QUANTITATIVE ASPECTS OF RELEASE OF OXYTOCIN BY SUCKLING IN UNANAESTHETIZED RABBITS

1963 ◽  
Vol 44 (4) ◽  
pp. 581-592 ◽  
Author(s):  
Anna-Riitta Fuchs ◽  
Gorm Wagner
Keyword(s):  
Milk Yield ◽  
Essential Role ◽  
Post Partum ◽  
Lactation Period ◽  
Milk Ejection ◽  
Once Daily ◽  
Milk Flow

ABSTRACT A method of estimating oxytocin output following physiological stimuli is described which is applicable to experiments in conscious, undisturbed and unrestrained animals. The method consists of recording the uterine responses in puerperal rabbits with a permanently inserted intrauterine balloon as an index of neurohypophysial activation. Previous work has been confirmed on the essential role of oxytocin in milk ejection in rabbits. Only negligible amounts of milk are obtained by the young without any endogenous or exogenous oxytocin, but normal release of oxytocin can occur in spite of diminished or completely inhibited milk flow. The amount of oxytocin released during suckling depends on the strength of the stimulus in a characteristic fashion, and the strength of stimuli again depends both on the number of young suckling simultaneously and on their physical maturity. In the early puerperium (up to 3–4 days post-partum) each suckling young evokes a response comparable to that of 0.5–1.0 mU of oxytocin injected intravenously, whether suckling alone or together with its litter-mates. Only a few grams of milk are removed by each young at that time. After this period, the suckling of 1 or 2 young separately still elicits the release of only a small amount of oxytocin (1–2 mU), but during suckling of a whole litter from 50 to 100 mU are liberated, which corresponds to 10–15 mU for each young. The full milk yield can only be obtained by each young while suckling simultaneously with the whole litter. The amount of oxytocin released is independent of the duration of suckling, of the quantity of milk available, and of the milk flow. Once lactation has been established, the oxytocin output during suckling on an »once-daily« regime remains fairly constant at least for a large part of the lactation period. It is possible that at the end of the lactating period, the amount secreted during suckling is increased to about 250 mU or even more.

scholarly journals Effect of weaning system and type of milk flow on milk production of crossbred ewes improved Valachian and Tsigai with Lacaune

10.5219/1071 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 275-279
Author(s):  
Lucia Mačuhová ◽  
Vladimír Tančin ◽  
Juliana Mačuhová ◽  
Michal Uhrinčať ◽  
Milan Margetin
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Time Machine ◽  
Milk Ejection ◽  
Once Daily ◽  
Flow Parameters ◽  
Milk Flow ◽  
Total Milk ◽  
Electronic Recording ◽  
Milk Level

Improved Valachian (IV x LC; n = 41) and Tsigai (TS x LC; n = 44) crossbred ewes with Lacaune were used to study the effects of three weaning systems on milk production. Prior to parturition, ewes were assigned to one of the following three treatments for the first 53 day of lactation: 1) ewes weaned from their lambs at 24 h postpartum and afterwards machine milked twice daily (MTD), 2) ewes, beginning 24 h postpartum, kept during the daytime with their lambs and allowed them to suckle for 12 h, nights separated from their lambs for 12 h and machine milked once daily in the morning (MIX), and 3) ewes exclusively suckled by their lambs (ES). After the treatment period, lambs were weaned from MIX and ES ewes, and all three groups were machine milked twice daily. Furthermore, ewes were evaluated according to number of live-born and weaned lambs (with one (n = 35) or with two lambs (n = 50)). The measurements of milk yield and milk flow were performed on 110 ±5 day of lactation by the equipment for graduated electronic recording of the milk level in a jar in one-second intervals. No significant differences were observed in the measured values (total milk yield, machine milk yield, latency time, milking time, machine stripping, milk flow rate, and machine milk yield in 30 and 60 s) among weaning treatments and between ewes with one or two lambs and evaluated breeds too. The highest occurrence of one peak milk flow (milk flow without milk ejection) was found out in MTD ewes (50%) compared to MIX (19%) and ES (17%). In conclusion, the different systems of weaning did not influence the milk yield and milk flow parameters in the mid-lactation.

