Udder Stimulation Research Articles

Tactile, Auditory, and Visual Stimulation as Sensory Enrichment for Dairy Cattle.

Several types of enrichment can be used to improve animal welfare. This review summarizes the literature on the use of mechanical brushes, tactile udder stimulation, music, and visual stimuli as enrichment methods for dairy cows. Mechanical brushes and tactile stimulation of the udder have been shown to have a positive effect on milk yield and overall behavioral repertoire, enhancing natural behavior. Classical music reduces stress levels and has similarly been associated with increased milk yield. A slow or moderate tempo (70 to 100 bpm) at frequencies below 70 dB is recommended to have this positive effect. Evidence on the impacts of other types of enrichment, such as visual stimulation through mirrors, pictures, and color lights, or the use of olfactory stimuli, is equivocal and requires further study.

Exploring factors influencing machine milk yield of dairy cows in cow-calf contact systems: Cow behavior, animal characteristics, and milking management

The objective of this study was to explore factors contributing to low machine milk yield of cows with cow-calf contact. Danish Holstein dairy cows were assigned to 1 of 3 cow-calf contact treatments: full-time with the calf (n = 24), part-time with the calf between morning (a.m.) and afternoon (p.m.) milking and separated overnight (n = 23), or separated from the calf at birth (n = 23). Behavior of cows (stepping and kicking in the parlor) and milking procedures (teat or udder stimulation frequency, preparation duration) were recorded at a.m. and p.m. milking on 2 d during wk 4 and 6 of the treatment period (8 milkings per cow). Full-time cows had the lowest machine milk yields (mean ± SE; 6.1 and 6.0 ± 0.7 L at a.m. and p.m. milking, respectively), whereas part-time cows had similar yield to no-contact cows at a.m. milking (19.6 ± 0.7 L) and similar yield to full-time cows at p.m. milking (6.4 ± 0.7 L). Lower machine milk yields in cows with calf contact could not be fully attributed to milk consumption by the calf; however, they also could not be explained by differences in cow parity, calf sex, milking procedures (stimulation frequency; preparation duration), or stepping and kicking (restless) behavior at milking. All cows showed more restless behavior at p.m. milking, which weakly negatively affected machine milk yield, but this was unrelated to stimulation frequency in cow-calf contact cows, indicating that there may be other sources of discomfort or stress at the time of milking for these cows. Part-time versus full-time calf contact improved daily machine milk yields, but low machine milk yield issues merit further research so that cow-calf contact systems can be sustainable for producers.

Estimation of udder emptying based on milk constituents of strip samples after milking

Milk ejection disorders were induced by oxytocin receptor blockade. We tested the hypothesis that the degree of udder emptying at incomplete milk ejection can be estimated based on the concentration of various milk constituents in different milk fraction samples. To induce different levels of spontaneous udder emptying (SUE) 10 Holstein dairy cows were milked either with or without i.v. injection of the oxytocin receptor blocking agent atosiban (ATO). In ATOearly, 12 µg/kg BW ATO was injected immediately before and in ATOlate directly after a 1-min manual udder preparation. The normal milking routine served as the control treatment. In all 3 treatments the udder was completely emptied by the i.v. injection of 10 IU oxytocin (OT) at the end of spontaneous milk flow. During all experimental milkings 4 milk samples were taken in all treatments: at the start of udder preparation (foremilk; FM), immediately after cessation of spontaneous milk flow and cluster detachment by hand stripping (strip milk; SM), from spontaneous removed milk in bucket 1 (milk before OT; MBOT) and from the milk obtained after OT injection in bucket 2 (milk after OT; MAOT). Fat, protein, lactose, and electrolytes (Na, Cl, and K) were measured in each milk sample. In addition, electrical conductivity (EC) was determined in parallel to continuous milk flow recording. The treatments induced individual degrees of SUE; therefore, the final evaluations of data were based on SUE classes instead of treatments. The most pronounced differences of milk constituents at different degrees of SUE were found for the milk fat content. The fat content of SM and MBOT remained almost unchanged up to 60% SUE, but was considerably higher if >80% of the milk was spontaneously removed. The concentrations of Na and Cl were highest and of K lowest if less than 20% of milk was received in the different samples. The EC was higher in SM and MBOT if <20% of milk was received. In conclusion, the blockade of the OT effect influences primarily the fat content, which confirmed an OT-induced fat secretion during milking. Similar effects are likely found in situations of disturbed milk ejections, caused by a lack of or reduced release of OT in response to different degrees of tactile udder stimulation. Our results show that the measurement of fat content and the EC in SM samples collected after cluster detachment can be used to estimate the completeness of udder emptying.

