Duration Of Lactation Research Articles

Analysis of Sirtuin 1 and Sirtuin 3 at Enzyme and Protein Levels in Human Breast Milk during the Neonatal Period.

Breast feeding is regarded as the preferred nutrition modality for children during the first few months of life. It not only furthers growth and development but also is supposed to impact later life. The first 1000 days are regarded as a critical window for development, even beyond infancy. The physiological basis underlying this beneficial effect is not clear. Sirtuins are important regulatory proteins of metabolism and are supposed to play a critical role in ageing and longevity as well as in diseases. In the present study, we developed novel methods to assay sirtuin 1 and sirtuin 3 at enzyme activity (via fluorometry) and protein levels (by Western blot) in the aqueous phase and in the cell pellet of human breast milk and assessed the impact of ongoing lactation during the neonatal period. Sirtuin activities in the aqueous phase were negatively correlated with the duration of lactation in the neonatal period. There was no correlation of sirtuin activities in the cell pellet with the duration of lactation. The amounts of sirtuin 1 and sirtuin 3 measured by Western blot were negatively correlated with the lactation period.

Determining the Factors Affecting Long-Term and Short-Term Survival of Breast Cancer Patients in Rafsanjan Using a Mixture Cure Model.

Background: Breast cancer is one of the most common causes of death among women worldwide and the second leading cause of death among Iranian women. The incidence of this malignancy in Iran is 22 per 100,000 women. These patients have long-term survival time with advances in medical sciences. The present study aimed to identify the risk factors of breast cancer using Cox proportional hazard and Cox mixture cure models. Study design: It is a retrospective cohort study. Methods: In this cohort study, we recorded the survival time of 140 breast cancer patients referred to Ali Ibn Abitaleb Hospital in Rafsanjan, Iran, from 2001 to 2015. The Kaplan-Meier curve was plotted; moreover, two Cox proportional hazards and the Cox mixture cure models were fitted for the patients. Data analysis was performed using SAS 9.4 M5 software. Results: The mean age of patients was reported as 47.12 ±12.48 years at the commencement of the study. Moreover, 83.57% of patients were censored. The stage of disease was a significant variable in Cox and the survival portion of Cox mixture cure models (P=0.001). The consumption of herbal tea, tumor size, duration of the last lactation, family history of cancer, and the type of treatment were significant variables in the cured proportion of the Cox mixture cure model (P=0.001). Conclusion: The Cox mixture cure model is a flexible model which is able to distinguish between the long-term and short-term survival of breast cancer patients. For breast cancer patients, cure effective factors were the stage of the disease, consumption of herbal tea, tumor size, duration of the last lactation, family history, and the type of treatment.

Determining the Factors Affecting Long-Term and Short-Term Survival of Breast Cancer Patients in Rafsanjan Using a Mixture Cure Model.

Background: Breast cancer is one of the most common causes of death among women worldwide and the second leading cause of death among Iranian women. The incidence of this malignancy in Iran is 22 per 100,000 women. These patients have long-term survival time with advances in medical sciences. The present study aimed to identify the risk factors of breast cancer using Cox proportional hazard and Cox mixture cure models. Study design: It is a retrospective cohort study. Methods: In this cohort study, we recorded the survival time of 140 breast cancer patients referred to Ali Ibn Abitaleb Hospital in Rafsanjan, Iran, from 2001 to 2015. The Kaplan-Meier curve was plotted; moreover, two Cox proportional hazards and the Cox mixture cure models were fitted for the patients. Data analysis was performed using SAS 9.4 M5 software. Results: The mean age of patients was reported as 47.12 ±12.48 years at the commencement of the study. Moreover, 83.57% of patients were censored. The stage of disease was a significant variable in Cox and the survival portion of Cox mixture cure models (P=0.001). The consumption of herbal tea, tumor size, duration of the last lactation, family history of cancer, and the type of treatment were significant variables in the cured proportion of the Cox mixture cure model (P=0.001). Conclusion: The Cox mixture cure model is a flexible model which is able to distinguish between the long-term and short-term survival of breast cancer patients. For breast cancer patients, cure effective factors were the stage of the disease, consumption of herbal tea, tumor size, duration of the last lactation, family history, and the type of treatment.

