Differential responses of rumen and fecal fermentation and microbiota of Liaoning cashmere goats after 2-hydroxy-4-(methylthio) butanoic acid isopropyl ester supplementation.

The 2-hydroxy-4-(methylthio) butanoic acid isopropyl ester (HMBi), a rumen protective methionine, has been extensively studied in dairy cows and beef cattle and has been shown to regulate gastrointestinal microbiota and improve production performance. However, knowledge of the application of HMBi on cashmere goats and the simultaneous study of rumen and hindgut microbiota is still limited. In this study, HMBi supplementation increased the concentration of total serum protein, the production of microbial protein in the rumen and feces, as well as butyrate production in the feces. The results of PCoA and PERMANOVA showed no significant difference between the rumen microbiota, but there was a dramatic difference between the fecal microbiota of the two groups of Cashmere goats after the HMBi supplementation. Specifically, in the rumen, HMBi significantly increased the relative abundance of some fiber-degrading bacteria (such as Fibrobacter) compared with the CON group. In the feces, as well as a similar effect as in the rumen (increasing the relative abundance of some fiber-degrading bacteria, such as Lachnospiraceae FCS020 group and ASV32), HMBi diets also increased the proliferation of butyrate-producing bacteria (including Oscillospiraceae UCG-005 and Christensenellaceae R-7 group). Overall, these results demonstrated that HMBi could regulate the rumen and fecal microbial composition of Liaoning cashmere goats and benefit the host.

Effects of dietary forage neutral detergent fiber and rumen degradable starch ratios on chewing activity, ruminal fermentation, ruminal microbes and nutrient digestibility of Hu sheep fed a pelleted total mixed ration.

Pelleted total mixed ration (P-TMR) feeding, which has become a common practice in providing nutrition for fattening sheep, requires careful consideration of the balance between forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) to maintain proper rumen functions. The present study aimed to investigate the effects of the dietary FNDF/RDS ratio (FRR) on chewing activity, ruminal fermentation, ruminal microbes, and nutrient digestibility in Hu sheep fed a P-TMR diet. This study utilized eight ruminally cannulated male Hu sheep, following a 4 × 4 Latin square design with 31 d each period. Diets consisted of four FRR levels: 1.0 (high FNDF/RDS ratio, HFRR), 0.8 (middle high FNDF/RDS ratio, MHFRR), 0.6 (middle low FNDF/RDS ratio, MLFRR), and 0.4 (low FNDF/RDS ratio, LFRR). Reducing the dietary FRR levels resulted in a linear decrease in ruminal minimum pH and mean pH, while linearly increasing the duration and area of pH below 5.8 and 5.6, as well as the acidosis index. Sheep in the HFRR and MHFRR groups did not experience subacute ruminal acidosis (SARA), whereas sheep in another two groups did. The concentration of total volatile fatty acid and the molar ratios of propionate and valerate, as well as the concentrate of lactate in the rumen linearly increased with reducing dietary FRR, while the molar ratio of acetate and acetate to propionate ratio linearly decreased. The degradability of NDF and ADF for alfalfa hay has a quadratic response with reducing the dietary FRR. The apparent digestibility of dry matter, organic matter, neutral detergent fiber, and acid detergent fiber linearly decreased when the dietary FRR was reduced. In addition, reducing the dietary FRR caused a linear decrease in OTUs, Chao1, and Ace index of ruminal microflora. Reducing FRR in the diet increased the percentage of reads assigned as Firmicutes, but it decreased the percentage of reads assigned as Bacteroidetes in the rumen. At genus level, the percentage of reads assigned as Prevotella, Ruminococcus, Succinivibrio, and Butyrivibrio linearly decreased when the dietary FRR was reduced. The results of this study demonstrate that the dietary FRR of 0.8 is crucial in preventing the onset of SARA and promotes an enhanced richness of ruminal microbes and also improves fiber digestibility, which is a recommended dietary FRR reference when formulating P-TMR diets for sheep.

Forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) are key components of carbohydrates in the diet for ruminants, which would reflect saliva secretion and the acid production potential of feed. However, appropriate FNDF to RDS ratios (FRR) applicable to ruminants under the condition of pelleted total mixed ration (P-TMR) feeding have not been reported. In this study, we investigated the effects of the dietary FRR on chewing activity, ruminal fermentation, ruminal microbial communities, and nutrient digestibility of Hu sheep under P-TMR feeding. The results indicate that reducing dietary FRR levels would induce acidosis in sheep, which negatively affected fiber utilization and ruminal bacterial communities. The FRR of 0.8 was a recommended dietary FRR when formulating a P-TMR diet for fattening sheep, as indicated by decreased ruminal acidosis risk and increased richness of ruminal microbes in the rumen as well as nutrient digestibility.

The effect of first-lactation calving season, milk production, and morphology on the survival of Simmental cows.

Longevity in dairy and dual-purpose cattle is a complex trait which depends on many individual and managerial factors. The purpose of the present study was to investigate the survival (SURV) rate of Italian Simmental dual-purpose cows across different parities. Data of this study referred to 2 173 primiparous cows under official milk recording that calved between 2002 and 2020. Only cows linearly classified for type traits, including muscularity (MU) and body condition score (BCS) were kept. Survival analysis was carried out, through the Cox regression model, for different pairwise combinations of classes of milk productivity MU, BCS, and calving season. Herd-year of first calving was also considered in the model. SURV (0 = culled; 1 = survived) at each lactation up to the 6th were the dependent variables, so that, for example, SURV2 equal to 1 was attributed to cows that entered the 2nd lactation. Survival rates were 98, 71, 63, 56, and 53% for 2nd, 3rd, 4th, 5th, and 6th lactation, respectively. Results revealed that SURV2 was not dependent on milk yield, while in subsequent parities, low-producing cows were characterized by higher SURV compared to high-producing ones. Additionally, cows starting the lactation in autumn survived less (47.38%) than those starting in spring (53.49%), suggesting that facing the late gestation phase in summer could increase the culling risk. The present study indicates that SURV in Italian Simmental cows is influenced by various factors in addition to milk productivity. However, it is important to consider that in this study all first-calving cows culled before the linear evaluation - carried out between mid- and late lactation in this breed - were not accounted for. Finding can be transferred to other dual-purpose breeds, where the cows' body conformation and muscle development - i.e. meat-related features - are often considered as important as milk performance by farmers undertaking culling decisions.

Periparturient blood T-lymphocyte PD-1 and CTLA-4 expression as potential predictors of new intramammary infections in dairy cows during early lactation (short communication).

BACKGROUND: The periparturient period in dairy cows is marked by immunosuppression which increases the likelihood of infectious disorders, particularly also mastitis. An in-depth understanding of peripartum leukocyte biology is vital for the implementation of highly successful post-partum disease prevention measures. Immune checkpoint molecules, such as programmed death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4), are critical inhibitory receptors expressed on immune cells, particularly T cells, that drive immunosuppressive signaling pathways. However, the potential role of immune checkpoint molecules expression in T-cells on udder health has never been explored. Thus, the association between the occurrence of new postpartum intramammary infections (IMIs) and the expression of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) on blood T-cells during the peripartum period was investigated. RESULTS: In this study, the incidence of IMIs by any pathogen in early lactation was not associated with a higher expression of PD-1 and CTLA-4 in the periparturient period. However, the incidence of IMIs by major pathogens throughout the first month of lactation was significantly associated with higher expression of PD-1 at 14 days before calving (P = 0.03) and CTLA-4 at parturition (P = 0.03) by blood T-cells. Also, the expression of CTLA-4 at D0 (P = 0.012) by T-cells was associated with the occurrence of persistent IMIs during the first month of lactation. CONCLUSIONS: To our knowledge, this is the first report to investigate the expression of PD-1 and CTLA-4 by blood T-lymphocytes during the periparturient period in dairy cows and to explore their relationship with the incidence of new IMIs in the postpartum period. Thus, a comprehensive understanding of leukocyte biology during peripartum would appear to be a prerequisite for the identification of resilient dairy cows or targets innovative (immunological) non-antibiotic approaches in the transition period.

Inflammatory response in dairy cows caused by heat stress and biological mechanisms for maintaining homeostasis.

