• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.22-27
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• 2012

The experiment involved observations of 2,514 Holstein-Friesian cows to determine the effects of environmental factors (cow's age, calving season, weight and sex of calves, housing system) and genetic factors on gestation length in dairy cattle and the correlation between gestation length and other reproductive traits (calving ease, stillbirth rates and placental expulsion). Genetic parameters were estimated based on the sires of calved cows (indirect effect) and the sires of live-born calves (direct effect). The following factors were found to contribute to prolonged gestation: increasing cow's age, male fetuses and growing fetus weight. Optimal gestation length was determined in the range of 275-277 days based on calving ease and stillbirth rates. The heritability of gestation length was estimated at 0.201-0.210 by the direct effect and 0.055-0.073 by the indirect effect. The resulting genetic correlations suggest that the efforts to optimize (prolong) gestation length could exert an adverse influence on the breeding value of bulls by increasing perinatal mortality and calving difficulty. The standard errors of the investigated parameters were relatively high, suggesting that any attempts to modify gestation length for the purpose of improving calving ease and reducing stillbirth rates should be introduced with great caution.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1417-1429
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• 2004

The objective of the paper was to study the drinking and other related behavior of dairy cows (Bos taurus). There were 142 Holstein dairy cows observed and compared in this study. The experiment was designed on the basis of two different housing systems (wet pad with forced ventilation cooling house and open house); two different seasons (winter and summer); four different stages (high milk yielding cows, low milk yielding cows, dry cows, and heifers); and grouping (home and visitor animals). All cows had free access to water. Dairy cows spent 13.8 min/day drinking in wet-pad house and 11.7 min/day in open house. owever, there was no significant difference in the duration of water drinking between these two housing systems (p>0.05). The water consumption was significantly higher in wet-pad housed animals (68 L/day) than open-housed animals (31.5 L/day) (p<0.05). A significant interaction between housing and grouping (p<0.05) was found. Home and visitor animals spent more time drinking in open house, wet-pad house, respectively. A highly significant interaction was found between housing and drinking time during the day (p<0.001). Animals in open house drank more during the morning (6:00 to 10:00 h), whereas wet-pad housed animals drank in the afternoon (14:00 to 15:00 h) and evening (18:00 to 20:00 h). The average time a cow spent in drinking in summer was not ignificantly different from that of drinking in winter. However, the water intake was significantly higher in summer (61.9 L/day) than in winter (38.6 L/day) (p<0.05). Drinking activity showed a highly significant interaction between season and physiological stage (p<0.01). High milk yield cows spent more time drinking in summer than in winter, whereas cows in all other stages followed the opposite drinking pattern. Grouping exchange did not influence the drinking behavior of dairy cows in either season (p>0.05); both home and visitor animals spent almost the same time in drinking water. A strong significant interaction between season and time during the day was found(p<0.01), suggesting that animal's high drinking frequency occurred during the daytime for both seasons, with a peak midday in winter and two peaks at 10:00 h in the morning and 19:00 h in summer. Thus, drinking behavior was associated with the cooler time of day in summer and with the warmer hours of day in winter. High and low milk yielding cows and heifers spent 15.3 min/day, 14.3 min/day, and 12.8 min/day, respectively, in water drinking activity, but there was no significant difference among them (p>0.05). There was, however, a significant difference in water drinking activity found in dry cows, which spent less time in drinking at 8.2 min/day (p<0.05).

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.479-486
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• 2006

