• Journal of Animal Science and Technology
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• 제58권10호
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• pp.38.1-38.6
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• 2016

Background: Despite the importance of relationships between somatic cell score (SCS) and currently selected traits (milk, fat and protein yield) of Holstein cows, there was a lack of comprehensive literature for it in Iran. Therefore we tried to examine heritabilities and relationships between these traits using a fixed-regression animal model and Bayesian inference. The data set consisted of 1,078,966 test-day observations from 146,765 primiparous daughters of 1930 sires, with calvings from 2002 to 2013. Results: Marginal posterior means of heritability estimates for SCS ($0.03{\pm}0.002$) were distinctly lower than those for milk ($0.204{\pm}0.006$), fat ($0.096{\pm}0.004$) and protein ($0.147{\pm}0.005$) yields. In the case of phenotypic correlations, the relationships between production and SCS were near zero at the beginning of lactation but become increasingly negative as days in milk increased. Although all environmental correlations between production and SCS were negative ($-0.177{\pm}0.007$, $-0.165{\pm}0.008$ and $-0.152{\pm}0.007$ between SCS and milk, fat, and protein yield, respectively), slightly antagonistic genetic correlations were found; with posterior mean of relationships ranging from $0.01{\pm}0.039$ to $0.11{\pm}0.036$. This genetic opposition was distinctly higher for protein than for fat. Conclusion: Although small, the positive genetic correlations suggest some genetic antagonism between desired increased milk production and reduced SCS (i.e., single-trait selection for increased milk production will also increase SCS).

• 한국축산시설환경학회지
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• 제5권3호
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• pp.181-188
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• 1999

This study was carried out to investigate the effect of blowing fan for reducing heat stress in lactating dairy cows in summer. Treatment conditions were divided into 3 types ; No blow(T1), blow to oblique angle(T2) and blow to right angle(T3). Feed intake milk yield, respiration rate, rectal temperature and plasma cortisol concenration were measured to investigate the effect of hot environment on the physiological, productive responses in lactating dairy cows. The results obtained are summarized as follows: The daily milk yields were 20.47, 22.82 and 24.31kg per head in T1, T2 and T3 during experimental period, respectively. The respiration rate was significantly (p<0.05) higher in T1 than those of T2 and T3. The rectal temperature in T1(39.4$^{\circ}C$) was higher than those of T2(39.1$^{\circ}C$), (P<0.05). The plasma cortisol concentration was higher in T1 than those of T2 and T3(P<0.05). It was suggested that blowing fan installed in the pen was effective means to reduce heat stress.

• Journal of Nutrition and Health
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• 제32권1호
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• pp.83-89
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• 1999

The present study was conducted to investigate the yields of volume, thiamin and riboflavin from the milk of twenty-five Cesarean-section women, and their ingestion in infants. We measured the consumed volume of human milk of infants by the test-weighing method, and thiamin riboflavin contents were determined by fluorescence spectroscopy during the first 7 days postpartum. Thiamin contents of the milk averaged 24.3, 24.0, 27.4 and 30.2ug/100g. Thiamin and riboflavin contents of the milk both increased during the lactation ps mod(p<0.05). The first secretion of breast milk occurred from the 4th to 5th day postpartum in Cesarean-section women. The consumed volume of human milk was 63, 81, 104 and 133g/day at 4, 5, 6 and 7 days postpartum and the consumed volume of formula milk was 58, 176, 292, 323, 308, 321 and 318g/day at 1, 2, 3, 4, 5, 6 and 7 days postpartum and the consumed volume of formula from the human and formula milk were 26.6, 91.0, 151.0, 172.5, 169.2, 175.9 and 172.9ug/day. Total daily riboflavin ingestion from the human and formula milk were 26.6, 91.0, 151.0, 172.5, 169.2, 175.9 and 172.9ug/day. Total daily riboflavin ingestion from the human and formula milk was 48.7, 166.8, 277.6, 318.2, 312.0, 327.0 and 335.7ug/day at 1, 2, 3, 4, 5, 6 and 7 postpartum. These results suggest that the milk secretion of Cesarean-section women is delayed a few days and the yield volume of milk is less than that of normal delivery women, but thiamin and riboflavin contents of the milk are not different from those of milk of normal-delivery women.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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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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• 제16권3호
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• pp.359-367
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• 2003

