0.0361{\pm}0.0006%$ which was significantly higher during the summer season. With milk yield, concentrations of fat, protein and SCC in milk decreased but concentrations of lactose and urea in milk and body condition score (BCS) were not altered. Concentrations of fat, protein, lactose, total solids, SNF, and urea in milk were significantly affected by stage of lactation ($P{\leq}0.0001$) but SCC was not changed. Parity of dairy cows had a significant effect on concentrations of fat ($P{\leq}0.02$), lactose ($P{\leq}0.0001$), total solids ($P{\leq}0.002$), and SNF ($P{\leq}0.0001$) in milk and milk yield ($P{\leq}0.0005$) but did not change concentrations of urea and protein in milk. Somatic cell count had significant positive correlationship with percentages of fat, protein and total solids ($P{\leq}0.0001$), respectively, but had negative correlationship with percentages of urea and lactose in milk and milk yield ($P{\leq}0.0001$). Milk urea concentration was negatively correlated with concentrations of protein, fat, total solids, and SNF in milk and milk yield ($P{\leq}0.0001$) and, according to regression analysis using milk urea concentration and SCC, following equation was obtained; $Y(MU)=3.688{\times}10^{-2}-4.04{\times}10^{-7}{\times}X(SCC{\times}1,000)(r^2=0.0038$, $P{\leq}0.0001$). We studied balance between protein and energy supplies to dairy cows in each farm based upon milk urea and protein concentrations, and results showed that 137 of total 178 farms fed cows unbalanced amounts of dietary protein and energy.

• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.22-28
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• 2003

Increasing conjugated linoleic acid (CLA) content in dairy products has been a research Interest due to the potential health benefits resulted from consuming CLA. Attempts were made to obtain high level natural CLA containing fatty acid fractions from milk fat through bovine feeding of sunflower oil (SO) and urea fractionation. SO feeding changed the fatty acid profile of milk fat. increasing the CLA content five-fold at eight weeks of trial. Milk fat obtained from S0-fed cows was hydrolyzed to free fatty acids, which were then fractionated with urea at various ratios. The profiles of fatty acids were also greatly influenced by urea fractionation. Long-chain unsaturated fatty acids, Including CLA, were concentrated in milk fat after the fractionation, whereas saturated long-chain counterparts were eliminated. The highest level of CLA was achieved by the fractionation at 2:1 urea/fatty acid ratio (UFR2). CLA level was elevated 2.5-fold, and the Cl8:1/C18:0 fatty acid ratio was increased 120 times after the fractionation. The level of CLA in high CLA-milk fat (24mg/g fat) obtained from the feeding study was further increased through urea fractionation up to 52mg/g fat, 10 folds as high as CLA in the control milk fat (5mg/g fat).

• Journal of Animal Science and Technology
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• 제46권3호
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• pp.335-346
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• 2004

본 연구는 MUN 함량과 관련하는 사양관리적 요인 및 착유우 자체의 생리적요인을 알아보고 또한 이것이 유생산 능력과 어떠한 관계가 있는지 알아보기 위하여 수행하였다. 본 연구에 이용된 자료는 1999년부터 2002년까지 농협중앙회에서 수행한 129,645두로부터 조사된 890,434 기록의 산유능력검정 자료를 이용하였으며 매 검정일 유량, 3.5% 지방보정유량, MUN함량 및 검정일 체세포 지수에 대한 최적통계모형을 적합하여 이들간의 관계를 규명하였다. 분석 결과 여름철에 MUN 함량이 가장 높았다. 이러한 MUN 함량은 유량과 고도의 비선형적인 정의 관계가 있는 것으로 추정되었다. MUN 함량 21${\sim}$24mg/dl에서 산유량이 가장 많았고 MUN 함량이 24mg/dl 이상일 경우에는 유량이 감소하는 경향을 보였다. 또한 MUN 함량은 산치와 상호 관련성이 있는 것으로 조사 되었는데, 산차가 증가할수록 MUN 함량은 증가하였으며 3${\sim}$4산에서 MUN 함량이 많은 것으로 추정되었다. 또한 MUN 함량은 체세포 수와도 밀접한 관계가 있는 것으로 분석되었는데 MUN 함량이 21${\sim}$24mg/dl에서 체세포 지수가 가장 적은 것으로 추정되었으며 MUN 함량과 SCS간에는 부의 상관관계가 있는 것으로 분석되었다. 유지방율 및 유단백율은 각 유기별, 분만년도별, 계절별, 착유일 및 우유내 요질소 함량에 따라 크게 영향을 받는 것으로 조사되었다. 여름철에 MUN이 증가하는 반면 유지방율 및 유단백율이 가장 낮은 것으로 조사되었다. 특히 유단백율은 비유일이 경과됨에 따라 점차 감소하였는데 각 산차별 MUN과 유단백율과의 관계는 모든 산차에서 MUN이 증가함에 따라 유단백율이 감소하였다. 특히 이러한 감소의 크기는 3산차에서 가장 큰 것으로 나타났다. 이는 사료내 에너지와 단백질의 균형적인 공급이 우유내 MUN과 유단백율의 비율에 지대한 영향을 미쳤기 때문인 것으로 사료되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권12호
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• pp.1667-1673
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• 2000

