• Asian-Australasian Journal of Animal Sciences
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• 제25권9호
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• pp.1216-1222
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• 2012

Somatic cells count (SCC), milk yield (MY) and pedigree information of 2,791 first lactation cows that calved between 1990 and 2010 on 259 Thai farms were used to estimate genetic parameters and trends for SCC and its genetic association with MY. The SCC were log-transformed (lnSCC) to make them normally distributed. An average information-restricted maximum likelihood procedure was used to estimate variance components. A bivariate animal model that considered herd-yr-season, calving age, and regression additive genetic group as fixed effects, and animal and residual as random effects was used for genetic evaluation. Heritability estimates were 0.12 (SE = 0.19) for lnSCC, and 0.31 (SE = 0.06) for MY. The genetic correlation estimate between lnSCC and MY was 0.26 (SE = 0.59). Mean yearly estimated breeding values during the last 20 years increased for SCC (49.02 cells/ml/yr, SE = 26.81 cells/ml/yr; p = 0.08), but not for MY (0.37 kg/yr, SE = 0.87 kg/yr; p = 0.68). Sire average breeding values for SCC and MY were higher than those of cows and dams (p<0.01). Heritability estimates for lnSCC and MY and their low but positive genetic correlation suggested that selection for low SCC may be feasible in this population as it is in other populations of dairy cows. Thus, selection for high MY and low SCC should be encouraged in Thai dairy improvement programs to increase profitability by improving both cow health and milk yield.

• Journal of Animal Science and Technology
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• 제57권12호
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• pp.46.1-46.19
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• 2015

Background: This study examined whether activation of innate immunity and alterations of carbohydrate and lipid metabolism precede development of subclinical mastitis (SCM). Methods: Blood samples were collected from the coccygeal vein from 100 Holstein dairy cows at -8, -4, disease diagnosis week, and +4 weeks postpartum. Six healthy cows (controls - CON) and six cows that showed clinical signs of SCM were selected for serum analyses. All serum samples were analyzed for acute phase proteins (APP) haptoglobin (Hp) and serum amyloid A (SAA); proinflammatory cytokines including interleukin 1 (IL-1), IL-6, and tumor necrosis factor (TNF) and serum lactate, BHBA, and NEFA concentration. Data of DMI, milk production, and milk composition were recorded and analyzed. Results: The results showed that cows with SCM had greater concentrations of SAA, TNF (P < 0.01), and lactate before expected day of parturition (P < 0.05) compared to CON cows. Cows with SCM showed greater concentrations of lactate starting at -8 weeks (P < 0.05) and TNF starting at -4 weeks prior to the expected day of parturition (P < 0.01). Interestingly, at -4 weeks, concentrations of IL-1 and Hp were lower in cows with SCM compared to healthy cows (P < 0.01) followed by an increase during the week of disease diagnosis (P < 0.05). Subclinical mastitis was associated with lower DMI, at -4 weeks before calving, milk production (P < 0.05) and increased somatic cell counts (SCC) (P < 0.01). Conclusions: Results of this study suggest that SCM is preceded by activated innate immunity and altered carbohydrate metabolism in transition dairy cows. Moreover the results support the idea that Hp, lactate, and SAA, at -8 weeks, and TNF and IL-1 at -4 weeks can be used as early indicators to screen cows during dry off for disease state.

• 한국수정란이식학회지
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• 제25권1호
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• pp.21-27
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• 2010