Climate change increases global temperatures, which is lethal to both livestock and humans. Heat stress is known as one of the various livestock stresses, and dairy cows react sensitively to high-temperature stress. We aimed to better understand the effects of heat stress on the health of dairy cows and observing biological changes. Individual cows were divided into normal (21-22 °C, 50-60% humidity) and high temperature (31-32 °C, 80-95% humidity), respectively, for 7-days. We performed metabolomic and transcriptome analyses of the blood and gut microbiomes of feces. In the high-temperature group, nine metabolites including linoleic acid and fructose were downregulated, and 154 upregulated and 72 downregulated DEGs (Differentially Expressed Genes) were identified, and eighteen microbes including Intestinimonas and Pseudoflavonifractor in genus level were significantly different from normal group. Linoleic acid and fructose have confirmed that associated with various stresses, and functional analysis of DEG and microorganisms showing significant differences confirmed that high-temperature stress is related to the inflammatory response, immune system, cellular energy mechanism, and microbial butyrate production. These biological changes were likely to withstand high-temperature stress. Immune and inflammatory responses are known to be induced by heat stress, which has been identified to maintain homeostasis through modulation at metabolome, transcriptome and microbiome levels. In these findings, heat stress condition can trigger alteration of immune system and cellular energy metabolism, which is shown as reduced metabolites, pathway enrichment and differential microbes. As results of this study did not include direct phenotypic data, we believe that additional validation is required in the future. In conclusion, high-temperature stress contributed to the reduction of metabolites, changes in gene expression patterns and composition of gut microbiota, which are thought to support dairy cows in withstanding high-temperature stress via modulating immune-related genes, and cellular energy metabolism to maintain homeostasis.

Method for evaluating milk production in mouse mammary gland.

Lactation is a characteristic physiological function of mammals and is important for nourishing infants and the dairy industry; however, the molecular mechanisms underlying the function remain to be elucidated. A technique to directly evaluate the quantity and quality of milk in mice is necessary for the study of the lactation mechanism in vivo. By measuring the changes in milk amount after different durations of milk accumulation (0-24 h) using a ductal cannulation technique and oxytocin supplementation, we estimated the milk production rate at a single mammary gland level. In addition, collected milk was available to assess milk quality, including creamatocrit, osmolarity, and concentrations of ions, lactose, and total protein. Moreover, as a proof of principle, the effects of intraductal administration of a hypertonic solution to the abdominal mammary gland were examined. This stimulation increased milk amount, possibly by osmosis, compared with the contralateral control gland. These results demonstrated that this method is useful for examining the lactation ability and mechanisms in vivo. Studies using this method will contribute to the further understanding of lactation mechanisms in mammals.

Protein Dynamic Landscape during Mouse Mammary Gland Development from Virgin to Pregnant, Lactating, and Involuting Stages.

The mammary gland undergoes significant physiological changes as it undergoes a transition from virgin to pregnancy, lactation, and involution. However, the dynamic role of proteins in regulating these processes during mouse mammary gland development has not been thoroughly explored. In this study, we collected mouse mammary gland tissues from mature virgins aged 8-10 weeks (V), day 16 of pregnancy (P16d), day 12 of lactation (L12d), day 1 of forced weaning (FW 1d), and day 3 of forced weaning (FW 3d) stages for analysis using DIA-based quantitative proteomics technology. A total of 3,312 proteins were identified, of which 843 were DAPs that were categorized into nine clusters based on their abundance changes across developmental stages. Notably, DAPs in cluster 2, which peaked at the L12d stage, were primarily associated with mammary gland development and lactation. The protein-protein interaction network revealed that the epidermal growth factor (EGF) was central to this cluster. Our study provides a comprehensive overview of the mouse mammary gland development proteome and identifies some important proteins, such as EGF, Janus kinase 1 (JAK1), and signal transducer and activator of transcription 6 (STAT6) that may serve as potential targets for future research to provide guidelines for a deeper understanding of the developmental biology of mammary glands.

The role of endoplasmic reticulum stress in metabolic diseases and mammary epithelial cell homeostasis in dairy cows.