The current study was conducted to examine the effect of feeding and management practices on milk quality and dairy farm productivity in Korea. Fifty dairy farms in Gyunggi (11), Gangwon (22), Chungnam (17) provinces were surveyed to collect data on the herd size, housing style, feeding management, waste disposal, milking practices and milk yield. Milk tank samples from all farms under study were also collected to enumerate its composition and quality parameters. Large dairy herds are equiped with better housing, milking and waste control facilities than medium and small dairy herds. Higher concentrate feeding to lactating cows was noticed in small dairy herds (47.51 %) than in medium (32.59 %) and large dairy herds (31.82 %). The decrease in concentrate feeding to lactating cows with increase in number of cows per farm resulted in a simultaneous increase in the use of imported forages. Bacterial count in milk was affected by housing and milking facilities at dairy farms. Higher bacterial counts (Coliform and E. coli) in milk were observed in cows housed in stanchion than those under free stall with saw dust bedding. The bacterial counts were higher with bucket milking system than with pipe-line and parlour systems. The increase in the number of dairy cows per farm and thus better management and milking facilities resulted in a reduction in somatic cell score. Milk yield (per cow) was higher in herds with less somatic cell score. Average milk protein concentration was between 2.89 to 2.98 % and milk urea nitrogen was between 21.81 to 23.31mg/ml on surveyed dairy farms. This study concluded that large herd size with better dairy cow management facilities is crucial to produce quality milk with better dairy farm income.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.672-678
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• 2006

The objective of this study was to investigate whether milk performance is impacted by the housing of heifers from the second to the seventh day of life, the method of feeding milk from the second week of life to weaning, the sire lineage and by the season of birth and season of calving. From 32 Holstein heifer-calves, which spent their first day of life in a loose housing maternity pen with their mother, 19 heifers were randomly placed in hutches (IH), and 13 stayed in a loose housing maternity pen (MP). At the seventh day IH heifers were assigned to one of two treatments, 10 heifers were randomly taken from IH and relocated to a loose housing pen with an automatic feeding station (AD), 9 calves stayed in hutches with bucket drinking (BD). MP heifers were moved to a group pen with nursing cows (UD). All animals were weaned at the age of 8 weeks (56 days) and kept in group pens. After calving, they were in free-stall housing. Trial cows were divided according to the sire, season of birth and calving. The five-factorial ANOVA revealed that among all the factors taken into account in this study, only sire lineage and season of birth had significant effects. The production of milk, FCM and protein were higher in the MP group than in the IH group. The UD group tended to have the highest production of milk, FCM, protein, lactose, SNF and total solids (TS) and the AD group the lowest. The content of fat and TS were highest in the AD group. Effects of the sire were significant for average daily gains (ADG) from birth to weaning ($0.55{\pm}0.03kg$, p<0.05), contents of fat ($3.81{\pm}0.08%$, p<0.05), protein ($3.13{\pm}0.02%$, p<0.05), and TS ($12.67{\pm}0.12%$, p<0.05). In the season of birth evaluation, statistical difference was found only in the content of protein ($3.13{\pm}0.13%$, p<0.05). Cows born in March-May had the highest % protein and cows born in June-August the lowest ($3.21{\pm}0.04$ vs. $3.06{\pm}0.05%$). Dairy cows born and subsequently calving in December-February had the highest production of milk, protein and TS, and dairy cows born in June-August the lowest. FCM and fat yields were highest in the group born in September-November and lowest in the group born in June-August.

• Journal of Animal Environmental Science
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• v.1 no.1
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• pp.9-19
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• 1995

This study was carried out to investigate the effect of sawdust bedding barn on manure handing, management labour and physiological aspect of dairy cows, and then to establish the criteria on the optimum utilization method of sawdust bedding barn. 46 tie stall barns and 49 sawdust bedding barns were surveyed to cmopare the milk productivity between two different barns, and also 5 tie stall barns, 15 sawdust bedding barns and 1 rice hull bedding barn were selected to study the utilization situation of sawdust barn in Kyung-Ki province area. The major results obtained were as follows; 1. The roof material of sawdust barn were consisted of 66% vinyl house, 23% PVC light and 11% slate and galvanum coated tin. Most of the floor structure was earth ground with the rate of the approximately 82%. 2. The average occupied area of sawdust bed per cow was 15.2 $m^2$, depth that 30 cm and the utilization period was 12 months. 3. Milk Yield was significantly higher at sawdust barn than at tie stall barn(P<0.01). Bacterial and somatic cell count in raw milk were less at the sawdust barn than in tie stall barn. However, there was not significance difference between two barns. 4. The labour hour needed to cow management in the sawdust barn was approximately 48% of that of tie stall barn. 5. The temperature and moisture content measured in sawdust bed were closely affected by seasonal ambient temperature. The skin and hair of cow were much cleaner at the PVC light roofed sawdust barn than any other roof materials. 6. The additives used for improving of fermentation did not show any effect on temperature and moisture content in sawdust bed. When the ambient temperature was $30.4^{\circ}C$, the surface temperature of measured 1 cm above the sawdust bed was $12.2^{\circ}C$ lower and the temperature of 100 cm above the sawdust bed was $2.4^{\circ}C lower under shading net facility than that of vinyl roofed one.7. The hoof length of miking cow was 7.95 cm in tie stall and 9.19 cm in sawdust barn with high significance (P<0.01). And disease occurence such as mastitis and foot-rot tended to decrease in the sawdust barn. 8. The number of total bacteria and coliform bacteria were less in the sawdust bed compared with earth ground resting area. And a parasite strongyloides papillosus was detected but without any infected cow. 9. The nitrate($NO_3N$) content in non-roofed earth ground resting area and earth ground under the sawdust bed was likely to pollute the ground water. 10. In economic point of view, rice hull bedding barn was the cheapest among different systems. And in the sawdust bedding barn PVC light + slate roofed barn was most desirable, and vinyl roofed one the least.

