• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.49-55
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• 1994

This study was conducted to compare the of rearing native and cross-bred dairy cows and returns received from them. For this purpose, 144 cows of 132 household from 24 villages were randomly selected. of them, 96 were native cows and 48 were cross-bred cows. The study revealed that among the structure of cost components, labour charge occupied the major share in the total cost of milk production per litre. The total cost of rearing native and cross-bred cows was Tk. 14,155 and Tk. 19,854 per annum, respectively. The average net cost of milk production per litre was Tk. 14.12 for native cows and Tk. 0.52 and for cross-bred cows were Taka 3.40. The benefit-cost ratio of milk per litre was higher (1:1.33) in cross-bred cows than native ones (1:1.04). The study further showed that in comparing with bulk line cost, the price of milk per litre received by the farmers was higher in cross-bred cows than native cows. Therefore, the study recommends dairying with cross-bred cows as encouraging and viable commercial enterprise in Banfladesh.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.4
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• pp.410-415
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• 1998

The effects of the proprotion of cows inseminated by young A. I. bulls on genetic improvement in the Japanese Holstein population were examined using a simulation technique. The proportion of recorded cows inseminated by young A. I. bulls was assumed to be from 10% to 100% of the total number of recorded cows. The expected total genetic improvement was estimated for all cows and recorded and non recorded cows. The effects of the above were remarkable in the schemes that proven sires were used to produce recorded and non recorded cows for a limited time. Also the increase in the rates for -the expected total genetic improvement was larger when the proportion of recorded cows that were inseminated by young A. I. bulls was about 10% to 40%. When the expected total genetic improvement was estimated for the entire population, we found that the highest values were in a range of about 40 to 60% recorded cows that were inseminated by young A. I. bulls. On the other hand, the expected total genetic improvement that was only estimated in recorded cows dramatically decreased for more than 40% of the recorded cows. The results of this study showed that the optimal proportion of recorded cows inseminated with young A. I. bulls should be about 30% in the Japanese Holstein population.

• 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).

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1214-1218
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• 2004

Data on 958 Karan Fries (KF) and 780 Karan Swiss (KS) cows, born during 1974 to 1992 at National Dairy Research Institute, Karnal were evaluated for causes of culling and their impact on milk performance and herd strength. Causes of culling were classified as voluntary culling (low milk yield) and involuntary culling (other than milk yield). The milk yield of cows was evaluated inretrospectively by estimating expected breeding value (EBV) on the basis of first lactation yield (FLY) and all available lactation yield (ALY). The culling rate of KF cows over the years varied from 10.89 (1988) to 33.92% (1991) with an overall average of 20.96% and in KS from 19.91 (1984) to 33.74% (1989) with an overall average of 25.01%. Reproductive disorders, teat and udder problems, low milk production, health and locomotive disorders were the major reasons of culling accounted respectively for 5.56, 4.97, 4.61, 3.18 and 2.24% of herd strength in KF cows. The corresponding causes of culling were 6.20, 6.26, 7.69, 1.49 and 2.67% of herd strength in KS cows. The involuntary culling of cows accounted for 82.4% in K F and 76.1% in KS cows of total culling. The average annual disposal rate in KF and KS was 26 and 30% whereas annual replacement rate was 24 and 26% respectively. The EBV of involuntary culled cows on the basis of FLY and ALY was 3,111 and 3,515 kg in KF; and 2,669 and 2,940 kg in KS cows respectively. The EBV of selected cows on the basis of FLY and ALY was 3,242 and 3,549 kg in KF and 2,893 and 3,245 kg in KS cows respectively. The average breeding value of involuntary culled cows was not significantly different from selected cows in both the herds. The high rate of involuntary culling of potential cows might be major factor responsible for declined performance and size in these herds. The results indicated that higher genetic gain (2.14% of herd average in KF and 3.49% of herd average in KS) could be obtained by restricting the involuntary culling (50% of total culling) through improved management practices and increasing replacement rate.

