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Background: Breastfeeding offers significant health benefits, but its practice and success can vary. While research on induced lactation in cisgender women has been documented, there is limited research on lactation induction in transgender women., Case Presentation: A 50-year-old transgender woman undergoing hormone therapy and living with a pregnant partner sought to co-feed using induced lactation. After approval by the hospital ethics committee, a regimen of estradiol, progesterone, and domperidone was initiated, accompanied by nipple stimulation. Lactation was successfully induced and maintained, with milk composition analysis indicating high levels of protein and other key nutrients. This case, the seventh reported, highlights the complexity of lactation induction in transgender women, considering factors such as age, obesity, and insulin resistance. The nutrient profile of the milk suggests its suitability for infant feeding, despite some differences from typical human milk., Conclusions: Induced lactation is feasible in transgender women, expanding the understanding of non-puerperal lactation and its potential in diverse family structures. Further research is warranted to optimize lactation induction protocols in transgender women., (© 2024. The Author(s).)

Background: Infections with (tricho-)strongyles, Dictyocaulus viviparus or Fasciola hepatica have been shown to reduce milk production in dairy cows. However, the current published studies focused on one single helminth infection by neglecting helminth co-infections and their possible (additive) effects on host performance. Hence, for the first time, we investigated differences in the impact of patent helminth co-infections versus mono-infections on milk production parameters in individual cows., Methods: A total of 1583 dairy cows from 27 herds were included in this study. Faecal samples were examined in 2015 and 2021/2022 to determine the number of eggs/larvae per gram faeces for (tricho-)strongyles, D. viviparus, F. hepatica and rumen flukes. The cows were classified as non-infected, mono-infected and co-infected. Linear mixed models were applied to analyse the association between infection status (non-infected vs. mono-infected vs. co-infected) with milk yield, milk protein and milk fat content by including potential confounders., Results: Infections with (tricho-)strongyles, D. viviparus, F. hepatica and rumen flukes were detected in 100%, 28.6%, 50.0% and 21.4% of herds, and 27.4%, 2.6%, 10.8% and 0.8% of faecal samples in 2015, while 100%, 0.0%, 86.7% and 60.0% of herds and 52.3%, 0.0%, 13.3% and 26.8% of faecal samples were positive in 2021/2022. Co-infections with two or more helminth taxa were detected in 74.4% of herds and 5.0% of faecal samples in 2015, and in 93.3% of herds and 21.7% of faecal samples in 2021/2022. The correlations between strongyle EPG, D. viviparus LPG and F. hepatica EPG were significantly positive in 2015. Significantly higher mean EPGs were identified in 2015 in faecal samples presenting co-infections with F. hepatica and one or two other helminth taxa than in faecal samples presenting F. hepatica mono-infections (P = 0.013). Although expected, the infection status (mono- or co-infected) had no significant impact on milk yield, milk protein and milk fat content in the linear mixed model analyses based on individual faecal examinations., Conclusions: Patent helminth co-infections had no additive detrimental impact on milk production parameters in the present study. This might be a result of presumably low worm burdens, but should be confirmed in future studies., (© 2024. The Author(s).)

This systematic review and meta-analysis aimed to estimate the prevalence of pregnancy- and lactation-associated osteoporosis in postpartum women within 1 year of delivery. We searched MEDLINE via PubMed and Igaku Chuo Zasshi for articles published in English or Japanese from the inception of the database to September 2021. Two researchers independently screened and included observational studies reporting the prevalence of pregnancy- and lactation-associated osteoporosis in postpartum women within 1 year of delivery. Of the 3,425 screened records, 8 articles centered on postpartum women were included in the review. Seven studies used dual-energy X-ray absorptiometry for assessing bone mineral density, while one used a quantitative ultrasound method. In the seven studies that used dual-energy X-ray absorptiometry, the parameters used to define osteoporosis were the T-score (two studies), Z-score (three studies), both T- and Z-scores (one study), and young adult mean (one study). Evaluation timeframes included 1 week (three studies), 1-2 months postpartum (three studies), and 1 week to 12 months postpartum (one study). The estimated prevalence of pregnancy- and lactation-associated osteoporosis defined by dual-energy X-ray absorptiometry was as follows: lumbar spine (six studies), 5% (95% confidence interval [CI], 0-13; heterogeneity [I 2 ] = 99%) and femoral neck (three studies), 12% (95% CI, 0-30; I 2 = 99%). Pregnancy and lactation were found to elevate the fracture risk in women, underscoring the necessity for a standardized assessment in diagnosing pregnancy- and lactation-associated osteoporosis. This imperative step aims to enable early detection and treatment of bone mineral loss among postpartum women.

Background: Goat milk is gaining popularity as a superior alternative to bovine milk due to its closer resemblance to human milk. Understanding the molecular processes underlying lactation is crucial for improving milk quality and production in goats. However, the genetic mechanisms governing lactation in goats, particularly in indigenous breeds like the Jakhrana, remain largely unexplored., Results: In this study, we performed a comprehensive transcriptomic analysis of Jakhrana goat mammary glands during early and late lactation stages. We isolated milk somatic cells and conducted RNA sequencing, followed by transcript quantification and mapping against the ARS1.2 Capra hircus reference assembly. Our analysis identified differentially expressed genes (DEGs) and commonly expressed genes (CEGs) across the lactation phases. Early lactation showed enrichment of genes encoding antimicrobial peptides and lubrication proteins, while late lactation exhibited heightened expression of genes encoding major milk proteins. Additionally, DEG analysis revealed upregulation of pivotal genes, such as the ABC transporter gene MRP4, implicated in modulating milk composition and quality., Conclusion: Our findings provide insights into the genetic mechanisms underlying lactation dynamics in the Jakhrana goat. Understanding these mechanisms could help in improving milk production and quality in goats, benefiting both the dairy industry and consumers., (© 2024. The Author(s).)

Climate change with increasing ambient temperatures negatively influences the biology of dairy cows and their milk production in the mammary gland (MG). This study aimed to elucidate the MG proteome, differences in milk composition, and ruminal short-chain fatty acid concentrations of dairy cows experiencing 7 days of heat stress [HS, 28 °C, temperature humidity index (THI) = 76], pair-feeding (PF), or ad libitum feeding (CON) at thermoneutrality (16 °C, THI = 60). Ruminal acetate, acetate/propionate ratio, and milk urea concentrations were greater, whereas milk protein and lactose were lower in HS than in control cows. Proteome analysis revealed an induced bacterial invasion of epithelial cells, leukocyte transendothelial migration, reduction of the pyruvate and carbon metabolism, and platelet activation in the MG of HS compared to CON or PF cows. These results highlight adaptive metabolic and immune responses to mitigate the negative effects of ambient heat in the MG.

Background: Despite increasing breastfeeding initiation rates in the United States, disparities in breastfeeding continuation and exclusivity by race and ethnicity persist., Research Aim: We aimed to understand the perceptions and experiences of Latina parents who received access to telelactation, and assessed the implications of integrating telelactation into pediatric settings., Methods: This cross-sectional qualitative study drew from participants enrolled in a randomized controlled trial about breastfeeding support. We recruited 20 participants from among those participating in a randomized controlled trial assessing the effect of telelactation on breastfeeding outcomes. The study design was informed by an Equity-Centered Model and authentic entry. We conducted a thematic content analysis through an iterative approach, where we systematically generated themes to describe code application patterns., Results: We identified three themes: (1) telelactation within the broader landscape of breastfeeding support; (2) perceptions of telelactation support; and (3) recommendations on the use of telelactation in the context of pediatric care. We found that participants had an escalation approach for seeking breastfeeding support and propose a new model: Breastfeeding Support Escalation Protocol, which can be applied to lactation support in pediatric care. Parents' perceptions and recommendations highlighted their desire for care coordination, expanded options for telelactation engagement, and care continuity, which are important reflections for pediatric offices considering integrating telelactation services into their practice., Conclusions: Latina parents found telehealth to be helpful and an acceptable alternative to in-person services. Pediatric offices can take steps toward becoming Breastfeeding-Friendly by partnering with telelactation services. More research is needed on the logistical implications and cost-effectiveness of telelactation services as part of the pediatric practice., Competing Interests: Disclosures and Conflicts of InterestThe authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The authors have no potential, perceived, or real conflicts of interest to declare. At the time of the study, Jill Demirci was Deputy Editor in Chief of the Journal of Human Lactation and At the time of the research, Gabriela Alvarado was a doctoral candidate and performed the work on this project under the supervision of Lori Uscher-Pines.

Objective: In this pilot study, we verified safe practices for breast milk expression, storage, and duration, based on bacteriological results., Results: We collected breast milk samples from three healthy lactating volunteers and analyzed the bacterial flora and changes in the viable bacterial counts (including those of Staphylococcus) of the samples. Although no consistent change could be observed in the abundance of a particular bacterial group in samples expressed under hygienic control conditions, viable bacterial counts were higher in self-expressed milk than in milk expressed under hygienic control conditions. In conclusion, increased hygiene awareness is vital during breast milk expression and storage., (© 2024. The Author(s).)

