• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.243-248
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• 2013

Q fever is a rickettsial infection caused by Coxiella burnetii that is transmitted from animals to humans. Modes of transmission to humans include inhalation, tick bites and ingestion of unpasteurized milk or dairy products. This survey was aimed at monitoring the seroprevalence of C. burnetii in bulk-tank milk (BTM) in Gyeongbuk province. In addition, the seroprevalence of C. burnetii was investigated at the herd level of dairy cattle in eastern Gyeongbuk province in which many dairy cattle are reared. Among 324 BTM samples collected from 20 country areas, 175 (54%) BTM samples from 15 (75%) country areas were positive for C. burnetii by ELISA. By regions, the seroprevalence of BTM samples in eastern, central, western and northern areas of Gyeongbuk province were 62.7%, 48.4%, 45.1%, and 41.4%, respectively. When analyzed in the dairy cattle reared in the eastern area where high seroprevalence occurred in BTM samples, 119 (24.2%) out of 492 dairy cattle were positive for C. burnetii. Seroprevalence of C. burnetii in dairy cattle was increased with daily milk yield of farm (P<0.05) and age (P<0.001). Since seroprevalence of C. burnetii is relatively high in both BTM samples and dairy cattle reared in Gyeongbuk province, further studies on the high risk farms and herds are needed to evaluate infection status and appropriate control programs in this region.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1122-1127
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• 2019

Objective: The objective of current study was to investigate the lactation performance and rumen fermentation characteristics of dairy cows fed a diet with alfalfa hay replaced by corn stover but supplemented with molasses. Methods: Sixteen Holstein cows in mid-lactation were randomly assigned to 1 of 2 dietary treatments: i) alfalfa based diet (AH), and ii) corn stover based diet supplemented with molasses (CSM). The experiment was conducted according to a $2{\times}2$ crossover design with 22-d each period, consisting of 17 d for adaptation and 5 d for data and samples collection. Results: Dry matter intake and milk yield were higher for cows fed AH than CSM (p<0.01). Milk protein content and nitrogen conversion were higher (p<0.05), while milk urea nitrogen was lower (p<0.01) for cows fed AH than CSM-fed cows. Contents of milk total solids, fat and lactose were not different between two groups (p>0.10). Total rumen volatile fatty acid concentration tended to be higher (p = 0.06) for cows fed AH than CSM-fed cows. Molar proportion of acetate was lower (p = 0.04), but valerate was higher (p = 0.02) in cows fed AH than CSM-fed cows. Rumen concentration of propionate, and isobutyrate, and ratio of acetate to propionate tended to be different (p<0.10) between two groups. The feed cost per kilogram of milk was lower in CSM than AH (p<0.01). No differences were found in feed efficiency and most plasma parameters tested (p>0.10). Conclusion: In comparison with AH diet, CSM diet could be fed to dairy cows without negative effect on feed efficiency, ruminal fermentation, but economically beneficial, indicating that CSM could be an alternative choice for dairy farms instead of AH to feed midlactation dairy cows.

• Animal Bioscience
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• v.35 no.7
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• pp.955-963
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• 2022

Objective: The aim of this study was to estimate genetic parameters for 305-day cumulative milk yield and components, growth, and reproductive traits in Guzerá cattle. Methods: The evaluated traits were 305-day first-lactation cumulative yields (kg) of milk (MY305), fat (FY305), protein (PY305), lactose (LY305), and total solids (SY305); age at first calving (AFC) in days; adjusted scrotal perimeter (cm) at the ages of 365 (SP365) and 450 (SP450) days; and adjusted body weight (kg) at the ages of 210 (W210), 365 (W365), and 450 (W450) days. The (co)variance components were estimated using the restricted maximum likelihood method for single-trait, bi-trait and tri-trait analyses. Contemporary groups and additive genetic effects were included in the general mixed model. Maternal genetic and permanent environmental effects were also included for W210. Results: The direct heritability estimates ranged from 0.16 (W210) to 0.32 (MY305). The maternal heritability estimate for W210 was 0.03. Genetic correlation estimates among milk production traits and growth traits ranged from 0.92 to 0.99 and from 0.92 to 0.99, respectively. For milk production and growth traits, the genetic correlations ranged from 0.33 to 0.56. The genetic correlations among AFC and all other traits were negative (-0.43 to -0.27). Scrotal perimeter traits and body weights showed genetic correlations ranging from 0.41 to 0.46, and scrotal perimeter and milk production traits showed genetic correlations ranging from 0.11 to 0.30. The phenotypic correlations were similar in direction (same sign) and lower than the corresponding genetic correlations. Conclusion: These results suggest the viability and potential of joint selection for dairy and beef traits in Guzerá cattle, taking into account reproductive traits.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1374-1388
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• 2007