Age dynamics of reproductive qualities of sows depending on the duration of the suckling period

The article studied the influence of sows' age on their reproductive qualities at the traditional - 28 days and shortened - 21 days duration of the suckling period. It was found that the total number of piglets born increased from the second reproductive cycle to the sixth inclusive. With the traditional duration of the suckling period, the most significant growth was observed during the third, fourth and fifth farrowing (8.0-8.6%), while with a reduced duration of the suckling period, it was significantly lower (3.8-4.9%). and lasted from the third to the fifth reproductive cycle. As sows' reproductive age increased, their fertility increased. Its highest growth in both terms of weaning of piglets was on the third farrowing and then gradually decreased. Sows with a reduced suckling period had a lower increase in fertility throughout reproductive life. The nest weight of piglets at birth increased until the third farrowing and then gradually decreased. With the traditional duration of the suckling period, the intensity of the increase in the nest weight of piglets born at the age of sows is higher compared to analogues in which the lactation period was reduced. Preservation of piglets in sows' nests deteriorated with increasing reproductive age. It worsened less intensely in sows with a reduced suckling period. The number of weaned piglets depended to a greater extent on the age of the sows and to a lesser extent on the length of the suckling period. From the third farrowing, it constantly decreases with increasing age of the sow, regardless of the length of the suckling period. The average weight of one piglet increases with the age of sows from the third farrowing, and its growth is more intense with a reduced duration of lactation. The increase in the weight of the nest of piglets at weaning is most significant for 3-5 farrowings, after which there was a decrease in this indicator for both periods of weaning piglets. A comprehensive assessment of the reproductive quality of sows using indices confirms the increase in sow productivity during the second - fourth reproductive cycle with a gradual decrease during the fifth to sixth farrowing, both in the traditional and reduced duration of the suckling period. It is proved that the sow age factor determines the probable influence on the number of piglets at weaning (9.43 %), their safety (5.56 %), the weight of the nest of piglets at weaning (1.87 %) and fertility (1.65 % ). While the suckling period factor affected the nest weight of piglets at weaning with a force of 28.49 %, the number of piglets at weaning with a force of 0.62 %, the safety of piglets before weaning at 0.19 % and did not affect the fertility of sows. Key words: sow, reproductive cycle, duration of lactation, fertility, safety, piglet.

Association of lactation with maternal risk of type 2 diabetes: A systematic review and meta-analysis of observational studies.

To investigate the association between lactation and maternal risk of type 2 diabetes, including a potential graded association according to lactation duration. A systematic review and meta-analysis of observational studies that investigated the reported association between lactation (irrespective of duration, intensity or mode) and maternal risk of type 2 diabetes was conducted. A total of 22 studies (17 cohort studies and five cross-sectional studies) were included in this systematic review, and 16 contributed to the meta-analysis. Studies that investigated the association of lactation with risk of type 2 diabetes in the first months after birth in women with gestational diabetes reported conflicting results. Studies with a longer follow-up showed a graded protective association for lactation and the risk of type 2 diabetes, with a potentially larger risk reduction in women with gestational diabetes than in those without gestational diabetes. Overall, ever versus never lactation was associated with a 27% lower risk of type 2 diabetes (RR 0.73, 95% CI [0.65, 0.83]). Each additional month of lactation was associated with a 1% lower risk of type 2 diabetes (RR 0.99, 95% CI [0.98, 0.99]). However, the overall quality of the studies was modest. Lactation is associated with a significantly reduced risk of maternal type 2 diabetes over the life course, particularly in women with gestational diabetes. The protective effect seems to increase with longer duration of lactation. Further research is warranted to understand whether this association is modified by exposure to other risk factors.