• Animal Bioscience
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• v.34 no.4
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• pp.575-583
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• 2021

Objective: The aim of the study was to determine the effect of parity and the stage of lactation on the metabolic profile of cows based on the basic chemical milk components and the blood parameters. Methods: The study material consisted of high-yielding Holstein-Friesian cows. In total, 473 cows were examined. According to the parity, cows were divided into four groups: primiparous (P), and multiparous in the second (M2), in the third (M3), and in subsequent lactations (M4). The feeding of cows was based on total mixed ration (TMR) ad libitum. Milk and blood samples were collected individually from each cow three times per standard lactation period. Results: Greater exacerbation of changes in the dynamics of the blood plasma parameters examined was proved for multiparous cows. The highest value of β-hydroxybutyrate acid (0.946 mmol/L) was found for multiparous cows from group M3 at the beginning of lactation. However, it was still in the normal range. The results showed aspartate aminotransferase, and gamma-glutamyl transferase (GGT) activities in dairy cows during lactation had significant variations taking in to account stage of lactation. The highest activity of GGT was found in the group of the oldest cows and measured from 26.36 U/L at the beginning of lactation to 48.75 U/L at the end of the lactation period. Conclusion: The time-related changes in the concentrations of the biochemical parameters described differ markedly among lactating cows, though the housing conditions on the research dairy farm are highly standardised. This indicates that the ability to cope with metabolic stress is mainly affected by the individual predispositions of cows and feed nutrient supply in different stage of lactation. Especially, the feed nutrient supply (in net energy for lactation), which was the best in TMR 1 in comparison TMR 3.

• Journal of Animal Environmental Science
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• v.1 no.2
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• pp.117-124
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• 1995

This study was carried out to investigate the effect of depth of sawdust bedding and ground material in dairy cattle barn. Treatment included the concrete floor with a 10cm or 30cm sawdust and the earth floor with a 30cm sawdust. Eighteen cows were assigned to 3 pens with 16.5㎥/head bedding area. The results obtained were as follows : 1. The temperature of sawdust bed was highest in the earth floor with 30cm sawdust, and the moisture content of sawdust bed was highest in the concrete floor with 10cm sawdust bed. 2. Cows defecate feces 9.2, 8.7 and 9.3 times a day in 10cm sawdust on concrete floor(10S+C), 30cm sawdust on concrete floor(30S+C) and 30cm sawdust on non concrete floor(30S+ NC) respectively. In average, they excreta 9.1 times/day(85.8%) in the sawdust beds and 1.5 times/day(14.2%) in the feeding alley. 3. The ratio of daily water amount deposited vapor to total water amount deposited in sawdust beds was 74.0%, 61.5% and 47.1% in 10S+C, 30S+C and 30S+NC respectively. 4. N.P.K contents in the sawdust beds were higher for 10S+C compared with other treatments. 5. When 30cm of sawdust was applied on the earth ground NO$_3$-N contents in the sawdust bed was 37.7, 14.1 and 15.0ppm in depth of 30, 60 and 90cm under the ground, respectively, indicating some possibility of water pollution.