Background: Mammographic density has been associated with breast cancer risk, and is modulated by established breast cancer risk factors, such as reproductive and hormonal history, as well as lifestyle. Recent epidemiological and biological findings underscore the recognized benefits of breastfeeding in reducing breast cancer risk, especially for aggressive subtypes. Current research exploring the association among mammographic density, breastfeeding, and breast cancer is sparse., Main Findings: Changes occur in the breasts during pregnancy in preparation for lactation, characterized by the proliferation of mammary gland tissues and the development of mammary alveoli. During lactation, the alveoli fill with milk, and subsequent weaning triggers the involution and remodeling of these tissues. Breastfeeding influences the breast microenvironment, potentially altering mammographic density. When breastfeeding is not initiated after birth, or is abruptly discontinued shortly after, the breast tissue undergoes forced and abrupt involution. Conversely, when breastfeeding is sustained over an extended period and concludes gradually, the breast tissue undergoes slow remodeling process known as gradual involution. Breast tissue undergoing abrupt involution displays denser stroma, altered collagen composition, heightened inflammation and proliferation, along with increased expression of estrogen receptor α (ERα) and progesterone receptor. Furthermore, elevated levels of pregnancy-associated plasma protein-A (PAPP-A) surpass those of its inhibitors during abrupt involution, enhancing insulin-like growth factor (IGF) signaling and collagen deposition. Prolactin and small molecules in breast milk may also modulate DNA methylation levels. Drawing insights from contemporary epidemiological and molecular biology studies, our review sheds light on how breastfeeding impacts mammographic density and explores its role in influencing breast cancer., Conclusion: This review highlights a clear protective link between breastfeeding and reduced breast cancer risk via changes in mammographic density. Future research should investigate the effects of breastfeeding on mammographic density and breast cancer risk among various ethnic groups and elucidate the molecular mechanisms underlying these associations. Such comprehensive research will enhance our understanding and facilitate the development of targeted breast cancer prevention and treatment strategies., (© 2024. The Author(s).)

Objective: To retrospectively analyze the clinical practicability and value of ultrasound-guided minimally invasive catheterization combined with compound Phellodendron Phellodendri liquid in the treatment of breast abscess during lactation., Methods: 139 patients with lactational breast abscess discharged from our hospital from January 2021 to November 2023 were selected. We divided them into groups according to treatment methods, analyzed whether there were statistical differences in observation indexes among groups and the risk factors affecting breastfeeding rate and treatment satisfaction., Results: We found that numerical rating scale(NRS) score and incidence of breast fistula in group A were significantly lower than other, the continuous decrease of postoperative drainage in group A was higher than other, there were significant differences among groups (p<0.001). Univariate analysis showed that recovery time, drainage tube placement time, postoperative redness and swelling regression time, scar length, and VAS score of six groups were statistically significant (p<0.001). We found that the overall satisfaction and the rate of continued breastfeeding in group A (96.2%) were higher than other, the differences were statistically significant(p<0.05). Logistic regression analysis revealed that the significant risk factors influencing treatment satisfaction included the time of drainage tube placement, postoperative redness and swelling regression time, treatment group, surgical method, NRS score on the first day after operation, postoperative drainage volume, healing time, scar length, flushing drugs, and VAS score. Postoperative redness and swelling regression time, treatment group, operation method and VAS score are all risk factors that influence the outcome of breastfeeding., Conclusion: Ultrasound-guided minimally invasive catheterization combined with compound cortex phellodendri fluid in the treatment of breast abscess during lactation can not only reduce the pain caused by dressing change, but also offer numerous advantages, including shorter healing time, beautiful appearance, lower incidence of breast fistula, high satisfaction and high rate of continued breastfeeding., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Lactation women, a highly concerned demographic in society, face health risks that deserve attention. Zinc oxide nanoparticles (ZnO NPs) are widely utilized in food and daily products due to their excellent physicochemical properties, leading to the potential exposure of lactating women to ZnO NPs. Hence, assessing the potential risks associated with ZnO NP exposure during lactation is critical. While studies have confirmed that exposure to ZnO NPs during lactation can induce toxic responses in multiple organs through blood circulation, the effects of lactational exposure on mammary tissue remain unclear. This research investigated the impairment of mammary tissue induced by ZnO NPs and its potential mechanisms. Through administering multiple injections of ZnO NPs into the tail vein of lactating ICR mice, our study revealed that ZnO NPs can deposit in the mammary tissues, downregulating key components of mammary epithelial barrier such as ZO-1, occludin, and claudin-3. In vivo, we also found that ZnO NPs can simultaneously induce apoptosis, necroptosis, and pyroptosis, called PANoptosis. Additionally, using EpH4-Ev cells to simulate an in vitro mammary epithelial barrier model, we observed that ZnO NPs effectively disrupted the integrity of mammary epithelial barrier and induced PANoptosis. Furthermore, we confirmed that PANoptosis was responsible for the mammary epithelial barrier disruption induced by ZnO NPs. Moreover, we identified that ZBP1 was the primary mechanism of ZnO NPs inducing PANoptosis. These discoveries are designed to enhance our comprehension of the mechanisms underlying mammary epithelial barrier disruption caused by ZnO NPs, and we aim to highlight the potential hazards associated with daily usage and therapeutic exposure to ZnO NPs during lactation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Statins are historically contraindicated during breastfeeding due to theoretical concerns of disruptions in infant development from drug exposure and nutritional changes in milk. Breastfeeding mothers requiring statins often discontinue statins or postpone treatment until breastfeeding cessation, contributing to delays in treatment up to 14 years. This study aims to determine the transfer of atorvastatin and its active metabolites into human milk and evaluate the infant's risk of drug exposure. Materials and Methods: Milk samples and health information were released from the InfantRisk Human Milk Biorepository for three women taking 20 mg, 40 mg, and 80 mg of atorvastatin daily at steady state conditions. The concentration of atorvastatin (AT) and its active metabolites, ortho-hydroxy AT (2OH AT) and para-hydroxy AT (4OH AT), was quantified in timed milk samples using liquid chromatography-mass spectrometry. Results: The highest absolute infant dose of AT was 0.00027 mg/kg/day, and the highest weight-adjusted relative infant dose of the combined analytes was 0.09%, far below established thresholds for infant safety. Milk cholesterol levels were within previously established norms in the range of 10 mg/dL. The mothers reported no adverse outcomes in the two exposed infants. Conclusions: The transfer of atorvastatin and its metabolites was exceedingly low. While the impact on milk composition in states of hyperlipidemia (whether treated or untreated) is not well understood, it is unlikely that the drug in the milk would be present in clinically significant levels to adversely affect a breastfed infant.

