• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1189-1192
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• 2000

The experiment was conducted on 69 cows to identify the quantitative variations of some economic traits of five genetic groups as $Local{\times}Friesian $ $F_1$, $Local{\times}Sahiwal$ $F_1$, Local (indigenous zebu type), $Local{\times}Sindhi $ $F_1$, and $Local{\times}Hariana$ $F_1$. The traits studied were age at weaning, age at first heat, age at first conception, services per conception, daily milk yield, lactation length, lactation yield and post partum heat period. The records on milking and reproduction performances of cows and heifers were obtained from farm register and by interviewing the farmers. It was observed that the lowest age at weaning, age at first heat and age at first conception were $5.37{\pm}0.24$, $27.17{\pm}1.72$ and $27.83{\pm}1.82$ months respectively in $Local{\times}Hariana$ $F_1$. Services per conception were lowest in $Local{\times}Sahiwal$ $F_1$ $(1.08{\pm}0.18)$ although not significantly (p>0.05) affected by farms, genetic groups and $farm{\times}genetic$ groups interaction. Average daily milk yield was highest in $Local{\times}Friesian$ $F_1$ $(5.81 {\pm}0.40 kg)$. Lactation length and lactation yield were highest in $Local{\times}Sahiwal$ $F_1$ ($299.38{\times}9.74$ days and $1863.00{\pm}141.00kg $ respectively). Average post partum heat period was lowest in $Local{\times}Sindhi$ $F_1$ ($3.19{\pm}0.38$ months). Least squares ANOVA showed that farm had significant (p<0.001) effect on age at weaning, age at first heat, age at first conception and post partum heat period. There was insignificant (p>0.05) effect of farm on services per conception, daily milk yield, lactation length and lactation yield, whereas genetic groups had a significant effect for all the traits under review except services per conception. $Farm{\times}genetic$ groups interaction was insignificant for all of the traits under consideration except age at weaning.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1093-1098
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• 2017

Objective: The aim of the current study was to describe the relationship between milk yield and lactation number, stage, length and milking frequency in Korean Holstein dairy cows using an automatic milking system (AMS). Methods: The original data set consisted of observations from April to October 2016 of 780 Holstein cows, with a total of 10,751 milkings. Each time a cow was milked by an AMS during the 24 h, the AMS management system recorded identification numbers of the AMS unit, the cow being milking, date and time of the milking, and milk yield (kg) as measured by the milk meters installed on each AMS unit, date and time of the lactation, lactation stage, milking frequency (NoM). Lactation stage is defined as the number of days milking per cows per lactation. Milk yield was calculated per udder quarter in the AMS and was added to 1 record per cow and trait for each milking. Milking frequency was measured the number of milkings per cow per 24 hour. Results: From the study results, a significant relationship was found between the milk yield and lactation number (p<0.001), with the maximum milk yield occurring in the third lactation cows. We recorded the highest milk yield, in a greater lactation length period of early stage (55 to 90 days) at a $4{\times}$ milking frequency/d, and the lowest milk yield was observed in the later stage (>201 days) of cows. Also, milking frequency had a significant influence on milk yield (p<0.001) in Korean Holstein cows using AMS. Conclusion: Detailed knowledge of these factors such as lactation number, stage, length, and milking frequency associated with increasing milk yield using AMS will help guide future recommendations to producers for maximizing milk yield in Korean Dairy industries.

• Asian-Australasian Journal of Animal Sciences
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• 제17권4호
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• pp.533-537
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• 2004