Daily variation of macronutrient concentrations in mature human milk over 3 weeks

Human milk (HM) composition is known to be highly variable, both between individuals and across the duration of lactation. It is less clear, however, to what extent fat, lactose and protein concentrations in HM change daily over shorter time periods in mature HM, and no studies have evaluated this to date. The aim of this study was to systematically assess and compare HM macronutrient concentrations in samples collected at different times of day, from left and right breasts and daily across a 3-week period in the same woman. Fifteen lactating women (1.6–4.9 months postpartum) collected daily pre-feed HM samples from both breasts each morning for 21 consecutive days and completed intensive sampling once a week (morning, afternoon and evening samples) during this period. Concentrations of fat, protein and lactose in HM did not differ according to time of day, day of week or breast used for collection. The results of this study suggest that pre-feed samples collected at any point across a 3-week period and from either the left or right breast provide comparable measures of fat, protein and lactose concentrations in mature HM, in pragmatic studies where women are collecting their own HM samples.Clinical trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12619000606189).

Breastfeeding history and the risk of overweight and obesity in middle-aged women

BackgroundThe increased metabolic activity required to sustain breastfeeding and its associated milk production helps to reduce maternal fat stores accumulated during pregnancy. This study aims to assess the association between breastfeeding duration and fatness indices in middle-aged women.MethodsThe analysis was carried out in a group of 7500 parous 55.5 ± 5.3 year old women included body mass index, body fat percentage, and waist-to-height ratio. The likelihood of excessive weight or obesity in relation to total breastfeeding time using multivariate logistic regression analyses.ResultsAn analysis of adjusted odds ratios did not show significant associations between breastfeeding duration and the risk of excessive weight and obesity in premenopausal women. After menopause, women who gave birth to 2 children and breastfed 1–6 and > 12 months had a lower risk of abdominal obesity (OR 0.70; 95% CI 0.50–0.99; p = 0.042; and OR 0.68; 95% CI 0.47–0.98; p = 0.039). Women who gave birth to 3 or more children and breastfed for 1–6 months, also showed a lower risk of overweight (OR 0.52; 95% CI 0.27–0.99; p = 0.047), compared to those ones that have never breastfed. There was no relationship found between the duration of lactation and the risk of excessive body fat.ConclusionBreastfeeding may have some beneficial, long-term effect on the risk of excessive weight and abdominal obesity in women.

Genetic association with boldness and maternal performance in a free-ranging population of grey seals (Halichoerus grypus).

Individual variation in quantitative traits clearly influence many ecological and evolutionary processes. Moderate to high heritability estimates of personality and life-history traits suggest some level of genetic control over these traits. Yet, we know very little of the underlying genetic architecture of phenotypic variation in the wild. In this study, we used a candidate gene approach to investigate the association of genetic variants with repeated measures of boldness and maternal performance traits (weaning mass and lactation duration) collected over an 11- and 28-year period, respectively, in a free-ranging population of grey seals on Sable Island National Park Reserve, Canada. We isolated and re-sequenced five genes: dopamine receptor D4 (DRD4), serotonin transporter (SERT), oxytocin receptor (OXTR), and melanocortin receptors 1 (MC1R) and 5 (MC5R). We discovered single nucleotide polymorphisms (SNPs) in each gene; and, after accounting for loci in linkage disequilibrium and filtering due to missing data, we were able to test for genotype-phenotype relationships at seven loci in three genes (DRD4, SERT, and MC1R). We tested for association between these loci and traits of 180 females having extreme shy-bold phenotypes using mixed-effects models. One locus within SERT was significantly associated with boldness (effect size = 0.189) and a second locus within DRD4 with weaning mass (effect size = 0.232). Altogether, genotypes explained 6.52-13.66% of total trait variation. Our study substantiates SERT and DRD4 as important determinants of behaviour, and provides unique insight into the molecular mechanisms underlying maternal performance variation in a marine predator.

