Milk Ejection Research Articles

A dynamic mammary gland model describing colostrum immunoglobulin transfer and milk production in lactating sows.

The physiology of the sow mammary gland is qualitatively well described and understood. However, the quantitative effect of various biological mechanisms contributing to the synthesis of colostrum and milk is lacking and more complicated to obtain. The objective of this study was to integrate physiological and empirical knowledge of the production of colostrum and milk in a dynamic model of a single sow mammary gland to understand and quantify parameters controlling mammary gland output. In 1983, Heather Neal and John Thornley published a model of the mammary gland in cattle, which was used as a starting point for the development of this model. The original cattle model was reparameterized, modified, and extended to describe the production of milk by the sow mammary gland during lactation and the prepartum production of colostrum as the combined output of immunoglobulins (Ig) and milk. Initially, the model was reparameterized to simulate milk synthesis potential of a single gland by considering biological characteristics and empirical estimations of sows and piglets. Secondly, the model was modified to simulate more accurately the responses to changes in milk removal rates. This was done by linking the ejectable milk storage capacity to the number of secretory cells rather than being constant throughout lactation. Finally, the model was extended to include the prepartum synthesis of milk and the kinetics of Ig into and out of the mammary gland. A progressive capacity of secretory cells to synthesize milk was used to differentiate the time between the onset of milk synthesis and Ig transfer. Changes in maximum milk removal rate, duration of milk ejection, and nursing interval exerted a great impact on the modeled milk output. Changes by ±60% in one of these parameters were capable of increasing milk output by 28% to 39% during the first 4 wk in lactation compared with the reference parameterization. This suggests that the ability of the piglet to remove milk from the gland exerts a key control on milk synthesis during lactation. Modeling colostrum as the combined output of Ig and milk allowed to represent the rapid decline in Ig concentration observed during the first hours after farrowing. In conclusion, biological and empirical knowledge was integrated into a model of the sow mammary gland and constitutes a simple approach to explore in which conditions and to what extent individual parameters influence Ig kinetics and milk production.

Effects of Maternal Hyperglycemia Associated with Snack Intake on Milk Ejection and Offspring Development

Effects of Maternal Hyperglycemia Associated with Snack Intake on Milk Ejection and Offspring Development

Impact of expression mode and timing of sample collection, relative to milk ejection, on human milk bacterial DNA profiles.

To investigate the impact of expression mode: electric breast pump or hand expression, and timing of sample collection: pre- and post-milk ejection on human milk (HM) bacterial DNA profiles. Three HM samples from the same breast were collected from 30 breastfeeding mothers: a pre-milk ejection pump-expressed sample (pre-pump), a post-milk ejection pump-expressed sample (post-pump) and a post-milk ejection hand-expressed sample (post-hand). Full-length 16S rRNA gene sequencing was used to assess milk bacterial DNA profiles. Bacterial profiles did not differ significantly based on mode of expression nor timing of sample collection. No significant differences were detected in the relative abundance of any OTUs based on expression condition (pre-pump/ post-pump and post-pump/post-hand) with univariate linear mixed-effects regression analyses (all P-values>0·01; α=0·01). Similarly, no difference in richness was observed between sample types (number of observed OTUs: post-pump/post-hand P=0·13; pre-pump/post-pump P=0. 45). Bacterial DNA profiles of HM did not differ according to either expression method or timing of sample collection. Hand or pump expression can be utilized to collect samples for microbiome studies. This has implications for the design of future HM microbiome studies.

Effect of various milking equipment on milk ejection in high-yielding cows

Improving modern dairy farming is based on the industry's development, which means transforming livestock farming into a competitive industry. The development of its technical and technological support is closely related to its functional ability to realize the genetic potential of biological objects of production with high-quality products, which is the defining criterion for the competitiveness of machinery and technology at the industry’s present stage of development. The purpose of the research was to study milk production technology based on a comprehensive assessment and implementation of modern milking equipment, maximizing animals’ genetic potential and industry efficiency. We proved that applying the ‘DeLaval’ milking parlor under the same feeding and keeping animals ensured the proper completeness of milking and increased cows’ milk yield. During the first, third, and highest lactations, the milk yield was 226 kg (P=0.05), 266 kg (P=0.05), and 214 kg (P=0.05), respectively. After-milking when applying ADM-8A averaged 175 ml, and only 45 ml when applying the ‘DeLaval’ parlor. When using the ‘DeLaval’ milking equipment, the milk production intensity of cows was 1.43 kg/min, and, with ADM-8A, it was 1.24 kg/min, which is 0.19 kg/min (P=0.001), or 15.3% higher.