• 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.

• Journal of Veterinary Clinics
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• v.34 no.3
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• pp.222-224
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• 2017

A retrospective study was designed to determine whether there were any differences in prepartal blood biochemical parameters between cows developed subclinical ketosis (SCK) and non-SCK cows. Data on blood biochemistry from 33 Holstein parturient cows (15 SCK and 18 non-SCK cows) in one farm for one year, were compared. Plasma beta-hydroxybutyrate, non-esterified fatty acid and glucose concentrations were utilized in the diagnosis of SCK and showed significant differences between SCK and non-SCK cows after calving. Before calving, however, only plasma total cholesterol concentration in SCK cows was significantly lower than that in non-SCK cows. Consequently, it seems that lower plasma total cholesterol concentration before calving is related to the occurrence of SCK immediately after calving.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.133-138
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• 1998

Plasma and milk samples of 24 periparturient Holstein cows were collected from 1 week prepartum to 10 week postpartum to measure the effects of parity on mineral status in periparturient cows. Cows were fed mainly mixed ration with the concentrate supplement during the experimental period to meet nutrient requirement of dairy cattle for TDN, protein, and minerals, Plasma Ca of cows decrease as parity increased, but plasma Mg, K, Fe and Zn were lowest in the first lactation cows. Plasma inorganic P, Na, and alkaline phosphatase were not affected by the parity. Plasma Ca, Fe and Zn of cows decreased at parturition, but plasma Mg increase. Plasma Ca of the first, second and third and more lactation cows at parturition were 9.65, 8.96, and 8.92 mg/dl, respectively. Colostral Ca, P, Mg, Na, and Zn were highest in the first lactation cows, although colostrum yield was lower. Milk yield from 1 to 10 weeks postpartum was lowest in the first lactation cows, but mineral concentrations in milk were not affected by the parity.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1721-1726
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• 2005

The characteristic smell of cow milk was suppressed when herbs were consumed by lactating dairy cows. But it is unclear whether or not peppermint ingestion affects the nutritional and milk production parameters in lactating dairy cows. The objective of this study was to examine the effect of peppermint feeding to lactating dairy cows on nutrient digestibility, energy metabolism, ruminal fermentation and milk production. Eight Holstein cows were given a diet supplemented with or without 5% of dried peppermint per diet on a dry matter basis. The digestion of nutrients from cows fed the diet with peppermint was significantly lower than that of the control group. Energy loss as methane and methane released from cows receiving the peppermint treatment was significantly lower than that in the control cows. Peppermint feeding to cows resulted in the promotion of thermogenesis. However, ruminal fermentation and milk production were not affected by peppermint feeding. In conclusion, peppermint ingestion by lactating dairy cows reduces the nutrient digestibility and methanogenesis, and changes energy metabolism.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.369-374
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• 1999

One hundred forty cows that have claw disorder have been used to study the association between lameness and reproductive disorders. Weak estrus owing to ovarian hypoplasia (41.4%) followed by follicular cyst (39.3%) was more frequent than any other disorders. Two hundred ninety-four cows have been used to study the association between lameness and calving to first service and calving to conception intervals depending on lactations, claw disease and floor conditions. And a comparison of number of services per conception between cows with lameness and cows free from lameness was carried out. The calving to first service intervals were significantly increased from average 78 to 102.5 days and calving to conception intervals were significantly increased from 109.6 to 150.6 days in cows with lameness. The calving to first service and calving to conception intervals were not significant different between lactations in cows with lameness. In comparison of calving to first service and calving to conception intervals in cows with lameness depending on claw disease and floor conditions, there was no significant difference. The average number of services per conception was increased from 1.73 to 2.57 in cows with lameness. Service numbers were more frequent during second lactation (3.0 services) but there was no significant difference between lactations in cows with lameness. Therefore, it is likely that the management of lameness is important factor on proper health control of cows and the cows with lameness show decreased fertility.

• 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.