This empirical descriptive case study explored the implementation of oxytocin massage to improve breast milk flow among post–Sectio Caesarea mothers in the Alamanda Ward of RSI PKU Muhammadiyah Pekajangan. Five participants were selected through purposive sampling based on predefined inclusion and exclusion criteria. Data were collected using structured observation sheets assessing lactation indicators, clinical responses, and implementation quality over three consecutive days. Findings indicate that oxytocin massage was associated with progressive stabilization of postoperative physiological conditions, enhanced maternal readiness for breastfeeding, and consistent clinical implementation aligned with institutional standard operating procedures. The integration of structured monitoring and complete documentation supported reliable evaluation of lactation outcomes within the case-study framework. The results highlight that effective implementation quality plays a crucial role in maximizing the neurohormonal mechanisms underlying milk ejection reflexes in post-surgical mothers. These findings support the incorporation of oxytocin massage as an evidence-informed, non-pharmacological nursing intervention to optimize lactation management in post–Sectio Caesarea care settings.

Replacing hexane with 2-methyloxolane (MeOx) for defatting soybean meal (SBM) requires adaptations of the SBM production process. These modifications may increase the concentration of Maillard reaction products and reduce the residual oil content in MeOx-defatted SBM compared with hexane-defatted SBM. In addition, despite desolventization, solvent residues may still be present in the SBM when fed to livestock. This study aims to ensure that the replacement of hexane with MeOx for defatting SBM does not affect the ruminal and milk fatty acid profiles nor the liver activity, liver functionality, and inflammatory status in dairy cows. A 4 × 4 Latin square design experiment was conducted with 16 primiparous dairy cows that received 4 dietary treatments: 100% hexane-defatted SBM (control diet, HEX), 67% hexane-defatted SBM plus 33% MeOx-defatted SBM (33MeOx), 33% hexane-defatted SBM plus 67% MeOx-defatted SBM (67MeOx), and 100% MeOx-defatted SBM (100MeOx). Diets contained 16% SBM on a DM basis and were iso-CP and iso-net energy. We collected feed, ruminal content, blood, and milk samples. We measured traits related to lipid digestion in the rumen and secretion in milk (feed, ruminal, and milk fatty acid profiles), energy metabolism (plasma acetate, BHB, nonesterified fatty acids, and glucose concentrations, as well as C isotopic discrimination between plasma and diet), liver integrity and functionality (plasma enzyme activities and serum albumin and plasma total bilirubin concentrations), and inflammatory status (blood cell counts and plasma cytokine concentrations). We used difference and equivalence tests for statistical analyses. Replacing HEX with 100MeOx resulted in likely equivalent milk fat content, fat yield, and major fatty acid profile. Stearyl-CoA desaturase activity in the mammary gland, indicated by the C14:1 cis-9-to-C14:0 ratio, was negatively linearly related to the proportion of MeOx-defatted SBM in the diet. We did not find evidence of strict equivalence between 100MeOx and HEX in ruminal fatty acid profile. However, only minor differences were observed. Plasma γ-glutamyltransferase, aspartate aminotransferase, and alanine aminotransferase activities, as well as total bilirubin concentration, were unlikely equivalent toward greater values with 100MeOx compared with HEX, suggesting slight changes in liver integrity and functionality with 100MeOx. The overall inflammatory status of dairy cows was unlikely equivalent between 100MeOx and HEX. However, significant differences were limited to blood basophil count and plasma chemokine C-C motif ligand 4 concentration that were negatively linearly related to the proportion of MeOx-defatted SBM in the diet, and plasma chemokine C-X-C motif ligand 8 concentration that was quadratically related to the proportion of MeOx-defatted SBM in the diet. Altogether, these results indicate that the replacement of hexane-defatted SBM with MeOx-defatted SBM in the diet of dairy cows resulted in likely equivalent lipid secretion in milk despite a slight reduction in stearyl-CoA desaturase activity in the mammary gland with MeOx-defatted SBM. In the context of this study (i.e., short-term exposure, high level of MeOx, low level of hexane), neither hexane-defatted SBM nor MeOx-defatted SBM impaired health, but slight changes in some indicators of liver integrity, liver functionality, and inflammatory profile may warrant further investigation (e.g., long-term exposure).

