• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.590-596
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• 1999

The effect of evaporative cooling in alleviating seasonal variations of dairy cows raised in AlMarai Dairy Farms in the Kingdom of Saudi Arabia were studied using milking record collected during the period of 1991 to 1996. The data included 13303 and 8137 records represented winter and summer calving seasons. Evaporative cooling system improved production for cows calved in summer. The least square means of milk yield were 9631 and 9556 liter for cows calved in winter and summer seasons but no significant differences (p<0.05) were observed between the yield of two seasons. No significant effect of season on calving under evaporative cooling on most of the biweekly points of the lactation curve. The farm, parity and milk level showed a significant effect on the shape of the curve. Functions of the lactation curve like initial yield, 305 MY, peak yield, time of peak and duration were estimated for each phase of the lactation curve.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1093-1101
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• 2003

Reproductive data, such as numbers of days to the first estrus and A.I. service postpartum, number of days to conception, number of A.I. services required for conception, interval between the first estrus and first A.I. service and the average interval of A.I. service in Thai native-Friesian crossbred and pure Friesian dairy cows, were compiled in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand. The data were analyzed statistically and the effect of milk production on these reproductive traits was investigated. The reproductive efficiency of purebred cows was obviously inferior when compared with crossbred animals, in spite of special care being given to the purebred only in order to alleviate the effect of a tropical climate and provide better feeding. However, the regression analysis between reproductive and lactational parameters revealed a definite antagonistic effect of lactation on reproduction, especially in the purebred cows, which had a larger amount of milk production and longer lactation period. If these effects of lactation were eliminated, there would be no evident difference in reproductive efficiency between purebred and crossbred cows in the conditions of this study. Among the reproductive parameters examined, the number of days to the first estrus and interval between the first estrus and first A.I. service were less affected by breed difference and the magnitude of lactation than other reasons.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.575-579
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• 2000

First lactation records of 683 Murrah buffaloes maintained at NDRI, Karnal which were progeny of 84 sires used for comparing the heritability estimates of age at first calving, first lactation milk yield and first service period under single and multiple trait models using restricted maximum likelihood (REML) method of estimation under an individual animal model. The results indicated that the heritability estimates may vary under single and multiple trait models depending upon the magnitude of genetic and environmental correlation among the traits being considered. Therefore, a single or multiple trait model is recommended for estimation of variance components depending upon the goal of breeding programme. However, there may not be any advantage of considering a trait with zero or near zero heritability and having no or very low genetic correlation with other traits in the model. Lower heritability estimates of part lactation yield (120-day milk yield) implied that there may not be any advantage of considering this trait in place of actual 305-day milk yield, whereas, comparable heritability estimates of predicted 305-day milk yield suggested that it could be used for sire evaluation to reduce the cost of milk recording under field conditions.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.331-334
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• 2003

The assessment of reproductive potentials of female gayal under semi-intensive management was conducted with 18 animals in Bandarban hilly area of Bangladesh. Age at first estrous (days), age at first conception (days), length of estrous cycle (days), number of service per conception (natural), gestation period (days), age at first calving (days), and calving interval (natural service) (days) of gayal were $598.2{\pm}168.44$, $723{\pm}169.94$, $21.86{\pm}2.93$, 1.41, $296.05{\pm}3.87$, $1014.42{\pm}260.32$ and $465{\pm}80.48$ respectively. Daily milk yield and lactation length of gayal were $304.98{\pm}30.46ml/day$ and $116.67{\pm}8.08days$. Gayal male calves had higher birth weight (19.67 kg) than female calves (15.58 kg) in first lactation. Birth weight increases in second and third lactation than first lactation in both male and female calves. Highest conception rate observed in winter season and 70.60% successful conception occur when service was given within 21-30 h of estrous. Maximum number of female gayal use to come in estrous in winter and calved in monsoon and autumn. Cervicitis and irregular heat were the most reproductive problems followed by metritis, case of abortion, anestrous and repeat breeding. From this study it was observed that the reproductive performance of gayal is very close with the domestic cattle. It may use as beef cattle for the hilly regions of Bangladesh.