Introduction: Breastfeeding is crucial in infant nutrition and bonding, recommended for at least 6 months and up to 2 years postpartum, providing health benefits for both infants and mothers. However, nipple trauma is common among lactating mothers. Moisturising therapies, such as hydrogel application, aim to promote the healing of nipple wounds. Despite various interventions proposed, comprehensive reviews evaluating the efficacy of moisturising therapies for nipple trauma are lacking. This review aims to appraise the effectiveness of moisturising therapy, particularly tailored for nipple trauma in lactating women., Methods and Analysis: This systematic review protocol adheres to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines and is registered in the International Prospective Register of Systematic Reviews. The focus will be on both randomised and non-randomised controlled trials addressing the treatment of nipple trauma in lactating women. In this context, 'moisturising therapy' is categorised as a non-pharmacological intervention applied directly to the nipple, excluding treatments for bacterial or fungal infections. The primary outcomes will include measures of the healing efficiency of nipple trauma and reduction in nipple pain. Searches will be conducted without date restrictions across multiple databases, including PubMed, CINAHL, the Cochrane Library, Web of Science, CiNii Research and Ichushi-Web, in addition to exploration of grey literature. Two independent reviewers will manage all stages of the review process, under the supervision of a third reviewer. Data extraction will encompass participant demographics, study methodologies, sample specifics and measured outcomes. Quality assessment will be conducted using the Joanna Briggs Institute Appraisal Checklist Tools., Ethics and Dissemination: Ethics approval is not required for this study. The findings of this review will be disseminated through academic publications, detailed reports and presentations at relevant conferences., Prospero Registration Number: CRD42023481761., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Thyroid hormones influence mammary gland differentiation and lactation by binding to thyroid hormone receptors. Hyperthyroidism disrupts pregnancy and lactation, affecting offspring growth and milk production. Despite maternal milk is a vital source of bioactive compounds and nutrients for newborns, it is unclear whether hyperthyroidism alters its composition, mainly immune factors. Therefore, our work aimed to evaluate the influence of hyperthyroidism on milk quality and immunological parameters during early lactation. Twelve-week-old female Wistar rats received daily injections of 0,25 mg/kg T 4 (HyperT, n=20) or vehicle (control, n=19) starting 8 days before mating and continuing throughout pregnancy. Rats were euthanized on day 2 of lactation for analyzing the impact of hyperthyroidism on mammary gland, serum and milk samples. HyperT pups exhibited reduced weight, length and head circumference with altered serum hormones, glucose and albumin levels. HyperT mammary gland analysis revealed structural changes, including decreased alveolar area, adipose tissue, increased connective tissue and reduced epithelial elongation, accompanied by decreased TRβ1 RNA expression. HyperT milk displayed lower caloric value and fat concentration. HyperT animals exhibited altered milk immune cell counts, displaying increased numbers of CD45 + and CD3 + cells and decreased CD11b/c + cells without changes on milk and serum IgA, IgG and IgG2a levels. In summary, we have demonstrated that hyperthyroidism affects mammary gland morphology, disrupts pup development and alters biochemical and immunological parameters. Our findings highlight the impact of maternal hyperthyroidism on offspring early development and milk immune composition, underscoring the importance of thyroid function in maternal and neonatal immune health., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Background: The liver-expressed antimicrobial peptide 2 (LEAP2) is a recently recognized anorectic and glucose-regulating hormone, with unknown role in lactation., Objectives: 1) Assess LEAP2 presence in human milk and putative associations with infant body weight and adiposity in the first year of life, 2) Evaluate the impact of maternal weight status on LEAP2 concentration and 3) Explore the relationship between infant plasma LEAP2 concentration and body weight and adiposity., Methods: This prospective cohort observational study assessed LEAP2 concentration in plasma and milk from lactating women with normal weight (n=26) or overweight/obesity (OW/OB, n=26) at six months postpartum and in 6-month-old infant plasma, examining associations with metabolic and anthropometric variables at 6 months and 1 year. Maternal plasma and milk leptin and insulin concentrations were also measured. LEAP2 expression in milk fat globules and single-cell-RNA-sequencing datasets was evaluated., Results: LEAP2 was detected in all milk samples assessed (2.08±0.65 ng/ml) and was positively associated with infant triceps (p=0.022, Cohen f 2 =1.25) and subscapular (p=0.008, f 2 =0.68) skinfolds at 1 year old. Maternal LEAP2 was positively associated with insulin (p=0.005, f 2 =0.30) and pre-pregnancy body mass index (BMI) (p=0.040, f 2 =0.17) and negatively associated with gestational weight gain (p=0.008, f 2 =0.25) and postpartum weight retention (p=0.036, f 2 =0.15). Maternal LEAP2 was higher in plasma (p=0.039), but not milk of lactating women with OW/OB. Infant plasma LEAP2 (1.98±0.28 ng/ml) was positively associated with weight (p=0.004, f 2 =0.63), BMI (p=0.049, f 2 =0.37), and weight-for-length (p=0.024, f 2 =0.35) z-scores at 1 year old, predominantly in males. No evidence of LEAP2 mRNA expression was found in mammary cells., Conclusions: Milk LEAP2 is a bioactive component that plays a role in infant fat accretion in the first year of life. While maternal LEAP2 responds to weight change in pregnancy and lactation, infant plasma LEAP2 might be involved in body weight regulation in early life., Clinical Trial Registry: This study was registered at clinicaltrials.gov as NCT05798676. https://clinicaltrials.gov/study/NCT05798676., Competing Interests: Declaration of Competing Interest ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. ☐ The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:, (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Background: The microbiota and metabolites in the gastrointestinal tracts of female animals at different reproductive periods are very important to the growth, development, and health of themselves and their offspring. However, the changes in the gastrointestinal microbiota and metabolites throughout reproductive period of different sheep breeds and their effects on the growth and development of offspring lambs are still unclear. Hence, this study presents an assessment of the reproductive hormone levels, immune levels, rumen microbiota, and metabolites in Hu sheep and Suffolk ewes at different reproductive periods and their effects on the growth and development of offspring lambs., Results: Hu sheep and Suffolk during non-pregnancy, pregnancy, and lactation were used as the research objects to determine reproductive and immune indexes of ewes at different periods, analyze rumen microbiome and metabolome, and track the growth performance and development of offspring lambs. The results showed that the reproductive hormone and immune levels of Hu sheep and Suffolk underwent adaptive changes across different reproductive periods. Compared with non-pregnancy, the microbial energy metabolism and lipid metabolism function decreased during Hu sheep pregnancy, and energy metabolism function decreased during lactation. In Suffolk, energy metabolism, glycan biosynthesis, and metabolism function were enhanced during pregnancy, and the metabolism of cofactors and vitamins was enhanced during lactation. Prevotella increased in Suffolk during pregnancy and lactation (P < 0.05) and was positively correlated with the birth weight and body size of the lambs (P < 0.05). Moreover, the abundances of Butyrivibrio and Rikenellaceae&#95;RC9&#95;gut&#95;group during pregnancy were positively correlated with the intestinal immunity of the offspring lambs (P < 0.05), thereby regulating the intestinal immunity level of the lambs. Metabolomic analysis revealed that the protein digestion, absorption, and amino acid metabolism of Hu sheep were enhanced during pregnancy, which provided amino acids for the growth and development of pregnant ewes and fetuses and was significantly correlated with the birth weight, body size, and intestinal immunity of lambs (P < 0.05). Simultaneously, there was an increase in acetate and propionate during the pregnancy and lactation period of both Hu sheep and Suffolk, providing energy for ewes during reproductive period. Moreover, the microbiota during the lactation period was significantly correlated with the milk quality and lambs daily gain (P < 0.05)., Conclusions: This study revealed the characteristic succession changes in the rumen microbiota and its metabolites at different reproductive periods in sheep breeds and their regulation of reproductive hormone and immune levels and identified their potential effects on the growth and development of offspring lambs. The findings provide valuable insights into the health and feeding management of different sheep breeds during the reproductive stage. Video Abstract., (© 2024. The Author(s).)

Background: Breastfeeding is crucial in providing infants with needed nutrition and immunity to foster their healthy growth and development; yet, optimal support from health workers is critical for it to be successful., Aim: To determine factors influencing tangible breastfeeding support among health workers in Nigeria., Methods: This cross-sectional study was conducted in Nigeria's six geopolitical zones between August 2022 and February 2023 among health workers ( N  = 2,922). Data were gathered through an interviewer-administered, validated questionnaire. Significant factors of tangible breastfeeding support were identified through multivariable logistic regression, and corresponding odds ratios with 95% confidence intervals were reported., Results: The mean age of the health workers was 28.6 ( SD  = 9.3) years. Just 45% (1,316) achieved optimal scores for tangible breastfeeding support. Only 31.4% (918) of lactation support providers/specialists practice tangible breastfeeding support and half (50.6%, 1,479) had a favorable attitude towards providing tangible breastfeeding support. About two-fifths (39.3%, 1,148) engaged caregivers in reviewing breast milk storage procedures, whereas, 54.6% (1,595) and 78.0% (2,279) of health workers assisted with breast pumps and breastfeeding attachment respectively. The odds of having optimal tangible breastfeeding support were higher for health workers aged 52 years or older compared to those aged under 20 years (aOR 1.88, 95% CI [1.13, 3.12]), a positive attitude (aOR 1.43, 95% CI [1.22, 1.69]), availability of a breastfeeding champion (aOR 1.47, 95% CI [1.21, 1.79]), 1.69]), provision of breast-pump videos (aOR; 2.33, 95% CI [1.85, 2.95]), and hand-expression videos (aOR; 1.41, 95% CI [1.02, 1.79]). (duplication)., Conclusion: Health workers' tangible breastfeeding support in Nigeria is suboptimal and is driven by age, service level, attitude, availability of breastfeeding champions, and appropriate practice aids. Targeted interventions to improve health workers' attitudes, technical skills, provision of aids, and task shifting to non-specialists are needed for optimal tangible breastfeeding support., Competing Interests: Disclosures and Conflicts of InterestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Human milk is a complex mix of nutritional and bioactive components that provide complete nourishment for the infant. However, we lack a systematic knowledge of the factors shaping milk composition and how milk variation influences infant health. Here, we characterize relationships between maternal genetics, milk gene expression, milk composition, and the infant fecal microbiome in up to 310 exclusively breastfeeding mother-infant pairs. We identified 482 genetic loci associated with milk gene expression unique to the lactating mammary gland and link these loci to breast cancer risk and human milk oligosaccharide concentration. Integrative analyses uncovered connections between milk gene expression and infant gut microbiome, including an association between the expression of inflammation-related genes with milk interleukin-6 (IL-6) concentration and the abundance of Bifidobacterium and Escherichia in the infant gut. Our results show how an improved understanding of the genetics and genomics of human milk connects lactation biology with maternal and infant health., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

When infants cannot directly breastfeed after birth, mothers are advised to initiate lactation through mechanical expression. Families are recommended to target an expression volume of at least 500-750 mL by Day 14 after birth, as this is considered a 'critical window' to establish milk supply. This is challenging for many mothers after a very preterm birth. This article explores the relationship of early milk quantity and later full breastmilk feeding as a 'gold standard' outcome, using statistical techniques designed for diagnostic tests. A cohort of 132 mothers of infants born at 23 + 0 to 31 + 6 weeks' gestational age submitted expressing logs on Day 4, 14 and 21 after birth and provided later feeding outcome. Using receiver operating characteristic (ROC) analysis, the following 24-h milk quantities were identified as associated with high probability of full breastmilk at 36 weeks' post-menstrual age (PMA): on Day 4, ≥250 g (specificity 88%; positive predictive value 88%) and on Day 21 ≥650 g (specificity 88%; positive predictive value 91%). The following values were identified as associated with low probability of full breastmilk at 36 weeks' PMA: on Day 4 <50 g (sensitivity 92%; negative predictive value 72%) and on Day 21 <250 g (sensitivity 90%; negative predictive value 70%). Participants exceeding the high thresholds had 3-4 times increased likelihood of full breastmilk, whereas those below the low thresholds had 3-5 times lower likelihood. These thresholds have potential as targets for families, to provide individualised prognostic information and to help clinicians target more intensive lactation support., (© 2024 The Author(s). Maternal & Child Nutrition published by John Wiley & Sons Ltd.)