High-yielding dairy cows undergo various physiological stresses during the transitional phase of the calving cycle. In this period, they experience negative energy balance, subjecting the liver to significant metabolic stress from an influx of nonesterified fatty acids. This metabolic stress not only impairs liver function but also diminishes milk production. Early lactation dairy cows may develop endoplasmic reticulum (ER) stress in the liver, potentially leading to liver-related diseases and contributing to ER stress in mammary epithelial cells, resulting in decreased milk production. Natural products that alleviate ER stress have been identified, and if further in vivo studies confirm their efficacy, they have potential as feed additives to prevent disease and reduce milk yield. Conversely, physiological levels of ER stress play a role in mammary gland development and positively influence protein synthesis in milk. Understanding the threshold level of ER stress in mammary tissue and its detailed mechanisms will be crucial in dairy farming.

The Concentration of Lactoferrin in Breast Milk Correlates with Maternal Body Mass Index and Parity.

Background: Lactoferrin (LF) is a multifunctional glycoprotein found in human milk and body fluids, which has been shown to play a vital role in regulating the immunity and supporting the intestinal health of infants. Aim: This study evaluated the association between maternal/parturient factors and LF concentration in the breast milk of Chinese mothers. Methods: 207 breast milk samples were collected from healthy mothers with in the first year of lactation. Maternal and parturient information was collected for these participants through questionnaires. The content of lactoferrin in breast milk was detected by liquid chromatography, and macronutrient concentration in breast milk was measured by human milk analyzer in only 109 samples. Results: Our findings demonstrated that the LF content was much higher within the first month of lactation than it was after that period (p < 0.05). When compared with normal and lean mothers, the LF content of obese mothers was considerably higher (p < 0.05). The parity and LF content showed a favorable correlation. The proportion of LF to total protein tended to decrease as lactation progressed. Protein, fat, dry matter, and energy content were significantly positively correlated with LF content (p < 0.001). Conclusion: Early breast milk tends to have a higher level of LF, and the change of LF concentration in breast milk is associated with the parity and body mass index of the mother.

Acute and chronic sleep restriction differentially modify maternal behavior and milk macronutrient composition in the postpartum rat.

BACKGROUNDS: Sleep restriction is considered a stressful condition itself, causing a wide variety of physiological alterations, from cognitive and hormonal to immunological status. In addition, it is established that stress in mother rats can modify milk ejection, milk composition, and maternal care of the pups. Also, sleep disturbances during the early stages of motherhood are a common feature of all studied species. In this context, while the impacts of sleep disruption in non-lactating animals were extensively investigated, its repercussions during the initial phases of motherhood have been poorly explored. Therefore, we wonder if maternal behavior, milk ejection and its macronutrient composition would be disrupted when mother rats are subjected to an additional acute or chronic sleep restriction to the already existing sleep disturbances. METHODS: Lactating rats were implanted with unilateral electrodes for polysomnographic recordings and for deep brain electrical stimulation into mesopontine waking-promoting area (for sleep deprivation). During the early postpartum period (postpartum day 5-9), mother rats were randomly assigned into one of three groups: chronic sleep restriction group (CSR; 6 h of sleep deprivation/day for five consecutive days), acute sleep restriction group (ASR; 6 h of sleep deprivation only for one day), or undisturbed group (control group). Active maternal behaviors (retrievals of the pups into the nest, mouthing, lickings [corporal and anogenital] and sniffing the pups) and passive maternal behaviors (kyphotic and supine nursing postures) were evaluated during a 30 min period without sleep restriction immediately after the sleep restriction or control period. The litter weight gain was assessed every day, and on the last experimental session mothers were milked for posterior macronutrients analysis (protein, carbohydrates and fat). RESULTS: When compared to control group, CSR decreased the amount of milk ejected in the middle days of the sleep restriction period, while ASR did not affect this parameter. Moreover, ASR reduced milk protein content compared to control and CSR groups. Finally, compared to the control group, CSR reduced active maternal behaviors towards the end of the treatment days. CONCLUSIONS: We demonstrated that not only acute but also chronic sleep restriction impacts on the postpartum period, each one affecting different aspects of maternal behavior and lactation. Our results suggest the existence of a homeostatic recovery mechanism in breastfeeding during CSR, possibly ensuring the survival of the litter, while the decline in active maternal behaviors appears to be cumulative.

Behavioural responses related to increasing core body temperature of grazing dairy cows experiencing moderate heat stress.