The increase in the total number of cows on farms, which breed Korean Native Cattle (KNC), is associated with many problems. In particular, the services per conception and calving interval have increased. In this study, we examined the effect of dietary supplementation with vitamin and mineral complex on the estrus rate, pregnancy rate, gestation length, and birth weight of KNC calves. Multiparous or primiparous KNC were divided into 3 groups with 40 heads per group. Experimental group 1 was administered a consisting of 35,000 IU vitamin A, 100 IU vitamin E, 200 mg $\beta$-carotene, 200 mg Zn methionine, and 1.5 mg Se. Experimental group 2 was administered a vitamin complex (100 g/day) consisting of 100 IU vitamin E and 200 mg $\beta$-carotene. In the case of multiparous KNC, the estrus detection rate in the control group was 90.0% and those in the experimental groups were 75.0% to 95.0%. However, the first-service pregnancy rate after parturition in the control group was 41.2%, which was significantly lower than that in the experimental groups (71.0% to 76.7%; p<0.05). The average duration of pregnancy in the group supplemented with the vitamin complex was days, which was similar to that in the case of the control group. The birth weight of calves from cows fed with vitamin complex was 25.3 to 27.0 kg, which was similar to that in the case of the control group (25.2 to 26.0 kg). In the case of primiparous KNC, no differences in the estrus rate, pregnancy rate, gestation length, or the birth weight of calves were noted between the groups. Thus, dietary supplementation vitamin and mineral complex have no effect on the reproductive efficiency in primiparous cows, but the pregnancy rate was observed to have increased in multiparous KNC with these supplements.

• 한국수정란이식학회지
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• 제15권3호
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• pp.255-261
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• 2000

The objective of this study was to improve the efficiency of bovine embryo transfer by transferring of Hanwoo embryos into Hanwoo or Holstein recipients. The cryopreserved or fresh in vitro produced(IVP) embryos were transferred into uterine horn contralaterally or ipsilaterally to the corpus luteum. The recipients were inseminated by artificially on the next day of estrus. The pregnancy was diagnosed by rectal palpation at 60∼90 days after transfer of the embryos. The pregnancy rate by transfer of one or two embryos was 78%(7/9) and 74%(31/42), respectively. The pregnancy rates according to the grade of corpus lutea of recipients was 75% (20/27) and 82.0%(18/22) at the grade of A and B, respectively. Ten(67.0%) of 15 Holstein recipients transferred with IVP Hanwoo embryos and 5(42.0%) of 12 Holstein recipients transferred with frozen IVP Hanwoo embryos were pregnant. The single and twin calving ratio in Hanwoos was 77.0%(10/13) and 23.0%(3.13) in the recipients transferred with IVP embryos and 64.0%(7/10) and 27.0%(3/10) in the recipients transferred with frozen IVP embryos, respectively. Twenty-four pregnant cows following transfer of IVP embryos, 21(88.0%) calved the normal calves, and 2(8.3%) aborted. When the frozen IVP embryos were transferred, 16 pregnant cows calved 14(88.0%) normal calves and 2(13.0%) aborted. In conclusion, when one or two IVP bovine embryos were transferred into recipients, the A and B grade of corpus luteum resulted in high pregnancy rates. For the production of twin calves, transfer of the IVP or frozen IVP embryos could be suitable.

• 한국수정란이식학회지
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• 제29권2호
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• pp.189-194
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• 2014

The reproductive disorders are the major causes of reproductive infertility in cows that affect the total annual calf crop, resulting in great economic loss in Bangladesh. The aim of the study was to find out the reproductive disorders (RD) in dairy cows that markedly influences the reproductive performances in aspect of Bangladesh. A total number of 1658 dairy cows were selected according to their body condition score (BCS) in different farms at the southern part of Bangladesh during the period of 2011 to 2012. The preliminary data (basic information) were collected directly from the dairy farmer's record books and asking questions according to a prescribed questionnaires as well as the diagnosis of RD was presumptively confirmed on the basis of history, clinical signs and examination of animals by ultrasonography and others necessary tools. There are thirteen major reproductive disorders were identified. Overall prevalence of reproductive disorders at that area were 23%, among of these anoestrus 5.1%, repeat breeder 3.7%, metritis 4.4%, poor heat detection 1.6%, ovarian cyst 0.36%, retain placenta 4.6%, dystocia 0.97% and pyometra 0.24%. It is indicated that anoestrus and retention of placenta after calving was most hazardous cause of infertility whereas the metritis and repeat breeder were the second line of consequence. RD had shown significantly higher incidence in low BCS (${\leq}2$) than that of fair (2.5) and very good (${\geq}3{\sim}3.5$). In conclusion, the highest RD especially anoestrus and retention of placenta is very alarming for reproductive loss which might be needed further research to identify the specific cause of these disorders for establishment a profitable dairying and dairy population.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.784-793
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• 2004