СПОСОБ ОЦЕНКИ ИНДИВИДУАЛЬНЫХ ОСОБЕННОСТЕЙ МОЛОКООТДАЧИ КОРОВ ПРИ РАЗНЫХ ТЕХНОЛОГИЯХ ДОЕНИЯ

The aim of the research is to study the possibility of using a latent period of the ejection of the first portion of milk in order to evaluate the individual characteristics of the milk ejection features of cows using the technology of bucket milking and robotic milking. Two experiments were conducted on cows of Black-Motley breed. Under the first experiment, the individual characteristics of the milk ejection were shown using the technology of bucket milking. Under the second experiment, they were determined for the technology of robotic milking. The first experiment was conducted on 12 mature cows. They were milked with a serial milking machine. The process of lactation was recorded by means of a bucket counter. The parameters of milk ejection were defined by analyzing the curve of lactation and making calculations. The second experiment was conducted on 30 first-calf heifers. Cows were milked on robotic installation the Astronaut A4 of Lely Company (the Netherlands). The data of the information system of herd management Lely T4C have been used for the analysis. Depending on the indicator of a latent period of the first milk portion ejection in both experiments three groups of cows (I–III) have been isolated. The ability of milk ejection in the first group was identified as high, in the second group – average and in the third group – low. Both experiments showed that the value of a latent period of the first milk portion ejection determined the milk ejection ability of cows. The increase in the period of the first milk portion ejection has been found among cows as their milk ejection ability decreses. The currently used milking technology shows that the reduced milk ejection among cows leads to the decrease in the indicators of the average and maximum intensity of milk ejection, the first two minutes of milking and also it leads to longer duration of milking. Using the robotic milking, the authors found that the first-calf heifers with the short period of the first milk portion ejection are characterized by the shortest duration of treating the teats and staying in the milking parlor, the average duration of milk ejection from the each quarter of the udder, as well as high values of the average and maximum intensity of milk ejection. The first-calf heifers with slow milking capacity are characterized by the longest duration of treating the teats and staying in the milking parlor, the average duration of milk ejection from the each quarter of the udder, as well as the lowest values of the average and maximum intensity of milk ejection. This suggests that the selection of first-calf heifers with high milk ejection ability will help to increase the productivity of automatic milking systems during the milking process. It is proposed to use the value of a latent period of the first milk portion ejection in the breeding activities.

The pressure oscillation in the inter-wall chamber of the teat cup

Factors influencing the vacuum gauge pressure in the inter-wall chamber of milking teat cups of a milking machine with a pneumo- and electromagnetic pulse generator with a combined collector are analyzed. The main factors of research and the limits of their variation are formed, the matrix of multifactor planned experiment is developed, and also results of experimental researches are received. According to the results of experimental studies, the regression equations in coded and real or natural values are derived, which characterize the dependence of pressure oscillation in the inter-wall chamber of milking teat cups on the pulsation frequency, milk ejection intensity and the ratio between strokes. A graphical model of interpretation of regression dependence based on experimental data is built. Student's t-test, Fisher's and Cochran’s criteria are calculated, which show the adequacy and reproducibility of the obtained model of the technological process using of the experimental pulse generator with combined collector of the milking machine.

A New Milking Technology: “Stimulactor” For Lactating Camels

The aim of this study was to develop a new milking machine for camels that guarantees high milk yield and quality whilst maintaining udder health. After a great effort, the new milking machine “StimuLactor for Camels” has been developed by Siliconform Germany. All the requirements of camels were tested on 5 dromedary camels over a period of one year. Our development was based on two main aspects: first, on the technical basis of the milking machine (type of machine, with or without a claw piece, kind of pulsation, vacuum level, type of teat cup liner and pulsation rate and ratio) which have to be adapted to the requirements of a camel’s udder and teats. The second important aspect was the calf’s suckling behaviour. The first results with the new milking technology have clearly shown that the system milks as the calf sucks. It can be used without the presence of the calf during the course of milk removal. Furthermore, the results proved that milk ejection reflex was induced and the milk was let down during the milking process. In conclusion, the new milking technology “StimuLactor for Camels” was adapted to the physiological, morphological and anatomical requirements of lactating camels.

