Changes in milk fat globule membrane proteins along lactation stage of Laoshan dairy goat

The milk fat globule membrane(MFGM)is a complex structure with numerous functions,and its composition is affected by many factors.There have been few systematic investigations on goat MFGM proteome profiling during lactation.Individual milk samples from 15 healthy dairy goats were obtained at six lactation time points for investigation of the MFGM proteome using both data-independent acquisition(DIA)and data-dependent acquisition(DDA)proteomics techniques combined with multivariate statistical analysis.Using the DIA method,890 variably abundant MFGM proteins were discovered throughout the lactation cycle.From 1 to 240 d,butyrophilin subfamily 1 member A1,lipoprotein lipase,perilipin-2,and adipose triglyceride lipase were upregulated,while APOE,complement C3,clusterin,and IgG were downregulated.Furthermore,from 1 to 90 d,annexin A1,annexin A2,and antithrombin-ll were downregulated,then upregulated by d 240.Albumin had a high degree of connectedness,indicating that it was a key protein,according to protein-protein interaction research.Overall,our findings gave new insights into the biological features of MFGM protein in goat milk throughout lactation,which may aid in the creation of specialized MFGM products and infant formula.

Effect of care intervention with a health education form for breastfeeding on breast distension,pain,and lactation in postpartum mothers

BACKGROUND Breastfeeding not only meets the nutritional needs of newborn growth and development but also promotes uterine contraction and discharge of lochia,which helps in maternal recovery.However,some mothers experience abnormal lactation and breast swelling due to a lack of breastfeeding knowledge,painful cesarean incisions,anesthesia,negative emotions,and other factors,resulting in a reduced breastfeeding rate,which adversely affects neonatal and maternal health.AIM To explore the effects of care intervention with a health education form for breastfeeding on breastfeeding-related conditions.METHODS In this study,207 mothers with postpartum breast pain and difficulty lactating were selected and divided into intervention and control groups using a random number table.Both groups of mothers were provided with basic nursing and related treatment measures after delivery.The intervention group additionally received care intervention with a health education form for breastfeeding.The scores of lactation volume,breast distension and pain,breastfeeding rate,breastfeeding self-efficacy,treatment effect,and complication rate of the two groups were compared.RESULTS After treatment,the breast pain score of the intervention group was significantly lower than that of the control group,while the lactation score,score of Breastfeeding Self-Efficacy Scale Short Form scale,parent-child communication score,maternal-infant interaction score,total score of maternal-infant communication,and breastfeeding rate of the intervention group were significantly higher than those of the control group.After intervention,the overall therapeutic effect of the intervention group was better than that of the control group,and the complication rate of the intervention group was lower than that of the control group.CONCLUSION Breastfeeding health education and nursing intervention combined with basic clinical treatment have good clinical effects in managing postpartum breast distension and pain and increasing lactation yield.

Postpartum depression and partner support during the period of lactation:Correlation research and its influencing factors

BACKGROUND Postpartum depression(PPD)not only affects the psychological and physiological aspects of maternal health but can also affect neonatal growth and development.Partners who are in close contact with parturient women play a key role in communication and emotional support.This study explores the PPD support relationship with partners and its influencing factors,which is believed to establish psychological well-being and improve maternal partner support.AIM To explore the correlation between PPD and partner support during breastfeeding and its influencing factors.METHODS Convenience sampling was used to select lactating women(200 women)who underwent postpartum examinations at the Huzhou Maternity and Child Health Care Hospital from July 2022 to December 2022.A cross-sectional survey was conducted on the basic information(general information questionnaire),depression level[edinburgh postnatal depression scale(EPDS)],and partner support score[dyadic coping inventory(DCI)]of the selected subjects.Pearson’s correlation analysis was used to analyze the correlation between PPD and DCI in lactating women.Factors affecting PPD levels during lactation were analyzed using multiple linear regression.RESULTS The total average score of EPDS in 200 lactating women was(9.52±1.53),and the total average score of DCI was(115.78±14.90).Dividing the EPDS,the dimension scores were:emotional loss(1.91±0.52),anxiety(3.84±1.05),and depression(3.76±0.96).Each dimension of the DCI was subdivided into:Pressure communication(26.79±6.71),mutual support(39.76±9.63),negative support(24.97±6.68),agent support(6.87±1.92),and joint support(17.39±4.19).Pearson’s correlation analysis demonstrated that the total mean score and individual dimension scores of EPDS during breastfeeding were inversely correlated with the total score of partner support,stress communication,mutual support,and cosupport(P<0.05).The total mean score of the EPDS and its dimensions were positively correlated with negative support(P<0.05).Multiple linear regression analysis showed that the main factors affecting PPD during breastfeeding were marital harmony,newborn health,stress communication,mutual support,negative support,cosupport,and the total score of partner support(P<0.05).CONCLUSION PPD during breastfeeding was associated with marital harmony,newborn health,stress communication,mutual support,negative support,joint support,and the total DCI score.