Exposure to direct solar radiation, high ambient temperature, lack of wind movement, coupled with own metabolic heat production, makes grazing dairy cows vulnerable to heat stress. In pastures, it would be beneficial to monitor heat stress by observable changes in behaviour. We hypothesised that grazing dairy cows exhibit behavioural changes due to increasing heat load in temperate climate. Over two consecutive summers, 38 full-time grazing Holstein dairy cows were investigated in 12 experimental periods of up to 3 consecutive days where the cows were repeatedly exposed to various levels of moderate heat load determined by the comprehensive climate index (CCI). The CCI defines the ambient climate conditions, combining air temperature, relative humidity, solar radiation and wind speed. Vaginal temperature (VT) was automatically measured as an indicator of heat stress. In addition, as a less invasive method, we investigated if reticular temperature (RET) can be indicative of heat stress on pastures. Walking activity, lying-, feeding, and ruminating durations were recorded continuously with sensors. Respiration rate (RR), proximity to and competition at the water trough, social licking, self-licking, inter-individual distance, and fly intensity were directly observed. Data were analysed in the morning (0900-1100 h) and during the hottest time of day when cows were on pasture (1230-1430 h). The VT and RET showed similar patterns in relation to the CCI, suggesting that RET can be suitable for continuous monitoring of heat stress on pastures. In the morning, the cow's VT and RET did not relevantly react to the CCI. During the period 1230-1430 h, the cow's mean VT (mean vaginal temperature (VTMEAN); range: 37.7-40.3 °C) and mean RET (mean reticular temperature; range: 37.0-41.1 °C) were positively related to the mean CCI (mean comprehensive climate index) in this period (mean ± SD: 25.9 ± 5.71 °C). For cows with greater VTMEAN, an increased mean RR and decreased durations of walking, lying, feeding, and ruminating were found. These cows were also more likely to be in proximity to the water trough and to have small inter-individual distances. Changes in these traits seem to reflect behavioural adaptations to heat stress in a temperate climate and could be used to detect the heat stress in individual dairy cows on pastures.

Behavioural variability, physical activity, rumination time, and milk characteristics of dairy cattle in response to regrouping.

In the commercial dairy industry worldwide, it is common practice to periodically regroup cows as part of their management strategy within housed systems. While this animal husbandry practice is intended to improve management efficiency, cows may experience social stress as a result of the social environment changes, which may have an impact on their behavioural patterns, performance, and welfare. We investigated whether regrouping altered dairy cows' behaviour and impacted their cortisol concentration (a physiological marker of stress), oxytocin, milk yield, and quality in a robotic milking system. Fifty-two lactating cows (17 primiparous; 35 multiparous) were moved in groups of 3-5 individuals into established pens of approximately 100 cows. Behaviour of the regrouped cows was directly observed continuously for 4 h/day across 4-time blocks (day-prior (d-1), day-of regrouping (d0), day-after (d + 1), and 6-days after (d + 6) regrouping). Cows were categorised as being with others, alone, or feeding every 2.5 min prior to the assessment of behavioural dynamics. Milk yield (MY) and composition, total daily activity, and rumination time (RUM) data were extracted from the Lely T4C management program (Lely Industries, Maassluis, the Netherlands), and milk samples were collected for cortisol and oxytocin concentration analyses; data were analysed using linear mixed-effect modelling. Primiparous cows were less likely to be interacting with others on d + 1 than d-1 compared with multiparous. However, average bout duration (minutes) between being alone and feeding activity states were similar on d-1, d + 1, and d + 6, for both primiparous and multiparous cows. A reduction in the average alone and feeding bout duration was observed on d0. Multiparous cows spent significantly more total time being alone on d0 compared to d-1. Neither regrouping nor parity statistically influenced milk DM content, energy, or cortisol concentration. Primiparous cows produced 3.80 ±â€¯2.42 kg (12.2%) less MY on d + 1 compared to their d-1, whereas multiparous cows did not change MY. A significant decrease of 0.2% fat was found in both parity groups following regrouping and remained low up to d + 6. Daily activity in both parity groups increased significantly and RUM reduced after regrouping. A significant decrease in oxytocin concentration was observed in all cows on d + 1. The results, specifically for primiparous cows, indicated a negative impact of regrouping on social interactions, due to changes in the social environment which may lead to short-term social instability. Multiparous cows may benefit from previous regrouping experiences.