Supplementary feeding strategies were evaluated from pre-calving throughout lactation on 24 dual-purpose Mpwapwa breed cows in their second or greater lactation, weighing 246-455 kg. The Mpwapwa breed is an established breed of 4 Bos indicus breeds and 8% of Bos taurus. The cows were penned and stall-fed individually. Eight weeks before calving to eight weeks after calving, the cows were divided into two groups and offered hay ad libitum with either 2 kg DM (L) or 4 kg DM/day (H) concentrates. Nine weeks after calving half of the cows on L-level continued with 2 kg DM/day (L-L) while the remainder received 4 kg DM concentrate daily (L-H). Half of the cows on H-group continued with 4 kg DM/day (H-H) while the remainder received 2 kg DM/day (H-L). The concentrate mixture comprised of sunflower seed cake (33%) and maize bran (67%). The cows consumed all the concentrate offered. Hay DM intake was similar (6.8 kg/day) and tended to decrease the last two weeks before calving increased again after calving. Live weight change and body condition score were similar across treatments before calving but differed after calving (p<0.05). Heavier cows with higher condition score pre-calving had a higher body weight loss and regained weight later. After treatment reallocation, live weight change and condition differed between treatments (p<0.05). Calves were allowed to suckle milk from one quarter. The amount of milk suckled and calf weight gains were not significantly different between treatments. The cows were removed from the experiment when the milk yield was below 4 kg per day. Cows on treatment H produced 6.2 kg and on treatment L 5.0 kg saleable milk/day (p<0.05) during the first 8 weeks post partum. During the period 9-18 weeks post partum the saleable daily milk on H-H, L-H, H-L and L-L were 5.2, 4.8, 4.7 and 4.3 kg, respectively (p>0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.587-591
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• 2014

Automatic milking systems (AMS) rely upon voluntary cow traffic (the voluntary movement of cattle around a farm) for milk harvesting and feed consumption. Previous research on conventional milking systems has shown differences between dairy cow breeds for intake and milk production, however, the ability to manipulate voluntary cow traffic and milking frequency on AMS farms through breed selection is unknown. This study investigated the effect of breed (Holstein Friesian versus Illawarra) on voluntary cow traffic as determined by gate passes at the Camden AMS research farm dairy facility. Daily data on days in milk, milk yield, gate passes and milking frequency for 158 Holstein Friesian cows and 24 Illawarra cows were collated by month for the 2007 and 2008 years. Illawarra cows had 9% more gate passes/day than Holstein cows over the duration of the study; however, the milking frequency and milk yield of both breeds were similar. Gate passes were greatest for both breeds in early lactation and in the winter (June to August) and summer (December to February) seasons. These findings highlight an opportunity to translate increased voluntary cow movement associated with breed selection into increased milking frequencies, milk production and overall pasture-based AMS performance.

• Journal of Nutrition and Health
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• 제27권8호
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• pp.794-804
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• 1994

This study was conducted to investigate the relationship between lactational capacity and intakes of energy and energy-yielding nutrients. Food consumption, intakes of carbohydrate, protein, fat and energy and quantity and proximate composition of milk of 11 lactating Korean mothers were determined at 1, 2 and 3 months postpartum longitudinally. Food consumption was estimated using a 24-hour recall method ; intakes of energy and energy-yielding nutrients were calculated according to the Food Composition Table. Daily milk production was estimated using a 72-hour test-weighing method ; protein, fat, lactose and energy concentrations were analyzed. Average intakes of energy and protein were 1974$\pm$386㎉/day and 67.0$\pm$12.3㎉/day, these were 73% and 74% of the Korean Recommended Allowances, respectively. Average milk yield was 720.1$\pm$123.3ml/day containing energy 59.6$\pm$9.5㎉/dl, protein 1.1$\pm$0.1g/dl, fat 2.7$\pm$0.8g/dl, and lactose 6.3$\pm$0.3g/dl. No relationship existed between the intakes of carbohydrate, protein, fat and energy and the quantity and proximate composition of the milk. However, the intakes of energy, carbohydrate and vegetable protein were inversely related to the concentrations of energy and lactose in the milk. This result indicates that lactational capacity may be affected by the other factors excluding intakes of energy and energy-yielding nutrients and a high intake of energy may not guarantee optimal lactational capacity.

• Journal of Animal Science and Technology
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• 제50권5호
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• pp.591-600
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• 2008

본 연구는 암소의 산유량, 송아지의 생시 체중, 3개월령 체중 및 포유기 일당증체량들 간의 상관관계를 규명하기 위하여 실시하였다. 분석에 이용된 자료는 축산기술연구소 대관령지소(현 축산과학원 한우시험장)에서 2002년 6월부터 11월 사이에 128쌍 그리고 2003년 4월부터 11월 사이에 94쌍 등 총 222쌍의 암소와 포유중인 송아지로부터 조사하였는데 조사된 형질 중 암소의 산유량은 포유전후 체중차를 이용하여 추정하였다. 조사된 형질들은 모두 어미소 형질로 간주하여 분석을 하였는데 유전모수 추정은 A-I REML(average information restricted maximum likelihood) 추정치를 제공하는 Meyer(2006)의 WOMBAT package를 이용하여 실시하였다. 일일 산유량과 24시간 보정 산유량의 유전력은 각각 0.39와 0.36으로 두 추정치 간에 차이가 없었다. 어미소 형질로 간주하여 추정한 송아지의 생시체중, 3개월령 체중 및 포유기 일당증체량에 대한 유전력은 각각 0.28, 0.17 및 0.18로서 생시체중의 유전력은 3개월령 체중이나 포유기 일당증체량의 유전력에 비해 약간 큰 편이었으며 3개월령 체중과 포유기 일당증체량 간에는 유전력의 크기에서 차이가 없었다. 일일 산유량은 생시체중, 3개월령 체중 및 포유기 일당증체량에 대한 모체 효과 들과의 유전 상관계수가 각각 0.59, 0.79 및 0.68이었다. 일일산유량이 3개월령 체중이나 포유기 일당증체량의 모체효과 간에 높은 유전상관 관계가 있는 것으로 나타난 결과에 근거할 때 한우 집단에서 송아지의 포유기 일당증체량 또는 3개월령 체중의 모체 유전 효과에 대한 선발을 통해 암소들의 산유량에 대한 유전적 개량을 실현할 수 있을 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권1호
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• pp.75-85
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• 2012