Experience of using plant complexes in physiological completion of lactation

Ending breastfeeding is often quite a challenge for women, justifying the need for qualified medical counseling and accompaniment by a doctor. Quite frequently during weaning the baby, women complain about pain, discomfort and swelling of the breasts, which affects their overall physical and psychological well-being. However, due to possible rather serious side effects, medical support for stopping lactation is mostly recommended for women with clinical indications.Research aim: to determine the effectiveness of the proposed method with Normomens for physiological completion of lactation.Materials and methods. The study involved 65 women with an average duration of lactation 9 ± 1.23 months. Patients were divided into two groups: group 1 included 34 women who received Normomens according to the scheme to stop lactation; group 2 included 31 patients who did not receive any medication. Patients were gynecological examined and counseled by oncologist. Patients' diaries included questions about the duration of lactation, presence and severity of mastalgia according to the Visual Analogue Scale, necessity of analgesics, frequency of breast pumping per day, features of psycho-emotional state according to the Hospital Anxiety and Depression Scale. Prolactin levels were also determined at the screening visit and on 25th day after weaning.Results. On the background of Normomens use the process of lactation completion was significantly easier, its completion came mostly on the 3–4 day after drug use, patients almost never complained of pain and discomfort in mammary glands, they less frequently breast pumped and had a more stable psycho-emotional state compared to the control group. Рrolactin level with usage of Normomens had a quick decrease compared to the control group.Conclusion. Normomens using for support the physiological finishing of lactation lead to acceleration of involutive processes in mammary glands, reduces pain severity and prevented psycho-emotional disorders in women.

Influence of the duration of lactation and the season of the year on the manifestation of diseases that cause culling of animals

The article describes animal diseases as the reasons for their culling. The number of animals culled from the herd was analyzed depending on the duration of lactation. It was found that in most cases (20.1%) the culled animals had lactation duration close to standard. It was revealed that the largest number of dairy cows, both during the completed lactation and in the first 100 days of lactation, drop out of the herd due to obstetric and gynecological diseases (42.0-45.9%). Internal non-communicable diseases, as a factor in animal retirement, are in second place in terms of prevalence. In the studied population of animals, 30.7-33.4% of cases of culling of animals as a result of these diseases were found. Assessment of the structure of internal non-communicable diseases showed that diseases of the digestive system (40.0-43.1%) and diseases of the respiratory system (36.6-38.4%) prevail among them. Analysis of the seasonality of internal non-communicable diseases showed that most often diseases of the digestive system, respiratory system, metabolism and endocrine organs contribute to the culling of animals in the spring (26.7, 30.0 and 33.3% respectively), and diseases of the cardiovascular system cause the withdrawal of animals in winter (37.7%).

Тривалість продуктивного використання корів у стадах української чорно-рябої молочної породи в умовах племінних господарств Тернопільської області

Goal. To study the duration of productive use of cows of Ukrainian black-motley dairy breed in breeding herds of farms of Ternopil region, and to substantiate the principles of breeding and zootechnical work for effective selection of cattle with a projected long term of economic use in the Western region of Ukraine. Methods. Primary zootechnical documentation is studied of experimental farms on the following indicators: life expectancy, economic use and lactation, lifetime milk yield, milk fat yield, and average lifetime fat content in milk, as well as a comprehensive final indicator of average milk yield per 1 day of life, economic life, economic use and lactation (according to the generally accepted zootechnical methods for the period of 2009–2020). Correlation analysis was used to determine the nature, direction and relationship between exterior constitutional characteristics and productivity of cows with indicators of the effectiveness of their lifelong use. Statistical processing of research results and correlation analysis were carried out by methods of variation statistics according to M.O. Plokhynskyi, Ye.K. Merkurieva. Results. The presence is fixed of genetic diversity of cows because determines the longevity of livestock and the possibility of selection for the duration of exploitation of animals. Correlation analysis established the possibility of predicting the efficiency of lifelong use by individual indicators. There is a reliable relationship between the age of the first calving with lifelong milk yield, lifelong fat content in milk, the average duration of lactation, economic use, life. The links between lifelong milk yield and the duration of economic use, life, the average duration of lactation, and indicators of lifelong productivity and economic use are highly reliable. A significant influence of paratype factors on the formation of lifelong milk yield was revealed. Conclusions. The highest on average (among the studied indicators) reliable relationship (relative variability) with the efficiency of lifelong use are the indicators of the age of the first calving, duration of economic use, life, the average duration of lactation.