197 Evaluating the Associations Between Piglet’s Characteristics at Birth and Growth Performance During Lactation Period on Piglets from Hyperprolific Sows

Abstract This study aimed to identify the impact of birth body weight (BBW) and average daily gain (ADG) during the first week (ADG07) on the weaning body weight (WBW) of piglets from hyperprolific sows, as well as to evaluate the role played by other perinatal factors against the ADG07 and WBW. A total of 1,398 piglets [(Landrace x Yorkshire) x Pietrain] born from 87 sows between first and tenth parity (mean ± SD: 3.7 ± 2.2) were used. Each farrowing was monitored to record birth order (BO), birth time (BT), BBW, sex (SX), rectal temperature (RT), and total number of piglets born. Vitality score (VS) was established by monitoring udder stimulation and number of completed circles around the enclosure. At day 1 of life, litters were equalized to 15 piglets (62.17 ± 19.44 % BBW &amp;gt; 1.15 kg piglets; 37.83 ± 19.44 % BBW ≤ 1.15 kg piglets per litter). Piglets were individually weighed after litter equalization, at day 7, and at weaning (26.1 ± 0.45 d). Linear mixed models were fitted to the two study outcomes (ADG07 and WBW) and all possible explanatory variables. The adoptive sow was used as the random effect. Stepwise backward elimination of fixed effects was done to obtain optimized models. Differences between optimized models with or without fixed effects interactions were tested by ANOVA. The individual impact of BBW and ADG07 on WBW was analyzed with individual linear mixed models including only the explanatory variable to be studied (BBW or ADG07). The interaction BBW x RT (P &amp;lt; 0.001) fitted the best model for ADG07 prediction (Marginal R-sq = 0.22). Concerning the BBW, despite being a significant predictor (P &amp;lt; 0.001), it did not explain a great fraction of the variation of ADG07 (R-sq = 0.21). Increments of 100 g in BBW were associated with ADG07 increments of 8.9 g/d. The WBW final model (Marginal R-sq = 0.64) had BBW (P &amp;lt; 0.001), ADG07 (P &amp;lt; 0.001), and VS (P = 0.03) as significant predictors. Individual linear mixed models showed that ADG07 was a better predictor than BBW on WBW (R-sq = 0.59 vs. 0.31). Interaction BBW x ADG07 was significant (P &amp;lt; 0.001), indicating that ADG07 had a greater impact on WBW in piglets with low BBW. Regarding VS, piglets with the best VS at birth had better WBW compared with piglets with the least VS at birth (7.06 ± 1.92 vs. 6.47 ± 1.87 kg). These results suggest that growth performance during the first week has at least an equivalent influence as BBW on WBW, giving an early-life window of opportunity to apply strategies to improve the future performance of the piglets. The VS and RT have a significant role in ADG07 and WBW models.

Effects of dietary and milking frequency changes and administration of cabergoline on clinical udder characteristics in dairy cows during dry-off