Effect of positive tactile stimulation and prepartum milking routine training on behavior, cortisol and oxytocin in milking, milk composition, and milk yield in Gyr cows in early lactation

Positive interactions with humans can improve cow behavior and facilitate farm management, especially in dairy production systems in which milking occurs daily. Therefore, this study aimed to investigate the impact of positive tactile stimulation on behavior, and its effect on the milking routine, milk ejection, and milk yield of Gyr cows. Experiment 1 was performed with 40 cows: 20 cows (5 primiparous and 15 multiparous) received positive tactile stimulation (by hands and brushes) in the aisle of the corral during the prepartum period for 14 days; the other 20 cows (5 primiparous and 15 multiparous) did not receive any kind of tactile stimulation (control). Experiment 2 was performed with 40 heifers: 20 heifers were trained to enter the milking parlor and were progressively submitted to positive tactile stimulation (by hands and brushes) and to the milking routine during the prepartum period in the milking parlor for 14 days; the other 20 heifers did not receive any kind of training or tactile stimulation (control). Behavioral data were observed during the beginning of lactation: when the animal entered the milking parlor (stalled, needed help, and attempted to escape), during milking preparation (reaction to udder massage and to the strip cup test), and during milking (reaction to teat cups and whether the animal pulled off the teat cups). Milk yield and residual milk volume were measured and milk samples were collected for analysis of milk composition, somatic cell count, and cortisol and oxytocin in milk. All the experimental cows were suckled on one teat by their calf. Entry into the milking parlor and preparation of the animal for milking are the most critical moments for detecting reactivity to milking procedures. At the same time, the two positive stimulations studied (i.e., handling in the corral or training in the milking parlor) were efficient in improving the behavior of Gyr cows at the beginning of lactation, thus demonstrating that prepartum positive stimulation was effective at reducing the negative behavior of cows during the firsts milkings. Indeed, the percentual of residual milk in primiparous cows subjected to positive milking training was significantly lower than those measured in untrained primiparous and multiparous cows. This result is very promising because it indicates that Gyr heifers, when positively stimulated and trained in the milking routine during the prepartum period, will maintain adequate behavior and excellent milk ejection during their firsts milkings.

Mex3c mutation affects lactation through impairing milk ejection in female mice.

Mouse Mex3c encodes RNA-binding proteins of variant length through alternative splicing. Its mutation results in multiple defects including growth retardation, perturbed energy balance, and defective antiviral innate immunity. Here we report that Mex3c mutation affects mammary gland development and lactation in female mice. Pups of Mex3c mutant dams die of starvation soon after birth. Milk contents are present in the alveoli but deficient in the ducts of the mammary glands in mutant mice. Mutant mice do not show prolactin or oxytocin deficiency. They also develop myoepithelial cells in the mammary glands. Mex3c is expressed in the mammary gland epithelium. Our data suggest that functional defects in mammary gland epithelium or myoepithelial cells could cause lactation defects.

The Effect of Pre-milking Stimulation on Teat Morphological Parameters and Milk Traits in the Italian Water Buffalo.

