• Korean Journal of Veterinary Research
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• v.42 no.2
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• pp.163-170
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• 2002

The relationship between level of milk composition and conditions of ovary and uterus were analyzed in Holstein cows at seven farms participating in a reproductive herd health management program. Milk data were taken from 503 early lactating cows between 30 and 60 days in milk with reproductive examination with ultrasonography from september 1999 to August 2000. Milk fat, protein and solid-not-fat concentration in the herds were $3.70{\pm}1.08%$, $2.97{\pm}0.35$, and $8.41{\pm}0.61%$, respectively. The reproductive disorder relative to normal cows had higher risk in the cows that the level of protein was lower than 2.70%. Also, the higher milk fat than 4.50% were associated with a higher risks in the uterine disease and follicular cysts. Therefore, the cows with the fat to protein ratio of > 1.30 had higher risks for reproductive disorder such as cystic ovarian diseases, inactive ovaries and endometritis. These results indicated that cows diagnosed with reproductive disorder were energy deficient prior to reproductive disorder diagnosis. Consequently, milk fat and protein analyses may be used serve as a monitoring tool for condition of ovary and uterus in early lactating cows

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.658-664
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• 2002

This study was conducted to determine a proper feeding regime for lactating Holstein cows during the warm season in Taiwan. In Feeding Trial, 21 lactating Holstein cows were randomly allotted into three feeding regimes in a Completely Randomized Design. The feeding regimes were roughage fed ad libitum along with concentrate fed either twice daily (2C) or four times daily (4C), and total mixed ration (TMR) for 8 weeks. No significant differences among the three feeding regimes were found in body weight changes, and intakes in terms of dry matter, crude protein and net energy. For milk yield and 4% FCM yield, 4C were higher than the other two feeding regimes (p<0.05). No significant differences were found in milk compositions or differences noted in the yields of the respective milk components. TMR was worse than 2C and 4C (p<0.05) in milk production efficiencies in terms of dry matter intake per kg milk yield, crude protein intake per kg milk protein yield, as well as dry matter intake, net energy intake and crude protein intake per kg 4% FCM yield. Three ruminally fistulated Holstein dry cows were randomly assigned into the same three feeding regimes in a 3${\times}$3 Latin Square Design. No significant differences were found among the feeding regimes in ruminal pH, ammonia nitrogen, total VFA concentration, molar percentages of VFA, and acetic acid: propionic acid ratio (C$_2$/C$_3$). Taken all together, roughage fed ad libitum and concentrate fed four times daily was the better feeding regime for lactating cows during the warm season in Taiwan.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1689-1694
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• 2004

This study was conducted to develop a novel adjustment factors for 305 days using 138,103 lactation records and 1,770,764 daily records, which were based on environmental circumstances such as herd year, season, age at calving, dry period and lactating stages. The present study showed that the change of persistency of cows at the first parity from total lactacting characteristics was slowly processed, while it was rapidly changed in cows at the second parity stage. Particularly, there was an outstanding difference between the first and second parity cows. Milk yield and composition increased as the age at calving was increased. In addition, milk yield and composition were higher at the first parity on fall compared with others, and those were higher at the more than second parity on fall and winter compared with other parity stages and seasons. The cow of dry group was included into lactating records of more than second parity stage. The data indicated that optimal results arose from 45-70 days of dry period. Milk yield was decreased when dry period was longer or shorter than 45-70 days. The lactating days were divided into 17, 28 and 38 stages to compare the multiplicative correction factors. The factor was effective at 28 stages on the first parity. The total correlation coefficients were 0.93832, 0.95058 and 0.95076 at the present correction factor, 17 stage and 28 stage, respectively. At second parity, the factor was higher in dry group 1 and 3 at 17 stage, and it was higher in dry group 2 at 28 stage compared with others. Therefore, the present study showed that the percent squared bias (PSB), which was calculated from the novel correction factor, was better than previously used correction factors. Also, the present study indicated that the bias of the novel correction factor was improved, and this factor could be more accurate compared with others.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1090-1097
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• 2001