Study on the Application Effect of Flexible Nursing Care in Patients with Postpartum Urinary Retention and its Effect on Lactation

Objective: To study the application effect of flexible nursing in patients with postpartum urinary retention and its effect on lactation. Methods: A total of 200 cases of postpartum urinary retention patients admitted between January 2021 and January 2022 were selected and randomly grouped into two groups, a control group (conventional nursing) and an observation group (flexible nursing), of 100 cases each. The time of onset of lactation, the lactation volume score, urinary indicators, the amount of post-partum hemorrhage, and the quality of life score of the two groups were compared. Results: The observation group’s lactation initiation time (21.41 ± 1.52) h and lactation volume score (2.11 ± 0.52) were better than that of the control group (P < 0.05). The observation group’s first urination time (2.11 ± 0.51) min was lower than the control group, while the urinary retention completely relieved time (33.12 ± 8.61) h, and first urinary volume (262.17 ± 52.41) mL was higher than that of the control group (P < 0.05). The amount of postpartum hemorrhage in the observation group (151.21 ± 22.12) mL was less than that in the control group (P < 0.05). The scores of somatic functioning (86.25 ± 2.20), psychological functioning (91.56 ± 1.45), social functioning (89.25 ± 2.45), and material life (89.75 ± 1.45) of the observation group were higher than those of the control group after nursing (P < 0.05). Conclusion: Flexible nursing care in patients with postpartum urinary retention exhibited significant nursing effects and lactation function was effectively improved.

Lactation breast abscess treated with Gualou Xiaoyong decoction and painless lactation manipulation:A case report and review of literature

BACKGROUND Breast abscess during lactation is a severe complication of acute mastitis,which can lead to discomfort,high fever,breast fistula,sepsis,septic shock,breast damage,disease persistence and frequent hospitalization.Breast abscesses may also lead the mother to discontinue breastfeeding,thereby harming the infant’s health.The predominant pathogenic bacteria are Staphylococcus aureus,Staphylococcus epidermidis and Streptococcus.The incidence of breastfeeding abscesses in breastfeeding women ranges between 4.0%and 11.0%.In cases of breast abscess,the rate of cessation of lactation is 41.0%.In instances of breast fistula,the rate of cessation of lactation is very high(66.7%).Furthermore,50.0%of women with breast abscesses must be hospitalized and treated with intravenous antibiotics.Treatment includes antibiotics,abscess puncture and surgical incision and drainage.The patients suffer from stress,pain and easily induced breast scarring;the disease’s progression is prolonged and recurrent,interfering with infant feeding.Consequently,it is crucial to discover an adequate cure.CASE SUMMARY A 28-year-old woman with a breast abscess was treated with Gualou Xiaoyong decoction and painless breast opening manipulation 24 d after cesarean delivery.On the 2nd d of treatment,the patient’s breast mass was significantly reduced,the pain was significantly reduced,and the general asthenia was improved.All conscious symptoms disappeared after 3 d,breast abscesses faded after 12 d of treatment,inflammation images disappeared after 27 d,and normal lactation images were restored.CONCLUSION In treating breast abscesses during breastfeeding,the combination of Gualou Xiaoyong decoction and painless lactation provides a positive therapeutic impact.This disease’s treatment offers the advantages of a short course of treatment,no need to discontinue breastfeeding and the ability to rapidly mitigate symptoms,which can be used as a reference in clinical practice.