Variation in maternal lactation practices associated with changes in diurnal maternal inflammation.

While the importance of human milk in shaping infant immune function is well established, the impact of at-the-nipple (ATN) breastfeeding on maternal immune status has been understudied. Since lactation evolved to support infant survival and boost maternal fitness, we predict that ATN breastfeeding will confer benefits on maternal immune function. We measure the absolute and relative frequency of different infant feeding methods (ATN breastfeeding, pumping, donated milk, other supplementation) used by postpartum women in Seattle, WA (USA). We implement Bayesian modeling to estimate the effects of ATN breastfeeding on diurnal change in secretion rate of "pro-inflammatory" salivary cytokines and C-reactive protein (CRP). Our results show that most mothers in our sample used a variety of infant feeding methods, with pumping as the most common alternative to ATN breastfeeding. We find that ATN breastfeeding is associated with non-linear effects on diurnal IL-8 and CRP. Furthermore, we find that women who report zero versus ubiquitous ATN breastfeeding exhibit opposing diurnal patterns in CRP secretion rate. This study provides evidence that variation in maternal lactation practices corresponds to differences in maternal immune responses, highlighting how measuring lactation as a continuous variable can further enhance understanding of postpartum maternal physiology.

Lactation body condition loss impaired conceptus development and plasma progesterone concentration at day 8 post-ovulation in primiparous sows.

The current study investigated effects of dietary amino acid (AA) availability on lactational body condition loss and metabolic status, in relation to reproductive parameters after weaning up to Day 8 post-ovulation. Primiparous sows (n = 35) were allocated to one of two lactation diets containing either low crude protein (CP, 140 g/kg) with a low percentage (8%) of slow protein in total protein (LL, n = 18) or high CP (180 g/kg) with a high (16%) percentage of slow protein (HH, n = 17). The HH diet was expected to improve AA utilization by supplying more AA, in a more gradual fashion. The diets did not affect sow body condition loss during lactation, while the HH diet tended to increase litter weight gain during the week 3 of lactation (Δ = 1.3 kg, P = 0.09). On Day 14 post-farrowing, HH diet led to higher plasma urea both pre-feeding and post-feeding (Δ = 2.3 mmol/L, P < 0.01, Δ = 2.4 mmol/L, P < 0.01, respectively), whilst plasma creatinine, NEFA and IGF-1 were similar. No dietary effects on reproductive parameters were found, however several relationships were found between body condition and reproductive parameters. Sows with higher body weight on Day 1 or Day 21 post-farrowing had greater follicle size on Day 3 post-weaning (ß = 0.03 mm/kg, P < 0.01, ß = 0.04 mm/kg, P < 0.01, respectively). At Day 8 post-ovulation, plasma progesterone concentration was negatively related to loin muscle loss (ß = -0.67 ng/ml · mm-1, P = 0.02), backfat loss (ß = -2.33 ng/ml · mm-1, P = 0.02), and estimated body fat loss (ß = -0.67 ng/ml · mm-1, P = 0.02). Both plasma progesterone and the number of corpora lutea were positively related to the energy balance during lactation (ß = 0.03 ng/ml · ME MJ-1, P = 0.01, ß = 0.01 CL/ME MJ, P = 0.02, respectively). The conceptus size at Day 8 post-ovulation was negatively related to body weight loss (ß = -0.01 mm/kg, P = 0.01), estimated body fat loss (ß = -0.02 mm/kg, P = 0.03) and estimated body protein loss (ß = -0.06 mm/kg, P = 0.04), and was positively related to the energy balance during lactation (ß = 5.2*10-4 mm/ME MJ, P = 0.01). In conclusion, body protein and fat losses during lactation reduced subsequent plasma progesterone concentration and conceptus development at Day 8 post-ovulation.

Exposure to the psychedelic substance 25 H-NBOMe disrupts maternal care in lactating rats and subsequently impairs the social play behavior of the offspring.