Nine tons of fresh rice straw from early-maturing varieties was ensiled with 50 g urea $kg^{-1}$ DM straw in plastic bags immediately after threshing. Five months after storage, preserved straw was used to partially replace elephant grass (Pennisetum purpureum, Schumach) for lactating cows. Eight crossbred Holstein lactating cows (75% of Holstein blood) in their second to fourth lactation and in mid-lactation were arranged in a balanced design with two squares consisting of $4\;periods{\times}4\;treatments$ (100% grass ad lib. as a control; 75% grass+urea treated fresh rice straw (UTrFRS) ad lib.; 50% grass+UTrFRS ad lib.; 25% grass+UTrFRS ad libitum) in one square. A concentrate supplement was given at a rate of 400 g per day per kg of milk produced. Samples of fresh straw taken in the field and UTrFRS and elephant grass taken at feeding time were evaluated in a degradation trial with 3 fistulated heifers (undefined blood ratio of crossbred of Sindhi and local yellow cattle). Straw preserved for 5-9 months was in nearly all cases of good quality. Crude protein (CP) content was increased 2.1 fold and 48 h dry matter loss (DML) was 20% higher compared to dry straw. Elephant grass cultivated intensively was low in DM content and 10% higher in 48 h DML compared to UTrFRS. Dry matter intake (DMI) was higher for the mixture of UtrFRS and Elephant grass, and highest when one-third of the roughage was UTrFRS. Higher DMI of mixed roughage diets was probably due to the low DM content of elephant grass in the sole grass roughage diet. Increasing substitution of elephant grass with UTrFRS up to 75% of the roughage component increased milk fat content and had no effect on milk yield and other milk composition parameters. Feeding UTrFRS, partially replacing elephant grass in the diets of lactating cows in the dry season can reduce the cost of roughage.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.857-864
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• 2006

The aim of this study was to apply the Cornell net carbohydrate and protein system (CNCPS) in subtropical Taiwan. This was done by means of 3 trials, viz, in situ, lactation and metabolic trials, the latter using the urinary purine derivatives (UPD) to estimate the ruminal microbial yield. Dietary treatments were formulated according to different nutrient requirement systems including, (1) a control NRC78 group on NRC (1978), (2) a NRC88 group on NRC (1988), and (3) a CNCPS group on Cornell Net carbohydrate and protein system model. Results from the lactation trial showed that DM intake (DMI) was higher (p<0.05) in the NRC78 than the other treatment groups. The treatments did not significantly influence milk yield, but milk yield after covariance adjustment for DMI was higher in the CNCPS group (p<0.05). The FCM, milk fat content and yield were greater in both the NRC78 and the NRC88 group over the CNCPS group (p<0.05). The treatments did not significantly influence the DMI adjusted FCM. The solid-non-fat and milk protein contents were higher in the CNCPS group (p<0.05) with or without DMI covariance adjustment. Lactating efficiency was higher in the CNCPS group (p<0.05) compared to the other groups. The significantly lowest milk urea-N (MUN) with better protein utilization efficiency in the CNCPS group (p<0.05) suggested that less N would be excreted into the environment. Cows in the CNCPS group excreted significantly more and the NRC88 group significantly less urinary purine derivatives (UPD) implying that more ruminal microbial protein was synthesized in the CNCPS over the NRC88 group. The CNCPS could become the most useful tool in predicting the trends in milk yield, microbial yield and MUN.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.821-827
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• 2002