Pregnancy and lactation-associated osteoporosis with pyogenic spondylitis:A case report

BACKGROUND This case report presents a patient with pyogenic spondylitis(PS)associated with lactation-related osteoporosis during pregnancy.The 34-year-old female patient experienced low back pain for one month,beginning one month postpartum,with no history of trauma or fever.Dual-energy X-ray absorptiometry of the lumbar spine revealed a Z-score of-2.45,leading to a diagnosis of pregnancy and lactation-associated osteoporosis(PLO).The patient was advised to cease breastfeeding and take oral calcium and active vitamin D.Despite these interventions,her symptoms worsened,and she had difficulty walking one week later,prompting her to revisit our hospital.CASE SUMMARY Lumbar magnetic resonance imaging(MRI)scans showed abnormal signals in the L4 and L5 vertebral bodies and intervertebral space,while an enhancement scan displayed abnormal enhanced high signals around the L4/5 intervertebral disc,suggesting a lumbar infection.A needle biopsy was performed for bacterial culture and pathological examination,culminating in a final diagnosis of pregnancy and lactation-related osteoporosis with PS.Following treatment with antiosteoporotic medications and antibiotics,the patient’s pain gradually subsided,and she returned to normal life within five months.PLO is a rare condition that has garnered increasing attention in recent years.Spinal infections during lactation in pregnancy are also relatively uncommon.CONCLUSION Both conditions primarily manifest as low back pain but require distinct treatments.In clinical practice,when diagnosing patients with pregnancy and lactation-associated osteoporosis,the possibility of spinal infection should be considered.A lumbar MRI should be conducted as needed to prevent delays in diagnosis and treatment.

Milk Yield of Holstein Cows Induced into Lactation Twice Consecutively and Lactation Curve Models Fitted to Artificial Lactations

Nineteen multiparous barren Holstein cows were subjected to an induction of lactation protocol for 21 d administering estradiol cypionate （2 mg kg-1 of body weight （BW） d-1, on day 1 to 14）, progesterone （0.10 mg kg-1 of BW, on day 1 to 7）, lfumethasone （0.03 mg kg-1 of BW, on day 18 to 20） and recombinant bovine somatotropin （rbST;500 mg per cow, on day 1, 6, 16 and 21）. At the end of lactation and with a minimum of a 2-mon dry period, the same cows were again hormonally induced into lactation. Cows in both lactations were not artiifcially inseminated, they were milked 3 times daily and received rbST throughout lactation. Mean accumulated milk yield at 305 d in milk （DIM） did not differ between the ifrst and second induced lactations （（9 710 ＆#177;1 728） vs. （9 309＆#177;2 150） kg;mean＆#177;SD）. Total milk yield （（12 707＆#177;3 406） vs. （12 306＆#177;4 218） kg;mean＆#177;SD） and lactation length （（405＆#177;100） vs. （410＆#177;91） d;mean＆#177;SD） were not different between the ifrst and second induced lactations. In a second study, 15 empirical models including exponential, power law, yield-density, sigmoidal and miscellaneous models were compared for their suitability by modeling 12-mon （n=334）, 18-mon （n=164） and 29-mon （n=22） lactation cycles of Holsteins cows induced into lactation and treated with rbST throughout the lactation. Hoerl （Y=ab1/xxc）, Wood （Y=axb exp（cx）） and Dhanoa （Y=ax（bc）exp（cx）） models were equally suitable to describe 12-mon lactations. An exponential model with ifve parameters （Y=exp（a＋bx＋cd2＋e/x）） showed the best ift for milk yield for 18-mon lactations. The rational model （Y=a＋bx/1＋cx＋dx2） was found to produce the closest ift for 29-mon lactations. It was concluded that, with the protocol used in the present study, multiparous cows respond favorably to a second cycle of induced lactation, with milk yield similar to that experienced during the ifrst cycle. Thus, dairy producers might be able to lengthen the productive life of infertile high producing cows with a renewal of artiifcial lactation, which would imply an overall reduction in voluntary culling of cows. Also, various equations used to describe the lactation curves demonstrated the potential for iftting monthly milk records of Holstein cows with prolonged lactations and induced hormonally into lactation.