Climate change is an urgent threat to perinatal and infant health, with the greatest effects of climate change exposures being felt disproportionately by global majority communities who have been most harmed by systems of oppression. Human milk feeding is one recognized solution to bolster climate resilience. Yet, policies and practices to support human milk as a climate solution are inconsistent and under-prioritized, which is unsurprising given the lack of alignment between human history and current cultural context with regard to lactation and human milk access. This paper presents a new framework on lactation as a climate solution, which is unique in its incorporation of the critical history of cooperative breastfeeding in our species. Rooted in anthropogeny, or the study of human origins, and antiracist principles of lactation, the Allomilk Framework highlights five concepts of the ideal application of human milk as a climate solution, bridging ancient allonursing with present-day lactation and human milk access. These ideal applications-and the proposed development of measures to operationalize them-will advance the field through a shared understanding of the qualities that should be prioritized in the assessment of policies and practices at the intersection of climate resilience and human milk access. Application of the Allomilk Framework to assess and design future policies and practices will advance the field by increasing the potential for climate resilience and climate mitigation while working with-rather than against-the importance of cooperative breastfeeding in human history., Competing Interests: Disclosures and Conflicts of InterestThe author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Selenomethionine (SeMet) is an important nutrient, but its role in milk synthesis and the GPCR related to SeMet sensing is still largely unknown. Here, we determined the dose-dependent role of SeMet on milk protein and fat synthesis and proliferation of mammary epithelial cells (MECs), and we also uncovered the GPCR-mediating SeMet function. At 24 h postdelivery, lactating mother mice were fed a maintenance diet supplemented with 0, 5, 10, 20, 40, and 80 mg/kg SeMet, and the feeding process lasted for 18 days. The 10 mg/kg group had the best increase in milk production, weight gain of offspring mice, and mammary gland weight and acinar size, whereas a higher concentration of SeMet gradually decreased the weight gain of the offspring mice and showed toxic effects. Transcriptome sequencing was performed to find the differentially expressed genes (DEGs) between the mammary gland tissues of mother mice in the 10 mg/kg SeMet treatment group and the control group. A total of 258 DEGs were screened out, including 82 highly expressed genes including GPR37 and 176 lowly expressed genes. SeMet increased milk protein and fat synthesis in HC11 cells and cell proliferation, mTOR and S6K1 phosphorylation, and expression of GPR37 in a dose-dependent manner. GPR37 knockdown decreased milk protein and fat synthesis in HC11 cells and cell proliferation and blocked SeMet stimulation on mTOR and S6K1 phosphorylation. Taken together, our data demonstrate that SeMet can promote milk protein and fat synthesis and proliferation of MECs and functions through the GPR37-mTOR-S6K1 signaling pathway.

Ensuring optimal infant nutrition is crucial for the health and development of children. Many infants aged 0-6 months are fed with infant formula rather than breast milk. Research on cancer cell lines and animal models is limited to examining the nutrition effects of formula and breast milk, as it does not comprehensively consider absorption, metabolism, and the health and social determinants of the infant and its physiology. Our study utilized small intestine organoids induced from human embryo stem cell (ESC) to compare the nutritional effects of breast milk from five donors during their postpartum lactation period of 1-6 months and three types of Stage 1 infant formulae from regular retail stores. Using transcriptomics and untargeted metabolomics approaches, we focused on the differences such as cell growth and development, cell junctions, and extracellular matrix. We also analyzed the roles of pathways including AMPK, Hippo, and Wnt, and identified key genes such as ALPI, SMAD3, TJP1, and WWTR1 for small intestine development. Through observational and in-vitro analysis, our study demonstrates ESC-derived organoids might be a promising model for exploring nutritional effects and underlying mechanisms.

Background: Breastfeeding self-efficacy is a woman's self-belief and confidence in her perceived ability to breastfeed. This modifiable determinant is strongly associated with breastfeeding initiation, exclusivity, and duration. It is unclear how important the timing of breastfeeding self-efficacy measurement and interventions are. The prenatal period appears underexplored in the literature and yet a prenatal focus provides increased opportunity for breastfeeding self-efficacy enhancement and further potential improvement in breastfeeding outcomes. This scoping review aims to synthesise the evidence on prenatal breastfeeding self-efficacy, describing for the first time the theoretical frameworks, measurement tools, and interventions used in the prenatal period., Methods: 8 databases were searched using the PCC framework (Problem: breastfeeding, Concept: self-efficacy, Context: prenatal period). From 4,667 citations and 156 additional sources identified through grey literature and snowballing, data were extracted from 184 studies and 2 guidance documents. All were summarised descriptively and narratively., Results: Just over half (57%) of included studies stated their theoretical underpinning, with Bandura's Self-Efficacy Theory / Dennis' Breastfeeding Self-Efficacy Framework predominant. Only half of intervention studies incorporated theory in their design. More intervention studies were undertaken in the past decade than previously, but the level of theoretical underpinning has not improved. Prenatal interventions incorporating theory-led design and using components addressing the breadth of theory, more frequently reported improving breastfeeding self-efficacy and breastfeeding outcomes than those not theory-led. Intervention components used less frequently were vicarious or kinaesthetic learning (52.5%) and involvement of social circle support (26%). The Breastfeeding Self-Efficacy Scales were the most common measurement tool, despite being designed for postpartum use. Overall, issues were identified with the late prenatal timing of breastfeeding self-efficacy investigation and the design, content and phraseology of measurements and interventions used in the prenatal period., Conclusion: This review provides novel insights for consideration in the design and conduct of breastfeeding self-efficacy studies in the prenatal period. Future research should aim to be theory-led, commence earlier in pregnancy, and embed the breadth of self-efficacy theory into the design of interventions and measurement tools. This would provide more robust data on prenatal breastfeeding self-efficacy's role in impacting breastfeeding outcomes., (© 2024. The Author(s).)

Sarcopenia is characterised by the loss of skeletal muscle mass and function, which leads to a high risk of increased morbidity and mortality. Maternal malnutrition has been linked to impaired development of skeletal muscle of the offspring; however, there are limited studies that report the long-term effect of a maternal low-protein diet during lactation on the ageing of skeletal muscles. This study aimed to examine how a maternal low-protein diet (LPD) during lactation affects skeletal muscle ageing in the offspring. Pups born from control mothers were lactated by mothers fed with an LPD. Post-weaning, mice were either maintained on an LPD or switched to a control, normal-protein diet (NPD). In males, an LPD mainly affected the size of the myofibres without a major effect on fibre number and led to reduced grip strength in ageing mice (24 months). Female mice from mothers on an LPD had a lower body and muscle weight at weaning but caught up with control mice at 3 months. During ageing, the muscle weight, myofibre number and survival rate of female pups were significantly affected. These findings highlight the effect of an LPD during lactation on skeletal muscle ageing, the lifespan of offspring and the importance of sexual dimorphism in response to dietary challenges.

Hidradenitis suppurativa (HS) is a chronic skin condition that significantly impacts patients' quality of life. HS is often challenging to treat. In this review, we discuss the unique characteristics of HS in four special populations: children, the elderly, pregnant individuals, and breastfeeding mothers. In children, diagnosis may be delayed due to atypical and early HS disease presentations. HS management plans must take into consideration the lack of rigorous efficacy and safety data of HS treatments in this population. However, it is important to weigh the risk of treatments against the risk of untreated HS and the morbidity and mortality risk that having HS confers. Pregnancy poses unique challenges for women with HS, with their condition possibly worsening during pregnancy and increased risk of fetal death. Management strategies during pregnancy must consider both maternal and fetal safety. Similarly, breastfeeding mothers require thoughtful medication selection to balance symptom management with infant safety. In the elderly, HS may present more severely and is often complicated by comorbidities. Treating HS in this population should safely accommodate patients' additional health conditions. Furthermore, this review highlights the overall paucity of primary literature addressing management in these populations, underscoring the need for further research to optimize HS care across all stages of life., (© 2024. The Author(s).)

The most common and efficient iron supply to prevent neonatal anaemia in piglets is the injection of iron dextran or gleptoferron. This treatment is problematic in organic farms because organic specifications strictly limit the use of chemically synthesised allopathic drugs. Based on the observation that piglets raised outdoors rarely develop anaemia, we hypothesised that piglets satisfy their iron needs by ingesting soil from their environment. Therefore, we compared the efficacy of a 100-mg intramuscular iron dextran injection (Iron, 8 litters, n = 98 piglets) at 4 days (d) of age (d4), to a daily ad libitum supply of dried soil (Soil, 8 litters, n = 101) or dried peat-like river silt (Peat, 8 litters, n = 102) from d4 to weaning (at 49 days of age, d49). Pigs were raised according to organic farming rules. Blood was collected on three males and three females per litter on d4, 20, 41, 50 and 69. BW was similar in the three groups on d4, 20, 41, 50 and 69 (P > 0.1). During the experiment, piglets were affected by a severe digestive E. coli episode but litter mortality rate between d4 and d69 did not differ between groups (P > 0.1). Blood haemoglobin concentration (Hb) was similar in all groups on d4, 50 and 69. However, on d20, Hb was higher in Peat and Iron groups than in the Soil group (P < 0.001), and on d41 and d50, Hb was higher in the Peat group than in Iron and Soil groups (P < 0.001). Mean red blood cell volume (RBCV) remained stable over time in the Peat group. In comparison, RBCV dropped in the Soil group on d20 and d41 (P < 0.001), and in the Iron group on d41 (P < 0.001). Soil and Iron group RBCV returned values similar to the Peat group by d69 (P > 0.1). In conclusion, soil supply in the pen was not sufficient to ensure a satisfactory iron intake in piglets, unlike peat-like river silt, which enable to reach haemoglobin concentrations above 80 mg/mL for over 90% of the piglets from d20 and, over 100% of piglets at weaning. The daily supply of the silt proved more efficient than the 100-mg iron injection beyond 20 days., (Copyright © 2024. Published by Elsevier B.V.)

