Onset Of Lactation Research Articles

Feeding behavior in relation to ovarian cyclicity in cows with no or a short dry period

The objective of this study was to investigate relations between feeding behavior (FB) variables focusing on intake of the basal ration during 3 wk prepartum until 3 wk postpartum, and postpartum onset of luteal activity (OLA) in dairy cows subjected to no (0-d) or a short (30-d) dry period (DP). Feeding behavior of the basal ration intake (concentrate intake excluded) was continuously recorded by computerized feeders for 123 dairy cows and analyzed from 3 wk prepartum to 3 wk postpartum. Cows were subjected to a DP length: 0-d DP (n = 81), or 30-d DP (n = 42). Milk progesterone concentration was determined 3 times per week until 100 DIM to determine OLA, which was classified as early OLA (<21 DIM) and late OLA (≥21 DIM). Relations between FB and OLA class were analyzed using mixed models. During 3 wk prepartum, FB differed between parity class (parity 2 or ≥3 after calving). Cows with a 30-d DP prepartum, regardless of their OLA class, had more visits per meal, higher meal duration, total meal time, total daily feeding time, and lower feed intake and feeding rate compared with cows with 0-d DP. During the first 2 d postpartum, cows with OLA <21 had more visits per day and visits per meal compared with cows with OLA ≥21. During the first 3 wk postpartum, cows within the 30-d DP group with OLA <21 had greater meal size, feed intake, and feeding rate compared with cows with OLA ≥21 of this group. Cows within the 0-d DP group with OLA <21 had higher meal duration, total daily meal time, total daily feeding time, and meal size, but a lower feeding rate compared with cows with OLA ≥21 of this group. Concluding from the current study, cows with OLA <21 had a postpartum FB that reflected a cow with faster recovery from parturition and better adaptation to onset of lactation compared with OLA ≥21. No or a short DP affected prepartum FB, suggesting that prepartum management affects FB. This study provides evidence of different FB between cows with different timing of resumption of ovarian cyclicity.

Effects of Lactobacillus fermented plant products on dairy cow health, production, and environmental impact

During the onset of lactation, dairy cows experience increases in metabolic demands causing an increase in metabolic and oxidative stress that may result in disorders and reduced milk production. Dairy cows also represent a source of negative environmental impacts. Accordingly, natural products which alleviate these stresses and sources of environmental pollutants would be beneficial. The objective of this experiment was to determine how commercial products Lactobacillus fermented seaweed (Ecklonia radiata) (SWO; Animal Health Tonic; AgriSea Ltd.; Paeroa, NZ) and Lactobacillus fermented seaweed plus terrestrial plants (SWP; Fortress+; Agrisea Ltd.; Paeroa, NZ) influence dairy cow oxidative stress, environmental impacts, and production. Pregnant multiparous Holstein-Friesian × Jersey cross dairy cows (n = 27; body weight = 488.8 ± 47.6, mean ± SD) received daily oral doses of water (CON), SWO, or SWP. During the prepartum period (i.e., last third of gestation) the cows received 5-mL of their respective treatments once daily and this dose was increased to 100-mL per cow per d following calving. Ruminal fluid and blood samples were collected on d 0, 38, and 80 and blood samples were again collected 3 days after calving. Total volatile fatty acids concentrations in ruminal fluid were 26% greater (P = 0.05) in animals administered SWP compared with CON during the prepartum period. The CON cows had greater (P < 0.05) whole blood glutathione peroxidase activity than cows on SWP and SWO at all-time points following treatment application. After 80-d of administering the treatments and 3-d post calving, SWO and SWP had greater (P < 0.05) total antioxidant status of plasma (marker of ability to reduce oxidants). Three days after calving, the SWO and SWP cows had less (P < 0.05) plasma non esterified fatty acid concentrations and urea nitrogen than CON cows. Further, the SWP treatment had the lowest concentration of milk urea N and was less (P < 0.05) than CON. Accordingly, the calculated daily urinary N excretion of SWP was 18.0% lower (P < 0.05) than CON and SWO had a tendency (P = 0.07) to have 14.7% lower urinary N excretion than CON. Collectively, these results highlight the ability for these Lactobacillus fermented plant products to reduce oxidative stress during the onset of lactation in dairy cows and to reduce environmental impacts. This experiment provides important information for the improvement in periparturient dairy cows’ health and environmental impacts, which have economically important implications.