Effects of Diets with Different Corn-to-Soybean Ratios on Performance of Lactational Rex Rabbits

[ Objective] To study the effects of diets with different com-to-soybean ratios on production performance of lactational Rex rabbits and select the best feed formula. [Method] A total of 80 lactational healthy Rex rabbits （similar age, body weight and delivery time） were randomly divided into five groups, 16 in each group. The Rex rabbits in group I were fed with corn-based meal diet, group II with soybean-based meal diet, group III with the developed corn-soybean meal diet, group IV with corn-soybean meal free diet, and group CK with conventional corn-soybean meal diet. During the lactation period, the changes in the lactation performance, growth rate of baby rabbits, weight and feed costs were observed. [ Result] The lactation performance of mother rabbits and the growth rate of baby rabbits in the experimental groups were similar to that in the control group. The weaning survival rate of the group III was the highest, but it was not significantly higher than that of the control group. The weaning survival rate of the other three groups was lower than that of the control group （P〈0.05）. The weight loss of mother rabbits in the group I, II and III was not significantly different from that of the control group, but the weight loss of the group IV was higher than that of the control group （ P 〈 0.01 ）. [ Conclusion] Diets with appropriate corn-to-soybean ratios not only reduce feed costs but also give the best feeding effects.

Jugular arginine supplementation increases lactation performance and nitrogen utilization efficiency in lactating dairy cows

Background: Enhancing the post-ruminal supply of arginine(Arg), a semi-essential amino acid(AA), elicits positive effects on milk production. Our objective was to determine the effects of Arg infusion on milk production parameters and aspects of nitrogen(N) absorption and utilization in lactating dairy cows. Six lactating Chinese Holstein cows of similar body weight(508 ± 14 kg), body condition score(3.0 ± 0), parity(4.0 ± 0), milk yield(30.6 ±1.8 kg) and days in milk(20 ± 2 d) were randomly assigned to 3 treatments in a replicated 3 × 3 Latin square design with 21 d for each period(1 week for infusion and 2 weeks for washout). Treatments were 1) Control: saline;2) Arg group: saline + 9.42 g/L L-Arg;3) Alanine(Ala) group: saline + 19.31 g/L L-Ala(iso-nitrogenous to the Arg group). Milk production and composition, dry matter intake, apparent absorption of N, profiles of amino acids(AA) in blood,urea N in urine, milk, and blood, and gene expression of AA transporters were determined.Results: Compared with the Control or Ala group, the infusion of Arg led to greater expression of AA transporters(SLC7 A2 and SLC7 A8) and apparent uptake of free AA in the mammary gland, and was accompanied by greater milk yield, milk protein yield and milk efficiency(calculated by dividing milk yield over feed intake), together with lower concentration of urea N [regarded as an indicator of N utilization efficiency(NUE)] in blood and milk. Furthermore, in the cows infused with Arg, the NUE was higher and the concentration of urea N in urine was lower than those in the Ala group, although no differences were detected in NUE and urea N in urine between the Control and Arg group.The infusion of Ala had no effect on those indices compared with the Control.Conclusions: Overall, enhancing the post-ruminal supply of Arg via the jugular vein had a positive effect on the synthesis of milk protein at least in part by increasing gene expression of some AA transporters and uptake of free AA by mammary gland.