Dysphoric Milk Ejection Reflex (D-MER) is defined as an undesirable feeling that some breastfeeding women experience within seconds of milk letdown. D-MER can impact maternal psychological well-being and breastfeeding continuation, but it is an understudied phenomenon. To uncover and understand D-MER among breastfeeding women within 3 years of birth who self-identified as having experienced D-MER. This descriptive qualitative research study was conducted to uncover and understand breastfeeding experiences of women who self-identify as experiencing D-MER. We conducted in-depth interviews with 13 women about their D-MER experience(s). Interview data were qualitatively analyzed using Braun and Clarke's thematic analysis for descriptive studies. We found four themes that captured participants' perceptions, emotional reactions, and behavioral responses to D-MER: (A) Breastfeeding concessions and toleration; (B) Something does not feel "normal"; (C) I remember a feeling like this before; and (D) This is real, and recognition is validating. Themes reflected an outsized influence of D-MER on participants' breastfeeding goals, trajectories, and maternal identities. Participants expressed frustration about the lack of recognition and help for D-MER among healthcare providers, but relief in understanding, often through social media, that D-MER was considered a real, physiological condition. Participants were able to reduce, but not eliminate, D-MER symptoms through trial-and-error processes, including distraction, operant conditioning, and mindfulness/relaxation. D-MER had a profound, negative impact on participants' breastfeeding experiences and led to decisions to stop breastfeeding or consider stopping before a participant had originally intended. Research is needed to develop interventions that reduce or eliminate D-MER symptomology.

A feeding trial was conducted with lactating cows to evaluate the feed value of domestic dry-crushed corn grain. The corn grains were treated using a feed rice grain-crushing machine with a roll clearance of 0.2 mm. Six lactating cows were assigned to diets ensiled into a total mixed ration containing either steam-flaked (SF) or dry-crushed corn (DC). Group DC tended to have increased milk protein concentration and nitrogen secretion in milk, and decreased blood non-esterified fatty acid concentrations (p = 0.05, 0.06, and 0.08). Whereas, this group showed significantly higher dry matter intake per kg body weight, non-fiber carbohydrate, and starch digestibility (p = 0.04, 0.03, and < 0.001). No significant differences were found between the treatments in terms of lactation performance, nitrogen balance, rumen fluid profile, or total tract digestibility, suggesting that in lactating cows, the feeding value of dry-crushed corn was equal to or greater than that of steam-flaked corn. This finding suggests that crushing is an effective and practical method for processing domestic corn grain in dairy diets and that dry-crushed domestic corn grain can serve as an effective alternative to imported steam-flaked corn, potentially enhancing nutrient utilization in lactating cows.

Effects of prenatal exposure to hexafluoropropylene oxide dimer acid on rat and offspring mammary gland development and associated hormone levels.

Assessing the role of the ABCG2 transporter in plasma levels and secretion into milk of aflatoxins B2 and G1.

Scutellaria baicalensis root possesses potent anti-inflammatory and antioxidant properties, along with its ability to stimulate mammary cells, thereby enhancing milk yield. The present study investigated the effect of SB supplementation in lactation diet on colostrum and milk production, litter survival and growth, oxidative status, and inflammation in lactating sows. On day 108 of gestation, 24 sows were assigned to either a control group (CON; n = 12) that were fed according to the Danish nutrient standard or a CON diet supplemented with Scutellaria baicalensis root (SB; n = 12) and fed the diet until day 28 of lactation. Piglets were individually weighed at birth and weekly during lactation. Colostrum was sampled during farrowing, while milk was collected weekly during lactation. Blood samples were collected on day 112 of gestation, day of farrowing, day 3, 10, and 17 of lactation and analyzed for oxidative and inflammation biomarkers. Supplementation with SB did not affect litter number at birth but increased average birth weight of the piglet (P = 0.002). Litter weight was greater in SB supplemented sows (P < 0.05) during lactation. Colostrum concentration of lactose increased (P < 0.01) but that of protein and solid-not-fat (both P < 0.01) decreased with SB supplementation. Total daily protein secretion in milk increased (P = 0.02), while lactose (P = 0.09) and solid-not-fat (P = 0.07) tended to increase with SB supplementation. Supplementation with SB tended to increase milk yield (P = 0.06), litter number in lactation (P = 0.08), and litter survival (P = 0.10) compared to non-supplemented sows. Supplementation with SB affected neither oxidative stress nor inflammation status biomarkers. In conclusion, SB supplementation increased piglet birth weight, sow milk production, and litter growth performance during lactation, but did not influence oxidative status and inflammation.