Interleukin-6 increases at the onset of lactation and promotes mammary glycolysis: insights from clinical and cellular studies

Interleukin-6 increases at the onset of lactation and promotes mammary glycolysis: insights from clinical and cellular studies

Growth hormone increases at the onset of lactation and promotes mammary metabolism: Insights from clinical and cellular studies

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Clinical and cellular studies highlight a role for insulin at the onset of lactation in promoting mammary glycolysis and oxidative phosphorylation

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Investigating hormones triggering the onset of sustained lactation (INSIGHT) pilot study

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Thyroid hormones promote mammary metabolic pathways required for milk synthesis: Relevance to the onset of lactation

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Contribution of Early Breastfeeding Initiation to Onset of Lactation in Postpartum Mothers and Breastfeeding in Midwives Independent Practice

After the baby is born, the production and release of breast milk do not occur immediately because there is still a transition of hormones in the mother’s body. Early Breastfeeding Initiation (IMD) is crucial in stimulating breast milk production. This study aimed to analyze the contribution of IMD to the onset of lactation. This type of research is pre-experimental with a one-shot case study design. The population in the implementation of this study were all couples of post-partum and breastfeeding mothers and their babies who gave birth and met the inclusion criteria. This study used a sample of 36 people. Collecting data was carried out using the observation and post-test methods. The Spearman rank correlation test analyzed data. The analysis results show a p-value of 0.000 0.05 and a correlation coefficient of 0.601, so H0 is rejected, and H1 is accepted. It shows a strong, significant, and unidirectional contribution between the implementation of IMD and the onset of lactation. The results of this study can then be used as a reference for further breastfeeding guidance strategies both in the third trimester of pregnancy and in the postpartum period.

Effects of omega-3 supplementation on components of the endocannabinoid system and metabolic and inflammatory responses in adipose and liver of peripartum dairy cows

BackgroundDietary supplementation of omega-3 fatty acids can reduce the activation of the endocannabinoid system (ECS) by decreasing the availability of arachidonic acid, thus lowering endocannabinoids (eCBs) levels. The ECS is a modulator of energy metabolism, stress response and inflammation in mammals, yet there is little information on the roles of the ECS in transition dairy cows. During the periparturient period, the adipose tissue and liver are the main metabolic organs that participate in the adaptations of dairy cows to onset of lactation; however, exceeded adipose tissue lipolysis and accumulation of lipids in the liver have adverse effects on cows’ physiology. Here we aimed to examine whether omega-3 supplementation during the transition period will modulate ECS activation and affect metabolic and inflammatory indices in postpartum dairy cows, by supplementing twenty-eight transition Holstein dairy cows with either saturated fat (CTL) or encapsulated flaxseed oil (FLX). Components of the ECS, metabolic and inflammatory markers were measured in blood, liver, and subcutaneous adipose tissue.ResultsFLX supplementation reduced feed intake by 8.1% (P < 0.01) and reduced plasma levels of arachidonic acid (by 44.2%; P = 0.02) and anandamide (by 49.7%; P = 0.03) postpartum compared to CTL. The mRNA transcription levels of the cannabinoid receptor 1 (CNR1/CB1) tended to be lower (2.5 folds) in white blood cells of FLX than in CTL (P = 0.10), and protein abundance of ECS enzyme monoacylglycerol lipase was higher in peripheral blood mononuclear cells of FLX than in CTL (P = 0.04). In adipose tissue, palmitoylethanolamide levels were lower in FLX than in CTL (by 61.5%; P = 0.02), relative mRNA transcription of lipogenic genes were higher, and the protein abundance of cannabinoid receptor 2 (P = 0.08) and monoacylglycerol lipase (P = 0.10) tended to be higher in FLX compared to CTL. Hepatic 2-arachidonoylglycerol tended to be higher (by 73.1%; P = 0.07), and interlukin-6 mRNA transcription level was 1.5 folds lower in liver of FLX than in CTL (P = 0.03).ConclusionsNutritional supplementation of omega-3 fatty acids seems to partly modulate ECS activation, which could be related to lower feed intake. The altered ECS components in blood, adipose tissue and liver are associated with moderate modulations in lipid metabolism in the adipose and inflammation in liver of peripartum dairy cows.