The experiment was conducted to test the hypothesis that supplementing diets of lactating first parity sows with a mixture of carbohydrases (CS) improves lactation performance and second parity reproductive performance. The CS used in this study contained 7 units/g of $\alpha$-1,6-galactosidase, 22 units/g of $\beta$-1,4-mannanase, $\beta$-1,4-mannosidase and trace amounts of other enzymes. Twenty primiparous sows (Newsham Hybrid) were allotted to either the control group (no CS supplement) or the CS group (0.1% CS supplement) and fed the experimental diets during 21 d lactation period. Sows and nursing pigs were weighed at birth and weekly until weaning. Days of weaning-to-estrus were recorded. Sows had free access to feed and water. Feed intake of sows was measured daily. During the second parity gestation and lactation, all the sows were fed the same gestation and lactation diets and their reproductive performance was measured. During the second parity, there were 14 sows (7 sows per group) remained productive. For the first lactation, maternal body weight loss of the CS group was smaller (p<0.05) than that of the control group. There was no difference in litter weight gain between two groups. Voluntary feed intake of sows did not differ between the two groups. Days of weaning-to-estrus of the CS group were smaller (p<0.05) than those of the control group. In the second parity, there was no difference in the reproductive performance between the two groups. In conclusion, supplementing CS in the diet of lactating sows during the first parity decreased body weight loss and days of weaning-to-estrus of sows. However, these effects of the CS supplementation in the first parity were not successfully carried over to the second parity.

• Nutrition Research and Practice
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• 제9권4호
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• pp.433-438
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• 2015

BACKGROUND/OBJECTIVES: Breast milk is the best available food for optimum growth and development of infants and the breastfeeding rate is increasing in Korea. The purpose of this study is to measure the concentrations of macronutrients and to evaluate their changes according to lactation period in breast milk from lactating Korean women. SUBJECTS/METHODS: Milk samples were obtained from 2,632 healthy lactating women (mean age; $32.0{\pm}3.3years$), where the lactating period was up to a period of 8 months, who also volunteered to participate in the Human Milk Macronutrient Analysis Research. Lactose, protein, fat and water content in the breast milk samples were analyzed with infrared spectrometry using MilkoScan FT-2. RESULTS: The mean macronutrient composition per 100 mL of mature breast milk was 7.1 g for lactose, 1.4 g for protein and 3.0 g for fat, and energy content was 61.1 kcal. The protein concentration was significantly lower in milk samples at 1-2 weeks (2.0 g/dL) to 2-3 months (1.4 g/dL) than those at 0-1 week (2.2 g/dL), but it was similar among samples from 3-4 months to 7-8 months (1.3 g/dL). Mean lipid levels varied among different lactational period groups (2.7-3.2 g/dL), but presented no significant difference. Lactose concentration in the milk samples did not differ with lactation period. Maternal body mass index was positively related to protein and lipid breast milk contents, but was negatively related to lactose content. General linear models examining the associations between maternal variables and milk macronutrient content revealed that lactation period had a major impact on protein and lipid, but not on lactose content in breast milk. CONCLUSIONS: These results warrant future studies to explore factors that may be associated with changes in macronutrient content in human milk.

• 농업과학연구
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• 제40권4호
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• pp.333-338
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• 2013

Sources of energy and rumen undegradable protein (RUP) have been used to meet nutrient requirements for high producing dairy cows. However studies for manipulation the levels of energy and RUP in diets have been mainly achieved using dairy cows at early-lactation period. The objective of this study thus, was to investigate the effects of different energy and rumen undegradable protein (RUP) levels on dry matter intake and milk yield in Holstein cows at mid-lactation period. Basal diet was prepared as TMR to meet nutrient requirements for dairy cows at mid-lactation according to NRC recommendation. Cows of control group (Con) were fed only basal diets while ground corn (0.5 kg/d), heat-treated soybean meal (0.5 kg/d), and their mixture (0.25 kg of each supplements/d) were added to diets for cows of treatment groups (T1, T2, and T3 respectively) to modulate the level of energy and RUP contents in diets. Addition of energy or RUP source in basal TMR did not affect in total DMI while TMR intake tended to be higher in Con compared to T3. Cows fed T3 diets tended to show increased milk yield and MUN content than those of Con. Cows for T2 as well as T3 had lower ADG (P<0.05) compared with those of Con. We concluded that the addition of RUP source in diets for dairy cows on mid-lactation period might cause the decrement of DMI and ADG.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.895-899
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• 2002

