• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1231-1236
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• 2005

Genetic parameters for first lactation milk production based on test day (TD) records of 56319 Iranian Holstein cows from 655 herds that first calved between 1991 and 2001 were estimated with restricted maximum likelihood method under an Animal model. Traits analyzed were milk yield and milk fat percentage. Heritability for TD records were highest in second half of the lactation, ranging from 0.11 to 0.19 for milk yield and 0.038 to 0.094 for milk fat percentage respectively. Estimates for lactation records for these traits were 0.24 and 0.26 respectively. Genetic correlations between individual TD records were high for consecutive TD records (>0.9) and decreased as the interval between tests increased. Estimates of genetic correlations of TD yield with corresponding lactation yield were highest (0.78 to 0.86) for mid-lactation (TD3 to TD8). Phenotypic correlations were lower than corresponding genetic correlations, but both followed the same pattern. For milk fat percentage no clear pattern was found. Results of this study suggested that TD yields especially in mid-lactation may be used for genetic evaluation instead of 305-day yield.

• Journal of Nutrition and Health
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• v.24 no.1
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• pp.48-57
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• 1991

The longitudinal changes on human milk volume per day and lactational performance of Korean primiparae(n=9) and multiparae(n=6) from 0.5 month to 5 months after parturition have been studied by test-weighing method. The human milk volume per day tended to increase during lactation. The mean volume to the 3rd month of lactation was 643m1 for primiparae and 654m1 for multiparae, and it was 647 $\pm$ 182m1 for both of them. The mean volume to the 5th month of lactation was 648m1 for primiparae and 668m1 for multiparae, and it was 658$\pm$186$m\ell$ for both of them. The peak volume was observed at the 1st month of lactation in 8 women of 15 lactating women, that is, 53.3% . The high distributions of the individual mean volume to the 5th month were found 550~650$m\ell$(40.0% ) and 650~750$m\ell$(26.7% ). and 13 women of 15 lactating women(86.6% ) were observed below 750m1. The number of feeding per day was 7.7~9.3 to the 5th month and the mean volume per feeding was 65~101$m\ell$. While the former tended to decreased, the latter increased during lactation. The human milk volume was correlated with the peak volume. but not with maternal age. weight before delivery. maternal height and birth weight. As mentioned above, the human milk volume of Koreans was about 658$\pm$ 186$m\ell$ and 86.6% of it was below 750$m\ell$. So the human milk volume, referred to as 800$m\ell$ in recommended dietary allowances for Koreans might be estimated over real amount. It is necessary to study according to regions. socioeconomic levels. maternal nutritional status and the early stage of lactation.

• Journal of Animal Science and Technology
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• v.52 no.1
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• pp.57-64
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• 2010

This study was conducted to compare the aspects of behavior between miniature pigs and conventional sows during gestation and lactation periods. Miniature pigs and conventional sows at 3 parity were used in this experiment with 4 pigs per treatment. The behavioral patterns and stereotyped behaviors were observed on day 60 and 90 of gestation, at farrowing, and on day 10 of lactation before and after the feeding. On 60 and 90 days of pregnancy, both treatments showed the tendency of frequent lateral lying rather than other postures. On ventral lying, eating and drinking, miniature pigs spent more time than conventional pigs at day 90 of gestation (P<0.01, P=0.0539, P<0.05, respectively). The occurrence of stereotyped behaviors included bar biting and bar mouth chewing. At 90 day of pregnancy was observed, conventional pigs was higher than miniature pigs (P<0.05). At farrowing, miniature pigs spent more time on ventral lying, standing and walking than conventional sows (P<0.05), however, there were more frequency of drinking and eating. And on day 10 of lactation, there was no significant difference in stereotyped behaviors between miniature pigs and conventional sows. In conclusion, miniature pigs were generally more sensitive than conventional sows although sows were reared in stall during gestation and lactation period and the behavioral pattern during lactating period showed the similarity between miniature pigs and conventional sows for protection of nursing pigs. In consideration of the general reproductive performance of conventional sows, the high sensitivity and stress of miniature pigs did not affect the reproductive performance of miniature pigs.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.230-233
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• 1996

The purposes of this study was to investigate selenium content of human milk and selenium intake of breast-fed infants at each period of lactation longitudinally. The human milk intake in breast-fed infants was measured by test weighing method from 20 lactating mothers at 1,2 and 3 months postpartum. Selenium content in the milks was determined by atomic absorption spectrophotometry with hydride generation after wet digestion of samples. Selenium intake in breast-fed infants was calculated by multiplying human milk intakes by selenium contents. The milk intakes were 640, 726 and 715g/day at 1,2 and 3 months postpartum. The selenium contents in human milk were characterized by a pattern of slight decline with advancing stage of lactation;13.1, 11.5 and 9.8$\mu\textrm{g}$/L at 1,2 and 3 months during lactation. There was a large individual variation at any stage of this study. The mean dietary selenium intakes in breast-fed infants were 8.38, 8.32 and 6.97$\mu\textrm{g}$/day at 1,2 and 3 months postpartum, respectively. The mean daily intakes on a body weight basis were gradually decreased during the course of lactation.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.690-694
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• 2013