The Association of Lactation Duration with Visceral and Pericardial Fat Volumes in Parous Women: The CARDIA Study.

Lactation is associated with lower risks for cardiovascular disease in women. Organ-related adiposity, which plays significant roles in the development of cardiometabolic diseases, could help explain this observation. We evaluated the association of lactation duration with visceral (VAT) and pericardial (PAT) fat volumes in women. Data were obtained from 910 women enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study (1985-1986) without diabetes prior to pregnancy who had ≥1 birth during 25 years of follow-up and had VAT and PAT measured from computed tomographic scans in 2010-2011. Cumulative lactation duration across all births since baseline was calculated from self-reports collected at periodic exams. At baseline, the average age of women (48% black, 52% white) was 24 ± 3.7 years. After controlling for baseline age, race, smoking status, body mass index, fasting glucose, family history of diabetes, fat intake, total cholesterol, physical activity, and follow-up covariates (parity, gestational diabetes), the mean fat volumes across categories of lactation [none (n = 221), 1-5 months (n = 306), 6-11 months (n = 210), and ≥12 months (n = 173)] were 122.0, 113.7 105.0, and 110.1 cm3 for VAT and 52.2, 46.7, 44.5, and 43.4 cm3 for PAT, respectively. Changes in body weight from the first post-baseline birth to the end of follow-up mediated 21% and 18% of the associations of lactation with VAT and PAT, respectively. In this prospective study, longer cumulative lactation duration was associated with lower VAT and PAT volumes, with weight gain partially mediating these associations.

Measures of Lactation Outcomes in Women Delivering Preterm Infants.

Mother's own milk (MOM) is well known to decrease prematurity-related morbidities, yet mothers delivering preterm infants often produce insufficient quantities of milk to provide these benefits. Although a critical need exists for research to support lactation success in this vulnerable population, development and investigation of interventions to increase available MOM for infant consumption requires consistent, valid, and reliable measures of lactation outcomes. The aim of this study was to compare and contrast methods of measuring lactation outcomes in mothers of preterm infants and evaluate their advantages and disadvantages. Measures of lactation outcomes were reviewed and synthesized. Insights on best practices and future research directions are provided. Volume of MOM produced, lactation duration, and time to onset of secretory activation are important measures of lactation success. The most valid and reliable measure of milk production is likely weighing each vial of expressed milk combined with test weighing when infants breastfeed. Measures of lactation duration should include actual days mothers lactated rather than limiting to infant consumption of MOM as a proxy for duration and include not only whether mothers are lactating at infant discharge but whether they are also lactating at other health-relevant time points during hospitalization. Although time to onset of secretory activation is an important lactation outcome, information regarding valid and reliable indicators of onset in women delivering preterm infants is limited, and investigation of such indicators is a research priority. Variables that may affect lactation outcomes, including time to initiation of expression following delivery, duration of expression sessions, expression method, time spent in skin-to-skin care, maternal demographics and comorbidities, as well as maternal intent to lactate, must be considered when researchers investigate lactation outcomes in mothers of very low birth weight infants. Consistent and valid measures of lactation outcomes are required to produce reliable results from which evidence-based practice recommendations can be developed in order to improve lactation success in this vulnerable population.