Purpose: The World Health Organization's International Agency on Research for Cancer has determined that glyphosate is "probably carcinogenic to humans." There is a great public interest to investigate whether glyphosate are detected in breast milk. Thus, the goal of this study was to assess the concentration of glyphosate and its main metabolite in breast milk. Materials and Methods: Liquid chromatography was performed at 25°C using a Luna NH 2 , 50 × 2 mm, 3⎛ m (Phenomenex) analytical column. Electrospray ionization mass spectrometry was collected using negative ionization mode. The calibration curve for glyphosate ranged from 10 to 250 ng/mL. The detection limit was 1 ng/mL. Results: Breast milk samples were collected from 74 women, which included vegans ( n = 26), vegetarians ( n = 22), and nonvegetarians ( n = 26). One of the 74 milk samples contained a detectable concentration of glyphosate and an additional 7 were found to contain aminomethylphosphonic acid. Conclusions: In breast milk samples collected mainly from women residing in urban regions of the United States, glyphosate detection was rare. Consistently, breastfed infants have a low or minimal risk of being exposed to glyphosate through ingestion of mother's milk. It is possible that the presence/absence and/or level of concentration of milk glyphosate depend on a place of residency and time of breastfeeding vis-à-vis time of its agricultural application.

Cow-calf contact (CCC) rearing is becoming an increasingly popular alternative to the common practice of early separation of cow and calf in dairy management. Milkability can be impaired in nursing cows, which contributes to the loss of machine milk yield caused by calf intake, especially in pure dam-calf contact (DCC) systems. The aims of this study were (1) to describe the current status quo of DCC rearing regarding management and milking and (2) to evaluate the effects of DCC (suckling and milking vs. milking alone) and the effects of different types of DCC on milkability parameters, teat condition, and behavior during milking on Swiss DCC farms. By means of 17 telephone interviews with DCC farmers, we collected data on DCC management, housing, separation and weaning processes, milking procedures and techniques, and perceived milkability problems. Subsequently, we collected data on 10 of the interviewed DCC farms (183 cows): 4 DCC farms with a whole-day contact (WDC) system, 3 farms with DCC before milking (CBM), and 3 farms with DCC after milking (CAM). Five farms on which calves had no contact with dams were chosen as reference farms (178 cows). Using a milk flow meter, the occurrence of ejection disorders, bimodality of the milk flow curve, machine milk yield, duration of the decline phase, and duration of prestimulation were measured. The average mouthpiece chamber vacuum during the main milking phase and hind leg activity during milking were measured using a pressure sensor and an accelerometer, respectively. After cluster removal, the teat condition was evaluated, and a stripping milk sample was taken for fat content analysis. The interview results revealed that 8 of the 17 farms surveyed had a WDC system, and 2 farms operated a daytime DCC system. Contact before milking was applied by 3 farms, and 3 farms allowed CAM. On one farm, calves had access to dams 3 times a day. A great diversity in cow-calf management was found. In the on-farm data collection, 20 milkings of a total of 701 milkings examined met the criteria for a clear ejection disorder, with 17 of these observations occurring on WDC farms and none on reference farms. The stripping milk fat content was lower in nursing cows, indicating a lower degree of udder emptying. Machine milk yield was higher in nursing CAM cows than in nursing WDC and CBM cows. Farm types did not differ regarding teat condition, hind leg activity, or the occurrence of bimodal milk flow curves. In conclusion, the large variation in individual management approaches to DCC rearing even within DCC types, such as calf housing or cow breeds, implies caution when interpreting results. Contact after milking may be the system most beneficial for some productivity parameters, but adequate calf supply must be ensured. Higher amounts of milk remaining in the udder after cluster removal indicate that nursing can affect milkability, but future research should consider the effects of udder filling before milking to better interpret the fat content of stripping milk., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

We investigated the short- and long-term effects of different forage types supplemented in preweaning dairy calves on growth performance, blood metabolites, rumen fermentation, bacterial community, and milk production during first lactation. A total of 60 healthy 30-d-old female Holstein calves were blocked by birth date and body weight and randomly assigned to 1 of 3 groups (n = 20): normal milk and pelleted starter feeding (CON), supplemented with chopped oat hay (OAH; 75.0 g/d per calf [DM basis]), or alfalfa hay (ALF; 75.0 g/d per calf [DM basis]). The forage supplementation started when calves were 30 d old (d 1 of the experimental period) and ended when they were 73 d old (d 44 of the experimental period, when calves were weaned). Milk and feed intakes and fecal consistency scores were recorded daily. Growth performance, rumen fluid, and blood samples were collected biweekly. After weaning, all the calves were integrated with the same barn and diets. After calving, the milk production was recorded daily. During the experimental period, the OAH group had greater solid feed and total DM intakes and greater rumen pH than the CON group (P ≤ 0.04), but had lower forage intake and CP digestibility than the ALF group (P ≤ 0.04). The ALF group had higher rumen pH and blood BHB concentration (P ≤ 0.04), lower fecal score (P = 0.02), and greater ether extract digestibility (P = 0.02) than the CON group. The ALF and OAH groups had lower concentrations of ruminal total VFA (P = 0.01). Still, the ALF group had a greater proportion of acetate and a relative abundance of cellulose degradation-related bacteria (Lachnoclostridium&#95;1 and Oribacterium) and a lower relative abundance of inflammation-related bacteria (Erysipelotrichaceae&#95;UCG-009) in the rumen compared with CON. Interestingly, the average milk production from 6 to 200 DIM was greater in the ALF group (P < 0.01), even though no significant effects were found on the rumen fermentation parameters and blood metabolites at 200 DIM. Generally, alfalfa hay supplementation in preweaning dairy calves had positive effects in the short- and long-term for rumen development, health status, and future milk production., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Background: Concentrations of vitamin D (VitD) and 25-hydroxyvitamin D (25OHD) in breastmilk are low despite the essential role of VitD for normal infant bone development, yet additional metabolic forms of vitamin D may be present. This study evaluates the contribution of sulfated vitamin D metabolites, vitamin D 3 -sulfate (VitD 3 -S) and 25-hydroxyvitamin D 3 -sulfate (25OHD 3 -S) for lactating women and assesses the response to high-dose VitD 3 supplementation., Methods: Serum and breastmilk were measured before and after 28 days with 5000 IU/day VitD 3 intake in 20 lactating women. Concentrations of VitD 3 -S and 25OHD 3 -S in milk, and 25OHD 2 , 25OHD 3 , 25OHD 3 -S, VitD 3 and VitD 3 -S in serum were determined by mass spectrometry., Results: Baseline vitamin D status was categorized as sufficient (mean ± SD serum 25OHD 3 69 ± 19 nmol/L), and both serum VitD 3 and 25OHD 3 increased following supplementation (p < 0.001). 25OHD 3 -S was 91 ± 19 nmol/L in serum and 0.47 ± 0.09 nmol/L in breastmilk. VitD 3 -S concentrations were 2.92 ± 0.70 nmol/L in serum and 6.4 ± 3.9 nmol/L in breastmilk. Neither sulfated metabolite significantly changed with supplementation in either serum or breastmilk., Conclusions: Sulfated vitamin D metabolites have prominent roles for women during lactation with 25OHD 3 -S highly abundant in serum and VitD 3 -S distinctly abundant in breastmilk. These data support the notion that 25OHD 3 -S and VitD 3 -S may have physiological relevance during lactation and nutritional usage for nursing infants., Competing Interests: Conflict of interest The authors have no commercial or financial conflicts of interest to declare., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The unitary mammary gland is a synapomorphy of therian mammals and is thought to have evolved from the pilosebaceous organ in the mammalian stem lineage from which the lactogenic patch of monotremes is also derived. One of the key lines of evidence for the homology of the nipple and the lactogenic patch is that marsupials have retained a transient hair associated with developing mammary glands. However, these structures have not been documented since the early 20th-century drawings of Ernst Bresslau. In this study, we examine the developing mammary organs of Monodelphis domestica and document the presence of mammary hairs in 12-week-old females, as well as their absence after 18 weeks of age. Histochemical staining for cystine confirms the structures as keratinized hairs. Milk ducts of both juvenile and adult nipples show a division between KRT18 + luminal epithelium and KRT14 + ACTA2 + myoepithelium. These patterns match those in eutherians and suggest a conserved ductal morphology and mechanism of milk expulsion. Finally, PTHLH, a peptide hormone which promotes homeotic transformation of hairy skin into hairless nipples in the mouse, was detected in the Monodelphis milk duct during the mammary hair stage, suggesting that the mutual exclusivity of "hairless nipple" and "hair" organ identity is derived in eutherian mammals. These results reveal shared characteristics of the M. domestica nipple with both the eutherian nipple and the pilosebaceous organ, consistent with the evolutionary derivation of the mammary gland from an ancestral hair organ via developmental individualization of pilosebaceous and mammary identities., (© 2024 The Author(s). Journal of Morphology published by Wiley Periodicals LLC.)