Berberine supplementation modulates the somatotropic axis and ameliorates glucose tolerance in dairy goats during late gestation and early lactation

BackgroundPregnancy, parturition, and the onset of lactation represent an enormous physiological and hormonal challenge to the homeostasis of dairy animals, being a risk for their health and reproduction. Thus, as a part of the homothetic changes in preparturition period, goats undergo a period of IR as well as uncoupled GH/IGF-1 axis. The objective for this study was to determine the effect of berberine (BBR) during the peripartal period on hormonal alteration and somatotropic axis in dairy goats as well as glucose and insulin kinetics during an intravenous glucose tolerance test (IVGTT). At 21 days before the expected kidding date, 24 primiparous Saanen goats were assigned randomly to 4 dietary treatments. Goats were fed a basal diet from wk. 3 antepartum (AP) until wk. 3 postpartum (PP) supplemented with 0 (CTRL), 1 (BBR1), 2 (BBR2), and 4 (BBR4) g/d BBR. Blood samples were collected on days − 21, − 14, − 7, 0, 7, 14, and 21 relative to the expected kidding date. An IVGTT was also performed on day 22 PP.ResultsCompared with CTRL, supplementation with either BBR2 or BBR4 increased DMI at kidding day and PP, as well as body conditional score (BCS) and milk production (p ≤ 0.05). On d 7 and 14 PP plasma glucose was higher in BBR2- and BBR4-treated than in CTRL. The glucagon concentration was not affected by BBR during the experimental period. However, supplemental BBR indicated a tendency to decrease in cortisol concentration on days 7 (p = 0.093) and 14 (p = 0.100) PP. Lower plasma GH was observed in BBR than in non-BBR goats (p ≤ 0.05). Plasma IGF-1 concentration was enhanced in both BBR2 and BBR4 at kidding and day 7 PP (p ≤ 0.05). During the IVGTT, glucose area under the curve (AUC), clearance rate (CR), T1/2, and Tbasal was lower (p ≤ 0.05) in both BBR2 and BBR4 goats as compared with CTRL. Likewise, the insulin CR was higher (p ≤ 0.05) in goats receiving either BBR2 or BBR4 which was accompanied by a lower insulin T1/2 and AUC.ConclusionsAltogether, our results indicated an improved glucose and insulin status along with the modulation of the somatotropic axis and glucose and insulin response to IVGTT in dairy goats supplemented with 2 and 4 g/d BBR.

Perilipin-2 promotes lipid droplet-plasma membrane interactions that facilitate apocrine lipid secretion in secretory epithelial cells of the mouse mammary gland.

Secretory epithelial cells (sMEC) in mammary glands of lactating animals secrete lipids by a novel apocrine mechanism in which cytoplasmic lipid droplets (LD) contact and are enveloped by elements of the apical plasma membrane (APM) before being released into the lumen of the gland as membrane bound structures. The molecular properties of LD-APM contacts and the mechanisms regulating LD membrane envelopment and secretion are not fully understood. Perilipin-2 (Plin2) is a constitutive LD protein that has been proposed to tether LD to the APM through formation of a complex with the transmembrane protein, butyrophilin1a1 (BTN) and the redox enzyme, xanthine oxidoreductase (XOR). Using mice lacking Plin2 and physiological inhibition of apocrine lipid secretion, we demonstrate that LD-APM contact and envelopment are mechanistically distinct steps that they are differentially regulated by Plin2 and independent of LD secretion. We find that Plin2 is not required for formation of LD-APM contacts. However, it increases the percentage of LD that contact the APM and mediates enlargement of the LD-APM contact zone as LD undergo membrane envelopment. The effects of Plin2 LD-APM interactions are associated with increased abundances of BTN, XOR and Cidea, which are implicated as mediators of LD-APM contact formation, on membranes surrounding secreted LD, and with promotion of glycocalyx remodeling at LD-APM contact sites. We propose that Plin2 does not directly mediate contact between LD and the APM but acts by enhancing molecular interactions that stabilize LD-APM contacts and govern membrane envelopment of LD during apocrine lipid secretion. Plin2 does not appear to significantly affect the lipid content of milk in fully lactating animals, but it does increase lipid secretion at the onset of lactation in primaparous dams, which suggest a role in facilitating apocrine lipid secretion in sMEC during their initial transition to a secretory phenotype.