An experiment was conducted to compare the effect of the same amount of 18:2 offered either as 18:2n-6 or as a mixture of unprotected 18:2c9t11 and 18:2t10c12 on feed intake, milk components as well as plasma and milk fatty acid profile. Fifteen cows were blocked by milk yield and milk fat percentage and within block assigned randomly to 1 of 3 treatments (n = 5). Each cow passed a 12-d adjustment period (AP) on a basal diet. After the AP cows received 1 of 3 supplements during an 18-d experimental period (EP). The supplements contained either 1.0 kg ground sunflower seeds (S), 0.5 kg conjugated linoleic acid (CLA)-oil (C) or 0.75 kg of a mixture of ground sunflower seeds and CLA-oil (2:1; SC). All 3 supplements contained the same amount of 18:2 either as CLA (${\Sigma}18$:2c9t11+18:2t10c12, 1:1) or as 18:2c9c12. During the last 2 d of AP and the last 4 d of EP feed intake and milk yield were recorded daily and milk samples were collected at each milking. Blood samples were collected from the jugular vein on d 11 of AP and d 15 and 18 of EP. The 18:2 intake increased in all treatments from AP to EP. Regardless of the amount of supplemented CLA, the milk fat percentage decreased by 2.35 and 2.10%-units in treatment C and SC, respectively, whereas in the treatment S the decrease was with 0.99%-unit less pronounced. Thus, C and SC cows excreted daily a lower amount of milk fat than S cows. The concentration of trans 18:1 in the plasma and the milk increased from AP to EP and increased with increasing dietary CLA supply. While the concentration of 18:2c9t11 and 18:2t10c12 in the plasma and that of 18:2t10c12 in the milk paralleled dietary supply, the level of 18:2c9t11 in the milk was similar in C and CS but still lower in S. Although the dietary concentration of CLA was highest in treatment C, the partial replacement of CLA by sunflower seeds had a similar inhibitory effect on milk fat synthesis. Comparable 18:2c9t11 levels in the milk in both CLA treatments implies that this isomer is subjected to greater biohydrogenation with increasing supply than 18:2t10c12. The fact that unprotected 18:2t10c12 escaped biohydrogenation in sufficient amounts to affect milk fat synthesis reveals opportunities to develop feeding strategies where reduced milk fat production is desirable or required by the metabolic state of the cow.

• Asian-Australasian Journal of Animal Sciences
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• 제32권3호
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• pp.334-340
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• 2019

Objective: The objective of this study was to investigate the genetic components of daily milk yield and to re-rank bulls in South Korea by estimated breeding value (EBV) under heat stress using the temperature-humidity index (THI). Methods: This study was conducted using 125,312 monthly test-day records, collected from January 2000 to February 2017 for 19,889 Holstein cows from 647 farms in South Korea. Milk production data were collected from two agencies, the Dairy Cattle Genetic Improvement Center and the Korea Animal Improvement Association, and meteorological data were obtained from 41 regional weather stations using the Automated Surface Observing System (ASOS) installed throughout South Korea. A random regression model using the THI was applied to estimate genetic parameters of heat tolerance based on the test-day records. The model included herd-year-season, calving age, and days-in-milk as fixed effects, as well as heat tolerance as an additive genetic effect, permanent environmental effect, and direct additive and permanent environmental effect. Results: Below the THI threshold (${\leq}72$; no heat stress), the variance in heat tolerance was zero. However, the heat tolerance variance began to increase as THI exceeded the threshold. The covariance between the genetic additive effect and the heat tolerance effect was -0.33. Heritability estimates of milk yield ranged from 0.111 to 0.176 (average: 0.128). Heritability decreased slightly as THI increased, and began to increase at a THI of 79. The predicted bull EBV ranking varied with THI. Conclusion: We conclude that genetic evaluation using the THI function could be useful for selecting bulls for heat tolerance in South Korea.