• Asian-Australasian Journal of Animal Sciences
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• v.24 no.4
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• pp.479-484
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• 2011

The study was conducted on 20 Holstein X Sahiwal cross bred dairy cows, with an average milk production of $2,752{\pm}113.79$ liters in $284{\pm}5.75$ days during a single lactation, that were divided in to two groups of 10 animals. We investigated the oxidative stress and antioxidant status during the transition period in dairy cows. In this study, plasma level of MDA was considered as an indicator of lipid peroxidation and SOD, catalase, GSH and GSHPx as antioxidants. The lipid peroxidation was significantly (p<0.001) higher in cows during early lactation as compared to the cows in advanced pregnancy. A significant positive correlation (r = +0.831, p<0.01) was determined between MDA and catalase in early lactating cows. In early lactating cows, blood glutathione was significantly lower than in advanced pregnant cows. However, early lactating cows showed non-significant negative correlation for all antioxidant enzymes with lipid peroxidation. In conclusion, dairy cows seemed to have more oxidative stress and low antioxidant defense during early lactation or just after parturition than advanced pregnant cows, and this appears to be the reason for their increased susceptibility to production diseases (e.g. mastitis, metritis, retention of fetal membranes etc.) and other health problems.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1332-1339
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• 2019

Heat stress exerts a substantial effect on dairy production. The temperature and humidity index (THI) is widely used to assess heat stress in dairy operations. Herein, we review the effects of high temperature and humidity on body temperature, feed intake, milk production, follicle development, estrous behavior, and pregnancy in dairy cows. Analyses of the effects of THI on dairy production have shown that body temperature is an important physiological parameter in the evaluation of the health state of dairy cows. Although THI is an important environmental index and can help to infer the degree of heat stress, it does not reflect the physiological changes experienced by dairy cows undergoing heat stress. However, the simultaneous measurement of THI and physiological indexes (e.g., body temperature) would be very useful for improving dairy production. The successful development of automatic detection techniques makes it possible to combine THI with other physiological indexes (i.e., body temperature and activity), which could help us to comprehensively evaluate heat stress in dairy cows and provide important technical support to effectively prevent heat stress.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.369-375
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• 2003

The ultrasonography was performed in 77,924 subestrous dairy cows from 680 dairy farms at 57 districts. The cows were examined for confirmation of resumption of ovaries and uterus after 30 days postpartum, for early pregnancy diagnosis after 30 days post-insemination, confirmation of pregnancy at 8 month post-insemination, and for diagnosis of reproductive dysfunctions, respectively. The results of reproductive examination by ultrasonography in 77,924 dairy cows were ovarian disorders 35,452 (46.8%), uterine disorders 10,721 (13.8%), pregnancy and pregnant failure 24,044 (30.8%), adhesion of reproductive tracts 167 (0.2%), freematins 13 (0.01%) and others 6,527 (8.4%) cows, respectively. The 13,732 (49.6%) cows out of 27,694 cows were treated for silent heat or error of estrus detection, 3,473 (12.5%) cows for follicular cysts, 815 (3.0%) cows for luteal cysts, 606 (2.2%) cows for inactive ovaries, 4 (0.01%) cows for granulosa cell tumors, and 6,455 (23.3%) cows for endometritis, respectively. The indices of reproductive efficiencies before (2001-08-10) and after (2003-07-20) periodical examination of reproductive status were as follows; the mean intercalving interval were shortened from 471 days to 383 days, the mean interval calving to conception were shortened from 187 days to 99 days, the mean interval calving to first service were shortened from 105 days to 67 days, the mean cows showing heat by 60 days postpartum were increased from 33% to 89%, the mean conception rate to first service were increased from 43% to 68%, and the mean service per conception were shortened from 2.6 times to 1.8 times, respectively. These results suggest that periodical examination of reproductive status would be useful for the improvement of the reproductive performance in dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.345-349
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• 2005