Lysozyme activity in buffalo milk in relation to the period of lactation, parity of animal, weather conditions and udder infections was studied. Effect of storage and heat processing of milk on lysozyme activity was determined. Lysozyme activity was higher in buffalo milk than in cow milk. Buffalo colostrum showed lysozyme activity 5 times of that in mature milk. Lysozyme activity in buffalo milk was not influenced by the parity of animal and the stage of lactation, however, it increased during extreme whether conditions (winter and summer). Lysozyme in both cow and buffalo milk exhibited maximum activity at pH 7.4. Buffalo milk lysozyme was fully stable while the cow milk lysozyme was partly inactivated by pasteurization (low temperature-long time as well as high temperature-short time treatments). Lysozyme in buffalo milk was more stable than in cow milk during storage and heat treatment. A 10 to 50-fold increase in milk lysozyme activity was observed in mastitic cows. An assay of lysozyme activity in milk can be used to diagnose mastitis in cattle but not in buffaloes. Some buffaloes exhibited 1000 fold greater lysozyme activity and moderately raised somatic cell count in milk, but there was no sign of mastitis in these animals. A possible role of milk lysozyme in prevention of mastitis in buffaloes is discussed.

• Asian-Australasian Journal of Animal Sciences
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• 제8권3호
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• pp.219-221
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• 1995

Data on productive and reporductive performance of native cows maintained at Savar Dairy Farm, Central Cattle Breeding Station (CCBS), Savar, Dhaka, were collected from the periods of 1980-1988. The mean calving to first breeding during the second parity was longer (p < 0.01) than the fourth and fifth parities (152 vs 105 and 96 days respectively). There was no difference on the parameters like first breeding to conception, service period, gestation length, number of services per conception and total milk yield over the parities. The mean calving interval during the second parity was longer (p < 0.05) than the fourth and fifth parities. The mean lactation length during the first parity was longer (p < 0.01) than those of second, third, fourth and fifth lactations (317 vs 237, 266, 250 and 247 days respectively). The mean per day milk yield during the first lactation was lower (p < 0.01) than those of second, third, fourth and fifth lactations (1.88 vs 2.55, 2.75, 2.54 and 2.57 kg respectively). The mean dry period was longer in first lactation (p < 0.05) compared to third and fifth lactations (209 vs 141 and 129 days respectively).

• 한국가축번식학회지
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• 제23권2호
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• pp.95-103
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• 1999

본 연구는 초산의 Wistar 계 rat를 이용하여 포유기간 중 제한포유시기와 이유시기를 조절하여 혈중 progesterone 수준을 검토하였다. 정상포유군 (NL)은 포유자의 수를 8 마리로 조절하였으며, 제한포유군 (RL)과 완전이유군 (W)은 RL0, RL5, RL10, RL15 및 RL20, 그리고 W0, W5, W10, W15 및 W20으로 각각 5 개 군으로 구분하여, 제한포유군은 각 개시일에 포유자의 수를 8마리에서 4마리로 조절하였으며, 완전이유군은 각 개시일에 포유자의 수를 완전히 이유시켰다. 1. 포유자의 발육상태는 제한포유군에서 정상포유군보다 성장이 유의적 (P＜0.05)으로 증가하였고, 또한 분만직후 (RL0) 와 포유 5(RL5), 10(RL10), 15(RLl5) 일에 제한포유를 실시한 군에서는 시간이 경과함에 따라 정상포유군에 비해 유의적 (P＜0.05) 으로 증가하였으나, 포유 20 일(RL20) 에 제한포유군에서는 정상포유군과 차이가 없었다 . 초산 rat 의 임신기간은 21.53$\pm$0.04일이었고 산자수는 13.75$\pm$0.07 마리였다. 2. 포유기간 중 모체의 성주기 변화는 정상포유군은 발정징후가 관찰되지 않았으나 분만직후 제한포유군은 20 일을 전후하여 불규칙적인 성주기가 관찰되었고, 분만직후 완전이유군은 10일을 전후하여 정상적인 성주기가 관찰되었다. 3. 정상포유군의 progesterone 농도는 포유 0 일에 33.16$\pm$2.64ng/$m\ell$에서 포유 10 일에 122.55$\pm$3.68ng/$m\ell$ 까지 증가하여 포유 20 일까지 높은 수준을 유지하다가 그 후 25 일에 97.30$\pm$3.21ng/$m\ell$ 까지 급속히 감소 (P＜0.05) 하였다. 포유초기 (RL0, RL5)와 포유중기 (RL10)의 제한포유군은 제한포유실시 이후 5일 까지는 정상포유군과 같은 수준을 유지하다가 그 후 급격히 (P＜0.05) 감소하였다. 결론적으로 흰쥐에 있어서 분만 후 포유자의 포유자극이 모체 난소의 기능에 중요하게 작용하는 것으로 사료된다.