Water buffaloes (Bubalus bubalis) are very sensitive to environmental stimulus before and during milking, and this explains why disrupted milk ejections due to blood oxytocin level instability are frequent in this species. According to the literature, the manual stimulation (MS) of teats before milking promotes oxytocin release and allows milk ejection to start within 2–3 min. However, the pre-milking stimulation of teats is not always part of the milking routine in Italian buffalo farms; moreover, buffaloes with unstable milk let-down are sometimes treated with exogenous oxytocin (OX). Different types of pre-milking stimulation can impact differently on the mammary gland epithelium and structures and, therefore, on milk yield. In this study, we observed the changes in teat morphological traits before and after the application of three types of stimuli, i.e., no manual stimulation (NS), MS, and OX, in buffaloes reared in an Italian dairy farm. In particular, measurements were available for 23 and 21 buffaloes for front and rear teats, respectively. Subsequently, the effect of the pre-milking stimulation type was estimated on teat morphological characteristics and on milk traits recorded after the application of stimuli. The results showed that the teat canal length was shorter (P < 0.05) after stimulation in the case of MS and OX compared to NS. Cistern diameter was overall greater for MS and lower for OX. On the contrary, teat wall thickness was greater and lower for OX and MS, respectively. Milk yield and quality (fat, protein, and somatic cell score) were similar across the three types of pre-milking stimulation. In perspective, the impact of these types of pre-milking stimulation should be evaluated on a large scale, and the focus might be put on mammary gland epithelium integrity, mastitis incidence, and other udder health indicators in milk, e.g., electrical conductivity, differential somatic cell count, lactose content, and sodium and chloride concentration.

Prophylactic Use of Meloxicam and Paracetamol in Peripartal Sows Suffering From Postpartum Dysgalactia Syndrome

Postpartum dysgalactia syndrome (PPDS) is a major economic problem in modern sow farms. General treatment of PPDS consists of the use of oxytocin to promote milk ejection and non-steroidal anti-inflammatory drugs (NSAIDs) to alleviate inflammatory processes. So far, studies investigated the use of a single administration of NSAIDs after parturition in healthy and non-healthy sows. The current study investigated whether administration of meloxicam or paracetamol in sows prior to parturition improves sow and piglet health as well as performance in a farm with PPDS problems in sows. Sixty sows and 978 piglets from a Belgian farrow-to-finish farm were enrolled. Sows were randomly divided into three groups: a non-treated control group, a meloxicam-treated group and a paracetamol-treated group. Treatment was administered orally for 7 days from gestation day 113 onwards. Performance and health parameters investigated in sows were gestation length, farrowing duration, litter characteristics, colostrum yield and quality (Immunoglobulin G), litter weight gain, weaning-to-estrus interval, pregnancy rate, rectal temperature, acute phase proteins and inflammatory markers serum amyloid A, haptoglobin, interferon γ, interleukin 1β and 6 backfat, constipation and feed refusal. Performance and health parameters in piglets were birthweight, average daily weight gain, colostrum intake and mortality. Paracetamol-treated sows showed a significantly (P = 0.04) lower rectal temperature (mean ± SD: 38.09 ± 0.18°C) than the meloxicam-treated sows (38.24 ± 0.18°C), but not than the control group (38.22 ± 0.18°C). Sows of the paracetamol-treated group had a significantly (P = 0.001) longer gestation length (116.3 ± 0.9 days) than sows of the control group (115.3 ± 0.6 days), but not than meloxicam-treated sows (115.9 ± 0.9 days). No significant differences between the three groups were found for all the other parameters. In conclusion, the prophylactic oral administration of either meloxicam or paracetamol for 7 days starting 2 days prior to farrowing did not show beneficial effects on both health and performance parameters of sows and piglets.

The Effect of Intramuscular Oxytocin Injection on Milk Ejection in Dairy Cattles

Milking is a source of change in milk yield and milk quality determination, and one of the main events of milking is the oxytocin-mediated ejection reflex. Complete ejection of milk from the udder is due to the presence of high oxytocin during milking. The aim of this study is to investigate whether oxytocin administered intramuscularly has an effect on increasing milk ejection. In the study, 28 clinically healthy lactation Holstein cows were used, the lactation numbers and lactation periods of these cows were ignored in the evaluation. The study groups are divided into four groups, each consisting of seven cows. 50 IU oxytocin was given to group-1 five days before milking in the morning and evening, group-2 received 50 IU oxytocin once a day just before milking and the group-3 was given 50 IU oxytocin once before morning milking on the 1st, 3rd, and 5th days and the group-4 is a control group, oxytocin was not given to this group. Oxytocin injection was administered intramuscularly 30 minutes before milking. In the evaluation, the last five days of milk data before the application, five days of milk data during the application period and five days of milk data after the application period were taken into consideration. As a result of the study, we can say that the udder was not completely emptied with the intramuscular administration of oxytocin.