Does bone mobilization interfere with energy metabolism in transition cows?

The onset of lactation represents a challenge for both mineral homeostasis and energy metabolism in high-performing dairy cows. It has been shown that subclinical and clinical hypocalcemia increases the risk of ketosis and recent studies suggest that bone-derived endocrine factors could play a role in intermediary metabolism. Therefore, we analyzed serum samples from calculated d −7, calculated d −3, d +1, d +3, and d +7 relative to calving from 15 multiparous cows for total Ca, the bone resorption marker CrossLaps, the bone formation marker intact osteocalcin, undercarboxylated osteocalcin (ucOC), insulin, glucose, nonesterified fatty acids, β-hydroxybutyrate, and insulin-like growth factor 1. Serum concentrations of Ca on d −3 and d +1 were associated with parameters of energy metabolism on d +3 and d +7. As we found large variations for serum concentrations of ucOC already on d −7, we allocated the cows retrospectively to 3 groups: low ucOC, medium ucOC, and high ucOC. These groups differed not only in their ucOC dynamics, but also in insulin sensitivity estimated using the revised quantitative insulin sensitivity index (RQUICKI). High ucOC cows presented with the highest RQUICKI throughout the entire observation period. Our data further support the hypothesis that low serum Ca precedes disturbances of energy metabolism. Furthermore, from our preliminary results it can be assumed that the potential link between mineral homeostasis, bone turnover, and intermediary metabolism should be further investigated.

Effects of Dietary Inclusion of Spirulina platensis on the Reproductive Performance of Female Mink.

Simple SummaryProfitability of mink farming depends mainly on the reproductive performance of female animals. Many dietary practices applied previously, to improve health and productivity of mink. Spirulina platensis is a natural dietary supplement, widely used both for human and animal consumption. In previous studies, in many animal species, Spirulina platensis supplementation improved reproductive characteristics. To our knowledge, inclusion of Spirulina in a mink’s diet has not yet been adequately studied. To address this dearth of knowledge, we investigated the effect of dietary inclusion of Spirulina platensis on the reproductive performance of female mink from pre-mating season until kit weaning. A tendency for a higher whelping rate was detected in Spirulina platensis treated animals, while a significant increase in their body weight during pre-mating season was observed. Finally, Spirulina platensis treated animals lost significantly more body weight during late lactation, but without an adverse effect on their or their kit’s survival. Overall, it can be suggested that Spirulina platensis can be used in female mink diets without adverse effects. However, since in the present study only a single dose was used, further studies are required to investigate the effects of higher levels of supplementation.The objective of this study was to investigate the impact of providing Spirulina platensis (Spirulina) on reproductive performance of female mink. A total of 100 adult brown female mink (Mustela vison) were randomly and equally allocated to control group (C group), in which mink were fed basal diet and Spirulina group (Sp group), where mink received basal diet supplemented with 100 mg of Spirulina/kg of body weight. The experiment lasted 5 months, starting from 1 month prior to mating till kit weaning. Weight gain during pre-mating period was higher in Sp group compared to C group (p < 0.001). Sp group remained heavier until the onset of lactation. Subsequently, mink of Sp group lost more weight than C group (p < 0.001) but without an adverse effect on kit survival. A tendency for a higher whelping rate was detected in Sp group (93.61%) compared to C group (81.25%) (p = 0.07). Litter size, as well as weight of kits at weaning, did not differ between groups (p > 0.10). Finally, Sp group weaned numerically more kits compared to C group. Results obtained here showed that Spirulina treated animals tended to an increased whelping rate.