scholarly journals Comparison of maternal milk ejection characteristics during pumping using infant-derived and 2-phase vacuum patterns

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Hazel Gardner ◽  
Jacqueline C. Kent ◽  
Ching Tat Lai ◽  
Donna T. Geddes
Keyword(s):  
Physiological Response ◽  
Post Partum ◽  
Random Effect ◽  
Individual Variability ◽  
Phase Pattern ◽  
Milk Ejection ◽  
Convenience Sample ◽  
Mixed Effects Modeling ◽  
Milk Flow ◽  
Milk Volume

Abstract Background Milk ejection characteristics remain consistent throughout 12 months of lactation in women who expressed breastmilk with an electric breast pump. In addition these characteristics appear to remain constant when women are breastfeeding or pumping suggesting that milk ejection is a robust physiological response. It is not known whether the stimulation of an infant at the breast in the early post partum period influences milk ejection patterns or whether this is a programmed event. However, as more data become available on the mechanisms involved in infant feeding, pumping patterns mimicking the infant more closely may provide enhanced results. The objective of this study was to compare milk ejection characteristics obtained when using a novel infant-derived pumping pattern with an established 2-phase pattern. Methods A convenience sample of ten lactating mothers, 1 to 40 weeks of lactation with normal milk production were recruited in 2015. Each participated in two pumping sessions in which either a 2-phase pattern or infant-derived pattern were randomly assigned. Milk volume and milk ejection characteristics were recorded and the percentage of available milk removed (PAMR) was calculated. Statistical analysis used linear mixed effects modeling to determine any differences between breasts and pump patterns with the consideration of individual variability as a random effect. Results The number of milk ejections and milk ejection characteristics did not differ between patterns. Milk volumes removed were 53.6 ± 28.5 ml (PAMR 58.2 ± 28.4) for the 2-phase pattern and and 54.2 ± 26.3 ml (PAMR 52.2 ± 22.3) for the infant derived pattern. Peak milk flow rates were positively associated with the available milk (p = 0.0003) and PAMR (p = 0.0001), as was the volume of milk removed during each milk ejection (p = 0.001 and p = 0.0001). Conclusion An experimental pumping pattern designed to resemble infant sucking characteristics did not alter milk ejection characteristics or milk removal parameters compared with an established 2-phase pattern. Theses findings provide further evidence that milk ejection is a robust physiological response.

scholarly journals Lactation curves and persistency of White Fulani and Sokoto Gudali lactating cows

2020 ◽  
Vol 44 (4) ◽  
pp. 29-37
Author(s):  
O. E. Odegbile ◽  
I. I. Adedibu ◽  
C. Alphonsus
Keyword(s):  
Milk Yield ◽  
Preliminary Analysis ◽  
Post Partum ◽  
Prediction Equation ◽  
Coefficient Of Determination ◽  
Lactation Period ◽  
Lactating Cows ◽  
Lactation Curve ◽  
Breeding Programmes ◽  
White Fulani

The aim of this study was to determine the lactation curve traits of White Fulani (WF) and Sokoto Gudali (SG) lactating cows. Wood's gamma and Wilmink's curve parameters were employed to identify the lactation curve types and values for the parameters beginning yield (a) , coefficient of rising (b), coefficient of decreasing (c)t=timeande= is the exponential.The parameter assumed a fixed value derived from a preliminary analysis and disassociated with the time at peak yield were used to determine the shape and type of lactation curve. All Parameters in a typical lactation curves were positive, and in the event of one parameter being negative, the curve was considered to be an atypical lactation curve. Lactation records from WF (n=96)and SG (n=130) cows were recorded in the study area between year 2016-2017. Cows were hand-milked twice per day in the morning and evening from the 5 day post-partum till the end of the lactation period (260-270 days).Prediction equation of milk yield showed R values ranging from (32.00) in the SG to (35.00) in the WF. It was observed that the Wood's model curves were typical while Wilmink's model curves were atypical respectively. For typical lactation curves, a, b, c, persistency (S), time after parturition until the peak yield occurs (T ), maximum daily peak yield (Y ), and coefficient of determination (R ) were - 0.25±0.13, 1.08±0.07, 0.23±0.19, 2.34,51.00,2.62 and 97 for WF lactating cows and - 0.23 ± 0.14,1.13 ± 0.08, 0.07± 0.03, 2.33, 51.26, 2.58 and 96 for SG Lactating cows respectively. Parameters predicted by the Wood's model have the potential of being useful for breeding programmes in the SG and WF cows.  