The purpose of this study was to evaluate the effect of protected fat and heat-extruded soybean meal on the lactation performance of Holstein cows. Twenty-four cows, consisting of 20 lactating cows and 4 rumen-fistulated dry cows, were randomly allocated into four groups with 5 lactating cows and 1 fistulated cow in each group. A replicated 4${\times}$4 Latin square design with four 21 day periods, including 14 days of adaptation and 7 collection days within each period was employed. The experiment was a 2${\times}$2 arrangement, with or without heat-extruded soybean meal and protected fat inclusion. The dietary treatments consisted of supplements of (a) soybean meal (the control), (b) heat-extruded soybean meal, (c) protected fat, and (d) heat-extruded soybean meal and protected fat. The results showed that there were no significant differences in feed intake, milk yield, milk protein content, milk lactose content and body weight change between the dietary treatments. However, cows supplemented with protected fat showed a significantly increased (p<0.05) milk fat yield, 3.5% FCM and total solid yield. The increase in undegradable intake protein (UIP) via heat extruded soybean meal supplement significantly decreased the urea nitrogen concentration in the blood (p<0.05). Dietary fat inclusion significantly increased the blood cholesterol concentration (p<0.01) and decreased the ruminal pH value (p<0.01). Increased dietary UIP significantly decreased the ammonia nitrogen concentration in the rumen (p<0.01), but did not significantly influence the pH and VFA molar percentage in the rumen. It appears that dietary protected fat inclusion could improve milk fat and solid content. Increased dietary undegradable intake protein through heat extruded soybean meal did not improve milk yield. But it could alleviate the adverse effect of decreased milk protein due to dietary fat supplementation. Increased UIP could also decrease the ammonia nitrogen concentration in the rumen and plasma urea nitrogen concentration in the blood.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.635-646
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• 1996

To establish the effective ways to prevent bovine mastitis, the study has been performed to investigate the attributable factors causing down-regulation of immune responses in mammary gland of non-lactating cows. Lymphocytes from peripheral blood and mammary gland secretions(MGS) were obtained from normal healthy cows and mastitic cows, respectively. Cellular immune responses were examined by comparison of proportion of lymphocyte subpopulations using a set of monoclonal antibodies and flow cytometry. The results obtained are as follows. 1. Proportions of peripheral blood lymphocyte subpopulations expressing BoCD2 and BoCD4 molecules were 32.9%, 15.4% in mastitic cows and 43.3%, 28.3% in normal healthy cows, respectively. The ratios of BoCD4 to BoCD8 were 0.76 and 1.47, respectively. 2. Proportions of mammary gland lymphocyte subpopulations expressing BoCD2 and BoCD4 molecules were 18.5%, 8.3% in mastitic cows and 38.2%, 14.2% in normal healthy cows, respectively. The ratios of BoCD4 to BoCD8 were 0.6 and 2.0, respectively. 3. Proportions of T lymphocyte subpopulations from MGS were significantly lower than those from peripheral blood both in mastitic cows and normal healthy cows. However, lymphocyte subpopulations expressing ACT2 and ACT3, which represent activated T suppressor cells, were significantly higher in MGS than those in peripheral blood.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.1
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• pp.152-158
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• 2019

Objective: This study was conducted to evaluate the effect of water restriction (WR) on physiological and blood parameters in lactating dairy cows reared under Mediterranean climate. Methods: The trial lasted 16 days preceded by two weeks of adaptation to the experimental condition in spring 2014 on 6 dairy cows in mid-lactation. These cows were allowed water ad libitum for 4 days (W100) (hydration period), then split into 2 groups, one group has received 25% and the other 50% of water compared to their mean water consumption during the hydration period; then rehydrated for 4 days. Feed intake and physiological parameters: respiratory rate (RR), heart rate (HR), and rectal temperature (RT) were recorded twice a day. Blood was collected once a day and analyzed for serum concentration of glucose (Glc), triglycerides (TG), cholesterol (Chol), urea (Ur), creatinine (Crea), and total protein (TP) by enzymatic colorimetric method and cortisol (Cort) by radioimmunoassay. Results: Total dry matter intake (TDMI) was affected by WR. A decrease in TDMI was observed in WR groups compared to W100 group (effect, group, period, day, $group{\times}day$, $period{\times}day$: p<0.001). Also, WR resulted in a significant increase in RR, HR, RT in WR groups than in W100 group (effect, group: p<0.001). In addition, an increase in the serum concentration of Glc, TG, Chol, Ur, Crea, TP, and Cort was noted in WR groups (effect, group, period, day: p<0.001). Conclusion: This study has shown the ability of cows raised in a Mediterranean climate to cope with different levels of WR and thus reach a new equilibrium. As result, elucidates the important role of water as a limiting factor for livestock in environments with low water availability.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1433-1442
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• 2021