Major objective was to evaluate three doses of bST (POSILAC(R)) injected into Holstein cows during the transition period and through 56 d of lactation for potential to improve DMI, BCS, BW, metabolites, hormones, IGF-I and milk production. Biweekly injections of bST (0, 5.1, 10.2, or 15.3 mg bST/d) began 28 d before expected parturition and continued through 56 d postpartum. Twenty-three of the 25 multiparous Holstein cows assigned randomly to four groups completed experiment (7, 5, 6 and 5 cows/group, respectively). The DMI, BW and BCS were recorded weekly throughout the prepartum and postpartum periods and blood samples were collected thrice weekly for analyses of ST, insulin, $T_{4}$, $T_{3}$, IGF-I, glucose and NEFA. Milk yields were recorded daily through 60 d postpartum and milk components measured once weekly. Mathematical model for data analyses for prepartum and postpartum periods included treatment, calving month, and the two-factor interaction. Cows injected with 10.2 and 15.3 mg bST prepartum had greater mean prepartum concentrations of ST and IGF-I. Prepartum injections of bST did not affect prepartum BW or BCS. On average, cows injected postpartum better maintained their BCS during first 60 d of lactation (3.15$\pm$0.06, 3.12$\pm$0.007, 3.20$\pm$0.006 and 3.58$\pm$0.009). Treatments did not affect mean prepartum DMI but cows injected with 15.3 mg bST/d had greatest DMI and greatest mean daily MY during the first 3 wk and tended to be greater during first 60 d of lactation. Cows injected with two highest bST doses (10.1 and 15.2 mg/d) had greater mean postpartum concentrations of ST and $T_{3}$, but IGF-I, $T_{4}$, glucose and NEFA did not differ across groups. No adverse effects of bST treatment were observed.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.639-643
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• 2003

The data on 283 Sahiwal cows, sired by 16 bulls, maintained at Cattle Breeding Farm of Nagpur Veterinary College and Dairy Farm of Agricultural College, Nagpur, were considered for the estimation of genetic parameters. Variance and covariance estimates of first lactation traits were obtained using restricted maximum likelihood technique (REML). When first lactation milk yield (FLMY), first lactation length (FLL) and average daily yield (ADY) traits were considered for REML analysis, the heritabilities were $0.184{\pm}0.146$, $0.132{\pm}0.131$ and $0.141{\pm}0.133$, respectively. While, genetic and phenotypic correlations between them were medium to high except phenotypic correlations between FLL and ADY (-0.025). REML procedure considering FLMY, age at first calving (AFC) and first service period (FSP) combination exhibits heritabilities as $0.274{\pm}0.173$, $0.506{\pm}0.233$ and $0.274{\pm}0.172$, respectively. Genetic correlations were $-0.120{\pm}0.376$, $0.225{\pm}0.423$ and $0.365{\pm}0.331$ between FLMY and AFC, FLMY and FSP, AFC and FSP, respectively. Phenotypic correlations were 0.057, 0.289 and 0.123, respectively. Considering all five traits REML combination heritabilities estimated were $0.238{\pm}0.162$, $0.160{\pm}0.139$, $0.136{\pm}0.132$, $0.409{\pm}0.209$ and $0.259{\pm}0.168$ for FLMY, FLL, ADY, AFC and FSP, respectively. The genetic correlations were positive except FLMY and AFC. The phenotypic correlations were also positive except FLL and ADY, ADY and FSP. Almost all estimates were associated with high standard error.