Early mechanical stimulation of the nipple-areola receptors complex promotes the mammary milk ejection function in women delivered by cesarean section

2021 ◽  
Vol 50 (2) ◽  
pp. 38-41
Author(s):  
N. P. Alekseev ◽  
E. V. Omelyanjuk ◽  
N. E. Talalajeva
Keyword(s):  
Mammary Gland ◽  
Caesarean Section ◽  
Cesarean Section ◽  
Mechanical Stimulation ◽  
Post Partum ◽  
Milk Ejection ◽  
The Third ◽  
Milk Flow ◽  
Stimulation Of

Mechanical stimulation and milk ejection from mammary gland in women delivered by caesarean section since 1 day post partum by the breastpump with vacuum and compression stimuli promotes milk ejection function. On the third day postpartum the stimulated mothers had significantly more milk flow reflex peaks than those who were not subjected to stimulation during the 10 min milk ejection session.

Lactational changes in oxytocin release, intramammary pressure and milking characteristics in dairy cows

1991 ◽  
Vol 58 (2) ◽  
pp. 159-169 ◽  
Author(s):  
Harald Mayer ◽  
Rupert Bruckmaier ◽  
Dieter Schams
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Maximum Flow ◽  
Pressure Increase ◽  
Maximum Pressure ◽  
Early Lactation ◽  
Milk Ejection ◽  
Milk Flow ◽  
Oxytocin Release ◽  
Almost All

SummaryTwo experiments were conducted to investigate possible changes of milking-related oxytocin release (Expt 1) and of intramammary pressure and milking characteristics (Expt 2) throughout entire lactations in German Braunvieh dairy cows. Mean oxytocin concentrations after stimulation at onset of milking increased from 18·3 ± 15·9 to 30·7 ± 24·1 pg/ml in Expt 1 and decreased from 23·9 ± 17·6 to 15·4 ± 9·1 pg/ml in Expt 2, respectively, but remained above the level necessary to elicit complete milk ejection in both trials. Premilking baseline intramammary pressure had its maximum in early lactation until about month 4 and then decreased to ∼50% of its initial level. Ejection pressure followed a similar pattern, but dropped only to ∼75% of its maximum. This was due to the constant elevation of pressure increase, reaching its highest level in late lactation. Time from commencement of stimulation until maximum pressure exceeded 1 min in almost all instances even in early lactation and increased throughout lactation. Despite the normal decrease of milk yield average milk flow fell only slightly while maximum flow rate remained almost constant. Pressure increase, milk yield and milk flow were not different after 1 min and after extended stimulation. Thus there were no indications of a decreasing sensitivity of the milk ejection reflex during lactation, and milking characteristics were positively affected by intense teat stimulation. Suggestions for practical dairying are made.

scholarly journals Machine milking of dairy goats during lactation: udder anatomy, milking characteristics, and blood concentrations of oxytocin and prolactin

1994 ◽  
Vol 61 (4) ◽  
pp. 457-466 ◽  
Author(s):  
Rupert M. Bruckmaier ◽  
Chantal Ritter ◽  
Dieter Schams ◽  
Jürg W. Blum
Keyword(s):  
Milk Yield ◽  
Cross Sections ◽  
Dairy Goats ◽  
Milk Ejection ◽  
Blood Concentrations ◽  
Flow Rates ◽  
Machine Milking ◽  
The Third ◽  
Milk Flow