Given the critical role of maternal care in the neurodevelopment of offspring, this study aimed to investigate the effects of the psychedelic substance 25 H-NBOMe on maternal behavior in lactating rats and its subsequent impact on the social and neurodevelopmental behavior of the offspring. We administered two different dosages of 25 H-NBOMe (0.3 mg/kg and 1.0 mg/kg; i,p,) to lactating rats and observed changes in maternal behaviors, such as nest-building and pup retrieval, and in offspring behaviors, including social play. Behavioral assessments were complemented by physiological measurements to rule out general health or nutritional decline. 25 H-NBOMe significantly disrupted maternal behaviors, including nest-building and pup retrieval, without affecting the weight of dams or offspring. Offspring of exposed dams exhibited reduced social play behavior. Higher doses led to more pronounced disruptions, while lower doses, despite not visibly affecting maternal behavior, still impacted offspring behavior, suggesting potential direct effects of 25 H-NBOMe. The study highlights the potential risks associated with the use of 25 H-NBOMe during lactation, emphasizing its detrimental impact on maternal care and offspring development. These findings contribute to understanding the neurobiological effects of psychedelic substances during critical developmental periods and underscore the importance of avoiding their use.

Short communication: Temporal profiles of colostrum and milk haptoglobin and substance P in early lactation multiparous Holstein cows.

Milk markers have the potential to aid in the detection of cow disease in early lactation if the automation of milk analysis becomes commonplace. Characterising temporal profiles of milk markers in dairy cows will improve the understanding of basal concentrations in clinically healthy cows. The objective of this observational study was to characterise the variation and temporal profiles of colostrum and milk haptoglobin (Hp) and substance P concentrations within 21 days postcalving in clinically healthy multiparous Holstein dairy cows. Ninety Holstein dairy cows from a commercial dairy herd were included. Milk samples were collected on the day of calving (day 0), and on days 1 to 4, 7, 14, and 21 postcalving and concentrations of Hp and substance P in colostrum (days 0 to 3) and milk (days 4, 7, 14, and 21) were determined using Enzyme Linked Immunosorbent assay. Haptoglobin and substance P concentrations were, on average (raw means ± SD), 0.40 ± 0.26 µg/ml and 56.2 ± 38.7 pg/ml in colostrum, respectively, and 0.23 ± 0.23 µg/ml and 37.1 ± 27.8 pg/ml in milk, respectively. Haptoglobin and substance P were elevated and greatest 1 day postcalving (least squares mean ± SE of the mean; 0.53 ± 0.05 µg/ml and 46.5 ± 3.64 pg/ml, respectively) and substance P varied widely within 21 days postcalving. The presence of substance P in dairy cow colostrum was not documented previously. Elevated concentrations of Hp and substance P immediately postcalving may be due to physiological roles these inflammatory markers have in the dairy cow or neonate or may simply represent an accumulation in colostrum before the first milk is removed.

Effect of extended heat stress in dairy cows on productive and behavioral traits.

This study evaluates the response of dairy cows to short and extended heat stressing conditions (from 1 to 28 days), as expressed in changes in their behavior. Due to climate change, heat stress and strong heat waves are frequently affecting the productivity and behavior of dairy cows. In the five years under study from 2018 to 2022, two were characterized by extremely strong heat waves occurring in the region analyzed in this study (Northern Italy). The dairy cattle farm involved in this study is located in Northern Italy and includes about 1 600 Holstein Friesian lactating dairy cows. Phenotypic data were provided by the Afimilk system and compromised behavioral and productive traits. Behavioral traits analyzed were activity, rest time, rest bouts, rest ratio, rest per bout and restlessness. Production traits were daily milk yield, average milking time, somatic cell count, fat percentage, protein percentage and lactose percentage. Climate data came from the National Aeronautics and Space Administration/Prediction of Worldwide Energy Resources database. Heat stress was analyzed considering Temperature-Humidity Index (THI) averaged over 28 different time windows of continuous heat stress. Results showed that rest time and milk yield were the two traits most affected by the increased THI. Rest time was immediately affected by high THI, showing a marked decrease already from 1d window and maintaining this all over the other windows. Furthermore, results show that rest time and rest ratio were only slightly negatively correlated with milk yield (-0.14 and -0.15). In addition, heat stress has a different effect depending on parity and lactation stages on the studied traits. In conclusion, the results indicate that heat stress increases activity and compromises milk production, rest time and milk quality traits. Results further suggest that rest time can be a better parameter than activity to describe the effects of heat stress on dairy cattle. The novel approach used in this study is based on the use of different time windows (up to 28 days) before the emergence of undesired THI and allows to identify the traits that are immediately influenced by the undesirable THI values and those that are influenced only after a prolonged heat stress period.