Emerging evidence of the physiological role of hypoxia in mammary development and lactation

Hypoxia is a physiological or pathological condition of a deficiency of oxygen supply in the body as a whole or within a tissue. During hypoxia, tissues undergo a series of physiological responses to defend themselves against a low oxygen supply, including increased angiogenesis, erythropoiesis, and glucose uptake. The effects of hypoxia are mainly mediated by hypoxia-inducible factor 1 （HIF-1）, which is a heterodimeric transcription factor consisting of o and 13 subunits. HIF-1β is constantly expressed, whereas HIF-1α is degraded under normal oxygen conditions. Hypoxia stabilizes HIF-1α and the HIF complex, and HIF then translocates into the nucleus to initiate the expression of target genes. Hypoxia has been extensively studied for its role in promoting tumor progression, and emerging evidence also indicates that hypoxia may play important roles in physiological processes, including mammary development and lactation. The mammary gland exhibits an increasing metabolic rate from pregnancy to lactation to support mammary growth, lactogenesis, and lactation. This process requires increasing amounts of oxygen consumption and results in localized chronic hypoxia as confirmed by the binding of the hypoxia marker pimonidazole HCI in mouse mammary gland. We hypothesized that this hypoxic condition promotes mammary development and lactation, a hypothesis that is supported by the following several lines of evidence： i） Mice with an HIF-1α deletion selective for the mammary gland have impaired mammary differentiation and lipid secretion, resulting in lactation failure and striking changes in milk compositions; ii） We recently observed that hypoxia significantly induces HIF-1α- dependent glucose uptake and GLUT1 expression in mammary epithelial cells, which may be responsible for the dramatic increases in glucose uptake and GLUT1 expression in the mammary gland during the transition period from late pregnancy to early lactation; and iii） Hypoxia and HIF-1α increase the phosphorylation of signal transducers and activators of transcription 5a （STAT5a）in mammary epithelial cells, whereas STATS phosphorylation plays important roles in the regulation of milk protein gene expression and mammary development. Based on these observations, hypoxia effects emerge as a new frontier for studying the regulation of mammary development and lactation.

Splenic lymphangiomatosis showing rapid growth during lactation:A case report

Splenic lymphangiomatosis is a very rare condition that,from 1990 to date,has been described only nine times.In the present report,we describe the first case of splenic lymphangiomatosis with rapid growth during lactation in a 35-year-old woman.We also underline the difficultly in making an accurate preoperative diagnosis,despite more modern imaging techniques.Total splenectomy was considered to be the treatment needed,both to make a definitive diagnosis and to exclude the presence of malignancy.

Effects of the dietary nonfiber carbohydrate content on lactation performance, rumen fermentation, and nitrogen utilization in mid-lactation dairy cows receiving corn stover

Background: Corn stover(CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohydrate(NFC)might limit the utilization of a CS diet by lactating dairy cows. Thus, this study was conducted to investigate the lactation performance and rumen fermentation characteristics in lactating cows consuming CS with two contents of NFC compared to an alfalfa hay-containing diet. Twelve Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments:(1) low-NFC diet(NFC = 35.6%, L-NFC),(2) high-NFC diet(NFC = 40.1%,H-NFC), and(3) alfalfa hay diet(NFC = 38.9%, AH).Results: Intake of DM was lower for cows fed H-NFC compared to L-NFC and AH, while the milk yield was higher in AH than in H-NFC and L-NFC(P < 0.01). The feed efficiency(milk yield/DM intake, 1.15 vs. 1.08, P < 0.01) were greater for cows fed H-NFC than L-NFC. The contents of milk protein and lactose were not different among the groups(P > 0.11), but milk fat content was higher for cows fed H-NFC and L-NFC compared to AH(P < 0.01). The rumen ammonia nitrogen concentration and the concentrations of urea nitrogen in blood and milk were lower for cows fed H-NFC and AH compared to L-NFC(P < 0.05). The concentrations of rumen propionate and total volatile fatty acids were different among groups(P < 0.05) with higher concentration for cows fed AH compared to H-NFC and L-NFC, and acetate concentration tended to be different among groups(P = 0.06).Conclusions: From the results obtained in this study, it was inferred that the increased NFC content in a diet containing corn stover can improve the feed efficiency and benefit the nitrogen conversion.