SummaryForty-four goats were milked and milk flow recorded without or with 1 min manual prestimulation in early, mid and late lactation. Ultrasound measurements of cross sections of the whole mammary gland were performed in a water bath. In additional experiments with 15 goats, milk flow was recorded and frequent blood samples were taken for the determination of oxytocin and prolactin concentrations. Milk yield increased from the first to the third lactation and decreased markedly during the course of lactation. Average and peak milk flow rates were closely related to the actual milk yield. The ultrasound cisternal area was 27·4±1·5% of the entire udder half cross section. Milking characteristics were scarcely different without or with prestimulation, although oxytocin was released within 30 s after the start of prestimulation, whereas oxytocin concentrations without prestimulation increased only after the start of milking. Concentrations of prolactin were higher during July and August than in April, and increased similarly with or without prestimulation during milking. In contrast to dairy cows, prestimulation and an opportune release of oxytocin during milking does not significantly influence the course of milk flow in goats, and this is probably because large amounts of cisternal milk allow milk ejection to be induced only after the start of milking without causing bimodal or otherwise reduced milk flow.

Does breed affect nursing and reproductive behaviour in beef cattle?

2010 ◽  
Vol 90 (2) ◽  
pp. 137-143 ◽  
Author(s):  
J. Álvarez-Rodríguez ◽  
J. Palacio ◽  
I. Casasús ◽  
A. Sanz
Keyword(s):  
Beef Cattle ◽  
Post Partum ◽  
Beef Cows ◽  
Reproductive Behaviour ◽  
Similar Amount ◽  
Similar Time ◽  
Once Daily ◽  
Ad Libitum ◽  
Ovarian Cyclicity

This experiment was designed to assess the role of genetic differences in nursing behaviour and the resumption of post-partum ovarian cyclicity of beef cows with different types of calf management. Twenty-four multiparous winter-calving cows, 12 Parda de Montaña (PA) and 12 Pirenaica (PI), were randomly assigned to once-daily restricted nursing during 30 min (RESTR) or ad libitum nursing (ADLIB). Cow-calf behaviour was recorded at weeks 3, 8 and 13 of lactation. Results were compared within suckling system. Twice-weekly blood samples were drawn throughout lactation to analyse progesterone as an indicator of ovulation. Within each type of calf management, both breeds nursed their calves for a similar amount of time (23.0 and 57.2 min in PA vs. 25.9 and 59.0 min in PI, when nursing once daily or ad libitum, respectively; P > 0.10). Furthermore, ovarian cyclicity was initiated at a similar time after calving between breeds (70 vs. 73 d in PA and PI, respectively), although it was shorter in RESTR than in ADLIB (54 vs. 89 d; P < 0.001). Key words: Beef cattle, calf management, restricted nursing, post-partum anoestrus

scholarly journals Productive and reproductive performance of crossbred and indigenous dairy cows under smallholder farming system

1970 ◽  
Vol 7 (1) ◽  
pp. 69-72
Author(s):  
M Rokonuzzaman ◽  
MR Hassan ◽  
S Islam ◽  
S Sultana
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Post Partum ◽  
Farming System ◽  
Gestation Length ◽  
Lactation Period ◽  
Smallholder Farming ◽  
Stage Of Lactation ◽  
Heat Period ◽  
Daily Milk Yield

The present study was undertaken to investigate productive and reproductive performances of crossbreds and Indigenous dairy cows. A total of 400 dairy cows each are equal number of Friesian x indigenous (FI), Sahiwal x indigenous (SaI), Sindhi x indigenous (SiI) and indigenous (I) were selected from eight thanas in Jessore district. The study found that the daily milk yield from FI, SaI, SiI and I cows were 8.39 ± 2.01, 4.63 ± 0.96, 4.35 ± 1.12 and 2.38 ± 0.73 liters, respectively. The milk yield was found significantly (P<0.01) higher in first stage of lactation than that of second and third both in crossbreds and I dairy cows. The lactation period of crossbreds was significantly (P<0.01) higher than that of I cows. The service per conception was found higher in I cows and the gestation length was almost similar in all the groups. The post partum heat period and calving to first service were highest in SiI cows. The dry period and calving interval were higher in I cows. The age at first calving was almost similar in crossbreds but significantly (P<0.01) higher in I cows. The birth weight was significantly (P<0.01) lower in I than crossbred dairy cows. Considering all the parameters studied, FI showed better performance followed by SaI, SiI, and I. Keywords: Crossbreds; Indigenous; Dairy cows; Productive; reproduction performance DOI: 10.3329/jbau.v7i1.4801 J. Bangladesh Agril. Univ. 7(1): 69-72, 2009