Lactoferrin (LF) is an iron-binding immunoprotein of the mammary gland whose levels increase during mastitis and may be influenced by the metabolic status of the cow. During early lactation, dairy cows are exposed to a negative energy balance (NEB) and the associated increase in susceptibility to mastitis. However, the extent to which the metabolic profile influences LF secretion in milk during the postpartum period remains unclear. The objective of this study was to assess the associations between metabolic status and milk LF contents in Holstein cows (n = 122) in the first twenty days of lactation. Based on the milk LF contents, the cows were categorized into two groups: LF-LOW (≤123 mg/L; n = 81) and LF-HIGH (&gt;123 mg/L; n = 41). Serum indicators of energy and nitrogen metabolism, hepatic function, and selected macro-/microelements were measured; urine electrolytes and net acid–base excretion (U-ABB) were assessed; and milk composition, including somatic cell count (SCC), was determined. LF-HIGH cows showed higher SCC (p = 0.0516) and serum glucose (p &lt; 0.001), together with lower serum triglycerides (p = 0.0101) versus LF-LOW cows. Milk beta-hydroxybutyric acid (BHB) content was lower in the LF-HIGH group (trend, p ≈ 0.062). LF-HIGH also exhibited significantly greater natriuresis (p = 0.0078) and a more negative U-ABB (p &lt; 0.001), indicating higher acid–base load. In conclusion, elevated LF contents during the postpartum period were associated with the activation of local mammary gland immune defence and concurrent compensatory metabolic processes related to NEB, rather than with pronounced alterations in basic milk composition. Milk LF content may therefore be considered as a specific indicator of immunometabolic compensation during the early postpartum period, rather than as a general marker of overall cow health.

BackgroundDelayed lactogenesis II (DLII), defined as the onset of copious milk secretion after 72 h postpartum, is a common complication that may impair early breastfeeding success. Advanced maternal age and cesarean delivery are both known risk factors, yet few studies have developed predictive models to identify high-risk women. This study aimed to construct and internally validate a clinical prediction model for DLII among advanced-age women undergoing cesarean section.MethodsThis retrospective observational study analyzed the medical records of 325 women aged ≥35 years who underwent cesarean delivery at a tertiary maternal and child health hospital in Southwest China between January 2021 and January 2025. Maternal, obstetric, surgical, and neonatal variables were extracted from electronic medical records. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of DLII, and a nomogram was subsequently developed. Model discrimination and calibration were assessed using the area under the receiver operating characteristic (ROC) curve (AUC), Hosmer–Lemeshow goodness-of-fit test, and calibration plots with 1,000 bootstrap resamples.ResultsOf the 325 women included, 117 (36.0%) experienced DLII. Multivariate analysis identified maternal age (aOR = 1.15, 95% CI 1.01–1.32), pre-pregnancy body mass index (BMI; aOR = 1.10, 95% CI 1.00–1.22), primiparity (aOR = 1.74, 95% CI 1.02–2.96), and shorter gestational age (aOR = 0.71, 95% CI 0.55–0.91) as independent risk factors for DLII. In contrast, elective cesarean section and early postpartum practices (rooming-in within 24 h, breastfeeding initiation within 24 h, and early skin-to-skin contact) were associated with lower odds of delayed lactogenesis II after multivariable adjustment (all p < 0.05). The final model demonstrated excellent discrimination (AUC = 0.870, 95% CI 0.830–0.910) and good calibration (Hosmer–Lemeshow χ2 = 5.60, p = 0.692).ConclusionThis study established a reliable and clinically interpretable model for predicting delayed lactogenesis II among advanced-age women undergoing cesarean section. The model showed high accuracy and good internal validity, highlighting the relevance of maternal characteristics and early postpartum behaviors to lactation outcomes. The proposed nomogram may serve as a practical tool for early risk identification and targeted breastfeeding support in clinical settings.