Three experiments were conducted to investigate the hypothesis that cows grazing on pasture produce the highest proportion of c-9 t-11 CLA in milk fat and no further increase can be achieved through supplementation of diets rich in linoleic acid, such as full-fat extruded soybeans or soybean oil. In experiment 1, 18 lactating Holstein cows were used in a randomized complete block design with measurements made from wk 4 to 6 of the experiment. In experiment 2, three cannulated lactating Holstein cows were used in a $3{\times}3$ Latin square design. Each period was 4 wk with measurements made in the final wk of each period. Cows in both experiments were assigned at random to treatments: a, conventional total mixed ration (TMR); b, pasture (PS); or c, PS supplemented with 2.5 kg/cow per day of full-fat extruded soybeans (PES). In both experiments, feed intake, milk yield, milk composition, and fatty acid profile of milk and blood serum were measured, along with fatty acid composition of bacteria harvested from rumen digesta in experiment 2. In experiment 3, 10 cows which had continuously grazed a pasture for six weeks were assigned to two groups, with one group (n = 5) on pasture diet alone (PS) and the other group (n = 5) supplemented with 452 g of soy oil/cow per day for 7 d (OIL). In experiment 1, cows in PS treatment produced 350% more c-9, t-11 CLA compared with cows in TMR treatment (1.70 vs. 0.5% of fat), with no further increase for cows in PES treatment (1.50% of fat). Serum c-9, t-11 CLA increased by 233% in PS treatment compared with TMR treatment (0.21 vs. 0.09% of fat) with no further increase for cows in PES treatment (0.18% of fat). In experiment 2, cows in PS treatment produced 300% more c-9 t-11 CLA in their milk fat compared with cows in TMR treatment (1.77 vs. 0.59% of fat), but no further increase for cows in PES treatment (1.84% of fat) was observed. Serum c-9, t-11 CLA increased by 250% for cows in PS treatment compared with cows in TMR treatment (0.27 vs. 0.11% of fat), with no further increase for cows in PES treatment (0.31% of fat). The c-9, t-11 CLA content of ruminal bacteria for cows in PS treatment was 200% or more of TMR treatment, but no further increase in bacterial c-9, t-11 CLA for cows in PES treatment was observed. Supplementation of soy oil in experiment 3 also did not increase the c-9 t-11 CLA content of milk fat compared with cows fed a full pasture diet (1.60 vs. 1.54% of fat). Based on these findings, it was concluded that supplementing with feeds rich in linoleic acid, such as full-fat extruded soybeans or an equivalent amount of soy oil, to cows grazing perennial ryegrass pasture may not increase milk fat c-9 t-11 CLA contents.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.427-438
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• 1996