Homocysteine Hypothesis on the Impaired Peripheral but Not Central Nervous System Oxytocin Responses in Cystathionine γ-Lyase-Deficient Dam Mice.

An elevated plasma homocysteine level is an independent risk factor for cardiovascular diseases, neurological disorders, and pregnancy complications. We recently demonstrated partial lactation failure in cystathionine γ-lyase-deficient (Cth-/-) dam mice and their defective oxytocin responses in peripheral tissues: uterine (ex vivo) and mammary gland (in vivo). We reasoned that elevated levels of circulatory homocysteine in Cth-/- dam mice counteract with oxytocin-dependent milk ejection from the mammary gland. Based on our observation that those mice displayed normal maternal behaviors against their pups and adult Cth-/- male mice exhibited normal social behaviors against adult wild-type female mice, both of which are regulated by oxytocin in the central nervous system (CNS), we conducted the present study to investigate the amino acid profiles, including total homocysteine, in both blood and cerebrospinal fluid (CSF) of wild-type and Cth-/- female mice before pregnancy and at day 1 of lactation (L1). Serum levels of total homocysteine in wild-type and Cth-/- L1 dam mice were 9.44 and 188 µmol/L, respectively, whereas their CSF levels were below 0.21 (limit of quantification) and 3.62 µmol/L, respectively. Their CSF/serum level ratio was the lowest (1/51.9) among all 20 proteinogenic amino acids, sulfur-containing amino acids, and citrulline/ornithine in Cth-/- mice. Therefore, we hypothesize that the blood-brain barrier protects the CNS from high levels of circulatory homocysteine in Cth-/- dam mice, thereby conferring normal oxytocin-dependent maternal behaviors.

Effect of Music Therapy on Relaxation and Breastfeeding Anxiety

Clinical nurses on a postpartum unit noted an opportunity to improve patient care during the breastfeeding process. Although breastfeeding is perceived to be a natural physiological process, many postpartum women experience breastfeeding anxiety. Maternal anxiety decreases the milk production by inhibiting the milk ejection reflex. The 8A’s evidence-based practice model was used to answer the PICO (P—patient, problem or population; I–intervention; C–comparison, control, or comparator; O—outcome(s)) question. To determine whether, among postpartum breastfeeding women, music therapy increased relaxation and reduced breastfeeding anxiety. Scientific literature demonstrates that music therapy is an effective evidenced-based intervention to improve the following outcomes: milk volume, cortisol level, anxiety-related behaviors, and self-reported relaxation and anxiety. The health care system’s Institutional Review Board approved the project with exempt status on July 26, 2019 (IRB#:1908801). All breastfeeding women who were admitted to the postpartum unit were offered the opportunity to participate. Implementation occurred for those who agreed to participate (n = 30) during one of the feedings between 24 and 96 hours postpartum. Using disposable earphones, women were asked to listen to music of their choice (lullaby, instrumental, or piano with nature sounds) for at least 5 minutes before the breastfeeding session. They then began breastfeeding while the same music played through a speaker. After breastfeeding sessions were completed, the participants filled out self-reported surveys. Using Likert-scale surveys, breastfeeding women reported feeling significantly more relaxed after breastfeeding, as evidenced by a mean score of 6.07 (0 = not relaxed to 7 = very relaxed). The change in breastfeeding anxiety level through survey questions, “I have previously been anxious about breastfeeding,” and “I am anxious about breastfeeding in the future,” was statistically significant (p < .001). Music therapy increases relaxation, decreases breastfeeding anxiety, and, therefore, enhances the milk ejection reflex. Furthermore, past research has found that maternal anxiety decreases the chance of breastfeeding success and increases the risk for postpartum depression. Future projects could examine the effect of music therapy on exclusive breastfeeding rate, postpartum depression, and pumped-milk volume produced by mothers of premature newborns.

Fenugreek Stimulates the Expression of Genes Involved in Milk Synthesis and Milk Flow through Modulation of Insulin/GH/IGF-1 Axis and Oxytocin Secretion.