Musa sapientum L., commonly known as the banana flower (BF), is used as a galactagogue in Thai traditional medicine. This study aimed to assess the galactagogue potential of microencapsulated extracts from the BF and its impact on serum prolactin level, α-lactalbumin (LALBA), and aquaporin (AQP) protein levels in the mammary glands of lactating rats. Milk production was determined by measuring pup weight during the suckling period. The control group was administered distilled water orally, whereas Group II was administered domperidone at doses of 2.7 mg/kg. Groups III and IV were orally administered BF at doses of 250 and 500 mg/kg, respectively, from the 3rd day to the 12th day postpartum. On the 12th day, blood samples and mammary gland tissues were collected for analysis. Protein levels of AQP-1, AQP-3, AQP-5, LALBA, and serum prolactin were assessed. Additionally, a histopathological examination of the mammary glands was performed. BF doses of 250 and 500 mg/kg were found to increase milk production, pup weight, serum prolactin levels, and protein levels of AQP-1, AQP-3, and AQP-5 compared to the control group. Transverse sections of the mammary glands from rats treated with 250 and 500 mg/kg exhibited a marked increase in milk secretion within the alveoli. These findings suggest that BF possesses significant galactagogue activity.

Sensory afferents in the mammary papilla are eliminated during the lactation.

Galactorrhea, an abnormal milk secretion, is frequently triggered by medications that influence prolactin levels. This study aimed to identify high-risk drugs for drug-associated galactorrhea (DAG) and explore their characteristics using data from the FDA Adverse Event Reporting System (FAERS). We analyzed 6,195 DAG reports by applying four disproportionality analysis algorithms (ROR, PRR, MGPS, BCPNN) to detect positive signals. The analysis of 6,195 reports showed that DAG was most prevalent in patients aged 20-40 years, with a slight male predominance (55.52%). Oral medications were the primary cause (68.99%). A total of 32 drugs were strongly associated with DAG, with antipsychotics being the most frequently implicated class (N = 12), followed by antidepressants (N = 7) and hormone-related drugs (N = 6). Risperidone had the highest risk (ROR = 346.71) and report count (N = 3,378). This study provides a comprehensive list of high-risk drugs for DAG, offering critical data to guide safer prescribing and improve pharmacovigilance. Clinicians should be vigilant in monitoring for suggestive symptoms like galactorrhea, amenorrhea and sexual dysfunction, especially in high-risk individuals on long-term treatment with prolactin-elevating medications. These findings underscore the importance of patient safety and inform clinical practice.

Breastfeeding is the ideal source of nourishment, and major health organizations recommend exclusive breastfeeding for the first six months of life. However, hypogalactia (insufficient milk production) frequently impedes this goal, leading mothers to use galactogogues to stimulate and maintain milk secretion. These agents primarily function by influencing the neuroendocrine system, often by blocking hypothalamic dopaminergic receptors to enhance the release of prolactin, the key hormone for lactogenesis. This review systematically examines the scientific basis and traditional use of key natural galactogogues, focusing on those with documented efficacy. Trigonella foenum-graecum (Fenugreek) is the most researched, utilizing the steroidal saponin diosgenin and alkaloid trigonelline for rapid, pronounced lactogenic effects. Foeniculum vulgare (Fennel) acts as a dopamine-receptor antagonist via trans-anethole to directly stimulate prolactin. Silybum marianum (Milk Thistle), with its silymarin complex, indirectly supports lactation through hepatoprotective actions that optimize hormonal balance. Supplementary benefits are provided by Anethum graveolens (Dill), which exhibits oxytocin-like activity to aid milk ejection, and Nigella sativa (Black Cumin), which enhances mammary sensitivity through thymoquinone. While generally safe, informed clinical judgment is necessary regarding potential contraindications, such as Fenugreek's hypoglycemic effect. Ultimately, an integrated, evidence-based strategy (combining botanical support with conventional lactation counseling) offers the most comprehensive and effective approach for overcoming hypogalactia and ensuring sustained breastfeeding success.