Serum prolactin levels in women with excessive milk production. Normalization by transitory prolactin inhibition

1985 ◽  
Vol 109 (4) ◽  
pp. 463-466 ◽  
Author(s):  
F. Peters ◽  
F. Geisthövel ◽  
M. Breckwoldt
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Post Partum ◽  
Serum Levels ◽  
Serum Prolactin ◽  
Short Term ◽  
Milk Flow ◽  
Prolactin Inhibition ◽  
Prolactin Suppression

Abstract. Serum prolactin levels and milk yield were studied in 27 puerperae with excessive milk production (polygalactia) and compared with 30 normally lactating puerperae. In order to normalize polygalactia, 14 of these women were treated with 2.5 mg bromocriptine per day for 3 days starting on post-partum day 5, 13 women received placebo. Milk flow in polygalactic women started significantly earlier than in puerperae with normal milk yield and developed mean milk volumes of 816 g per day on post-partum day 4. Serum prolactin levels did not differ from levels of puerperae with normal milk yield. There was no correlation between serum prolactin and milk yield. Bromocriptine treatment resulted in a sharp but reversible decline of serum prolactin levels followed by a significant reduction of milk production. Bromocriptine could not be detected in milk specimens, while serum levels showed significant amounts. In placebo treated women prolactin levels and milk yield remained unaffected. These data indicate that serum prolactin concentrations of puerperae with polygalactia are within the normal post-partum range. Short term prolactin suppression by bromocriptine can reduce milk yield, without complete ablactation.

Small increases in peripheral noradrenaline inhibit the milk-ejection response by means of a peripheral mechanism

1984 ◽  
Vol 100 (3) ◽  
pp. 337-344 ◽  
Author(s):  
A. M. Lefcourt ◽  
R. M. Akers
Keyword(s):  
Milk Yield ◽  
Bolus Injection ◽  
Fold Increase ◽  
Response To Treatment ◽  
Milk Ejection ◽  
Milk Flow ◽  
Dependent Change ◽  
Peripheral Mechanism ◽  
Oxytocin Release ◽  
Second Peak

ABSTRACT The effects of exogenous noradrenaline on the milk-ejection response were determined for nine Holstein cows. Noradrenaline was injected (0·95 nmol/kg) 15 s after the start of teat stimulation (preparation) or infused (0·13 nmol/kg per min, after bolus injection of 0·47 nmol/kg) starting 10 min before milking for 20 min. Cows were prepared (udder wash and dry) for 1 min before milking. Both injection and infusion resulted in approximately a 3·5-fold increase in peripheral noradrenaline at 1·75 min after the start of milking (baseline noradrenaline 0·83 and 0·89 nmol/l plasma; at 4 min, 2·00 and 3·00 nmol/l). Prolactin release was delayed and oxytocin release enhanced, while milk yield was decreased by 8·6% for both treatments. The maximum rate of milk flow was also depressed by treatment. In contrast, milking time increased for injection and decreased for infusion. In addition, a milk-yield-dependent change in the pattern of milk flow was seen in response to treatment. In medium-yield animals, two distinct milk-flow peaks were apparent and injection delayed the time to the second peak. We conclude that physiologically meaningful increases in peripheral noradrenaline can inhibit milk-ejection response by means of a peripheral mechanism not involving inhibition of release of oxytocin. J. Endocr. (1984) 100, 337–344

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