We previously demonstrated galactagogue effect of fenugreek in a rat model of lactation challenge, foreshadowing its use in women’s breastfeeding management. To assess longitudinal molecular mechanisms involved in milk synthesis/secretion in dams submitted to fenugreek supplementation, inguinal mammary, pituitary glands and plasma were isolated in forty-three rats nursing large 12 pups-litters and assigned to either a control (CTL) or a fenugreek-supplemented (FEN) diet during lactation. RT-PCR were performed at days 12 and 18 of lactation (L12 and L18) and the first day of involution (Inv1) to measure the relative expression of genes related to both milk synthesis and its regulation in the mammary gland and lactogenic hormones in the pituitary gland. Plasma hormone concentrations were measured by ELISA. FEN diet induced 2- to 3-times higher fold change in relative expression of several genes related to macronutrient synthesis (Fasn, Acaca, Fabp3, B4galt1, Lalba and Csn2) and energy metabolism (Cpt1a, Acads) and in IGF-1 receptor in mammary gland, mainly at L12. Pituitary oxytocin expression and plasma insulin concentration (+77.1%) were also significantly increased. Altogether, these findings suggest fenugreek might extend duration of peak milk synthesis through modulation of the insulin/GH/IGF-1 axis and increase milk ejection by activation of oxytocin secretion.

Multiscale imaging of basal cell dynamics in the functionally mature mammary gland

The mammary epithelium is indispensable for the continued survival of more than 5,000 mammalian species. For some, the volume of milk ejected in a single day exceeds their entire blood volume. Here, we unveil the spatiotemporal properties of physiological signals that orchestrate the ejection of milk from alveolar units and its passage along the mammary ductal network. Using quantitative, multidimensional imaging of mammary cell ensembles from GCaMP6 transgenic mice, we reveal how stimulus evoked Ca2+ oscillations couple to contractions in basal epithelial cells. Moreover, we show that Ca2+-dependent contractions generate the requisite force to physically deform the innermost layer of luminal cells, compelling them to discharge the fluid that they produced and housed. Through the collective action of thousands of these biological positive-displacement pumps, each linked to a contractile ductal network, milk begins its passage toward the dependent neonate, seconds after the command.

Astrocytic Modulation of Supraoptic Oxytocin Neuronal Activity in Rat Dams with Pup-Deprivation at Different Stages of Lactation.

Appropriate interactions between astrocytes and oxytocin neurons in the hypothalamo- neurohypophysial system are essential for normal lactation. To further explore the mechanisms underlying astrocytic modulation of oxytocin neuronal activity, we observed astrocytic plasticity in the supraoptic nucleus of lactating rats with intermittent pup-deprivation (PD, 20h/day) at early (day 1-5) and middle (day 8-12) stages of lactation. PD at both stages decreased suckling duration and litter's body weight gain. They also significantly increased the expression of glial fibrillary acidic protein (GFAP) in Western blots while increased GFAP filaments and the colocalization of GFAP filaments with aquaporin 4 (AQP4) puncta in astrocyte processes surrounding oxytocin neuronal somata in immunohistochemistry in the supraoptic nucleus. Suckling between adjacent milk ejections but not shortly after them decreased molecular association between GFAP and AQP4. In hypothalamic slices from male rats, oxytocin treatment (0.1nmol/L, 10min) significantly reduced the length of GFAP filaments and AQP4 puncta in the processes but increased GFAP staining in the somata. These oxytocin effects were blocked by pretreatment of the slices with N-(1,3,4-Thiadiazolyl) nicotinamide (TGN-020, inhibitor of AQP4, 10µmol/L, 5min before oxytocin). In addition, inhibition of AQP4 with TGN-020 blocked excitation in oxytocin neurons evoked by prostaglandin E2, a downstream signal of oxytocin receptor and mediator of oxytocin-evoked burst firing, in whole-cell patch-clamp recordings. These results indicate that AQP4-associated astrocytic plasticity is essential for normal oxytocin neuronal activity during lactation and that PD-evoked hypogalactia is associated with astrocytic process expansion following increased GFAP and AQP4 expressions.

Maternal plasma levels of oxytocin during breastfeeding-A systematic review.