In this study, Saccharomyces cerevisiae culture fluid (SCCF) has been added to a diet of lactating dairy cows to attempt to improve the ruminal fermentation and potentially increase the dry matter intake (DMI) and milk yield. This study was conducted to investigate the effects of SCCF on the milk yield and blood biochemistry in lactating cows during the summer. Twenty-four Holstein dairy cows were randomly assigned to one of four treatments: (1) total mixed ration (TMR-1) (Control); (2) TMR-1 supplemented with SCCF (T1); (3) TMR-2 (containing alfalfa hay) (T2); and (4) TMR-2 supplemented with SCCF (T3). SCCF (5 ml/head, 2.0×10⁷ CFU/mL) was mixed with TMRs daily before feeding to dairy cows. The mean daily temperature-humidity index (THI) during this trial was 76.92 ± 0.51 on average and ranged from 73.04 to 81.19. For particle size distribution, TMR-2 had a lower >19 mm fraction and a higher 8-9 mm fraction than TMR-1 (p < 0.05). The type of TMR did not influence the DMI, body weight (BW), milk yield and composition, or blood metabolites. The milk yield and composition were not affected by the SCCF supplementation, but somatic cell counts were reduced by feeding SCCF (p < 0.05). Feeding SCCF significantly increased the DMI but did not affect the milk yield of dairy cows. The NEFA concentration was slightly decreased compared to that in the control and T2 groups without SCCF. Feeding a yeast culture of S. cerevisiae may improve the feed intake, milk quality and energy balance of dairy cows under heat stress.

• Animal Bioscience
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• v.34 no.10
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• pp.1623-1631
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• 2021

Objective: This study aimed to validate and evaluate the dry matter (DM) intake prediction model of the Korean feeding standards for dairy cattle (KFSD). Methods: The KFSD DM intake (DMI) model was developed using a database containing the data from the Journal of Dairy Science from 2006 to 2011 (1,065 observations 287 studies). The development (458 observations from 103 studies) and evaluation databases (168 observations from 74 studies) were constructed from the database. The body weight (kg; BW), metabolic BW (BW^0.75, MBW), 4% fat-corrected milk (FCM), forage as a percentage of dietary DM, and the dietary content of nutrients (% DM) were chosen as possible explanatory variables. A random coefficient model with the study as a random variable and a linear model without the random effect was used to select model variables and estimate parameters, respectively, during the model development. The best-fit equation was compared to published equations, and sensitivity analysis of the prediction equation was conducted. The KFSD model was also evaluated using in vivo feeding trial data. Results: The KFSD DMI equation is 4.103 (±2.994)+0.112 (±0.022)×MBW+0.284 (±0.020)×FCM-0.119 (±0.028)×neutral detergent fiber (NDF), explaining 47% of the variation in the evaluation dataset with no mean nor slope bias (p>0.05). The root mean square prediction error was 2.70 kg/d, best among the tested equations. The sensitivity analysis showed that the model is the most sensitive to FCM, followed by MBW and NDF. With the in vivo data, the KFSD equation showed slightly higher precision (R² = 0.39) than the NRC equation (R² = 0.37), with a mean bias of 1.19 kg and no slope bias (p>0.05). Conclusion: The KFSD DMI model is suitable for predicting the DMI of lactating dairy cows in practical situations in Korea.