Treatment of bilateral granulomatous lobular mastitis during lactation with traditional Chinese medicine: A case report

BACKGROUND Granulomatous lobular mastitis(GLM)is a type of benign chronic inflammatory disease that poses therapeutic challenges to healthcare providers.The diagnosis of GLM relies on tissue biopsy,and incorrect treatment may lead to delayed diagnosis,considerable aesthetic damage,and even mastectomy.CASE SUMMARY We report the case of a 37-year-old Chinese woman who was lactating and had GLM in both breasts.At the time of treatment,the right breast had a mass of approximately 15 cm×11 cm,which was hard and had poor mobility.Multiple skin ulcerations and pus spills were also observed on the surface of the breast.The left breast had a mass of about 13 cm×9 cm,which was hard and had poor mobility.CONCLUSION Herein,we report a case of bilateral GLM in a lactating woman that was successfully treated with traditional Chinese medicine(TCM),without the requirement for surgery or other treatments.Therefore,TCM may have advantages in the nonsurgical treatment of GLM.

Identification Effects of Pedometer on Estrus of Holstein Cows during Peak Lactation Period

[Objective]The paper was to discuss identification effects of pedometer on estrus of Holstein cows during peak lactation period. [Method]The estrus of Holstein cows during peak lactation period were identified by manual observation and pedometer monitoring. [Result]Compared with manual observation,the detection rate of estrus in Holstein cows using pedometer monitoring was increased by 24. 01%,which reduced the labor cost and enhanced accuracy rate. [Conclusion]The research could provide reliable basis for estrus identification of cows.

Sow performance in response to natural betaine fed during lactation and post-weaning during summer and non-summer months

Background: Two studies were conducted to evaluate the effects of dietary natural betaine on sow reproductive performance during summer(Exp. 1) and non-summer months(Exp. 2). Treatments were designed as a 2 × 2 factorial arrangement with factors including dietary betaine(0 or 0.2%) and period of supplementation(lactation or post-weaning until 35 days post-insemination). In Exp. 1, 322 and 327 sows and in Exp. 2, 300 and 327 sows representing young(parity 1 and 2) and mature(parity 3 to 6) sows, respectively, were used.Results: In Exp. 1, supplementation of betaine during lactation increased sow body weight losses(-11.95 vs.-14.63 kg;P = 0.024), reduced feed intake(4.12 vs. 4.28 kg/d;P = 0.052), and tended to reduce percentage of no-value pigs(P = 0.071). Betaine fed post-weaning reduced weaning-to-estrus interval(5.75 vs. 6.68 days;P = 0.054) and farrowing rate(86.74% vs. 91.36%;P = 0.060), regardless of parity group. Post-hoc analysis with sows clustered into 3 parity groups(1, 2 and 3, and 4+) indicated that betaine fed in lactation to parity 4+ sows(P = 0.026) and betaine fed post-weaning to parity 1 sows increased the number of pigs born in the subsequent cycle(P ≤ 0.05). In Exp. 2, betaine fed during lactation tended to reduce the weaning-to-estrus interval(6.64 vs. 7.50 days;P = 0.077) and farrowing rate(88.23% vs.83.54%;P = 0.089), regardless of parity group. Feeding betaine post-weaning reduced number of pigs born(13.00 vs.13.64;P = 0.04) and pigs born alive(12.30 vs. 12.82;P = 0.075), regardless of parity group.Conclusions: Using 0.2% betaine during the non-summer months did not benefit sow performance. During the summer, betaine supplementation in lactation increased subsequent litter size in parity 4+ sows. Betaine fed during the post-weaning period reduced the wean-to-estrus interval and farrowing rate, increased total number of pigs born for parity 1 sows and reduced total number of pigs born to parity 4+ sows. Further research is needed to determine if the detrimental effects on feed intake and farrowing rate may be correlated and depend on dietary betaine level.