The suitability of female cattle ($Brahman{\times}Holstein$) and buffaloes (Murrah / Jafarabadi) for work on a sugarcane crusher was tested. The animals were fed chopped sugarcane tops and elephant grass supplemented with rice bran and urea-molasses blocks. In experiment 1, six cattle and six buffaloes, (with three animals seven to eight months pregnant at the start of the experiment in each group), worked individually, alternate weeks for 90 minutes a day for 6 d/week. Within the 90 min, cattle did more work than buffaloes (p < 0.05), and non-pregnant animals did more than pregnant animals, but cattle crushed significantly (p < 0.05) more cane per day than buffaloes. During work animals lost weight, but gained the weight back during resting weeks, when fodder intakes were higher. There were no significant differences in live weight change and fodder intakes between pregnant and non-pregnant animals during the six weeks. In experiment 2, four pairs of lactating cows and buffaloes crushed sugarcane for 3 h/d, 6 d/week for three weeks. Work done was higher in cattle than buffaloes, but cane crushed was marginally lower. All animals lost weight during work, particularly in the first week, but gained weight during the week after work. Daily milk yield was lower during the working weeks ($-0.55{\pm}0.15kg$) than in the week before work. Butter fat yield showed no significant change. One buffalo showed ovarian activity and oestrus behaviour during the work. Two cows showed ovarian activity within one month after the work. It was concluded that pregnant and lactating cows and buffaloes can effectively operate a cane crusher, however a temporary reduction in milk yield can be expected in the working period, and ovarian activity may be suppressed.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.91-97
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• 2011

The objectives of this research were to investigate the system of rice intensification (SRI) on early growth, grain yield, and yield components under Chinese milk vetch residue-mulched no-tillage cropping systems at silt loam soil. The field was prepared as a split-plot design with three replications, main plots consisted of Dongjinbyeo, and Sobibyeo as a cultivar, and subplots consisted of $10{\times}10$ cm, $20{\times}20$ cm, and $30{\times}30$ cm as a planting density. Weed infestation during rice growing season was more severe in wider planting density $30{\times}30$ at 35 days after transplanting (DAT), and $20{\times}20$ cm at 95 DAT in both Sobibyeo and Dongjinbyeo. The maximum plant height was recorded in Sobibyeo compared with Dongjinbyeo, $10{\times}10$ cm and $20{\times}20$ cm planting density compared with $30{\times}30$ cm from 20 DAT until 60 DAT. Among the three planting densities, SPAD values were significantly greater in planting density of $20{\times}20$ cm both in Sobibyeo and Dongjinbyeo followed by $30{\times}30$ cm compared with closer planting density of $10{\times}10$ cm. The lowest grain yield was observed in wider planting density of $30{\times}30$ in both Sobibyeo and Dongjinbyeo due to lower number of panicle per unit area. Our findings suggest that optimum planting density for SRI in no-tillage paddy was $20{\times}20$ cm and it should be useful the systems to small-scale rice farmers in Korea as a sustainable farming system.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.476-484
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• 2015

The objective of this study was to estimate genetic and phenotypic parameters for linear type traits, as well as milk yield (MY), fat yield (FY) and protein yield (PY) in 18,831 Holstein cows reared in 495 herds in Brazil. Restricted maximum likelihood with a bivariate model was used for estimation genetic parameters, including fixed effects of herd-year of classification, period of classification, classifier and stage of lactation for linear type traits and herd-year of calving, season of calving and lactation order effects for production traits. The age of cow at calving was fitted as a covariate (with linear and quadratic terms), common to both models. Heritability estimates varied from 0.09 to 0.38 for linear type traits and from 0.17 to 0.24 for production traits, indicating sufficient genetic variability to achieve genetic gain through selection. In general, estimates of genetic correlations between type and production traits were low, except for udder texture and angularity that showed positive genetic correlations (>0.29) with MY, FY, and PY. Udder depth had the highest negative genetic correlation (-0.30) with production traits. Selection for final score, commonly used by farmers as a practical selection tool to improve type traits, does not lead to significant improvements in production traits, thus the use of selection indices that consider both sets of traits (production and type) seems to be the most adequate to carry out genetic selection of animals in the Brazilian herd.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.288-295
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• 2014