The aim of the present study is to obtain ecological data necessary for increasing the survival rate and effective individual management of fox cubs by analyzing the behavioral pattern during the lactation period. The subjects of the present study were baby foxes born in 2013 and taken care of at the species restoration technology institute, Korea National Park Service. Our analysis on the lactation of fox cubs and their appearance pattern outside the burrow revealed that the frequency and duration of lactation decreased with the growth of the cubs, whereas the frequency of the cubs venturing outside the den, activity time, and distance ventured increased. By the $30^{th}$ day after birth, in particular, the lactation behavior of the vixens largely decreased, and the activity of the cubs outside the den increased accordingly. Thus, for future management of the propagation of fox individuals for securing the original breed, it is necessary to increase the living food source. In addition, while capturing foxes for individual marking of cubs born in the wild, it is desirable to capture cubs older than 30 days not only for easy capture but also to minimize negative influence on the growth of the cub.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.523-531
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• 2008

Buffalo are a major source of milk production, contributing 12.1% in the World and 38.0% in Asia. The buffaloes are kept under peri-urban farming systems to produce milk for urban populations. Breeding is delayed in these herds to get more economic benefit because farmers believe that the pregnancy decreases milk production. The lactation milk value has been studied in this paper as an economic indicator. Complete milk yield records of 3,304 buffaloes was collected from a group of state farms. Economic traits including lactation yield, lactation length, calving interval (CI), dry period and milk yield per day of calving interval (MYPDCI) were derived from the data. The animals were grouped according to parity number (1-3), service period (G1 to G4, conceiving during <150, 150-200, 200-300 and >300 days post calving) and yield levels (HMY>2,500; MMY 2,001-2,500; and LMY 1,500-2,000 liters/ lactation). To study the effect of pregnancy on milk composition a research trial was conducted at a medium size private dairy farm, using forty lactating buffaloes of three yield levels and four service period groups, as described already. Milk was sampled on alternate weeks and analyzed for fat and protein contents (%). For quantifying the value of milk produced during a lactation period, the value corrected milk (VCM) was determined and converted to lactation milk value (LMV). Group means were compared for varicous parameters. Highest milk yield ($2,836.50{\pm}15.68$ liters/lactation) was recorded in the HMY animals of G4 group while lowest milk yield of $1,657.04{\pm}8.34$ liters/lactation was found in LMY of G1. Lactation was significantly increased with the extending of service period. The shortest dry period was recorded in HMY, parity 1, G1 animals and the longest in parity 2, MMY, G4.The CI was shortest in HMY, parity 1, and G1 animals and longest in LMY, parity 3, G4 buffaloes. The HMY, parity 2, G1 buffaloes showed the highest MYPDCI and the lowest value was recorded ($6.53{\pm}0.17$ vs. $2.76{\pm}0.04$ liter/day) for LMY, parity 1, G4 buffaloes. The VCM decreased with the delayed conception. This decreasing trend was higher in respect of the total yield but decrease in the VCM was smaller due to the increasing levels of fat and protein in the milk. The gap between the various production classes was reduced based on the VCM as compared with the yield per day of CI. LMV showed a consistent decline with extending service period in all three production groups. The study suggests that CI increased with delayed conception, showing a consistent trend in the low, moderate and high yielding buffaloes. There was a coherent declining pattern of milk yield with delaying conception, associated with prolonged CI. An animal conceiving at a later stage of lactation showed a decline in financial returns of 24 to 27% compared with those conceiving earlier.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.334-347
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• 2000

The present experiment was carried out to study the utilization of glucose in the mammary gland of crossbred Holstein cattle during feeding with different types of roughage. Sixteen first lactating crossbred Holstein cattle which comprised eight animals of two breed types, Holstein Friesian${\times}$Red Sindhi ($50{\times}50=50%$ HF) and Holstein Friesian${\times}$Red Sindhi ($87.5{\times}12.5=87.5%$ HF). They were divided into four groups of 4 animals each of the same breed. The utilization of glucose in the mammary gland was determined by measuring rates of glucose uptake and the incorporation of glucose into milk components in both groups of 50% HF and 87.5% HF animals feeding on either hay or urea treated rice straw. In early lactation, there were no significant differences of the total glucose entry rate and glucose carbon recycling among groups of crossbred animals feeding on either hay or urea treated rice straw. During lactation advance, the total glucose turnover rates and recycling of carbon glucose of crossbred HF animals feeding on urea treated rice straw were markedly higher than those of crossbred HF animals feeding on hay as roughage, whereas there were no significant changes for both groups of crossbred animals feeding on hay. The percentages and values of non-mammary glucose utilization showed an increase during lactation advance in the same group of both 50% HF and 87.5% HF animals. The percentage of glucose uptake for utilization in the synthesis of milk lactose by the mammary gland was approximately 62% for both groups of 87.5% HF and by approximately 55% for both groups of 50% HF animals feeding on either hay or urea treated rice straw. Intracellular glucose 6-phosphate metabolized via the pentose phosphate pathway accounted for the NADPH (reducing equivalent) of fatty acid synthesis in the mammary gland being higher in 87.5% HF animals during mid-lactation. A large proportion of metabolism of glucose via the Embden-Meyerhof pathway in the mammary gland was more apparent in both groups of 50% HF animals than those of 87.5 % HF animals during early and mid-lactation while it markedly increased for both groups of 87.5% HF animals during late lactation. It can be concluded that utilization of glucose in the mammary gland occurs in a different manner for 50% HF and 87.5% HF animals feeding on either hay or urea treated rice straw. The glucose utilization for biosynthetic pathways in the mammary gland of 50% HF animals is maintained in a similar pattern throughout the periods of lactation. A poorer lactation persistency in both groups of 87.5% HF animals occurs during lactation advance, which is related to a decrease in the lactose biosynthetic pathway.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.1
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• pp.23-26
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• 1989