Net absorption and liver metabolism of amino acids and heat production of portaldrained viscera and liver in multiparous sows during transition and lactation

Background:Determination of nutrient requirements in the late gestating and lactating sows is essential to optimize sow productivity.The objectives of the present study were to quantify amino acid(AA)fluxes and heat production across portal-drained viscera(PDV)and liver in multiparous sows during transition and lactation.Methods:Eight second parity sows were fitted with indwelling catheters in the femoral artery and in the mesenteric,portal and hepatic veins.Eight hourly sets of blood samples were taken starting 0.5 h before feeding at−10,−3,+3,and+17 d in milk(DIM).Blood gases,plasma metabolites and apparent total tract digestibility(ATTD)of nutrients were measured.Results:Feed intake,the ATTD of DM,energy,nitrogen,fat and crude fiber changed with DIM(P<0.001).Except for Glu,O2,and urea,all net portal fluxes were positive,and all were affected by DIM(P<0.05)and by sampling time(P<0.01).Compared with pre partum levels,net portal uptake of AA was 3-63%lower at+3 DIM but 40-100%higher at+17 DIM.Net portal fluxes of AA peaked at 1.5 to 2.5 h after feeding except for Glu,and they were positively correlated with changes in sow feed intake across DIM.The net portal recovery was low for Met(49%),Thr(54%),and His(54%)and high for the remaining essential AA(63-69%)and none of them differed across DIM.Net hepatic uptake(i.e.hepatic oxidation)of Lys,Thr,Ile,Leu and Phe peaked at 0.5 to 2.5 h after feeding,whereas uptake of Trp,Val,and His was constant,while that of Met was close to zero.Conclusion:The net portal recovery was substantially lower for Met,Thr,and His than the remaining essential AA.Hepatic AA oxidation peaks 0.5 to 2.5 h after feeding.The heat production in PDV and liver was approximately two-fold higher at peak lactation compared to other stages.The study suggests that lysine was the limiting AA in peak lactation but not in early lactation.

Effects of Chinese herbs on lactation of rat and performance of offspring

An experiment was conducted to study the effects of different Chinese herbs on lactation in the rat. Seventy-two Sprague Dawley female rats at gestation day 18 were assigned to 9 groups randomly, with 8 rats each. Control rats were offered basal diets until the end of the weaning period. Rats in the other 8 groups were administered diets supplemented with 1% Medulla tetmpanacis （MT）, Astragalus membranacens （AM）, Vaccaria segetalis （VS）, Leonurus heterophyllus sweet （LHS）, Radix rehmarmiae preparata （RRP）, Squama man/t/s （SM）, Schisandra chinensis （SC）, Ligustrum lucidum （LL）, respectively. After parturition, the litter size was culled to 8 pups per dam. Pup weight and milk yield were significantly higher in the VS, LHS, AM and SM groups than these in the control group during middle and late lactation （P〈0.05 or P〈0.01）. The weight and feed intake were not different in the dams fed either diet.

Effect of reduced energy density of close-up diets on dry matter intake,lactation performance and energy balance in multiparous Holstein cows

Energy intake prepartum is critically important to health, milk performance, and profitability of dairy cows. The objective of this study was to determine the effect of reduced energy density of dose-up diets on dry matter intake （DMI）, lactation performance and energy balance （EB） in multiparous Holstein cows which were housed in a free-stall barn and fed for ad libitum intake. Thirty-nine dry cows were blocked and assigned randomly to three groups fed a high energy density diet [HD, n = 13; 6.8 MJ of net energy for lactation （NEL）/kg; 14.0% crude protein （CP） ], or a middle energy density diet （MD, n = 13; 6.2 MJ NEh/kg; 14.0% CP）, or a low energy density diet （LD, n = 13; 5.4 MJ NEh/kg; 14.0% CP） from d 21 before expected day of calving. After parturition, all cows were fed the same lactation diet to d 70 in milk （DIM）. The DMI and NEE intake prepartum were decreased by the reduced energy density diets （P 〈 0.05）. The LD group consumed 1.3 last 24 h before calving. The milk yield and the postpartum kg/d （DM） more diet compared with HD group in the DMI were increased by the reduced energy density diet prepartum （P 〈 0.05）. The changes in BCS and BW prepartum and postpartum were not affected by prepartum diets HD group had higher milk fat content and lower lactose content compared with LD group during the first 3 wk of lactation （P 〈 0.05）. The energy consumption for HD, MD and LD groups were 149.8%, 126.2% and 101.1 % of their calculated energy requirements prepartum （P 〈 0.05）, and 72.7%, 73.1% and 7.5.2% during the first 4 wk postpartum, respectively. In conclusion, the low energy density prepartum diet was effective in controlling NF_L intake prepartum, and was beneficial in increasing DMI and milk yield, and alleviating negative EB postpartum.