IntroductionOxytocin is a key hormone in breastfeeding. No recent review on plasma levels of oxytocin in response to breastfeeding is available.Materials and methodsSystematic literature searches on breastfeeding induced oxytocin levels were conducted 2017 and 2019 in PubMed, Scopus, CINAHL, and PsycINFO. Data on oxytocin linked effects and effects of medical interventions were included if available.ResultsWe found 29 articles that met the inclusion criteria. All studies had an exploratory design and included 601 women. Data were extracted from the articles and summarised in tables. Breastfeeding induced an immediate and short lasting (20 minutes) release of oxytocin. The release was pulsatile early postpartum (5 pulses/10 minutes) and coalesced into a more protracted rise as lactation proceeded. Oxytocin levels were higher in multiparous versus primiparous women. The number of oxytocin pulses during early breastfeeding was associated with greater milk yield and longer duration of lactation and was reduced by stress. Breastfeeding-induced oxytocin release was associated with elevated prolactin levels; lowered ACTH and cortisol (stress hormones) and somatostatin (a gastrointestinal hormone) levels; enhanced sociability; and reduced anxiety, suggesting that oxytocin induces physiological and psychological adaptations in the mother. Mechanical breast pumping, but not bottle-feeding was associated with oxytocin and prolactin release and decreased stress levels. Emergency caesarean section reduced oxytocin and prolactin release in response to breastfeeding and also maternal mental adaptations. Epidural analgesia reduced prolactin and mental adaptation, whereas infusions of synthetic oxytocin increased prolactin and mental adaptation. Oxytocin infusion also restored negative effects induced by caesarean section and epidural analgesia.ConclusionsOxytocin is released in response to breastfeeding to cause milk ejection, and to induce physiological changes to promote milk production and psychological adaptations to facilitate motherhood. Stress and medical interventions during birth may influence these effects and thereby adversely affect the initiation of breastfeeding.

АДАПТИВНА КІБЕР-ФІЗИЧНА СИСТЕМА ПРОЦЕСУ ВИРОБНИЦТВА МОЛОКА

The basic principles of adaptation of machine milking technical system to the physiology of milk ejection of cows are considered. Main adaptation parameters and conditions of the technical system are grounded, under these parameters and conditions the self-tuning of technical system is possible. The structure of modules of adaptive cyber-physical control system of machine milking is developed, its functionalities are revealed, the method of coordination between discreteness of measurement of information and the quantization period is developed to ensure maximum reliability of the information. The memory size of the operational information about the process parameters is justified, as well as their structure and functional content. Functional content and structure of information about the technological process of the database is formulated. The general view of the main elements of the adaptive cyber-physical system of cows milking is given, as well as the results of work of the experimental adaptive cyber-physical system of the milk production.

Oxytocin in the dorsal raphe nucleus antagonizes the inhibition of maternal care induced by food deprivation

Lactation is indispensable for the pup's survival, but is considered a survival burden in dams under negative energy conditions. In the present study, we tested our hypothesis that oxytocin may facilitate energy investment to pups through behavioral control as well as milk ejection. Maternal care was observed in dams at 3 h but not 8 h after food deprivation. We investigated whether oxytocin in the dorsal raphe nucleus (DRN), which is involved in energy state-dependent regulation of maternal care, regulates maternal care. For this purpose, 2-pmol L368899, an oxytocin receptor antagonist, was injected into the DRN; after treatment, maternal care was inhibited in the dams with 3-h fasting, but not in the fed dams. In contrast, recovery of maternal care was observed in the dams with 8-h fasting who underwent 100-pmol oxytocin injection at the DRN. These results indicate that oxytocin in the DRN is required for displaying maternal behavior under fasting conditions, but not under fed conditions. Next, we investigated the site of oxytocin release. Presentation of pups decreased the oxytocin immunoreactivity at the paraventricular nucleus (PVN) of the hypothalamus in the 3-h-fasted dams, but not in the fed or 8-h-fasted dams. No change of the serum oxytocin level was observed. Few oxytocin-positive neurons projecting from the PVN to the DRN were detected through labeling with the retrograde tracer fluorogold. Oxytocin secreted at the PVN, which reaches the DRN, but not released as a hormone or neurotransmitter may mediate maternal care under food-restricted conditions.