Protocol for an observational study investigating hormones triggering the onset of sustained lactation: the INSIGHT study

IntroductionLactation is a hormonally controlled process that promotes infant growth and neurodevelopment and reduces the long-term maternal risk of diabetes, cardiovascular disease and breast cancer. Hormones, such as prolactin and...

Methionine Supplementation during Pregnancy of Goats Improves Kids' Birth Weight, Body Mass Index, and Postnatal Growth Pattern.

Simple SummaryMethionine is an essential amino acid that contributes to protein formation, fetal development, and milk synthesis. Thus, we hypothesized that a supplementation with Optimethione® during the last third of gestation in female goats will increase the maternal body live weight, the milk yield and milk composition and the offspring weight and body mass index at birth and postnatal performance. We fed (n = 30) or not (n = 30) herbal methionine Optimethione® to pregnant multiparous Alpine goats from gestational day 100 until delivery. We evaluated the productive variables from the dams and offspring. Maternal intake of herbal methionine Optimethione® during pregnancy did not increase the live weight or increase the milk yield and composition. However, the tested offspring variables were influenced by the maternal intake of herbal methionine Optimethione® during gestation by improving the birth weight, body mass index, and postnatal growth pattern. An increase in birth weight would be expected to increase neonatal survival up to weaning. Moreover, a relative fatness is required for reproductive success; thus, offspring that are born heavier and bigger can display a faster postnatal growth and accelerate the onset of puberty and increase reproductive success.The last third of gestation is a period of high energy and protein demand for the dam to support fetal growth and the following onset of lactation. Methionine is an essential amino acid that contributes to protein formation, fetal development, and milk synthesis; thus, is likely to have positive effects on the weight and size of the newborn and, afterward, milk yield and milk composition, which may improve growth patterns of the progeny. To test these hypotheses, we used 60 pregnant multiparous Alpine goats with similar live weights and gestational ages (~Day 100 of pregnancy; Mean ± SD; 1410 ± 14 days old and 50.4 ± 6.6 kg) and were separated into two groups: control and supplemented with the delivery. Treatments were T-MET (n = 30; received 1% herbal methionine Optimethione® dry matter based on from Day 100 of the pregnancy to delivery) or T-CTL (n = 30; served as the control and did not receive methionine). The methionine powder provided individual supplementation and was adjusted every week as the live weight and dry matter intake changed. At birth, the weight, body mass index (BMI), birth type, and sex of the kids were determined. Subsequently, the progeny was weighed weekly up to weaning. Two weeks after parturition, the milk composition was recorded weekly, and the milk yield was recorded monthly. The maternal live weight at the start (Mean ± SEM; T-CTL: 50.5 ± 1.1 vs. T-MET: 50.3 ± 1.3 kg) and end (T-CTL: 54.2 ± 1.3 vs. T-MET: 52.8 ± 1.4 kg) of the experiment did not differ statistically among treatments (p > 0.05); however, daily live weight changes tended to differ between groups (T-CTL: 73 ± 10 vs. T-MET: 51 ± 7 g day−1; p = 0.06). The birth weight (T-CTL: 3.1 ± 0.1 vs. T-MET: 3.5 ± 0.1 kg; p < 0.001), daily live weight change (T-CTL: 121 ± 6 vs. T-MET: 141 ± 6 g day−1; p < 0.01), and weaning weight (T-CTL: 8.3 ± 0.2 vs. T-MET: 9.3 ± 0.3 kg; p < 0.01) differed between treatments. The BMI at birth (T-CTL: 0.28 ± 0.01 vs. T-MET: 0.3 ± 0.01 units kg m−2; p < 0.01) and at weaning (T-CTL: 0.85 ± 0.1 kg vs. T-MET: 1.00 ± 0.06 units kg m−2; p < 0.05) differed between treatments. Milk components (protein, fat, lactose, and solids non-fat) and milk yield were similar between treatments (p > 0.05). It is concluded that the inclusion of methionine in the maternal goat diet during the last third of gestation increases the birth and growth variables of the progeny but without significant influence on the milk yield and composition.