Bzw2 Promotes Proliferation and Lactation of Mammary Epithelial Cell in Dairy Goat

Mitosis of mammary epithelial cell is foundation of mammal lactation. We developed a strategy of combined application of generation of longer cDNA fragments from the serial analysis of gene expression （SAGE） tags for gene identification （GLGI） to screen and identify genes influencing lactating ability of mammary epithelial cell in dairy goat. GLGI as a new tag identification technique was brought about with SAGE. Bzw2 was found as a candidate gene related to lactation by screening Long-SAGE library of mammary gland in dairy goat. Bzw2 cDNA was synthesized by switching mechanism at 5＂-end of RNA transcript （SMART） technology. The mRNA level of Bzw2 was relatively higher in early lactation than in other development stages of mammary gland. The proliferation of mammary epithelial cell was inhibited by transfecting specific shRNA of Bzw2. The mRNA levels of Stat5, Csn2 and Prlr were also down-regulated, suggesting the lactating ability of mammary epithelial cell was attenuated after Bzw2 RNAi. The reduction of mammary epithelial cell growth and lactation by Bzw2 RNAi was rescued through over-expression of Bzw2. These results revealed that Bzw2 might play an important role in lactation though the molecular mechanism was still unclear.

Regulation of amino acid transporters in the mammary gland from late pregnancy to peak lactation in the sow

Background: Milk protein is crucial for milk quality in sows and health of newborn piglets. Plasma amino acids(AA)in sows are important precursors for milk protein synthesis in the mammary gland. In order to study the regulation of AA transported in sow mammary glands and possible underlying mechanisms, we measured the expression of genes coding for milk proteins, AA transporter expressions, and plasma AA concentrations in sows at three different physiological stages(D-17, D1 and D17 of lactation), and then further investigated the regulation of AA transport across the cell membrane by adaptive mechanisms using pig mammary epithelial cells(PMEC) as an in vitro model.PMEC were cultured in DMEM:F12 with 4 amino acid concentrations(0 × AA complex, 1 × AA complex, 5 × AA complex,and 25 × AA complex). Classes of AA complexes evaluated in this study included neutral AAs(L-Ala + L-Ser + L-Cys), acidic AAs(L-Asp, L-Glu) and neutral + basic AAs(L-Ala + L-Ser + L-Cys + L-Lys).Results: Our results indicated that m RNA expression of genes coding for milk protein(αs1-casein, αs2-casein,β-casein and κ-casein) increased significantly with the advance of physiological stage(P < 0.05), and plasma concentrations of most AAs including threonine, serine, glutamate, alanine, valine, cysteine, methionine, isoleucine and tyrosine were greater at D1 of lactation compared with D-17 and D17 of lactation(P < 0.05). Additionally, protein and gene expressions of AA transporters including excitatory AA transporter 3(EAAT3), alanine/serine/cysteine/threonine transporter(ASCT1) and sodium-coupled neutral AA transporter 1(SNAT2) were greater in lactating sow mammary glands compared with sow mammary glands in late pregnancy(P < 0.05). The m RNA expressions of SLC38 A2, SLC1 A1,SLC6 A14 increased significantly in the cell mediums supplemented with 5 × and 25 × of AA complexes compared with those cells cultured in DMEM/F12 cell medium(P < 0.05). The m RNA expressions of SLC38 A, SLC1 A4, and SLC6 A14 also increased in EBSS cell medium compared to DMEM/F12. However, only m RNA expression of SLC38 A decreased when AA complex was added into EBSS(P < 0.05).Conclusion: AA transportation was positively regulated in sow mammary glands with the advance of physiological stage from late pregnancy to peak of lactation and AA transporters in PMECs were adaptively regulated by changed AA concentrations.