The climate and marketing system of raw milk in Taiwan create problems in balance feeding of protein and energy in lactating cows in Taiwan. Level of urea nitrogen both in bulk milk and serum reflects ruminal protein degradation and post-ruminal protein provision, whereas milk protein concentration responds to dietary energy intake and bacterial protein production in the rumen. Establishment of a range of reference standards in milk protein and urea nitrogen levels can be applied as a noninvasive economical feeding guide to monitor the balance of protein and energy intake. Standard reference levels of 3.0% milk protein and 11-17 mg/dL milk urea nitrogen (MUN) were established. Level of milk protein below 3.0% is regarded as indicating inadequate dietary energy whereas MUN below or above the range is regarded as a deficiency or surplus in dietary protein. Results from analysis of bulk a milk samples collected from 174 dairy herds over Taiwan showed that only one quarter (25.29%) of the herds received a balanced intake of protein and energy, 33.33% adequate protein with energy inadequate, 22.99% herds in protein surplus with energy inadequate, 10.35% herds in protein surplus with energy adequate, 4.6% protein deficiency with energy adequate, and 3.45% herds with both protein and energy inadequate. Energy inadequate herds accounted for 60% of the total dairy herds in Taiwan with 56% adequate, 38% surplus and 6% inadequate in protein. In comparing milk sampled from bulk milk on different seasons from Lee-Kang area in the southern Taiwan, the concentrations of milk fat and milk protein were significantly higher in the cool season (February) than in the warm season (August) (p<0.05), whereas the urea nitrogen in the milk was significantly lower in the cool season than in the warm season (p<0.05). This indicated that lactating cows had excess protein and/or inadequate energy intake in the warm season in this area. It appears that the major problem feeding in lactating cows is energy intake shortage, especially during the warm season in Taiwan.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.774-780
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• 2000

For this study three types of block such as medicated urea-molasses-mineral block (MUMMB, 7% urea), urea-molasses-mineral blocks ($UMMB_a$ 7% urea) and urea-molasses-mineral blocks ($UMMB_b$ 21% urea) were prepared. Naturally infested 24 indigenous dairy cows with gastrointestinal nematodes were used to study the effect of MUMMB, $UMMB_a$ and $UMMB_b$ on different parameters (body weight, milk yield, serum urea level, milk urea level). The cows were offered normal diet added with 250 g block per cow for every day. Straw and green grasses were used as basal diet in the ration. The managemental facilities for all cows of each group were similar. Cows were stall fed, calves were tied up at night and had free access to their dam during day time. Milking was done once daily in the morning. The daily average live weight gains by MUMMB, $UMMB_a$, $UMMB_b$, and control group (no block) were 52.08 g, 44.44 g, 48.58 g, and 1.41 g respectively. The live weight gain were statistically significant (p<0.01) in comparison to control group. The highest daily milk yield was observed in MUMMB treated cows (2.39 L/d); followed by $UMMB_b$ treated cows (1.82 L/d) and $UMMB_a$ treated cows (2.16 L/d). The lowest milk yield was found in control group (1.54 L/d). This result differs significantly (p<0.05) between treated groups and also with control group. During urea-molasses-mineral blocks $UMMB_a$, $UMMB_b$ licking milk urea level increased from initial $22.76{\pm}2.35mg/dl$ to $35.46{\pm}4.80mg/dl$ and initial $22.86{\pm}2.96mg/dl$ to $40.66{\pm}0.87mg/dl$ respectively. This variation of milk urea level was statistically significant (p<0.001). Similarly during $UMMB_a$, and $UMMB_b$ blocks licking, serum urea level increased in both treated groups from initial $22.76{\pm}2.60mg/dl$ to $32.68{\pm}2.21$ and initial $23.70{\pm}2.78mg/dl$ to $40.48{\pm}3.24mg/dl$, respectively. This variation of serum urea level was also statistically significant (p<0.001). Use of MUMMB instead of UMMB was proved better for milk production and live weight gain in dairy cows under the village condition of Bangladesh where balanced ration for dairy cows are a major scarcity. And various concentration of urea in blocks positively affect milk and serum urea levels of indigenous dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• 제17권4호
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• pp.479-484
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• 2004