• Journal of Nutrition and Health
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• v.31 no.9
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• pp.1433-1439
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• 1998

This study was performed to investigate the vitamin A intake of exclusively breast-fed infants and to compare the value with the Recommended Dietary Allollwances(BDA) for Korean infants. We examined retinol and ${\beta}$-carotene contents of breast milk in 32 lactating women by HPLC analysis and also the consumed volume of the milk of their infants by the test-weighing method during the first 5 months of lactation. Total vitamin A contents of the milk shelved 67.3, 56.5, 51.2, 45.2, 39.0 and 34.lR.E./100m1 at 0.5, 1, 2, 3, 4 and 5 months of lactation respectively. Vitamin A intake of breast-fed infants were 320, 371, 368, 325, 292 and 251R.E/day during the five-month nursing period. Vitamin A intake per body weight of breast-fed infants was measured at 86.4, 79.8, 63.6, 49.1, 40.0 and 31.9R.E/kg/day. Body weight gain of infants was not affected by the vitamin A intake from the milk during the lactation. We conclude that breast-fed infants most likely receives vitamin A from the milk adequately compared with the RDA for Korean infants. (Korean J Nutrition 31(9) : 1433-1439, 1998)

• Food Science of Animal Resources
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• v.21 no.4
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• pp.358-366
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• 2001

To investigate the compositions of Holstein colostrums, samples were collected at 12 hour-interval after 12hrs postpartum. Milk protein, milk fat, SNF and total solid content of the colostum rapidly decreased from 12 hours to 48 hours after calving whereas lactose was the lowest at 12 hours after calving. Ash content was not shown to changes during lactation periods. Immunoglobulin G(IgG) concentration was also significantly(p<0.05) high in both primiparous and multiparous colostrum collected at 12 and 24 hours after calving. IgG concentration of primiparous and multiparous colostrums at 12 hours after calving was 44mg/ml and 44.27mg/ml, respectively. There was no apparent difference in IgG level between primipara and multipara. Fatty acid composition of colostral lipid was not shown to changes during lactation period. However, lauric acid, myristic acid and total saturated, fatty acid were slightly decreased in multiparous colostral lipid. Capric acid, myristic acid and palmitoleic acid composition in primiparous colostral lipid were slightly higher than those of multiparous colostral lipid throughout all lactation periods.

• Journal of Nutrition and Health
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• v.26 no.9
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• pp.1098-1109
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• 1993

The purpose of this study was to investigate macro-mineral contents in human milk longitudinally from 2 days to 12 weeks postpartum. Milk samples were collected from 34 healthy lactating women. Calcium, Phosphorus, magnesium, sodium and potassium were analyzed. Concentrations of the minerals except for magnesium differed significantly within the lactation period. The levels of sodium and potassium declined linearly over the first 12 weeks of lactation, but that of phosphorus increased. Statistically significant quadratic trends were observed in phosphorus and sodium concentrations. There was no significant correlation between maternal age and mineral concentrations throughout the lactations period. In addition, no significant differences were found between the primipara and the multipara for mineral concentrations in human milk. Mineral intake of lactating women did not affect the individual mineral concentrations of milk. However, the protein and fat intake of lactating women had a significant correlation with sodium and potassium concentrations. The following four pairs of minerals : potassium and calcium, potassium and phosphorus, sodium and magnesium, and calcium and phosphorus showed a positive correlation with each other in human milk.