Going Full TeRM: The Seminal Role of Tissue-Resident Macrophages in Organ Remodeling during Pregnancy and Lactation.

During pregnancy and lactation, the uterus and mammary glands undergo remarkable structural changes to perform their critical reproductive functions before reverting to their original dormant state upon childbirth and weaning, respectively. Underlying this incredible plasticity are complex remodeling processes that rely on coordinated decisions at both the cellular and tissue-subunit levels. With their exceptional versatility, tissue-resident macrophages play a variety of supporting roles in these organs during each stage of development, ranging from maintaining immune homeostasis to facilitating tissue remodeling, although much remains to be discovered about the identity and regulation of individual macrophage subsets. In this study, we review the increasingly appreciated contributions of these immune cells to the reproductive process and speculate on future lines of inquiry. Deepening our understanding of their interactions with the parenchymal or stromal populations in their respective niches may reveal new strategies to ameliorate complications in pregnancy and breastfeeding, thereby improving maternal health and well-being.

A xenotransplantation mouse model to study physiology of the mammary gland from large mammals.

Although highly conserved in structure and function, many (patho)physiological processes of the mammary gland vary drastically between mammals, with mechanisms regulating these differences not well understood. Large mammals display variable lactation strategies and mammary cancer incidence, however, research into these variations is often limited to in vitro analysis due to logistical limitations. Validating a model with functional mammary xenografts from cryopreserved tissue fragments would allow for in vivo comparative analysis of mammary glands from large and/or rare mammals and would improve our understanding of postnatal development, lactation, and premalignancy across mammals. To this end, we generated functional mammary xenografts using mammary tissue fragments containing mammary stroma and parenchyma isolated via an antibody-independent approach from healthy, nulliparous equine and canine donor tissues to study these species in vivo. Cryopreserved mammary tissue fragments were xenotransplanted into de-epithelialized fat pads of immunodeficient mice and resulting xenografts were structurally and functionally assessed. Preimplantation of mammary stromal fibroblasts was performed to promote ductal morphogenesis. Xenografts recapitulated mammary lobule architecture and contained donor-derived stromal components. Mammatropic hormone stimulation resulted in (i) upregulation of lactation-associated genes, (ii) altered proliferation index, and (iii) morphological changes, indicating functionality. Preimplantation of mammary stromal fibroblasts did not promote ductal morphogenesis. This model presents the opportunity to study novel mechanisms regulating unique lactation strategies and mammary cancer induction in vivo. Due to the universal applicability of this approach, this model serves as proof-of-concept for developing mammary xenografts for in vivo analysis of virtually any mammals, including large and rare mammals.

Negative photoperiod induces an increase in the number of ovulations in dairy cattle.

This study sought to examine the impact of negative photoperiod on the incidence of multiple ovulations and pregnancies in dairy cattle. The study population consisted of 5,373 pregnant cows in their third or greater lactation that experienced their first post-partum pregnancy after spontaneous estrus. The positive photoperiod (increasing day-length) extends from December 22 to June 21, whereas the negative photoperiod (decreasing day-length) extends from June 22 to December 21. The odds ratios (ORs) for multiple ovulations and pregnancies in cows that became pregnant during the negative photoperiod and the remaining cows that became pregnant during the positive photoperiod were 1.4 and 1.3 (P < 0.0001), respectively. The ORs for cows that became pregnant ≥ 90 days in milk and the remaining cows that became pregnant < 90 days in milk were 4.3 and 4.1 (P < 0.0001), respectively. No significant differences were detected in the monthly rates of multiple ovulations or pregnancies during positive and negative photoperiods. Thus, the present study demonstrates that the ovarian function in cows is related to changes in day-length, with decreasing day-length being associated with greater multiple ovulation and pregnancy rates. The present study also shows that positive and negative photoperiods exhibit different trends. The results of this study are consistent with a growing body of work demonstrating the effects of photoperiod patterns on the reproductive physiology of cows, with clear implications for twin pregnancy prevention.