This study was conducted to evaluate the effect of mixing time for TMR (total mixed rations) mixed with corn silage on particle size, peNDF (physically effective neutral detergent fiber), laceration, and ruminal in situ dry matter degradation. The study also aimed to evaluate the effect of consumption of the TMR on the milk yield and milk components of mid-lactational dairy cows. TMRs were mixed for 30 minutes (T1) and 50 minutes (T2) using the same material. All samples were then analyzed with a Penn State Particle Size Separator (PSPS). The particle size of T1 was significantly lower in the bottom pan (8 mm>) than that of T2 (p<0.01). $peNDF_{&gt;8.0}$ was significantly higher in T1 (17.18%) than in T2 (13.85%) (p<0.01). For ruminal in situ dry matter degradation of particle retention (>19 mm), no significant difference was found after 72 hours incubation, although T1 degradation was significantly higher after 24 hours incubation (p<0.01). Milk yield was no different between the groups of cows, whereas the milk fat from T1 fed cows was significantly higher (p<0.01). The results show that feeding TMR mixed for 30 minutes to dairy cows may improve the physical value of forage without negative effects on the milk yield and milk components.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.287-296
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• 2010

This study was conducted to determine effects of fermented brown seaweed waste (FBSW) on milk production, composition and physiological responses as functional feed for 60 days in Holstein dairy cows. A total of 24 Holstein dairy cows (average age 49.33 months, average lactation days 175, Reproduction 2.0) were randomly allocated into control(basal diet), 1% FBSW (180g in basal diet) and 2% FBSW (360g in basal diet) groups with 8 replications for 60 days. Daily milk yield and composition (fat, protein, SNF, MUN) were not affected by FBSW supplementation, but Ca level in milk was significantly increased 4.29 mg/dl and 2.91 mg/dl in 1% and 2% groups compared to control group (p<0.05) at the end of the experiment, respectively. The somatic cell count (SCC) in milk was not significant. The plasma $T_4$ level (concentration) were increased in 1% and 2% FBSW compared to control group at the end of the experiment (p<0.05), but between triiodothyronine ($T_3$) and thyroxin ($T_4$) levels were not significant. Concentrations of plasma glucose in control, 1% FBSW and 2% FBSW groups were 64. 37mg/dl, 66.15mg/dl and 73.02 mg/dl and plasma NEFA level was 0.30~0.32 mEq/dl. Concentrations of BUN tended to be higher for FBSW group than control group. Although WBC, RBC, Hb, Hct, T-B, ALP, and GPT levels were not affected by FBSW supplementation, GOT level was significantly decreased in cows fed 1% FBSE diet compared to control group (P<0.05). Therefore we strongly suggest that the 1% FBSW supplementation in basal diet increases the milk yield and Ca level in Holstein dairy cows.

• Journal of Animal Science and Technology
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• v.55 no.5
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• pp.343-349
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• 2013

Data including 1,372,050 milk records pertaining to 438,019 cows from 1983 to 2011 collected during performance tests conducted by the National Livestock Cooperative Dairy Improvement Center were used to calculate milk income and profit of individuals and investigate the effects of production levels of early lactation (parity 1 and 2, respectively). Individuals with a moderate level of early lactation stayed longer in herds. Among parity 1, the 9,000 kg or higher group had a lower mean number of lactations than the overall mean of 3.13. The 7,000 kg or lower and 10,000 kg or higher groups had lower mean life time milking days than the overall mean of 1,076.8 days. Standard deviations of lifetime traits tended to decrease as production levels increased. For parity 2, the 11,000 kg or higher group had a lower mean number of lactation than the overall mean of 3.43. The lifetime milking days was highest in the 12,000 kg group (1,212.0 days), and generally smaller in the lower groups. Profit increased as the production level of groups increased for both parity 1 and 2. In groups with low production levels, profit of parity 1 was higher than that of parity 2, while the reverse was true in groups with high production levels. These results suggest that individuals in the low production groups had a greater likelihood to be culled due to reproductive or other problems. Furthermore, the accuracy of the prediction of lifetime profit of individuals with a milk yield of 305 days seems to be higher for parity 2 than parity 1; therefore, it is desirable to predict lifetime profit using the 305d milk yield of parity 2. In conclusion, breeding goals are based on many factors in functions for the estimation of profit; however, production levels during early lactation (parity 1 and 2) can be used as indicators of profit to extend profitability.