• Environmental Analysis Health and Toxicology
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• v.25 no.4
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• pp.279-286
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• 2010

Objectives : Platinum nanoparticles (PNPs) are potentially useful for sensing, catalysis, and other applications in the biological and medical sciences. However, little is known about PNP toxicity. In this study, adverse effects of PNPs on the postnatal development of mouse pubs were investigated. Methods : PNPs (size: 20 nm) were prepared and orally administered to mice during premating, gestation, and lactation periods (0.25 mg/kg, 0.5 mg/kg, and 1 mg/kg). Maternal and pup toxicity were evaluated. Results : PNPs did not affect blood biochemical parameters or mortality in dams during the experimental period. Histopathological signs were not observed and pup number was not different between the control and treated groups. Deformity and stillbirth were not observed in the pups. However, PNPs increased pup mortality and decreased the infant growth rate during the lactation period. Conclusion : PNPs may have adverse effects to the postnatal development of mouse pups.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.923-930
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• 2009

This study was conducted to compare three models: two random regression models with and without considering heterogeneity in the residual variances and a lactation model (LM) for evaluating the genetic ability of Holstein cows in Korea. Two datasets were prepared for this study. To apply the test-day random regression model, 94,390 test-day records were prepared from 15,263 cows. The second data set consisted of 14,704 lactation records covering milk production over 305 days. Raw milk yield and composition data were collected from 1998 to 2002 by the National Agricultural Cooperative Federation' dairy cattle improvement center by way of its milk testing program, which is nationally based. The pedigree information for this analysis was collected by the Korean Animal Improvement Association. The random regression models (RRMs) are single-trait animal models that consider each lactation record as an independent trait. Estimates of covariance were assumed to be different ones. In order to consider heterogeneity of residual variance in the analysis, test-days were classified into 29 classes. By considering heterogeneity of residual variance, variation for lactation performance in the early lactation classes was higher than during the middle classes and variance was lower in the late lactation classes than in the other two classes. This may be due to feeding management system and physiological properties of Holstein cows in Korea. Over classes e6 to e26 (covering 61 to 270 DIM), there was little change in residual variance, suggesting that a model with homogeneity of variance be used restricting the data to these days only. Estimates of heritability for milk yield ranged from 0.154 to 0.455, for which the estimates were variable depending on different lactation periods. Most of the heritabilities for milk yield using the RRM were higher than in the lactation model, and the estimate of genetic variance of milk yield was lower in the late lactation period than in the early or middle periods.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.12
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• pp.1712-1720
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• 2012

We investigated the effect of the amount of body condition loss in the dry period and early lactation in 42 high-yielding Holstein-Friesian cows on milk yield and the share of fatty acids in milk fat. Energy reserves were estimated based on the body condition scoring (BCS) and backfat thickness (BFT). Milk yield and milk composition were determined over 305-d lactation. From d 6 to 60 of lactation, the concentrations of 43 fatty acids in milk fat were determined by gas chromatography. Cows were categorized based on body condition loss from the beginning of the dry period to the lowest point of the BCS curve in early lactation into three groups: low condition loss group (L) ${\leq}0.5$ points (n = 14); moderate condition loss group (M) 0.75 to 1.0 points (n = 16) and high condition loss group (H) >1.0 points (n = 12). Cows whose body energy reserves were mobilized at 0.8 BCS and 11 mm BFT, produced 12,987 kg ECM over 305-d lactation, i.e. 1,429 kg ECM more than cows whose BCS and BFT decreased by 0.3 and 5 mm, respectively. In group H, milk yield reached 12,818 kg ECM at body fat reserve mobilization of 1.3 BCS and 17 mm BFT. High mobilization of body fat reserves led to a significant (approx. 5%) increase in the concentrations of monounsaturated fatty acids-MUFA (mostly $C_{18:1}$ cis-9, followed by $C_{18:1}$ trans-11), a significant decrease in the levels of fatty acids adversely affecting human health, and a drop in the content of linoleic acid, arachidonic acid and docosahexaenoic acid in milk fat. In successive weeks of lactation, an improved energy balance contributed to a decrease in the concentrations of unsaturated fatty acids (UFA) and an increase in the conjugated linoleic acid (CLA) content of milk fat.