Recent advances in human immunodeficiency virus (HIV) management during pregnancy and infant feeding encompass several key elements: expanded HIV testing guidance; growing evidence of safety, efficacy, and pharmacokinetic data favoring the use of preferred antiretroviral therapy (ART) during pregnancy and breastfeeding; increasing advocacy for the inclusion of pregnant individuals with HIV in clinical trials to expedite access to new ART; and updated guidelines supporting shared decision-making for choice of infant feeding methods in people with HIV., Competing Interests: Disclosure The authors report no financial or non-financial competing interests that are relevant to the content of this article, or other conflict of interest to disclose. All authors consent to publication of this manuscript. All authors contributed to conception and design of this review article. M. Espinal and S.A. Fisher drafted the initial manuscript. L.M. Yee provided critical content expertise for the manuscript. All authors critically revised the manuscript for important intellectual context. All authors have read and approved the final manuscript to be published and agree to be accountable for the accuracy and integrity of this work., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A dysregulated inflammatory response contributes to the occurrence of disorders in cows during the transition period from pregnancy to lactation. However, a detailed characterization of clinically healthy cows that exhibit an enhanced inflammatory response during this critical period remains incomplete. In this experiment, a total of 99 individual transition dairy cows and 109 observations (18 cows monitored in 2 consecutive lactations), submitted to similar transition management were involved to evaluate the relationship between elevated an inflammatory response and metabolic and oxidative status, as well as transition outcomes. Blood was taken at -7, 3, 6, 9, and 21 DIM, and concentrations of metabolic parameters (glucose, β-hydroxybutyric acid, nonesterified fatty acids [NEFA], insulin, IGF-1, and fructosamine) were analyzed. Additionally, oxidative parameters (proportion of oxidized glutathione to total glutathione in red blood cells, the activity of glutathione peroxidase [GPx] and superoxide dismutase, concentrations of malondialdehyde, and oxygen radical absorbance capacity) and acute phase proteins (APP) including haptoglobin (Hp), serum amyloid A (SAA) and albumin-to-globulin ratio (A:G) were determined in the blood at 21 DIM. The 3 APP parameters were used to group clinically healthy cows into 2 categories through k-medoids clustering (i.e., a group showing an acute phase response, APR; n = 39) and a group not showing such a response (i.e., non-APR; n = 50). Diseased cases (n = 20) were handled in a separate group. Lower SAA and Hp concentrations as well as higher A:G were observed in the non-APR group, although for Hp, differences were observed from the APR group and not from the diseased group. Only 1 of the 5 oxidative parameters differed between the groups, with the non-APR group exhibiting lower GPx activity compared with the diseased group. The non-APR group showed the highest IGF-1 levels among the 3 groups and and lower NEFA concentrations compared with the diseased groups. Cows in the diseased group also showed reduced dry matter intake and milk yield compared with clinically healthy cows, regardless of their inflammatory status. Moreover, the APR group exhibited temporarily lower activity levels compared with the non-APR group. These findings highlight that cows with a lower inflammatory status after 21 DIM exhibited better metabolic health characteristics and productive performance, as well as activity levels. Nevertheless, the detrimental effects of a higher inflammatory status in the absence of clinical symptoms are still relatively limited., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Perinatal nutrition exerts a profound influence on adult metabolic health. This study aimed to investigate whether increased maternal vitamin A (VA) supply can lead to beneficial metabolic phenotypes in the offspring. The researchers utilized mice deficient in the intestine-specific homeobox (ISX) transcription factor, which exhibits increased intestinal VA retinoid production from dietary β-carotene (BC). ISX-deficient dams were fed a VA-sufficient or a BC-enriched diet during the last week of gestation and the whole lactation period. Total retinol levels in milk and weanling livers were 2- to 2.5-fold higher in the offspring of BC-fed dams (BC offspring), indicating increased VA supplies during late gestation and lactation. The corresponding VA-sufficient and BC offspring (males and females) were compared at weaning and adulthood after being fed either a standard or high-fat diet (HFD) with regular VA content for 13 weeks from weaning. HFD-induced increases in adiposity metrics, such as fat depot mass and adipocyte diameter, were more pronounced in males than females and were attenuated or suppressed in the BC offspring. Notably, the BC offspring were protected from HFD-induced increases in circulating triacylglycerol levels and hepatic steatosis. These protective effects were associated with reduced food efficiency, enhanced capacity for thermogenesis and mitochondrial oxidative metabolism in adipose tissues, and increased adipocyte hyperplasia rather than hypertrophy in the BC offspring. In conclusion, maternal VA nutrition influenced by genetics may confer metabolic benefits to the offspring, with mild increases in late gestation and lactation protecting against obesity and metabolic dysregulation in adulthood. NEW & NOTEWORTHY A genetic mouse model, deficient in intestine-specific homeobox (ISX) transcription factor, is used to show that a mildly increased maternal vitamin A supply from β-carotene feeding during late gestation and lactation programs energy and lipid metabolism in tissues and protects the offspring from diet-induced hypertrophic obesity and hepatic steatosis. This knowledge may have implications for human populations where polymorphisms in ISX and ISX target genes involved in vitamin A homeostasis are prevalent.