Does parity and duration of lactation have any effect on the bone mineral density of the femur and lumbar spine in Indian women? A cross-sectional study from the Northeast region of India.

Background:The effects of multiple pregnancies and period of lactation on bone density have not been studied till date and there is very less data available, especially from developing countries like India. Lumbar spine and femoral neck were used to measure BMD and results were recorded.Objective:To find out the effect of parity and period of lactation on occurrence of osteoporosis in spine and femoral neck in women of the Northeast region of India.Materials and Methods:The cross-sectional study included 294 perimenopausal and postmenopausal women aged 30–65 year old. Age, body mass index (BMI), parity, total lactation period, menopausal status, duration of menopause socioeconomic status, and nutritional history were noted. The dual-energy X-ray absorptiometry system was used to measure the BMD of lumbar and femoral neck BMD. Multiple regression analysis was done for finding out the association of parity and lactation with BMD.Results:The parity was inversely related with BMD of lumbar spine (β = −0.138, P = 0.00423) and BMD of femoral neck (β = −0.142, P = 0.00487). This relation remained significant after adjusting for age, BMI, and duration of menopause. Period of lactation was also inversely correlated with BMD for lumbar spine (β = −0.0812, P = 0.0012) and BMD of femoral neck (β = −0.033, P = 0.0031).Conclusion:The number of parity and prolonged period of lactation have a negative effect on BMD in both regions especially in the lower socioeconomic strata with poor nutritional intake. Our data supports that parity and duration of lactation can be associated with future osteoporosis.

Variability of genetic correlations of milk yield and fertility traits in Simmental cows in different regions of Serbia

The Simmental breed of cattle is mostly reared in the central part of the Republic of Serbia, where it makes up about 80% of all breeds. In areas of more intensive cattle production, populations of cattle with pronounced milk yield are reared. In more extensive, as well as hilly and mountainous areas, somewhat less productive animals are raised. The main goal of this study was to examine the variability of genetic correlations of milk and fertility traits on the farms of individual agricultural producers using modern methods, depending on the breeding area, i.e. the region in which they are bred and reared. This study included 2589 controlled Simmental heifers, with lactations concluded during one year. All first calving heifers were housed and reared on agricultural family farms in the area of Central Serbia. The paper examines genetic correlations between the following traits of milk yield and fertility: duration of lactation, milk yield in standard lactation, milk fat content in standard lactation, milk fat yield in standard lactation, yield of 4% FCM in standard lactation, age at first calving, duration of service period. The results of the study of genetic correlations were obtained using mixed LSMLMW models (Harvey 1990). The examined genetic correlations of milk yield and fertility traits in Simmental cows showed pronounced variability depending on the breeding area where the cows are reared.

Protein levels and protease activity in milk from mothers of pre-term infants: A prospective longitudinal study of human milk macronutrient composition

The composition and enzymology of human milk changes throughout the lactation period, and differ for mothers who give birth prematurely compared to those who deliver at full-term. Understanding the composition of milk from mothers of very low birth weight premature infants is of great significance, and the objective of this study was to evaluate the composition, protein profile and plasmin activity of milk from mothers who delivered infants at different gestational ages. Samples of human milk were donated by women (n=74) in the Cork, Ireland, area who gave birth to full-term (>37 weeks gestation, FT), pre-term (32-37 weeks, PT) and very pre-term (≤32 weeks, VPT) infants. FT milk was collected at 1, 3, 6 and 10 weeks post-partum (PP), while PT and VPT milk was collected weekly until the FT due date of the infant and subsequently followed the FT protocol. Gestational age did not significantly affect lactose or fat content or total energy content of milk. However, protein content, and levels of some individual proteins, were significantly affected by both gestational age at birth and duration of lactation, with significantly higher protein levels in PT or VPT milk samples at 0-7 days and 1-2 months, respectively. Plasmin activity was significantly higher in VPT milk, indicating differences in proteolytic processing in milk. Compositional differences between the milk of mothers of term and pre-term infants were greatest in terms of the protein profile, which showed both qualitative and quantitative differences, as well as difference in proteolytic activity.