An impact of lactoferrin, serum albumin and secretory immunoglobulin A in actimicrobial activity of breast milk whey

The contribution of the antimicrobial activity of sIgA, lactoferrin, -lactalbumin, serum albumin, and lysozyme to the total antimicrobial activity of whey was evaluated. 66 breast milk samples from healthy women aged from 23 to 45 years collected at different periods of lactation were studied. It was found that along with proceeding the lactation period, not only the total antimicrobial activity (r = 0.944) decreased, but also the activity of the low molecular weight fraction containing the sum of antimicrobial peptides (r = 0.950). The median lactoferrin level varied from 3.46 mg/ml in colostrum down to 0.94 mg/ml one year after the onset of lactation that correlated with whey activity (r = 0.616). The concentration of sIgA was peaked in the whey of colostrum (5.01 mg/ml) and significantly reduced in mature milk, remaining approximately at the same level in subsequent periods of lactation (1.0 mg/ml). Serum albumin concentration significantly decreased while proceeding through lactation period (from 5.52 to 4.68 mg/ml) and correlated with whey activity (r = 0.589). Evaluating effects of the purified -lactalbumin on C. albicans cells within the range of 520 mg/ml by spectrophotometry and microscopy showed the absence of fungicidal activity. At the same time, purified lactoferrin, IgA, lysozyme, and serum albumin demonstrated a direct fungicidal effect. The activity of the IgA preparation at a concentration relevant to the sIgA content in the whey of the first day colostrum was 50.0%, and in the whey after 12 months 31.0%; lactoferrin 26.7% and 3.4%; serum albumin 15.0% and 17.7%; lysozyme 0.1% and 1.8%. Thus, the sum of the activities of these polypeptides at concentrations typical for the first-day colostrum was 91.7%, which is comparable to the total activity of this whey 82.4%. The sum of the activities of these polypeptides, typical for 12 months of lactation, was 53.9%, and the total whey activity relevant to this period was 64.5%. Therefore, IgA and lactoferrin contribute the most significant antimicrobial activity in the whey of colostrum, whereas after 12 month-breastfeeding IgA and serum albumin become most significant.

Maladaptation to the transition period and consequences on fertility of dairy cows

After parturition, dairy cows undergo a plethora of metabolic, inflammatory, and immunologic changes to adapt to the onset of lactation. These changes are mainly due to the homeorhetic shift to support milk production when nutrient demand exceeds dietary intake, resulting in a state of negative energy balance. Negative energy balance in postpartum dairy cows is characterized by upregulated adipose tissue modelling, insulin resistance, and systemic inflammation. However, half of the postpartum cows fail to adapt to these changes and develop one or more types of clinical and subclinical disease within 5 weeks after calving, and this is escorted by impaired reproductive performance in the same lactation. Maladaptation to the transition period exerts molecular and structural changes in the follicular and reproductive tract fluids, the microenvironment in which oocyte maturation, fertilization, and embryo development occur. Although the negative effects of transition diseases on fertility are well-known, the involved pathways are only partially understood. This review reconstructs the mechanism of maladaptation to lactation in the transition period, explores their key (patho)physiological effects on reproductive organs, and briefly describes potential carryover effects on fertility in the same lactation.

Effects of an Intravenous Infusion of Emulsified Fish Oil Rich in Long-Chained Omega-3 Fatty Acids on Plasma Total Fatty Acids Profile, Metabolic Conditions, and Performances of Postpartum Dairy Cows During the Early Lactation.