Progesterone is a regulator of the reproductive function and stimulates the development of glandular tissue of the mammary gland and milk secretion. Most of its effects are mediated by nuclear receptors, which are transcription factors. There is a limited amount of data on the frequency of distribution of genotypes and alleles of the progesterone receptor gene ( PGR ) and their association with morphofunctional parameters of the mammary gland in cattle, and all of them concern transboundary breeds. The purpose of the scientific work is to study the morphofunctional parameters of the mammary gland of the Kostroma and Holstein cows of different genotypes for the PGR gene in the conditions of breeding farms of the Kostroma region. The studies were carried out in 2024–2025 on breeding first-calf cows of the Kostroma ( n = 81) and Holstein ( n = 26) breeds. The relationship between the genotype of the PGR gene and the morphofunctional parameters of the mammary gland was determined. It was revealed that in the studied samples of cows of the Kostroma and Holstein breeds, the most common genotype is AA of the PGR gene (distribution frequency 0.568 and 0.462, respectively). However, carriers of the rare PGR GG genotype had optimal morphological parameters for machine and robotic milking and a bath-shaped mammary gland. Also, based on results of the first lactation, it was found that in the sample of the Kostroma breed, the milk yield of carriers of the PGR GG genotype was 9.26% and 14.29% higher than that of the carriers of the PGR АА and PGR А G genotypes ( p ≤ 0.5), respectively. Based on the data of the study, it was determined that carriers of the PGR GG genotype have morphofunctional parameters of the mammary gland that are preferable for machine and robotic milking, therefore it is necessary to continue research in this area on a larger number of animals and within other cattle populations.

Lactoferrin is an iron-binding glycoprotein with multiple functions, naturally occurring in milk, saliva, tears, and other mucosal secretions, and has been shown to possess antimicrobial and antiviral properties. This investigation aimed to examine the composition and role of lactoferrin in Capra hircus using computational techniques. In-silico tools were employed to characterize lactoferrin and explore its molecular interactions, including peptide cutter for enzymatic cleavage, CAMP for antimicrobial prediction, and molecular docking to assess its binding affinity with bacterial targets. Among the 54 peptides derived from lactoferrin, 13 positively charged peptides demonstrated significant antibacterial properties, validated through antimicrobial prediction tools. For structural validation, only the peptide with the highest length was selected for 3D modeling and analysis. The 3D structural model confirmed high similarity to known lactoferrin structures, highlighting conserved regions critical for antibacterial activity. The predicted structural model provided insights into the dynamic behavior of lactoferrin, exhibiting high similarity to other known lactoferrin structures which indicates its conserved nature across species in mammals. These findings highlight key regions involved in protein-protein interactions and structural characterization that reinforce its antimicrobial properties. Molecular docking and ADMET analysis manifest the best drug candidate that exhibit antimicrobial properties. Best docked compound enterobactin violate the toxicity profile. This study sets the stage for further experimental validation of these predicted interactions while shedding light on the molecular mechanisms underlying the multifunctional properties of lactoferrin in Capra hircus.

Negative modulation of maternal iodine deficiency and excess on milk lipid synthesis and secretion in lactating rats.

Mammary organoids bridge the gap between reductionist 2D systems and in vivo models by recapitulating bilayered epithelial architecture, branching, hormone responsiveness, and, in advanced platforms, functional readouts of lactation. This review synthesizes organoid models across the reproductive cycle, including branching morphogenesis, pregnancy-induced alveologenesis and milk secretion, and involution; it also surveys emerging directions, including embryonic/pluripotent and cross-species systems, as well as co-culture and organ-on-chip platforms that incorporate stromal, adipose, and immune elements. We outline priorities for building more complex, physiologically faithful ex vivo models that will enable mechanistic dissection of mammary development, yield comparative and translational insights, and create scalable platforms for perturbation and screening, advancing lactation research, breast cancer studies, and women's health in general.

Prolactin is a pituitary anterior lobe hormone that plays a crucial role in milk secretion from the mammary glands. Hyperprolactinemia is a common endocrine disorder characterized by abnormally elevated levels of prolactin in the serum. Recent research findings indicate that prolactin also exerts important physiological effects beyond lactation, including effects on brain health and the central nervous system. The gut-brain axis has become an important area of neuroscience research, providing insights into the complex interactions between the gastrointestinal system and the central nervous system. Future research may involve developing new probiotic therapies or optimizing the gut microbiota through dietary and lifestyle interventions. In addition, understanding the mechanisms by which hyperprolactinemia contributes to various neurological disorders and targeting prolactin for treatment are crucial areas of research. Therefore, this study aimed to investigate the correlation between hyperprolactinemia and brain health from the perspective of the gut-brain axis, with the goal of discovering new approaches for preventing and treating neurodegenerative and mental health conditions. This synthesis highlights potential strategies for future therapeutic interventions.