РІВЕНЬ МОЛОЧНОЇ ПРОДУКТИВНОСТІ ТА ВІДТВОРНА ФУНКЦІЯ ГОЛШТИНСЬКИХ КОРІВ РІЗНОГО ВІКУ ЗА ТРИВАЛОЇ ЛАКТАЦІЇ

Тривалість лактації піддослідних груп тварин коливалась у межах 845,9–915,5 доби, тобто була досить тривалою. Так, у лактуючих піддослідних корів І, ІІ і ІІІ (контрольної) груп тривалість лактації відповідно першої, другої та третьої була не лише тривалою, а й мала майже однаковий період, який становив у середньому 681,1–681,5 доби. У цей же час п’ятий лактаційний період у тварин V групи був дещо довший, оскільки тривав у середньому 629,4 доби, натомість у корів ІV групи четверта лактація становила 611,9 доби.
 За увесь лактаційний період корови І групи мали найвищий надій, який в середньому становив 18469,8 кг молока. При цьому, відносно найнижчим надоєм характеризувались корови ІV групи, у яких даний показник не перевищував 15617,3 кг. 
 Характеристика надою за 305 діб лактації дає можливість більш об’єктивно оцінити молочну продуктивність тварин. За результатами даної оцінки видно, що від корів ІV групи було отримано найвищий показник надою, який становив у середньому 11399,2 кг молока. Високим потенціалом продуктивності характеризувалися також корови V групи, удій яких упродовж 305 діб п’ятої лактації становив у середньому 10464,3 кг, що лише на 8,93 % (P<0,05) менше показника корів ІV групи у четверту лактацію.
 Первістки І групи характеризувались відносно найнижчим надоєм за 305 діб лактації, який становив у середньому 8486,1 кг молока, що було менше показника тварин ІV групи на 34,3 % (P<0,001).
 Таким чином, дуже тривала лактаційна функція голштинських корів від першої до п’ятої лактації характеризується досить високим рівнем молочної продуктивності, який найвищий у первісток та має тенденцію зменшення упродовж другої, третьої та четвертої лактацій та незначним підвищенням у п’яту. Натомість рівень продуктивності піддослідних корів, перерахований на 305–денну лактацію, вказує на найнижчий удій у первісток та поступове його зростання до четвертої лактації і деякого зниження у п’яту.
 Високий рівень молочної продуктивності піддослідних корів, з одного боку, та недостатня або пригнічена активність гапоталамо-гіпофізарно-гонадальної системи організму, з іншого, призвели до низької запліднюваності від штучного осіменіння та високого показника індексу осіменіння.

Macronutrient, immunoglobulin a and total antioxidant capacity profiles of human milk from 1 to 24\u2009months: a cross-sectional study in Thailand

