• 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.12 no.6
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• pp.895-900
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• 1999

The aim of this study was to evaluate the effect of incorporating wet sorghum distiller's grains (WSDG) as part of their diet on the lactating performance of dairy cows. Twenty-seven Holstein milking cows were selected, all in the early lactating stage, with an average weight of 550 kg, and producing an average of 30 kg of milk daily. The cows were divided into three groups according to milk yield and lactation and were fed different total mixed rations. The diets were formulated according to NRC (1989) recommendations in three rations to (1) control diet, (2) 15% WSDG diet and (3) 30% WSDG diet. The three different diets were all formulated as iso-nitrogen and iso-energetic diets. After one week adaptation period, the experimental feeding was conducted for 8 weeks. Three ruminal cannulated cows were also examined in order to investigate ruminal fermentation of the three total mixed rations. The results showed that the milk yield, as corrected to the 4.0% fat standard, had no significant difference among the control, 15% WSDG and 30% WSDG treatment groups (p>0.05). The daily dry matter intake of the control group was higher than the other groups (p<0.05). with respect to milk composition, milk fat, milk protein and total solids, there was no significant difference among the treatment groups (p>0.05). The energy efficiency of the 30% WSDG group were significantly higher than the other treatment groups (p<0.05). Ruminal pH value showed no difference among the treatment groups (p<0.05). Ammonia-nitrogen concentration in the control group was higher than the other treatment groups (p<0.05). The concentration of total ruminal volatile fatty acid was similar in all three dietary groups.

• 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.19 no.6
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• pp.837-844
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• 2006

Four, lactating dairy cows were randomly assigned according to a $2{\times}2$ Factorial arrangement in a $4{\times}4$ Latin square design to study supplementation of urea level (U) at 2 and 4% and sodium dl-malate (M) at 10 and 20 g/hd/d in concentrate. The treatments were as follows U2M10, U2M20, U4M10 and U4M20, respectively. The cows were offered the treatment concentrate at a ratio to milk yield at 1:2.5 and urea-treated rice straw was fed ad libitum. The results have revealed that rumen fermentation and blood metabolites were similar for all treatments. The populations of protozoa and fungal zoospores were significantly different as affected by urea level and sodium dl-malate. In addition, the viable bacteria were similar for amylolytic and proteolytic bacteria. Cellulolytic bacteria were significantly affected by level of sodium dl-malate especially Selenomonas ruminantium and Megasphaera elsdenii while Butyrivibrio fibrisolvens was significantly affected by level of urea supplementation. In conclusion, the combined use of concentrate containing high level of cassava chip at 75% DM with urea at 4% in concentrate and sodium dl-malate at 20 g/hd/d with UTS as a roughage could improv rumen ecology and microbial protein synthesis efficiency in lactating dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.12
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• pp.1705-1711
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• 2014

The objective of this study was to evaluate the effect of ruminally protected amino acids (RPAAs) and ruminally protected fat (RPF) supplementation on ruminal fermentation characteristics (in vitro) and milk yield and milk composition (in vivo). Fourteen mid-lactating Holstein dairy cows (mean weight $653{\pm}62.59kg$) were divided into two groups according to mean milk yield and number of days of postpartum. The cows were then fed a basal diet during adaptation (2 wk) and experimental diets during the treatment period (6 wk). Dietary treatments were i) a basal diet (control) and ii) basal diet containing 50 g of RPAAs (lysine and methionine, 3:1 ratio) and 50 g of RPF. In rumen fermentation trail (in vitro), RPAAs and RPF supplementation had no influence on the ruminal pH, dry matter digestibility, total volatile fatty acid production and ammonia-N concentration. In feeding trial (in vivo), milk yield (p<0.001), 4% fat corrected milk (p<0.05), milk fat (p<0.05), milk protein (p<0.001), and milk urea nitrogen (p<0.05) were greater in cows fed RPAAs and RPF than the corresponding values in the control group. With an index against as 0%, the rates of decrease in milk yield and milk protein were lower in RPAAs and RPF treated diet than those of basal diet group (p<0.05). In conclusion, diet supplemented with RPAAs and RPF can improve milk yield and milk composition without negatively affecting ruminal functions in Holstein dairy cows at mid-lactating.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1712-1718
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• 2001

An experiment was carried out to study the effect of monensin administration on mammary functions in crossbred Holstein cattle. Fourteen non-pregnant late lactating crossbred Holstein cattle, approximately 270 days postpartum, were selected for the experiment. They were divided into two groups of 7 animals each. Seven animals in the treated group were given sodium monensin orally in a slow-release capsule. Animals in both control and treated groups were fed the similar diet to maintain milk production and body score at 2.5. Rice straw was fed as a source of dietary fiber throughout the experimental period. After monensin administration, a significant increase in the molar percent of ruminal propionate (p<0.05) and a significant decrease in the molar percent of ruminal acetate (p<0.05) were apparent in comparison to the pretreated period. The ratio of acetate to propionate concentration decreased significantly after monensin administration (p<0.05), while it was maintained at the similar level throughout the period of experiment in the control group. Monensin did not affect the molar percent of ruminal butyrate and valerate. The concentration of milk allantoin between the control group and monensin treated group was not different. An excretion rate of allantoin in milk decreased in animals treated with monensin (p<0.05). Mammary blood flow did not show significant difference between control and monensin treated groups. The plasma glucose concentration, arteriovenous concentration difference and mammary gland uptake of glucose remained constant in both groups. Milk yield of the later stage of lactation in the control group declined during lactation advance while a tendency to increase in the milk yield was apparent after 21 days monensin administration. Milk compositions for concentration of lactose, fat and protein in both control group and monensin treated group did not change throughout the experimental periods. From these results, it can be concluded that the action of monensin could affect the ruminal fermentation pattern. Monensin could not increase milk yield in the late lactating period.