• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.131-136
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• 1994

In an effort to confirm true oestrus and to detect early pregnancy in Zebu cows (Bos indicus), sequential blood and milk samples were collected at the day of imsemination (Day 0) and days 14, 20 and 24 after insemination. Progesterone was determined in skimmed milk and plasma by solid phase radioimmunoassay (RIA). Of the cows thought to be in oestrus plasma, (n = 46) and milk (n = 58) samples demonstrated low progesterone concentrations ($0.99{\pm}0.11$ and $2.02{\pm}0.14nmol/l$) in 42 (91%) and 52 (90%) cases respectively. Thirty two (76%) and 30 (71%) cows were thought to be pregnant by plasma progesterone RIA ($20.23{\pm}1.03$ and $20.48{\pm}1.01nmol/l$) at days 20 and 24 respectively. At the same period, 40 (77%) and 37 (71%) cows were thought to be pregnant by milk progesterone RIA ($27.82{\pm}1.28$and $28.02{\pm}1.27nmol/l$). Assuming 100% accuracy for rectal examination of pregnancy diagnosis between days 60-65 postservice, the RIA was found to be 84% and 90% accurate for plasma and 84% and 92% accurate for milk at day 20 and 24, respectively. All cows thought to be non pregnant by progesterone measurement were correctly diagnosed. Progesterone assay at 24 days after oestrus may therefore be accurate for early diagnosis of pregnancy in Zebu cows.

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.406-414
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• 1995

Nitrogen(N) concentration of preterm(PT) and term (T) milk in various fractions, such as total, protein, nonprotein, whey protein and casein were determined at 2-5 days, 1, 2, 4 and 6 weeks of postpartum. The purpose of this study was to investigate the nitrogen concentration of human milk from mothers delivering at preterm and term, and the propriety of preterm milk for premature infants. The concentration of total N, nonprotein N, protein N, whey protein N and casein N in preterm milk was decreased significantly with time postpartum. Total N was 374mg/이 at colostrum, 232mg/dl at mature milk. Whey protein N was decreased from 42mg/dl at 2-5 days to 32mg/dl at 4-6 weeks. Protein N was 332mg/dl at colostrum, 202mg/dl at mature milk. The proportion of whey protein N and casein N were 39:61 at colostrum, 28:72 at mature milk. No difference were found between T and PT milk for total nitrogen excepted 2 weeks. In this report we show that nitrogen concentration except casetpt casein N is smaller in milk from mothers giving birth prematurely than in milk from mothers giving birth at term, over the first two weeks of lactationl But protein N was higher in preterm milk than term milk, whey protein nitrogen was lower. By comparing predicted nitrogen intakes to estimated requirements of preterm infants fed 150 to 200ml/kg/day of their own mother's milk, we predict that the quantities of protein provided would be adequate to meet the requirements of the prematured infants during the early weeks of life.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.247-252
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• 1990

Nine Holstein cows in mid lactation period were utilized to examine the effect of recombinant bovine somatotropin (BST) of tow companies (Company A, Company B) on milk production and milk composition under the feeding conditions of Korea. Treatments were 0 (Control), 25 mg BST/day from company A (BST A) and 25 mg BST/day from company B (BST B) injected subcutaneously, once daily beginning at $200{\pm}20$ days postpartum and continuing for 28 days. Cows were fed ad libitum a total mixed diet throughout the experimental period. BST treatments increased average 4% fat corrected milk yields and milk energy output over the 28-day treatment period. However, no differences were observed in dry matter intake, gross efficiency, energy intake and percent milk energy. Although there was a tendency for increased milk fat percent, there were no differences in milk composition and yields of major milk components except for milk fat yield with BST injection. Somatic cells of all groups were also characteristic of a well managed herd. Neither mean body condition score nor body weight was significantly (p <0.05) changed before and during BST treatment. BST concentration in milk remained in the range of control animals throughout the experimental period of BST treatment. Results indicate that short-term injection of recombinant bovine somatotropin from two companies to lactating dairy cow resulted in similar increased in milk yield without alteration of major milk components or feed intake.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.607-617
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• 1993