The study was conducted to assess the effect of milk production, parity, stage of lactation, season and individual milk components themselves on milk urea nitrogen (MUN) concentration and other milk components of 3,219 Holstein dairy cows in Korean dairy farms. The MUN concentrations in Korean dairy cows were estimated to 16.68$\pm$5.87 mg/dl. Milk yield was negatively correlated with fat and protein contents and somatic cell counts (SCC) in milk (p<0.01). The increasing MUN concentration has positive correlation with yield and fat content. By increasing somatic cell, milk yield was reduced and MUN level was increased. Cows in spring and winter produced more milk over 1.43 and 0.93 kg/day, respectively, than cows in summer (p<0.01). Milk urea nitrogen concentrations of milk produced in summer and fall were significantly lower (p<0.01) than those in spring and winter. Both MUN concentration and somatic cell counts were highest in winter. Milk yield was lower (p<0.01) in the first calving than other calving time and was tended to increase until the fifth parity and then decrease. Milk urea nitrogen and SCC were not related to parity of cows in this study. Milk yield and SCC were positively related to lactation period while MUN concentrations and milk fat and protein contents were negatively influenced by stage of lactation. In the present study, the relationship between MUN and reproduction of dairy cows was also investigated. Cow produced milk in high MUN concentrations (greater than 18 mg/dl) had more open days than cows in MUN concentrations less than 18 mg/dl. However, no significant difference between MUN concentration levels and frequency of artificial insemination was found in this study. It is suggested that although MUN values for nutritional management and measures of production or reproduction are used, non-nutritional factors should be considered.

• Asian-Australasian Journal of Animal Sciences
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• 제18권7호
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• pp.973-979
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• 2005

The present study was planned to examine the effect of different feeding regimens on milk urea concentration and milk protein concentration. The objectives are to describe the diurnal variations of milk urea (MU) concentration and to predict plasma urea (PU) concentration from MU concentration. Six lactating Murrah buffaloes were distributed in two groups and were fed two different diets in a crossover design. The diets consisted of leguminous crops as diet 1 (berseem (Trifolium alexandrinum)+concentrate mixture 1+wheat straw)) and non-leguminous crops as diet 2 (oats (Avana sativa)+concentrate mixture 2+wheat straw). All the diets were isocaloric and isonitrogenous. Each diet was fed to the animals for a period of 28 days, followed by a 10 day gap to obviate the carry over effect of the previous diet and then a switch over to the other diet. Digestibility trials were conducted on the last 7 days of each feeding period. Milk samples were collected on day 3, 7, 10, 14, 17, 21, 24 and 28 of the feeding period and blood samples were collected on the same day at morning within 30 minutes after morning milking. The average milk urea (MU) values (mg/dl) differed significantly (p<0.01) and were 44.83${\pm}$0.62 and 42.53${\pm}$0.73, respectively, for diets 1 and 2. Milk urea concentrations (mg/dl) also varied (p 0.01) among the days of feeding period, but were stabilized after 10th day of feeding period. In contrast, diets and days of feeding period had no significant effect on percent milk protein. Plasma urea concentration showed a significant (p<0.01) positive correlation (r = 0.93) with MU concentration. To predict the PU from MU the following equation was developed 'PU = 10.67${\pm}$0.76${\times}$MU (mg/dl) with $R^2$ = 0.87'. A clear diurnal variation of MU was found with lowered morning value (42.04${\pm}$0.68 mg/dl) than the evening value (45.32${\pm}$0.66 mg/dl). Present findings suggested that MU or PU concentration could be used as an indicator to monitor the feeding strategy. Plasma urea can be predicted from MU, whenever interpretation of milk urea data required consideration of diurnal variation.

• Asian-Australasian Journal of Animal Sciences
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• 제1권4호
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• pp.201-208
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• 1988

Fifty-six lactating Surti buffaloes, fed rice straw, were allocated to seven treatment groups as follows: 1. Straw supplemented with 2% urea (SS) + 1.5kg rice bran (RB) 2. Straw treated with 4% urea in an open stack (TS open) 3. TS open + 1.5 kg RB 4. TS open + 3.0 kg RB 5. TS open + 1.5 kg RB + 3.0 kg Gliricidia (Gl) 6. Straw treated with 4% urea in a closed pit (TS closed) 7. TS closed + 1.5 kg RB + 3.0 kg Gl Milk production, butterfat percentage and liveweight gain of cows and calves were measured and tested with analysis of variance. The results are: - The animals on urea treated straw (group 2) had a higher milk production (p<0.05), higher butterfat production (p<0.05) and less liveweight gain loss (p<0.05) than the animals on urea supplemented straw (group 1). Butterfat percentage also increased by treatment, although not significantly (p>0.05). - Increasing levels of rice bran (groups 3 and 4 compared to 2) increased total milk production and milked quantity of butterfat, while butterfat percentage decreased (p < 0.05). - Milk production increased (p <0.05) with extra rice bran added (group 4 compared to 3), but was not affected (p > 0.05) by Gliricidia addition (group 5 compared to 3). Butterfat percentage dropped with extra rice bran supplement (p <0.05). The lack of response to Gliricidia indicated that protein is not limiting in treated straw, or that Gliricidia protein is partly insoluble. - System of treatment had no effect on milk production (p >0.05), while supplementation with 1.5 kg RB and 3.0 kg Gliricidia increased production and caused a lower butterfat percentage (p <0.05) (groups 2, 5, 6 and 7 compared). A significant (p <0.05) interaction treatment system x supplementation was present. It was concluded, that both treatment and supplementation did affect milk production as well as milk composition. Gliricidia addition gave less effect than rice bran, indicating different requirements for starchy substances in the feed. Treatment of straw does not negatively affect butterfat production, it can increase butterfat production and even butterfat percentage.