We investigated the effects of 2 diet energy densities [normal lactation diet (NORM) vs. energy-reduced diet (REDU), both fed for ad libitum intake] and 2 daily milking frequencies [twice (2×) vs. once (1×)] during 1 week before the dry-off day, as well as effects of an injection of either a dopamine agonist [cabergoline (CAB); Velactis, Ceva Santé Animale, Libourne, France; labelled for use only with abrupt dry-off, e.g. no reduction in diet energy density or milking frequency before the last milking] or saline (SAL) following the last milking, on clinical udder characteristics of Holstein cows. During a week before and after the last milking, the following measures were recorded: palpation-based udder firmness and soreness; image-based hock-hock distance; responsiveness to mechanical udder stimulation and degree of udder fill measured with a dynamometer. Before the last milking, REDU cows displayed lower odds of having a firm udder and lower degree of udder fill, as well as lower responsiveness to mechanical udder stimulation, than NORM cows. After the last milking, REDU cows displayed shorter hock-hock distance compared with NORM cows. The effects of milking frequency on the clinical udder characteristics were unclear. Within 24 h following injection, CAB cows showed lower odds of having a firm udder, shorter hock-hock distance, and lower degree of udder fill than SAL cows, irrespective of treatment group before dry-off. In this study, reducing diet energy density prior to dry-off, and to some extent administering the dopamine agonist cabergoline after the last milking, resulted in fewest clinical udder changes.

Milk yield of West African Dwarf sheep as affected by udder stimulation, stage of lactation and parity

This study was conducted to investigate the milk yield of West African Dwarf sheep as affected by udder stimulation, stage of lactation and parity. The study involves 12 matured lactating ewes weighing between 16 and 24 kg live weights in a semi intensive system of management. For udder stimulation, the animals were divided into 2 groups; 6 animals were stimulated by massaging, cleaning and drying the udder for 2 minutes before milking while the other 6 were not stimulated, the udder were just milked. Stage of lactation was divided into 4; early, mid, late, and very late respectively with 3weeks interval for all the animals. 4 animals were on first parity while 8 animals were on second parity. The animals were allowed to graze on an established paddock consisting of Stylosanthes hamata, Panicum maximum, Pennisetum purpureum etc. for 5 hours and then supplemented with concentrate (17% CP at 5% body weight). Each quarter of the udder was hand milked unilaterally twice per week at 8.00am for 12 weeks. The result of the study showed that daily milk yield in each of the quarter of the udder (left and right) was not significantly (P&gt;0.05) different. Udder stimulation and stage of lactation had significant (P&lt;0.05) effect on daily milk yield while parity and mammary gland position (left and right ) did not significantly affect daily milk yield. The interaction between udder stimulation and stage of lactation as well as interaction between udder stimulation and parity had significant (P&gt;&lt;0.05) effect on daily milk yield in WAD sheep. Therefore it is recommended that sheep udder be stimulated at late and very late stages of lactation to enhance milk production. &gt;&lt;0.05) effect on daily milk yield while parity and mammary gland position (left and right ) did not significantly affect daily milk yield. The interaction between udder stimulation and stage of lactation as well as interaction between udder stimulation and parity had significant (P&lt;0.05) effect on daily milk yield in WAD sheep. Therefore it is recommended that sheep udder be stimulated at late and very late stages of lactation to enhance milk production.

Administration of carbetocin after the first piglet was born reduced farrowing duration but compromised colostrum intake in newborn piglets