Three experiments were carried out in which lactating Hereford ${\times}$ Friesian cattle walked up to ten kilometers a day for three periods of five days with two non-walking days between each walking period and in which the animals were fed different diets. Measurements were made of milk yield, milk constituent yields and concentrations and blood metabolite concentrations. Exercise caused significant reductions in milk yield and in the yields of lactose and milk protein. Milk fat yield was not reduced when animals were exercised. During exercise the concentrations of ${\beta}-OH$ butyrate and free fatty acids increased, whereas the concentrations of glucose, magnesium and inorganic phosphorus decreased. Diet influenced the effect of exercise on some blood metabolite concentrations.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1316-1322
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• 2000

Data were compiled and statistically analyzed on the lactation of 50% and 75% Thai native-Friesian crossbred and purebred Friesian cows that were fed at a national institute in Chiang Mai, Thailand. More than 30% higher milk production was obtained in the 75% crossbred compared with that in the 50%, but this amount of milk production in the upgraded breed was still about half that of purebred Friesians; 2,138 kg, least squares means during an average lactation period of 279 days in the 50% crossbred, 2,847 kg during 277 days in the 75% crossbred and 5,585 kg during 308 days in the purebred. Environmental stress due to tropical climate was alleviated by the use of electric fans and water sprinklers in the feeding house during the hot season, and improved diet seemed to enable purebred Friesians to keep their ability to produce a milk quantity of more than 6,500 kg per year. This special care was not given to crossbreds and significantly negative correlations were found between daily minimum temperature and humidity during the initial 100 days of lactation and total milk production and average daily milk yield in the 75% crossbreds. However, these correlations were not found in the 50% crossbreds.

• Journal of Dairy Science and Biotechnology
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• v.40 no.4
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• pp.163-172
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• 2022

Although the USA, Canada, and several EU countries allow raw milk cheese to be aged more than 60 days, these countries have strict standards for its aging conditions, such as temperature. Many developed countries have employed standards of identity which effectively prevent the manufacture and sale, of cheese made from unpasteurized milk (i.e., raw milk) in interstate commerce, unless such cheese has been aged for a minimum of 60 days. The microbiological safety of raw milk Camembert cheese, aged for more than 60 days, was evaluated using spiking experiments. We spiked Listeria monocytogenes into raw milk with different inoculation levels (high, medium and low). Camembert cheese was prepared from the inoculated raw milk, then aged in an incubator for up to 9 weeks (63 days). The number of cells was determined every week using the agar-plating method. Inoculated cells were completely eliminated, especially in Camembert cheese, after 60 days, and the reduction rate of cells was much faster in Camembert cheese. There were no significant differences in pH and water activity (aW) between the uninoculated cheese and the cheese samples in which Listeria monocytogenes was inoculated (p<0.05). The pH and aW of the Camembert cheese decreased throughout the storage period. In conclusion, the pathogenic bacteria used in this study did not affect the pH and aW of the Camembert cheese samples.

• Journal of Nutrition and Health
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• v.24 no.2
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• pp.77-86
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• 1991

Changes in total lipid content. total cholesterol content and fatty acid composition of human milk were investigated longitudinaly from 2-5 days to 12 weeks postpartum Milk samples were collected from 19 Korean lactating women at 2-5 days and at 1. 2. 4. 6. and 12 weeks postpartum. The obtained results were as follows : On average the daily energy intake protein intake and fat intake of Korean lactating women was 1812 kcal 72.5g and 29.8g respectively. The composition ratio of energy consis-ting of protein fat and carbohydrate was 16:15:69 The total lipid content increased from 1.39g/이 at 2-5 days to 2.86g/dl at 12 weeks ; while the total cholesterol concentration (mg/g) decreased significantly with time following postpartum. The total unsaturated fatty acids content was higher in colostrum than in mature milk. and the total saturated fatty acids were higher in mature milk. The average DHA content was 0.55% and the P/S ratio of human milk lipids was 0.37.

• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.61-64
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• 1995

The present study was conducted to examine the effect of recombinant bovine somatotrpin(${\gamma}$BST), which was administered to cow to promote milk production, on bST levels in milk. Fourteen cows were divided cows were divided into two groups: 1) control cows received neither ${\gamma}$bST nor vehicle, 2) treated cows were administered twice at two-week interval with 500 mg ${\gamma}$bST each cow byj after lst injection. Milk samples were taken on day 0 (prior to injection), day 7 (7 days after lst injection), day 21 (7 days after 2nd injection) and day 35 (21 days after 2nd injection). Milk bST concentration was measured by the radioimmunoassay method. There was no statistical difference(p<0.05) in milk bST levels between two groups showing bST levels in the range of 1.8 ng/m/ to 3.1 ng/m/. That is, ${\gamma}$bST administration did not increase bST levels in milk.

• Animal Bioscience
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• v.35 no.10
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• pp.1499-1511
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• 2022

Objective: This study was aimed to estimate the genetic parameters, including genetic and phenotypic correlations, of milk yield, lactation curve traits and milk composition of Thai dairy cattle from three government research farms. Methods: The data of 25,789 test-day milk yield and milk composition records of 1,468 cattle from lactation 1 to 3 of Holstein Friesian (HF) and crossbred HF dairy cattle calved between 1990 and 2015 from three government research farms in Thailand were analysed. 305-day milk yield was estimated by the Wood model and a test interval method. The Wood model was used for estimating cumulative 305-day milk yield, peak milk yield, days to peak milk yield and persistency. Genetic parameters were estimated using linear mixed models with herd, breed group, year and season of calving as fixed effects, and animals linked to a pedigree as random effects, together with a residual error. Univariate models were used to estimate variance components, heritability, estimated breeding values (EBVs) and repeatability of each trait, while pairwise bivariate models were used to estimate covariance components and correlations between traits in the same lactation and in the same trait across lactations. Results: The heritability of 305-day milk yield, peak milk yield and protein percentage have moderate to high estimates ranging from 0.19 to 0.45 while days to peak milk yield, persistency and fat percentage have low heritability ranging from 0.08 to 0.14 in lactation 1 cows. Further, heritability of most traits considered was higher in lactation 1 compared with lactations 2 and 3. For cows in lactation 1, high genetic correlations were found between 305-day milk yield and peak milk yield (0.86±0.07) and days to peak milk yield and persistency (0.99±0.02) while estimates of genetic correlations between the remaining traits were imprecise due to the high standard errors. The genetic correlations within the traits across lactation were high. There was no consistent trend of EBVs for most traits in the first lactation over the study period. Conclusion: Both the Wood model and test interval method can be used for milk yield estimates in these herds. However, the Wood model has advantages over the test interval method as it can be fitted using fewer test-day records and the estimated model parameters can be used to derive estimates of other lactation curve parameters. Milk yield, peak milk yield and protein percentage can be improved by a selection and mating program while days to peak milk yield, persistency and fat percentage can be improved by including into a selection index.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1111-1118
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• 2013

The objective of this study was to determine the effects of whole linseed supplementation on performances and milk fatty acid composition of dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The control group received 300 g of palm oil. The second group was supplemented with 344 g/d of top-dressed whole linseed plus 150 g of palm oil and the third group was supplemented with 688 g/d of top-dressed whole linseed. All cows also received ad libitum grass silage (Brachiaria ruziziensis), had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. Residual feeds were collected on 2 consecutive days weekly and at the end of the experiment. Feed samples were pooled to make representative samples for proximate and detergent analyses. Daily milk yields were recorded. Milk samples were collected on 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk samples were taken on d 56 of the experiment and subjected to milk fatty acid composition. The results showed no statistical significant differences in intakes, live weight change, milk yields and milk compositions, however, C18:1, C18:3 and unsaturated FAs were increased while saturated FAs were reduced by whole linseed supplementation. It is recommended that the addition of 300 g/d oil from whole linseed could be beneficial to lactating dairy cows in early lactation.