Reduced feed intake in early lactation prompts increased fat mobilization to meet dairy cow energy needs for milk production. The increased lipolysis in cows presents significant health risks with unclear mechanisms. The objectives of our study were to compare the longitudinal profiles of metabolites and lipids of serum from high- and low-lipolysis cows. Forty multiparous Holstein dairy cows were enrolled in the retrospective study. Serum samples were collected on d 7 before expected calving, as well as on d 5, 7, 14, and 21 postpartum. Dairy cows were grouped according to mean serum nonesterified fatty acids on d 5 and 7 after parturition as low (<0.600 mmol/L; n = 8; LFM) and high (>0.750 mmol/L; n = 8; HFM), indicating fat mobilization during early lactation. Lactational performance and serum metabolic parameters related to glucose and lipid metabolism, liver functions, oxidative status, and inflammatory responses were determined. Serum samples were subjected to liquid chromatography-MS-based metabolomics and lipidomics. Despite differences in postpartum BW change, there were no observed variations in milk yield and composition between the 2 groups. Serum β-hydroxybutyric acid, glucose, leptin, aspartate aminotransferase, IL-6, and tumor necrosis factor alpha were greater in cows with HFM than in cows with LFM. Serum adiponectin, revised quantitative insulin sensitivity check index, and albumin were lower in cows with HFM than in cows with LFM. Intensified fat mobilization in the HFM cows came along with reduced estimated insulin sensitivity, impaired liver functions, and increased oxidative stress and inflammatory responses. Differences in metabolic patterns were observed across the transition period when comparing serum blood matrixes (e.g., in different amino acids, acylcarnitines, and sphingolipids). The serum metabolome of the HFM cows was characterized by higher concentrations of glycine, acylcarnitines, carnosine, Cer(d20:0/18:0), Cer(d18:1/16:0), and Cer(t18:0/24:0) compared with LFM cows. The differential serum metabolites and lipids at different sampling times during the peripartum period were enriched in the sphingolipid metabolism. Differences in serum metabolic status parameters suggest that cows adopt varied metabolic adaptation strategies to cope with energy deficits postpartum. Our investigation found a comprehensive remodeling of the serum metabolic profiles in transition dairy cattle, highlighting the significance of alterations in sphingolipid species, as they play a crucial role in insulin resistance and metabolic disorders., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objectives of this study were to assess the effect of a reduced liner-open phase applied through flow-responsive pulsation (FRP), as a method to provide supplemental stimulation, on teat tissue conditions and milking characteristics in dairy cows. In 2 switch-back trials, 156 Holstein cows milked 3 times daily were assigned to the FRP or conventional (CON) group in alternating sequences. Trial 1 lasted for 35 d and was split into 5 alternating 1-wk periods of FRP and CON. The duration of trial 2 was 84 d, consisting of 4 alternating 3-wk periods of FRP and CON. Premilking udder preparation for both groups consisted of predipping, forestripping, and wiping the teats. Upon milking unit attachment, the FRP cows were milked at a pulsation rate of 50 cycles/min and a pulsation ratio of 30:70 until the preset milk flow threshold of 0.5 kg/min was reached. When the threshold value of 0.5 kg/min was reached, the pulsation was automatically switched to milking mode, which consisted of a pulsation rate of 60 cycles/min and a pulsation ratio of 70:30. Cows in the CON group were milked by milking mode (pulsation rate, 60 cycles/min; pulsation ratio, 70:30) immediately after attachment of the milking unit. We assessed machine milking-induced short-term changes to the teat tissue by palpation and visual inspection during trial 1, and we assessed teat-end hyperkeratosis in trial 2. Electronic on-farm milk meters were used to assess milking characteristics: milk yield (kg/milking session), milking unit-on time (s), 2-min milk yield (kg), peak milk flow rate (kg/min), and duration of low milk flow rate (s). Generalized linear mixed models were used to analyze the effects of treatment on the outcome variables. The odds of machine milking-induced short-term changes to the teat tissue were lower for cows in the FRP group than for those in the CON group: odds ratio (95% CI) = 0.41 (0.31-0.55). There were no meaningful differences in the odds of teat-end hyperkeratosis between the FRP and CON groups: odds ratio (95% CI) = 1.05 (0.38-2.89). The LSM (95% CI) of milking characteristics in the FRP and CON groups were 14.3 (13.8-14.7) and 14.3 kg (13.8-14.7) for milk yield, respectively; 272 (264-281) and 270 s (262-278) for milking unit-on time, respectively; and 5.0 (4.8-5.1) and 4.9 kg/min (4.7-5.1) for peak milk flow rate, respectively. The FRP group had lower odds of bimodality than the CON group: odds ratio (95% CI) = 0.67 (0.61-0.74). In reference to CON, the odds ratios (95% CI) in FRP were 1.05 (0.76-1.46) for kick-off and 1.02 (0.85-1.23) for milking unit reattachment. In this study, cows that were milked using FRP had lower odds of postmilking short-term changes to the teat tissue and lower odds of bimodal milk flow. We conclude that FRP may foster adequate teat stimulation in cows before the initiation of milk harvest and has the potential to improve teat tissue conditions., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this study was to determine quarters requiring antimicrobial treatment using either a benchtop somatic cell counter or culture with gram-positive selective media and compare the outcomes in these cows to those receiving blanket dry cow therapy (BDCT) in a randomized, controlled trial. We evaluated 2 novel methods of identifying cows with intramammary infections followed by selective antimicrobial treatment at a commercial dairy farm to determine their usefulness in decreasing antibiotic usage during the dry period without significant detrimental effects on milk quality and production. Cows (n = 840) were randomly allocated to one of 3 groups (BDCT, gram-positive selective media culture-based selective dry cow therapy [C-SDCT], and somatic cell count-based SDCT [S-SDCT]) the day before dry-off, and quarter-level milk samples (QLMS) were collected. The QLMS from cows in the S-SDCT group were evaluated using the cell counter, and quarters were treated if SCC was ≥200,000 cells/mL, whereas the QLMS from cows in the C-SDCT group were cultured, and quarters were treated if the culture showed growth. All cows in the BDCT received antimicrobial therapy, and all cows received an internal teat sealant regardless of treatment group. Outcomes measured were first and second DHIA test SCC, milk production through 60 DIM, cows leaving the farm, clinical mastitis, and bacteriologic new infections in a subset of quarters. Cows in both SDCT groups had fewer antimicrobial treatments than cows in the BDCT group as was expected, and cows in the C-SDCT group had fewer treatments than those in the S-SDCT group. Cows in both SDCT groups had a higher linear score at the first DHIA test (BDCT: 1.8, S-SDCT: 2.2, C-SDCT: 2.2); however, we found no other differences between groups regarding any other outcomes measured. Although antimicrobial use was significantly reduced, farms should use caution in adopting the benchtop analyzer and the selective media described in this study as ways to identify infected cows for dry cow therapy because they may result in increased linear scores early in lactation., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Researchers have reported the benefits of feeding rumen-protected methionine (RPM) during the peripartum on the health parameters of dairy cows. Rumen-protected Met has reportedly improved milk yield, milk components, and liver health, but the literature is scarce on its effects in commercial herds. Therefore, we aimed to determine the effects of feeding RPM (Smartamine M, Adisseo Inc., Antony, France) prepartum (8 g/cow per day) and postpartum (15 g/cow per day) on performance, metabolic profile, and culling rate of Holstein cows in a commercial herd. One hundred sixty-six (n = 166) Holstein cows, 58 nulliparous and 108 parous, were randomly assigned to 1 of 2 dietary treatments, consisting of TMR top-dressed with RPM (RPMet; 2.35% and 2.24% Met of MP for close-up and fresh cows, respectively) or without (control [CON] 2.03% and 1.89% Met of MP for close-up and fresh cows, respectively), fed from 21 ± 6 d prepartum until 16 ± 5 d postpartum. From 17 DIM until dry-off, all cows received RPMet. Daily milk yield was recorded, and milk samples were collected in the first and second weeks after calving to determine their composition. Blood samples were collected before the morning feeding on -14, -7, +1, +7, and +14 d relative to calving. Mortality and morbidity were recorded during the first 60 DIM. Cows supplemented with RPMet had greater milk yield during the first 16 DIM (31.76 vs. 30.37 kg/d; SEM = 1.04, respectively), and had greater milk fat content (4.45 vs. 4.10%; SEM = 0.11, respectively), but not milk total protein (3.47 vs. 3.39%; SEM = 0.04, respectively) and casein contents (2.74 vs. 2.66%; SEM = 0.04, respectively) than CON cows. Cows in RPMet had increased plasma Met concentrations than cows in CON (24.9 vs. 21.0 µmol/L; SEM = 1.2, respectively). Although morbidity was similar between treatments, the culling rate from calving until 60 DIM was lower for RPMet cows than for CON cows (2.4% vs. 12.1%; SEM = 0.02). In conclusion, cows receiving RPMet have greater milk yield, improved milk fat content, and a lower culling rate at 60 DIM than CON cows., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Flaxseed is the richest source of secoisolariciresinol diglucoside, which is converted by ruminal microorganisms primarily to the mammalian lignan enterolactone. Our objective was to investigate the effect of diets containing soybean meal or flaxseed meal (FM) supplemented with sucrose, flaxseed oil, or both, on milk enterolactone concentration yield, diversity, and relative abundance of ruminal bacterial taxa, ruminal fermentation profile, production performance, milk fatty acids (FA) yield, and nutrient utilization in dairy cows. Sixteen Holstein cows (8 multiparous [4 ruminally cannulated] and 8 primiparous) averaging (mean ± SD) 134 ± 54.1 DIM and 679 ± 78.9 kg of BW in the beginning of the study were assigned to treatment sequences in a replicated 4 × 4 Latin square design. Each experimental period lasted 25 d, with 18 d for diet adaptation and 7 d for data and sample collection. Diets were formulated to contain a 60:40 forage:concentrate ratio and included the following (DM basis): (1) 8% soybean meal and 23% ground corn (SBM); (2) 15% FM, 10.7% ground corn, and 5% sucrose (FLX+S); (3) 15% FM, 15.4% ground corn, and 3% flaxseed oil (FLX+O); and (4) 15% FM, 10.2% ground corn, 5% sucrose, and 3% flaxseed oil (FLX+SO). Compared with SBM, the concentration and yield of milk enterolactone increased in cows fed the FM diets but did not differ among FLX+S, FLX+O, and FLX+SO. The relative abundances of the phyla Firmicutes, Verrucomicrobiota, and Actinobacteriota, and those of the bacterial genera Lachnospiraceae NK3A20 group, Eubacterium coprostanoligenes group, Anaeromusa-Anaeroarcus, WCHB1-41, and p-251-o5 decreased, whereas Prevotella and NK4A214 group increased when comparing SBM against at least 1 diet containing FM. Furthermore, the relative abundances of Firmicutes and Actinobacteriota and those of Prevotella, Lachnospiraceae NK3A20 group, Eubacterium coprostanoligenes group, Acetitomaculum, Lachnospiraceae unclassified, NK4A214 group, and Anaeromusa-Anaeroarcus changed (increased or decreased) across the FLX+S, FLX+O, and FLX+SO diets. However, all these changes in the relative abundance of the ruminal bacterial taxa were not conclusively associated with the effect of diets on milk enterolactone. Diets did not affect ruminal pH and concentrations of NH 3 -N and total VFA. Dry matter intake and yields of milk, milk fat, and milk true protein all decreased in cows fed FLX+O or FLX+SO. Yields of milk total odd-chain FA, branched-chain FA, total <16C FA, and total 16C FA decreased with feeding FLX+O and FLX+SO. The apparent total-tract digestibilities of DM and OM were lowest in the FLX+S and FLX+O diets, with CP and ADF digestibilities lowest in cows receiving FLX+S or FLX+O, respectively. Urinary excretion of total N was lowest with feeding SBM. Contrarily, diets did not affect the urinary excretion of total purine derivatives. In brief, despite the effect of diets on the relative abundance of several ruminal microbiota phyla and genera, we were unable to conclusively associate these changes with increased milk enterolactone in FM-containing diets versus SBM., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Automated measurements of the ratio of concentrations of methane and carbon dioxide, [CH 4 ]:[CO 2 ], in breath from individual animals (the so-called "sniffer technique") and estimated CO 2 production can be used to estimate CH 4 production, provided that CO 2 production can be reliably calculated. This would allow CH 4 production from individual cows to be estimated in large cohorts of cows, whereby ranking of cows according to their CH 4 production might become possible and their values could be used for breeding of low CH 4 -emitting animals. Estimates of CO 2 production are typically based on predictions of heat production, which can be calculated from body weight (BW), energy-corrected milk yield, and days of pregnancy. The objectives of the present study were to develop predictions of CO 2 production directly from milk production, dietary, and animal variables, and furthermore to develop different models to be used for different scenarios, depending on available data. An international dataset with 2,244 records from individual lactating cows including CO 2 production and associated traits, as dry matter intake (DMI), diet composition, BW, milk production and composition, days in milk, and days pregnant, was compiled to constitute the training dataset. Research location and experiment nested within research location were included as random intercepts. The method of CO 2 production measurement (respiration chamber [RC] or GreenFeed [GF]) was confounded with research location, and therefore excluded from the model. In total, 3 models were developed based on the current training dataset: model 1 ("best model"), where all significant traits were included; model 2 ("on-farm model"), where DMI was excluded; and model 3 ("reduced on-farm model"), where both DMI and BW were excluded. Evaluation on test dat sets with either RC data (n = 103), GF data without additives (n = 478), or GF data only including observations where nitrate, 3-nitrooxypropanol (3-NOP), or a combination of nitrate and 3-NOP were fed to the cows (GF+: n = 295), showed good precision of the 3 models, illustrated by low slope bias both in absolute values (-0.22 to 0.097) and in percentage (0.049 to 4.89) of mean square error (MSE). However, the mean bias (MB) indicated systematic overprediction and underprediction of CO 2 production when the models were evaluated on the GF and the RC test datasets, respectively. To address this bias, the 3 models were evaluated on a modified test dataset, where the CO 2 production (g/d) was adjusted by subtracting (where measurements were obtained by RC) or adding absolute MB (where measurements were obtained by GF) from evaluation of the specific model on RC, GF, and GF+ test datasets. With this modification, the absolute values of MB and MB as percentage of MSE became negligible. In conclusion, the 3 models were precise in predicting CO 2 production from lactating dairy cows., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Background: Maternal undernutrition is a direct risk factor for infant growth faltering., Objectives: We evaluated the effect of postnatal balanced energy protein (BEP) supplementation in lactating women and azithromycin (AZ) in infants on infant growth outcomes., Methods: A randomized controlled superiority trial of lactating mother-newborn dyads was conducted in Karachi, Pakistan. Mothers intending to breastfeed their newborns with mid-upper arm circumference of <23 cm and live infants between 0 and 6 d of life were randomly assigned to 1 of 3 arms in a 1:1:1 ratio. Lactating mothers in the control arm received standard-of-care counseling on exclusive breastfeeding, nutrition, infant immunization, and health promotion plus iron-folate supplementation until the infant was 6 mo old. In intervention arm 1, mothers additionally received two 75-g sachets of BEP per day. In intervention arm 2, along with the standard-of-care and BEP to the mother, the infant also received 1 dose of azithromycin (20 mg/kg) at the age of 42 d . The primary outcome was infant length velocity at 6 mo. The total sample size was 957 (319 in each arm)., Results: From 1 August, 2018 to 19 May, 2020, 319 lactating mother-newborn dyads were randomly assigned in each arm, and the last follow-up was completed on 20 November, 2020. The mean difference in length velocity (cm/mo) between BEP alone and control was 0.01 (95% confidence interval [CI]: -0.03, 0.06), BEP plus AZ and control was 0.08 (95% CI: 0.03, 0.13), and between BEP + AZ and BEP alone was 0.06 (95% CI: 0.01, 0.11). There were 1.46% (14/957) infant deaths in the trial, and 17.9% (171/957) nonfatal events (injectable treatment and/or hospitalizations) were recorded., Conclusions: Postnatal maternal BEP supplementation and infant AZ administration could modestly improve infant growth outcomes at 6 mo, suggesting potential benefits in simultaneously addressing maternal and infant undernutrition. This trial was registered at clinicaltrials.gov as NCT03564652., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Mammary gland (MG) lactogenic differentiation involves epigenetic mechanisms. We have previously shown that hypothyroidism (HypoT) alters the MG transcriptome in lactation. However, the role of thyroid hormones (T3 and T4 a. k.a. THs) in epigenetic differentiation of MG is still unknown. We used a model of post-lactating HypoT rats to study in MG: a) Methylation and expression level of Gata3, Elf5, Stat6, Stat5a, Stat5b; b) Expression of Lalba, IL-4Rα and Ncoa1 mRNA; c) Histone H3 acetylation and d) Estrogen and progesterone concentration in serum. HypoT increases the estrogen serum level, decreases the progesterone level, promotes methylation of Stat5a, Stat5b and Stat6, decreasing their mRNA level and of its target genes (Lalba and IL-4Rα) and increases the Ncoa1 mRNA expression and histone H3 acetylation level. Our results proved that HypoT alters the post-lactation MG epigenome and could compromise mammary functional differentiation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