BackgroundAn extended duration of breastfeeding of up to two years is encouraged by many health authorities, but information regarding the composition of milk after one year postpartum is limited. The goal of this study was to determine the association between the duration of lactation and macronutrient contents, immunoglobulin A (IgA) levels and total antioxidant capacity (TAC) in human milk (HM), from 1 to 24 months postpartum.MethodsCross-sectional milk samples were collected between January and April 2019 from mothers with healthy full-term children who had been lactating for 1 to 24 months. The HM was biochemically analyzed for protein and carbohydrate contents by colorimetric assays. The fat content was determined by capillary centrifugation, and the energy content was calculated from the results of centrifugation assays. IgA levels and TAC were determined by ELISA and a Trolox equivalent antioxidant capacity (TEAC) assay, respectively. Pearson’s correlation coefficient and Spearman’s rank correlation coefficient were used to determine associations between months of lactation and milk composition, and multiple regression analysis was used to assess associations between months of lactation and milk composition adjusted for relevant covariates. Differences were considered significant at p < 0.05.ResultsOne hundred eighty-four milk samples were analyzed. The month of lactation was positively associated with the fat concentration (B = 0.31, SE = 0.09, p = 0.001), energy content (B = 3.11, SE = 0.92, p = 0.001), and IgA (B = 4.17, SE = 1.08, p < 0.001) but negatively associated with the carbohydrate concentration (B = − 0.22, SE = 0.01, p = 0.04). No association was observed between the month of lactation and the protein concentration or TAC after adjustment for maternal age, maternal BMI, birth order, and breastfeeding frequency.ConclusionThe duration of lactation was found to be positively associated with the fat, energy, and IgA content in HM for up to two years postpartum, and negatively associated with carbohydrate concentration. More prospective cohort studies are needed to obtain evidence-based knowledge regarding the changes in HM composition throughout the course of lactation.

Demographic, Social, and Personal Factors Associated With Lactation Cessation by 6 Weeks in Mothers of Very Low Birth Weight Infants.

Although mother's own milk decreases prematurity-associated morbidities, mothers of infants born preterm and very low birth weight experience a significantly shorter lactation duration. Little is known regarding factors associated with lactation cessation during the hospitalization of a very low birth weight infant. To determine demographic, social, and personal factors associated with lactation cessation by 6-weeks postpartum in mothers delivering very low birth weight infants. We used a retrospective, longitudinal, two-group comparison design using data from a randomized control study. Mothers of very low birth weight infants (N = 142) were enrolled from a labor and delivery unit associated with a Level 4 neonatal intensive care unit. Demographic, social, and health information was obtained from the medical records. Participants were surveyed regarding lactation goals, experience, and reason(s) for cessation. Participants who did not continue lactating for more than 6 weeks were more likely to be unemployed (p = .019), Medicaid eligible (p = .009), less educated (p < .031), smoke (p = .002), provide less skin-to-skin care (p = .007), and to delay the decision to provide their milk to their infant (p = .007). After Bonferroni adjustment, only minutes of skin-to-skin care remained statistically significant. Insufficient maternal milk production was the most common reason for lactation cessation. While the etiology of lactation cessation is often non-modifiable, strategies aimed at maintaining mother's own milk production, smoking cessation, increasing skin-to-skin care, and promoting an earlier decision to lactate, may prolong lactation duration in this vulnerable population.This RCT was registered (2012-00071) with ClinicalTrials.com on 6/28/2013.

Endocrine-disrupting chemicals and breastfeeding duration: a review.

The purpose of this review is to describe epidemiologic and toxicological literature investigating how endocrine-disrupting chemicals (EDCs) affect mammary gland development and function, thereby impacting lactation duration. Perfluoroalkyl and polyfluoroalkyl substances appear to reduce breastfeeding duration through impaired mammary gland development, lactogenesis, and suppressed endocrine signaling. Halogenated aromatic hydrocarbons have differing associations with lactation duration, likely because of the variety of signaling pathways that they affect, pointing to the importance of complex mixtures in epidemiologic studies. Although epidemiologic literature suggests that pesticides and fungicides decrease or have no effect on lactation duration, toxicology literature suggests enhanced mammary gland development through estrogenic and/or antiandrogenic pathways. Toxicological studies suggest that phthalates may affect mammary gland development via estrogenic pathways but no association with lactation duration has been observed. Bisphenol A was associated with decreased duration of breastfeeding, likely through direct and indirect action on estrogenic pathways. EDCs play a role in mammary gland development, function, and lactogenesis, which can affect breastfeeding duration. Further research should explore direct mechanisms of EDCs on lactation, the significance of toxicant mixtures, and transgenerational effects of EDCs on lactation.