• Asian-Australasian Journal of Animal Sciences
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• 제19권5호
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• pp.627-631
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• 2006

The objective of this study was to evaluate the association of genetic differences in the bovine leptin gene and milk yield, reproduction, body condition score (BCS), and plasma glucose level in Iranian Holstein cows. In total, two hundred and thirty eight cows were used and genotyped for a restricted fragment length polymorphism at the leptin gene locus. Two genotypes, AA and AB, have been distinguished which have the frequencies of 0.89 and 0.11, respectively. The genotypes were distributed according to the Hardy - Weinberg equilibrium ($x^2$ = 0.733). During the first 12 wk of lactation, milk yield and composition, live weight, BCS and plasma glucose were measured in 50 cows. Data were analyzed based on a repeated measures ANOVA. During this period, milk yield and composition, live weight, BCS and plasma glucose level were similar among the genotypes. The first cumulative 60-d milk yield, 305-d milk yield, days to first breeding, days open and days from first breeding to conception using previous lactation records were also analyzed using Standard Least Square within mixed models. Fixed effects were year, season, parity and age at calving, and sire. For the reproductive traits the cumulative first 60-d milk yield was also added to the model. Animal was fitted as a random effect. A significant association was detected between the RFLP-AB genotype and 305-d milk yield (p<0.05). The first 60-d cumulative milk yield was similar for the two genotypes (p = 0.21) and tended to be higher in the heterozygous cows. The heterozygous genotypes at the above mentioned locus had a trend to better reproductive performance than the homozygous. The results demonstrate that the RFLP B-allele can yield a higher 305-d milk production with a trend to better reproductive performance.

• Asian-Australasian Journal of Animal Sciences
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• 제12권3호
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• pp.336-340
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• 1999

Age at maturity was studied in 661 Nili Ravi buffaloes maintained at six dairy farms in Pakistan. The mean age at maturity in the overall data from the six farms was $976.49{\pm}9.2$ days. Significantly lower mean age at maturity $(957.93{\pm}10.68\;days)$ was observed at Military Dairy Farm, Khyber Okara, Military Daiiy Farm, Punjnad and Livestock Research Station, National Agricultural Research Centre, Islamabad (Group I) compared to $(1015.26{\pm}17.39\;days)$ other three Military Dairy Farms, Peshawar, Nowshera and Rawalpindi (Group II). The advantages associated to early age at maturity were as following. Male and female calves were heavier $(38.35{\pm}0.17\;and\;31.84{\pm}15kg,\;respectively)$ in Group I as compared to $(29.27{\pm}0.26\;and\;26.27{\pm}0.26kg)$ in Group II. Milk yield per lactation was significantly higher in Group I $(1912{\pm}12\;lit.)$ as compared to $(1833.36{\pm}16.56\;lit.)$ in Group II. Lactation length was significantly longer $(284.41{\pm}1.23\;days)$ in Group I as compared to $(277.77{\pm}2.02\;days)$ in Group II. Dry period and service period were significantly shorter $(241.59{\pm}4.18\;and\;217.05{\pm}4.95\;days,\;respectively)$ in Group I as compared to $(306.39{\pm}78\;and\;280.95{\pm}9.32\;days)$ in Group II. The mean age at first calving and sex ratio were low ($1282.75{\pm}10.14$ days and 100 ♀ ♀:130.7 ♂ ♂) in Group I as compared to ($1308.7{\pm}16.44$ days and 100 ♀ ♀:152.15 ♂ ♂) in Group II but the differences were non significant.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.983-988
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• 2007

The aim of this study was to examine the correlation between bovine casein (CN) mRNA expression levels in mammary epithelial cells and lactation period, the yields of milk proteins and other parameters. The cells were collected from each cow's milk, which contained somatic cell counts (SCC) of less than 100,000 cells/ml. The levels of ${\alpha}s1-$, ${\alpha}s2-$, ${\beta}$- and ${\kappa}$-CN mRNA expression were significantly correlated with each other in mammary epithelial cells (p<0.01). All cows produced either less than 30 kg/day/cow or a over 30 kg/day/cow level of milk yield (MY). It was shown that the CN mRNA expression levels decreased gradually from the calving period to late lactation, when MY was over 30 kg/day/cow. The SCC tended to increase gradually during the course of lactation, but it was negatively correlated with milk protein and CN yields (p<0.01) when MY was less than 30 kg/day/cow. Moreover, there was a tendency for a negative correlation between SCC and ${\alpha}s1$-CN and ${\beta}$-CN mRNA expression level, when MY was less than 30 kg/day/cow (p<0.05).