Carbetocin is an oxytocin-like compound with long acting properties that has recently been introduced to both human and domestic animal obstetrics. The aims of the present study were to evaluate the effects of carbetocin administration after the first piglet was born on farrowing duration, birth interval, colostrum consumption and vitality index in newborn piglets. In total, 186 sows and their offspring (n = 2611 piglets) were distributed into three groups: 1) CONTROL: sows were allowed to farrow naturally (n = 66); 2) OXY: sows were administered oxytocin 20 IU intramuscularly after the first piglet was born (n = 62); and 3) CARBE: sows were administered carbetocin 0.6 μg/kg intramuscularly after the first piglet was born (n = 58). The reproductive data of sows including farrowing duration, total number of piglets born per litter (TB), number of piglets born alive per litter (BA), proportion of stillborn piglets per litter (SB) and proportion of mummified fetuses per litter (MF) were recorded. Piglet vitality index including skin colour, integrity of the umbilical cord, heart rate, blood oxygen saturation, screaming score, udder stimulation score, movement capacity and number of completed circles around enclosure were determined. Birth weights of the piglets were measured immediately at birth and again at 24 h thereafter to determine the individual colostrum intake of the piglets. On average, the farrowing duration, birth interval and BA were 188.0 ± 95.7 min, 12.5 ± 18.3 min, and 12.3 ± 2.9 piglets per litter, respectively. The farrowing duration of the sows was reduced in CARBE group (151.2 ± 11.9 min) compared to OXY (180.2 ± 11.5 min, P = 0.003) and CONTROL (227.7 ± 11.2 min, P < 0.001) groups. Birth interval of piglets in all categories of birth weight in the CARBE group was shorter than those in the CONTROL group (P < 0.05). However, the colostrum yield of sows in CARBE group (2398 ± 133 g) was lower than CONTROL and OXY groups (3371 ± 125 g and 3549 ± 128 g, respectively; P < 0.001). Similarly, colostrum intake of piglets in the CONTROL and OXY groups was higher than in the CARBE group (276.4 ± 11.0 g, 286.4 ± 13.6 g and 225.3 ± 14.0 g, respectively; P < 0.05). The percentage of stillborn piglets in CARBE was higher than OXY (8.7 ± 1.1% vs 5.3 ± 1.1%, P < 0.05) but did not differ significantly compared to CONTROL (7.5 ± 1.1%, P > 0.05). The piglet movement capacity in CONTROL was lower than CARBE group (1.36 vs 1.48, P < 0.05) but was not different compared to OXY group (1.40, P > 0.05). In conclusion, administration of carbetocin after the birth of the first piglet reduced the farrowing duration of sows, but increased the number of stillborn piglets and reduced the colostrum yield of sows.

OPTIMUM TIME PERIOD OF EFFICIENT OPERATION OF MILKING LINER

The Republic of Belarus is the European leader in production of milk and dairy products. Milk-commodity farms and complexes use milking plants of domestic and foreign manufacturers. One of the most important items of any milking plant is milking liner, since the amount of milk received, health of animals and quality of milk depend on it largely. The new milking liner is of a high elasticity, flexibility, etc., providing efficient nipple massage, udder stimulation and intensive milk production. At prolonged operation of milking liner, it increases in length, the physical and mechanical properties vary, and numerous tiny cracks are formed on the inner surface which negatively affects automated milking process and leads to cow udder diseases. The paper shows that the milking liner should not affect the milk flow from the udder and at the same time should tightly fit the nipples above the sphincter area in order to protect them from damage by vacuum during vacuum phase and completely block vacuum on nipples at compression stroke to restore normal blood circulation in nipples. Flexibility (elasticity and rigidity) and elongation should be the main parameters of milking liner to perform these functions and requirements. The researches determined efficient service life periods of the most common in our country milking liner brand DD.00.041 depending on its properties variability, which should be determined in the number of milking operations.

The effects of different treatments of pre-milking manual tactile teat stimulation on day-to-day variation in milk yield, milk components, main milking phase, total milking time and average milk flow rate in crossbred cattle

The present study was carried out to investigate the effect of different treatments of udder stimulation on day to day variations in milk parameters in cross bred cows. In group T1, milk yield was positively (P<0.01) correlated with main milking phase, total milking time and average milk flow rate. Milking duration was significantly (P<0.01) correlated with total milking time and average milk flow rate. Total milking time was showed positive (P<0.01) correlation with average milk flow rate. Fat percentage had positive (P<0.05) correlation with SNF (r=0.46). Significantly (P<0.05) positive correlation was observed between total solids with lactose and ash content. SNF was significantly (P<0.05) correlated with acidity. Specific gravity was positively (r=0.59) correlated with total solids. In T2, milk yield was significantly (P<0.01) correlated with main milking phase, total milking time, average milk flow rate (r = 0.99) and negatively (P<0.05) correlated with fat percentage. Main milking phase had positive correlation with total milking time and average milk flow rate and negative correlation with fat percentage. Total milking time was significantly correlated with average milk flow rate. Average milk flow rate had negative correlation with fat percentage (r=-0.71). In T3, milk yield was significantly correlated with main milking phase, total milking time and average milk flow rate and negatively with fat percentage (r=-0.55). Total milking time and average milk flow rate were positively correlated with main milking phase and milking duration was negatively correlated with fat percentage (r=-0.54). Total milking time was positively correlated with average milk flow rate and negatively correlated with fat. Fat percentage was negatively correlated with average milk flow rate was with. Ash content and acidity were positively correlated with total solids.