A study was conducted to determine the effect of feeding chopped whole sugar cane compared to corn silage on performances of dairy cows during the dry season. Twenty four Holstein Friesian crossbred (>87.5% Holstein Friesian) lactating dairy cows in mid lactation; averaging 16.5${\pm}$2.0 kg of milk, 121${\pm}$22 days in milk, 54.5${\pm}$4.5 months old and 440${\pm}$31 kg live weight, were stratified for milk yield, days in milk, age, stage of lactation and body weight, and then randomly allocated to two treatment groups (12 cows in each group). The first group was fed corn silage together with commercial concentrate while the second group was fed chopped whole sugar cane together with commercial concentrate. All cows consumed similar DM, however, cows on corn silage consumed more CP while cows on chopped whole sugar cane consumed more $NE_{LP}$. No significant differences in performances between the two groups were observed except for final live weight and body weight change. Cows on chopped whole sugar cane showed higher final live weight and gained more weight than cows on corn silage. The present study clearly indicates that chopped whole sugar cane can be fed to lactating dairy cows, while giving similar milk yield to corn silage.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1244-1251
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• 2018

Objective: The objective of the present study was to elucidate the mechanism underlying liver metabolic perturbations in dairy cows exposed to heat stress (HS). Methods: Liquid chromatography massabl spectrometry was used to analyze metabolic differences in livers of 20 dairy cows, with and without exposure to HS. Results: The results revealed 33 potential metabolite candidate biomarkers for the detection of HS in dairy cows. Fifteen of these metabolites (glucose, lactate, pyruvate, acetoacetate, ${\beta}$-hydroxybutyrate, fumaric acid, citric acid, choline, glycine, proline, isoleucine, leucine, urea, creatinine, and orotic acid) were previously found to be potential biomarkers of HS in plasma or milk, discriminating dairy cows with and without HS. Conclusion: All the potential diagnostic biomarkers were involved in glycolysis, amino acid, ketone, tricarboxylic acid, or nucleotide metabolism, indicating that HS mainly affected energy and nucleotide metabolism in lactating dairy cows.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1433-1442
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• 2021

In this study, Saccharomyces cerevisiae culture fluid (SCCF) has been added to a diet of lactating dairy cows to attempt to improve the ruminal fermentation and potentially increase the dry matter intake (DMI) and milk yield. This study was conducted to investigate the effects of SCCF on the milk yield and blood biochemistry in lactating cows during the summer. Twenty-four Holstein dairy cows were randomly assigned to one of four treatments: (1) total mixed ration (TMR-1) (Control); (2) TMR-1 supplemented with SCCF (T1); (3) TMR-2 (containing alfalfa hay) (T2); and (4) TMR-2 supplemented with SCCF (T3). SCCF (5 ml/head, 2.0×10⁷ CFU/mL) was mixed with TMRs daily before feeding to dairy cows. The mean daily temperature-humidity index (THI) during this trial was 76.92 ± 0.51 on average and ranged from 73.04 to 81.19. For particle size distribution, TMR-2 had a lower >19 mm fraction and a higher 8-9 mm fraction than TMR-1 (p < 0.05). The type of TMR did not influence the DMI, body weight (BW), milk yield and composition, or blood metabolites. The milk yield and composition were not affected by the SCCF supplementation, but somatic cell counts were reduced by feeding SCCF (p < 0.05). Feeding SCCF significantly increased the DMI but did not affect the milk yield of dairy cows. The NEFA concentration was slightly decreased compared to that in the control and T2 groups without SCCF. Feeding a yeast culture of S. cerevisiae may improve the feed intake, milk quality and energy balance of dairy cows under heat stress.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.390-395
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• 2006