Treatment of mice with 0.04% anthranilic acid (AnA) as drinking water resulted in an apparent stimulation of pup's growth and food intake of mothers in their first lactations associated with an increased rearing rate and no alteration in plasma prolactin level. AnA showed no significant effects on the day of vaginal opening, the pattern of estrous cycles, plasma growth hormone level and endocrine organ weights of the female and male offspring. The growth of male offspring was significantly retarded by AnA, however, their reproductivity was quite normal. The results indicate the AnA can simulate lactation of mice through little modulation of endocrine systems.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.794-798
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• 2004

An attempt was made to improve the efficiency of growth and lactation performance of dairy heifers subjected to a stair-step growth scheme using rice straw as the sole roughage source. Twenty-four young Holstein heifers were randomly assigned to either control or test group. The control diet met the National Research Council (NRC) requirement, with heifers calving at 24 to 26 mo of age. The test group was individually fed according to a schedule of 3, 2, 4, 2, 5 and 2 mo in which feed intake was alternately 20% below or 25% above the NRC requirements. Heifers on the stair-step growth pattern gained more body weight and consumed less dry matter (10.80 and 11.22%, respectively), resulting an increasing growth efficiency compared with the control. Body condition, first estrus, first conception, services per conception and calving difficulty (data not shown) were not affected. Milk yield of the test group was 8.5% higher than that of the control group. During the early lactation period, the milk yield was significantly higher in the stair-step group than in that of the control group (p<0.05). Milk composition was not affected by compensatory growth induced by the stair-step scheme. Also, weight at calving and calf growth performance was not affected by stair-step growth. The results indicate that using rice straw as a sole roughage source in a stair-step compensatory growth scheme can contribute to the improvement of growth efficiency and early lactation performance.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1638-1652
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• 2000

Prolific females require better nutrition and feeding practice because of larger litter size and the substantial decline in body fat. Life-time pig output will be compromised if body protein and fat are not properly managed. First litter females are especially vulnerable because they can loose ${\geq}15%$ of whole-body protein. Conservation of body protein mass during first lactation minimizes wean to estrus interval and increases second litter size (up to 1.2 pigs). The ability to influence litter-size by amino acid nutrition is a new dimension in our understanding. A P2 fat depth below 12 mm at farrow and below 10 mm at wean compromised wean to estrus interval (>2 d) and next litter size (0.5 to 1.5 pigs) in sows. It is now clear that a 'modest' excess of feed during the first 72 h of pregnancy decreases embryo viability so that the potential for an increased litter size at birth is not realized. The capacity for milk production by prolific young sows is 25% higher than the standard used previously (NRC, 1988). First litter females averaged 9.82 kg milk/d for a 21 d lactation. Second and third litter counterparts averaged 10.35 kg/d. Milk production was 95% of peak by 10 d of lactation and sows were in greatest negative energy and lysine balance during the first 6 d. Nearly 45% of the total loss in body protein occurred within the first 6 d, but this could reduced to 30-35% by using a more aggressive feeding strategy after parturition. There appear to be 2 phases in lactation for lysine need (d 2-12 vs 12-21). Feeding to the higher level alleviates the second litter size decline. The lysine requirement for lactation can be predicted with accuracy, but we are not able to predict the second limiting amino acid. Mammary uptake of valine relative to lysine and recent work with practical diets suggest that the recent NRC (1998) pattern is realistic and that threonine and valine could be co-limiting for corn-soy diets for prolific sows nursing 10-11 pigs. Empirical studies are needed to refine the ideal pattern so that synthetic lysine can be used with more confidence. Milk fat output for the elite sow is extraordinary and poses an unnecessarily high energetic cost. Methods that reduce mammary fat synthesis will benefit the sow and may enhance piglet growth.