• 한국동물위생학회지
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• 제34권4호
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• pp.369-378
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• 2011

Incidence of mastitis is highest in dairy cows and it is a leader of all diseases and the economic losses, in dairy farms. The objective of this study is to analyse the incidence of clinical mastitis using the lactation number, lactation month and season of calving. In this study, we used 3,779 lactation data and animal health records collected from 1990 to 2006 at the National Institute of Animal Science. Out of 3,779 cows, a total of 1,721 cows were reported with clinical mastitis, which was 46.3%. The frequency of mastitis increased from 36.9% from first lactation to 56.0% by the fifth lactation. As many as 766 cows (46.9%) showed a recurrence of mastitis after 14 days, apart for two or more and chronic mastitis that were recorded for 657 cows (20.3%). This came to a total of 3,010 cases that had clinical mastitis in the herd for sixteen years. The distribution of incidence of clinical mastitis was highest during the first month of lactation at 24.4%, and it reached to 43.4% by the third month. The incidence of mastitis was even higher for cows in first lactation, showing 28.6% in the first month, and 42.9 percent by third month of lactation. Cows calved during the summer and winter months showed higher rate of incidence with 59.9% and 57.9% within 30 days of lactation, respectively. It is urgently needed to establish a preventative management for heifer cows during their expected first lactation and the clinical specific dry-period management strategies that influence the rate of clinical mastitis during the next lactation. The aim of this study is to present information that might be useful to improve clinical mastitis prevention.

• Animal Bioscience
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• 제35권10호
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• pp.1499-1511
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• 2022

Objective: This study was aimed to estimate the genetic parameters, including genetic and phenotypic correlations, of milk yield, lactation curve traits and milk composition of Thai dairy cattle from three government research farms. Methods: The data of 25,789 test-day milk yield and milk composition records of 1,468 cattle from lactation 1 to 3 of Holstein Friesian (HF) and crossbred HF dairy cattle calved between 1990 and 2015 from three government research farms in Thailand were analysed. 305-day milk yield was estimated by the Wood model and a test interval method. The Wood model was used for estimating cumulative 305-day milk yield, peak milk yield, days to peak milk yield and persistency. Genetic parameters were estimated using linear mixed models with herd, breed group, year and season of calving as fixed effects, and animals linked to a pedigree as random effects, together with a residual error. Univariate models were used to estimate variance components, heritability, estimated breeding values (EBVs) and repeatability of each trait, while pairwise bivariate models were used to estimate covariance components and correlations between traits in the same lactation and in the same trait across lactations. Results: The heritability of 305-day milk yield, peak milk yield and protein percentage have moderate to high estimates ranging from 0.19 to 0.45 while days to peak milk yield, persistency and fat percentage have low heritability ranging from 0.08 to 0.14 in lactation 1 cows. Further, heritability of most traits considered was higher in lactation 1 compared with lactations 2 and 3. For cows in lactation 1, high genetic correlations were found between 305-day milk yield and peak milk yield (0.86±0.07) and days to peak milk yield and persistency (0.99±0.02) while estimates of genetic correlations between the remaining traits were imprecise due to the high standard errors. The genetic correlations within the traits across lactation were high. There was no consistent trend of EBVs for most traits in the first lactation over the study period. Conclusion: Both the Wood model and test interval method can be used for milk yield estimates in these herds. However, the Wood model has advantages over the test interval method as it can be fitted using fewer test-day records and the estimated model parameters can be used to derive estimates of other lactation curve parameters. Milk yield, peak milk yield and protein percentage can be improved by a selection and mating program while days to peak milk yield, persistency and fat percentage can be improved by including into a selection index.