Effects of manual udder stimulation on milk partitioning and flow traits during the machine milking in dairy camels (Camelus dromedarius)

A total of 9 multiparous dromedary camels in late stage of lactation (287±8 DIM; 3.8±0.8 kg/d) were used to study the effect of manual udder stimulation on machine milking efficiency of dairy camels under intensive management condition. Experimental design consisted of 3x3 Latin square with 9 animals allocated randomly and equally to 3 treatment (T1=60 s, T2=90 s and T3=120 s). All camels were machine milked twice daily. Milk yield and milk flow parameters were recorded by Lactocorder® milk meters. Udder health was evaluated by California mastitis test (CMT) and somatic cell counts (SCC). Cisternal milk was determined 14 h after milking using Atosiban®. Volumes of machine milk (MM), machine stripping milk (MSM) and residual milk (RM) were recorded in duplicate. No subclinical mastitis was detected during the experimental period as indicated by the CMT ( 25%). The increase of udder stimulation from T1 to T3 decreased (p<0.05) the lag time (LT) (3.83 to 2.24 sec) in camels of G1 and the MSM (26.6 to 14.8%) as well as RM (46.1 to 31.4%) in camels of G2. Bimodal curves tended (P=0.08) to decrease from 43.6% to 28.1% when duration of udder stimulation increased from T1 to T3 in camels of G2. In conclusion, increase duration of manual udder stimulation to 90–120 s ameliorate the machine milking efficiency in harder milked camels at late stage of lactation. (Resume d'auteur)

Piglet behavior as a measure of vitality and its influence on piglet survival and growth during lactation

The aim of the study was to develop a vitality scoring method, based on piglet behavior and relate it to piglet growth and survival. From 21 sows (Sus scrofa), 287 piglets were used. After farrowing (d 0), piglets were weighed and tested for 4 behavioral parameters in a circular enclosure (55 cm diam.): movement capacity (M), udder stimulation (U), number of completed circles around the enclosure (NCC), and screaming (Sc). Piglets were weighed again on d 1, 2, 3, and 17. Piglet rectal temperature (RT) was recorded on d 0, 1, 2, and 3. Farrowing information of the sow was also recorded. Multiple regression analyses for survival and BW gain at weaning as dependent variables were performed. Piglet BW gain at weaning was influenced by BW at birth (P < 0.001), sow parity (P = 0.024), total number of piglets born alive per sow (P < 0.001), and sum of U and NCC parameters (UN; P = 0.023). Piglet survival during lactation was influenced by BW at birth (P = 0.015), UNCC parameter (P = 0.026), and RT on d 3 (P = 0.085). The sum of U and NCC parameters, in combination with BW at birth and information of the sow, might be useful to predict piglet growth survival during lactation, thus becoming a useful tool to improve piglet management during the first days of lactation. In conclusion, UNCC parameter seems to be an easy and useful way to assess piglet vitality for both scientific and commercial purposes.

The patterns of myoelectrical activity and reaction for teat stimulation recorded in highly productive dairy cows’ udders

The aim of the study was to evaluate electrical properties of the mammary gland of dairy cow during manual and mechanical milking and to adapt the electrographic method for analysis of udder physiology. Udder myoelectrical activity was measured on 10 healthy highly productive dairy cows of Slovak Pied cattle breed. The electrical activity of four quarters of the udder was recorded simultaneously using four bipolar electrodes. The udder was stimulated by delicate two-finger massage, manual milking and mechanical milking. During the experiment the duration of the reaction for stimulation and the amplitude of spike dischargers were listed. The udder stimulation through palpational massage of the teat end, manual and mechanical milking caused immediate reaction. The udder responded to stimulation with an increase in myoelectrical activity: increase in discharge frequency to 2.33 ± 0.6 per min and an increase in discharge amplitude with the average of 457 ± 147 µV. The average count of spike discharges was 3.86 ± 0.97, the average duration of the action potential was 8.12 ± 1.68 s and the average myoelectrical index was 31 ± 4%. Manual milking caused the highest increase in the udder myoelectrical activity. Evaluation of the mammary gland myoelectrical activity may provide an alternative method to study milk ejection disorders and to diagnose mastitis.