We studied the changes in the heart rate variability of lame and nonlame dairy cows in response to transrectal examination (TRE) and parlor milking. We hypothesized that lame cows experience greater stress, manifested in heart rate variability parameters, that serves as an argument to promote more caution in the everyday handling of lame animals. In the study, we selected 55 lame (with lesions on at least one hoof, otherwise clinically healthy, with locomotion scores 4 and 5 of 5-point scores) and 55 nonlame (clinically healthy, with locomotion scores 1 and 2 of 5-point scores) cows. The heart rate, root mean square of successive beat-to-beat intervals (RMSSD), the normalized unit of the high-frequency (HF) component of the spectral analysis and Poincaré measures (SD2/SD1) were compared between lame and nonlame cows during 5 distinct stages of TRE and 7 stages of parlor milking. Heart rate, RMSSD, and SD2/SD1 showed similar patterns during TRE and milking, while HF remained fairly constant during the studied phases. No distinct RMSSD, HF, or SD2/SD1 changes were observed during the phases expected to elicit a stress response. Between-group differences were only observed in terms of HF. Baseline HF was higher in lame cows than in nonlame ones, and such a difference in direction was observed throughout the whole procedure. During milking and TRE, the heart rate, RMSSD, and SD2/SD1 values showed temporal changes in times of higher physical activity: moving to and waiting in the holding pen and moving into the milking stalls in the parlor for preparation in both lame and nonlame cows. The differences in baseline HF (normalized units) between lame and nonlame cows cannot be fully explained based on available information. The lack of a distinct, stress-related change in heart rate variability parameters in both groups can originate in methodological challenges inherent in animal heart rate variability measurements in field conditions., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The presence of an autocrine factor in milk that can trigger mammary gland involution was proposed more than 50 yr ago. To provide evidence for the existence of one or more autocrine factors, 10 multiparous cows in late lactation were quarter-milked for 7 d. Following this baseline period, the right front quarter of each cow was left unmilked, and the other quarters were milked for 7 d. Before the last milking of that period, milk (mammary secretions) was collected aseptically from both front quarters. After that milking, 250 mL of the collected samples were infused in the cows' respective rear quarters. No quarters were milked for the following 7 d (milk stasis period), and quarter milking was then resumed in all quarters for the last 7 d of the experiment (remilking period). Quarter milk samples were collected during the baseline period, before the milk stasis period, and during the remilking period. These samples were used for measuring milk components and the concentration of involution markers (SCC, BSA, and lactoferrin). Samples of mammary secretions were collected manually from the quarters during the milk stasis period for involution marker determination. We extracted RNA from samples collected from front quarters before the last milking before the milk stasis period for microRNA (miRNA) determination. As anticipated, the longer milk stasis period implemented for the right front quarter resulted in a more advanced involution than in the left front quarter, based on the concentration of involution markers in the mammary secretions, lower milk production recovery, and changes in milk composition during the remilking period. All 3 involution marker concentrations in the mammary secretions increased in both rear quarters, but were greater in the right quarter secretions than in the left quarter secretions. Resuming milking reinitiated milk production in all quarters, but milk production recovery in the right rear quarters was less robust than that in the left rear quarters (54.3 ± 1.4% vs. 61.6 ± 1.4%, respectively). Milk from the quarters infused with mammary secretions (right rear) had a lower lactose content, but a higher milk protein content and higher SCC than the quarters infused with milk. We detected a total of 359 miRNAs, 76 of which were differentially expressed in milk and mammary secretions. Expression of bta-miR-221 and bta-miR-223 was upregulated in mammary secretions 34- and 40-fold, respectively. The results of the present experiment support the contention that milk stasis leads to the accumulation of one or more factors that trigger involution. The results also indicate that milk stasis leads to changes in the miRNA profile of the milk, but whether such changes are a cause or a consequence of the involution process remains to be established., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Microplastics have become a ubiquitous contaminant, but their fate in food animals is largely unknown. In this study, [ 14 C]-polystyrene microplastic (PS-MP) particles were orally dosed to lactating sheep to evaluate their absorption and disposition. Elimination of the [ 14 C]-PS-MP was predominately through faeces with faecal radioactivity peaking at 24 h post-dosing but continuing to be present throughout the entire 72 h study period. Only a small fraction (≤ 1%) of the dosed [ 14 C]-PS-MP was present in blood, milk, and urine. Pharmacokinetic analysis of blood plasma radioactivity, using non-compartment modeling, indicated rapid absorption (T 1/2 0.4 to 3 h) with slow elimination (T 1/2 37 to 48 h). Radioactivity in milk and urine had similar elimination patterns with radiocarbon activities peaking 24 h post-dosing with detectable elimination throughout the 72 h study period. No radioactivity was quantifiable in tissues at the 72 h withdrawal period.