This work was conducted to study the effect of rumen-protected choline (RPC) addition on milk performance and blood metabolic parameters in transition dairy cows. In Experiment 1, fourteen Chinese Holstein dairy cows were supplemented with 0 or 20 g/d of RPC from 7 d before expected calving to 21 d post partum. Feeding of RPC tended to increase milk yield and milk protein percentage, while milk fat and lactose percentage were not changed. Plasma concentrations of glucose tended to increase as cows consumed RPC, while plasma concentrations of triglycerides, very low density lipoproteins, cholesterol and nonesterified fatty acids were not significantly different between the two groups. In Experiment 2, thirty-six Chinese Holstein dairy cows were supplemented with 0, 30, 60 or 90 g/d RPC from 15 d before expected calving to 15 d post partum. Feeding of RPC tended to increase yield of milk and 4% fat-corrected milk for all the lactating cows, and milk composition was similar among the four groups. Plasma concentrations of glucose were remained at a higher level in 30 or 60 g/d RPC-supplemented groups, and nonesterified fatty acids were decreased in the 30 g/d group. Concentrations of triglycerides tended to reduce in 30 and 90 g/d RPC-supplemented animals, and cholesterol was reduced in 0 or 30 g/d group. These results suggest that RPC addition tended to increase milk yield and improve blood metabolic parameters during transition dairy cows, and feeding 30 g/d of RPC may be the optimal.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1125-1129
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• 2005

A study was conducted to determine the effect of feeding sugar cane silage compared to chopped whole sugar cane or grass silage on performances of lactating dairy cows during the dry season. Twenty four Holstein Friesian crossbred (>87.5% Holstein Friesian) lactating dairy cows in mid lactation; averaging 15.4${\pm}$3.2 kg of milk, 120${\pm}$23 days in milk, 50.5${\pm}$6.5 months old and 432${\pm}$39 kg live weight, were stratified for milk yield, days in milk, age, stage of lactation and body weight, and then randomly allocated to three treatment groups (8 cows in each group). All cows were fed 7.5 kg/d commercial concentrate plus ad libitum roughage according to treatment groups, which were grass silage, sugar cane silage or chopped whole sugar cane respectively. All cows consumed similar DM and produced similar milk and milk composition yields. However, cows on grass silage lost more weight than the other cows. The present study indicated that, during the dry season, sugar cane silage can be fed to lactating dairy cows, while giving similar milk yield to grass silage or chopped whole sugar cane.

• Korean Journal of Veterinary Research
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• v.59 no.1
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• pp.1-8
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• 2019

We aimed to identify predictive markers of peri- and postpartum disorders in dairy cows. Data regarding peri- and postpartum disorders, serum metabolites, body condition score (BCS), and rectal temperature, were collected from 227 dairy cows, which were allocated to healthy (n = 57) and diseased (n = 170) groups. Serum non-esterified fatty acid (NEFA) concentration was higher in diseased than healthy cows 4 weeks before (p < 0.01) and immediately after (p = 0.05) calving. Serum alanine aminotransferase (AST) activity was higher (p < 0.05) in diseased than healthy cows 1 and 2 weeks after calving, whereas total cholesterol (TCH) concentration was lower (p < 0.05-0.0001) in diseased cows 4 weeks before, and after calving. BCS was higher (p < 0.05) in diseased than healthy cows 4 weeks before calving, but lower (p < 0.01) in diseased cows 8 weeks after calving. Rectal temperature was higher (p < 0.05-0.01) in diseased than healthy cows between 2 and 14 days postpartum. In conclusion, high serum NEFA and AST concentrations and lower TCH concentration during the peripartum period, and high prepartum BCS and postpartum rectal temperature, could be used as biomarkers to predict the subsequent development of peri- and postpartum disorders.

• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.1021-1027
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• 1999

This study was carried out to determine the effects of ${\beta}-carotene$ on the control of mastitis in dairy cows during the dry period. The relationship between the levels of plasma ${\beta}-carotene$ and the status of udder health in Holstein dairy cows were investigated. Blood samples were collected from 117 cows to compare the levels of plasma ${\beta}-carotene$ in lactating cows. The levels of plasma ${\beta}-carotene$ were $1.82{\mu}g/ml$ in healthy cows(n = 65) and $1.12{\mu}g/ml$ in mastitic cows(n = 52), respectively(p < 0.01). In the experiment to compare the level of plasma ${\beta}-carotene$ in the cows at different stages of lactation, the plasma ${\beta}-carotene$ levels were $1.73{\mu}g/ml$ in lactating cows(n = 22), $1.29{\mu}g/ml$ in nonlactating cows(n = 35) and $0.43{\mu}g/ml$ in cows after calving(n = 16)(p < 0.05).