Changes in thermal nociceptive responses in dairy cows following experimentally induced Escherichia coli mastitis.

BackgroundMastitis is a high incidence disease in dairy cows. The acute stage is considered painful and inflammation can lead to hyperalgesia and thereby contribute to decreased welfare. The aim of this study was to examine changes in nociceptive responses toward cutaneous nociceptive laser stimulation (NLS) in dairy cows with experimentally induced Escherichia coli mastitis, and correlate behavioral changes in nociceptive responses to clinical and paraclinical variables.MethodsSeven Danish Holstein-Friesian cows were kept in tie-stalls, where the E. coli associated mastitis was induced and laser stimulations were conducted. Measurements of rectal temperature, somatic cell counts, white blood cell counts and E. coli counts were conducted. Furthermore, scores were given for anorexia, local udder inflammation and milk appearance to quantify the local and systemic disease response. In order to quantify the nociceptive threshold, behavioral responses toward cutaneous NLS applied to six skin areas at the tarsus/metatarsus and udder hind quarters were registered at evening milking on day 0 (control) and days 1, 2, 3, 6 and 10 after experimental induction of mastitis.ResultsAll clinical and paraclinical variables were affected by the induced mastitis. All cows were clinically ill on days 1 and 2. The cows responded behaviorally toward the NLS. For hind leg stimulation, the proportion of cows responding by stepping was higher on day 0 than days 3 and 6, and the frequency of leg movements after laser stimulation tended to decrease on day 1 compared to the other days. After udder stimulation, the proportion of cows responding by stepping was higher on day 1 than on all other days of testing. Significant correlations between the clinical and paraclinical variables of disease and the behavioral responses toward nociceptive stimulation were found.ConclusionsChanges in behavioral responses coincide with peaks in local and systemic signs of E. coli mastitis. During the acute stage of E. coli mastitis nociceptive thermal stimulation on hind leg and mammary glands results in decreased behavioral responses toward nociceptive stimulation, which might be interpreted as hypoalgesia.

Prediction of total quarter milk somatic cell counts based on foremilk sampling

Determination of somatic cell count (SCC) is used worldwide in dairy practice to describe the hygienic status of the milk and the udder health of cows. When SCC is tested on a quarter level to detect single quarters with high SCC levels of cows for practical reasons, mostly foremilk samples after prestimulation (i.e. cleaning of the udder) are used. However, SCC is usually different in different milk fractions. Therefore, the goal of this study was the investigation of the use of foremilk samples for the estimation of total quarter SCC. A total of 378 milkings in 19 dairy cows were performed with a special milking device to drain quarter milk separately. Foremilk samples were taken after udder stimulation and before cluster attachment. SCC was measured in foremilk samples and in total quarter milk. Total quarter milk SCC could not be predicted precisely from foremilk SCC measurements. At relatively high foremilk SCC levels (>300 x 10(3) cells/ml) foremilk SCC were higher than total quarter milk. At around (50-300) x 10(3) cells/ml foremilk and total quarter SCC did not differ considerably. Most interestingly, if foremilk SCC was lower than 50 x 10(3) cells/ml the total quarter SCC was higher than foremilk SCC. In addition, individual cows showed dramatic variations in foremilk SCC that were not very well related to total quarter milk SCC. In conclusion, foremilk samples are useful to detect high quarter milk SCC to recognize possibly infected quarters, only if precise cell counts are not required. However, foremilk samples can be deceptive if very low cell numbers are to be detected.