The broad focus of this review is on milk harvesting in machine-milked herds. With particular emphasis on: (1) milk secretion and storage dynamics in the udder, (2) milk ejection, (3) milk flow profiles and their effect on milking efficiency, (5) immunological activity and milking efficiency, (5) milking machine aspects of milk removal, and (6) the future potential of milking technology. Machine milking has evolved from its early mechanical beginnings into a technologically advanced, data-driven process that must balance speed, chosen completeness, and gentleness on teat tissue to support efficient milk removal and optimal udder health. This review summarizes the current understanding of milk harvesting from a physiological, mechanical, and managerial perspective and outlines the key factors shaping its future development. Fundamentally, milk harvesting is built upon a biological sequence involving milk synthesis, ejection, and removal. Milk synthesis occurs at the alveolar level and is influenced by local quarter-specific physiology. Milk ejection is driven by the oxytocin-mediated contraction of myoepithelial cells, a process sensitive to the degree of udder filling, familiarity with the milking environment, and cow-operator interactions. Milk flow profiles, shaped by these biological processes, provide crucial insights into milking efficiency and udder health outcomes. At the machine level, key variables include milking vacuum, pulsation characteristics, liner properties, and teatcup removal strategies. Optimal settings for each of these parameters depend on dynamic interactions with cow physiology and milking stage. Recent research highlights the need to consider these factors not in isolation but as part of an integrated milking system, where vacuum, pulsation, liner design, and timing of teatcup removal interact to affect milking speed, teat condition, and udder health. Automation of milking systems and indeed automated milking systems have driven a shift toward individualized milking at the quarter level, enabling more precise control of extraction timing and flow rate. The integration of real-time sensor data, machine learning, and adaptive milking parameters represents a major step forward in the optimization of milking systems. In the near future, distinctions between automated milking systems and conventional systems will become increasingly blurred, as both adopt automation and intelligent controls tailored to individual cows and quarters. This review also explores the role of immunological activity in shaping milking efficiency. Elevated SCC has been associated with altered milk flow curves and decreased productivity. There is emerging evidence suggesting that modern selection and management strategies may reduce the historical link between fast milking and mastitis risk. This relationship remains complex and context dependent. The detection and management of abnormal milk (supported by more advanced inline sensor systems) is expected to become a cornerstone of future milking technology. Looking forward, the drivers of change in milk harvesting will include labor availability, economic pressures, environmental concerns, animal health, and consumer expectations. A new era of biologically aware, data-informed, and precision-engineered milking systems is emerging. These systems will support the gentle, efficient removal of milk to a user-defined end point, tailored to each animal and each milking event.

Intramammary infections are common in nonlactating dairy cattle and have been shown to disrupt mammary tissue architecture in nonpregnant heifers. However, their effect on mammary development during pregnancy remains unclear. This study assessed the effects of IMI on mammary gland development in pregnant dairy heifers during late gestation. The study used 21 pregnant Holstein heifers, divided across 3 gestational stages (∼5.75, 6.75, and 7.75 mo of gestation; corresponding to 180 ± 2, 208 ± 2, and 238 ± 2 d pregnant, respectively). Using a contralateral quarter-pair design, a single culture-negative quarter of each heifer was infused with saline (SAL), and the contralateral quarter was challenged with 5,000 cfu of Staphylococcus aureus (CHALL). Mammary secretion samples were collected at various time points until tissue harvest at 21 d postchallenge, when animals were 6.5, 7.5, and 8.5 mo pregnant. Mammary tissue samples from the center and edge parenchymal regions were collected and evaluated for immune cell infiltration and tissue morphometry. Secretions from CHALL quarters had greater SCC and a greater proportion of neutrophils compared with SAL quarters. Mammary tissues from CHALL quarters exhibited increased immune cell infiltration in both the luminal and intralobular stromal regions and lower secretion score compared with SAL, regardless of gestational stage. Additionally, tissues from animals at later gestational stages showed reduced adipose tissue area and larger lobular areas, regardless of quarter treatment. At 8.5 mo of pregnancy, luminal areas in the edge regions of CHALL quarters were nearly 50% smaller than in SAL quarters, suggesting an increased risk to restricting milk accumulation and secretion capacity in the mammary gland. Additionally, in 7.5-mo pregnant heifers, CHALL quarters showed decreased epithelial areas and increased intralobular stromal areas in the central region. Lobular, adipose, and extralobular stromal areas did not differ markedly between CHALL and SAL quarters. Overall, the results of this study indicate that IMI induces tissue damage in mammary glands of pregnant heifers, with a greater effect during late gestation, and that the IMI-induced changes in tissue architecture were not consistent across all tissue mammary gland regions or gestational ages.