A group of 10 multiparous Italian Holstein cows were housed in individual tied stalls and infused with 150 ml of saline (CTR; 5 cows), or of 10% solution rich in long-chained omega-3 fatty acids (n3FA; 5 cows) at 12, 24, and 48 h after calving. From −7 to 21 days from calving (DFC), the body condition score, body weight, dry matter intake (DMI), and milk yield were measured, blood samples were collected to assess the plasma fatty acids (FA) and metabolic profiles, and milk samples were collected to assess the milk composition. Data underwent a mixed model for repeated measurements, including the treatment and time and their interactions as fixed effects. Plasma FA profile from n3FA cows had lower myristic and higher myristoleic proportions, higher cis-11,14-eicosadienoic acid and monounsaturated FA proportions at 3 DFC, and lower cis-10-pentadecanoic proportion at 10 DFC. Besides these, n3FA cows had higher eicosapentaenoic (EPA) and docosahexaenoic (DHA) proportions (1.09 vs. 0.71 and 0.33 vs. 0.08 g/100 g), confirming the effectiveness of the infusion in elevating plasma availability of these FA. The plasma metabolic profile from n3FA cows revealed a tendency toward a lower concentration of reactive oxygen metabolites at 1 DFC and lower haptoglobin at 2 and 3 DFC, reflecting a mitigated inflammatory state. Furthermore, n3FA cows had a higher DMI during the first week of lactation. Higher DMI of n3FA could account for the changes detected on their plasma FAs, the higher milk yield they had at 1 and 2 DFC, the reduced lactose and urea nitrogen content in their milk. Higher DMI could also account for the lower plasma urea that n3FA cows had at 1 and 2 DFC, suggesting a lower amount of endogenous amino acids deserved to gluconeogenic fate. Milk from n3FA cows had lower rennet clotting time and higher curd firmness, which is probably driven by a higher EPA and DHA inclusion in the milk fat. Together, these outcomes suggest that the infusion exerts a short-term anti-inflammatory action on dairy cows at the onset of lactation.

Transcriptome provides insights into bovine mammary regulatory mechanisms during the lactation cycle

ABSTRACT The molecular events underlying the lactation curve of dairy animals have long been a biological conundrum for mammary biologists, and a cause of a considerable loss of income for dairy farmers. To better understand the regulatory mechanisms and developmental processes of the mammary gland during the lactation cycle, whole-genome transcriptome profiles of bovine mammary tissues at five different lactation stages were investigated using the RNA-Seq technique. The differentially expressed genes were identified by comparing different lactation stage combinations. Gene expression changes were validated using quantitative reverse-transcription polymerase chain reaction. Some differentially expressed genes were found to locate in the known quantitative trait loci regions that are associated with multiple milk production traits. Proteins of potentially important genes were confirmed to be expressed in the mammary epithelium of dairy cows. An integrated analysis of differential gene expression indicated that internal development regularities underlying the shape of the milk production curve. First, the mammary gland is enriched in similar activities during lactation onset and involution, but in opposite regulatory directions. Second, the lactation stages before and after the milk peak shared similar biological processes that were mainly involved in extracellular matrix remodelling. The discoveries of the study provide information necessary to improve milk production.

Risk factors for self-reported insufficient milk during the first 6 months of life: A systematic review.

The objective of this systematic review was to identify multifactorial risk factors for self‐reported insufficient milk (SRIM) and delayed onset of lactation (DOL). The review protocol was registered a priori in PROSPERO (ID# CDR42021240413). Of the 120 studies included (98 on SRIM, 18 on DOL, and 4 both), 37 (31%) studies were conducted in North America, followed by 26 (21.6%) in Europe, 25 (21%) in East Asia, and Pacific, 15 (12.5%) in Latin America and the Caribbean, 7 (6%) in the Middle East and North Africa, 5 (4%) in South Asia, 3 (2.5%) in Sub‐Saharan Africa, and 2 (1.7%) included multiple countries. A total of 79 studies were from high‐income countries, 30 from upper‐middle‐income, 10 from low‐middle‐income countries, and one study was conducted in a high‐income and an upper‐middle‐income country. Findings indicated that DOL increased the risk of SRIM. Protective factors identified for DOL and SRIM were hospital practices, such as timely breastfeeding (BF) initiation, avoiding in‐hospital commercial milk formula supplementation, and BF counselling/support. By contrast, maternal overweight/obesity, caesarean section, and poor maternal physical and mental health were risk factors for DOL and SRIM. SRIM was associated with primiparity, the mother's interpretation of the baby's fussiness or crying, and low maternal BF self‐efficacy. Biomedical factors including epidural anaesthesia and prolonged stage II labour were associated with DOL. Thus, to protect against SRIM and DOL it is key to prevent unnecessary caesarean sections, implement the Baby‐Friendly Ten Steps at maternity facilities, and provide BF counselling that includes baby behaviours.