Induction of milk ejection and milk removal in different production systems1

Milk ejection is important during milking or suckling to obtain the alveolar milk fraction, which can represent more than 80% of the milk stored in the udder of dairy cows. In response to tactile teat stimulation, either manually or by the milking machine, milk ejection is induced by the release of oxytocin and resultant myoepithelial contraction. The time from the start of tactile stimulation until the occurrence of milk ejection spans 40 s to > 2 min and increases with a decreasing degree of udder filling. Therefore, cows need a longer prestimulation in the late stages of lactation or if the milking is performed shortly after the previous milking, whereas in full udders prestimulation is less important. Milk ejection is disturbed under several conditions, such as during milking in unfamiliar surroundings (i.e., a novel milking environment) or for several weeks immediately after parturition in primiparous cows. Disturbed milk ejection is due to a reduction of or absence of oxytocin release from the pituitary. The severity of disturbed milk ejection and the coping capacity toward a novel milking environment is related to cortisol release in response to ACTH (i.e., adrenal cortex activity). Therefore, susceptibility of individual cows to the inhibition of oxytocin release and milk ejection can be predicted by an ACTH challenge test. Comfortable surroundings, such as feeding in and lighting of the milking parlor, can increase the secretion of oxytocin. Overcoming the lack of oxytocin release by injection of exogenous oxytocin for an extended time results in a reduction of the mammary response to endogenous oxytocin. In different production systems, it has to be verified that udder stimulation is sufficient to prevent disturbed milk ejection. Different brands of automatic milking systems induce a sufficient prestimulation of the udder, even if a few minutes are needed for a successful onset of the teat clusters. Specific breeds used for less intense milk production may need the presence of their calves for sufficient oxytocin release during milking. In conclusion, in all milk production systems, the maximal possible reduction of stress has to be targeted and proper udder prestimulation must be performed for an optimal milking of the cow by the farmer.

Effect of pre-stimulation on milk flow pattern and distribution of milk constituents at a quarter level

The aim of this study was to investigate milk flow patterns and milk composition in relation to pre-milking udder stimulation. The milk of one quarter of each of the sixteen cows was removed separately and in the course of milking it was divided into six fractions (P – cisternal milk during milking without stimulation and the first 300 ml during milking with pre-stimulation, 0&amp;minus;25%, 25&amp;minus;50%, 50&amp;minus;75%, 75&amp;minus;100%, 75&amp;minus;100%, MS-machine stripping) and into five portions (25%, 50%, 75%, 100%, 100% + MS). Two milkings were performed during two consecutive evening milkings with or without manual stimulation. Pre-stimulation resulted in a reduction of milking time, duration of the increase and decline phase of milk flow, stripping yield, but it increased the peak flow rate as compared to milking without pre-stimulation (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). In both fractions and portions the content of fat increased steadily during milking and reached a maximum at MS. Lactose increased from P to 50&amp;minus;75% and then it decreased to MS. Significantly higher fat contents at 25% and 50% portions and in both protein and dry matter at 25% portions were found during milking with pre-stimulation as compared to no stimulation (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). The content of fat, protein and dry matter were also higher in both P and 0&amp;minus;25% fractions for milking with pre-stimulation (&lt;i&gt;P&lt;/i&gt; &lt; 0.05). Pre-stimulation positively influenced the parameters of milk flow and therefore the efficiency of milk removal and contributed to better distribution of components in milk fractions during milking.

Sensory and physiological determinants of maternal behavior in the goat ( Capra hircus)

Maternal behavior in the goat appears at the time of parturition, partly under the activating influence of vaginocervical stimulation. Mothers actively lick their neonate and rapidly establish a selective bond with their kid through olfactory recognition. They also develop visual and acoustic recognition of the kid within 4 h following birth. Acoustic recognition is present at 48 h. The establishment of maternal recognition can be impaired by underfeeding during the second half of pregnancy. There is no indication that the mechanisms controlling the onset of maternal behavior and bonding are different from those reported in sheep, despite the fact that lambs start to follow their mother within a few hours after birth and kids hide for about a week. During lactation, the cues provided by the kid are necessary for the maintenance of maternal responsiveness, but suckling itself does not appear of primary importance. The presence of the kid also modulates the hormonal response to udder stimulation and influences recovery of postpartum sexual activity when kidding (i.e. birthing) takes place in autumn. Finally, the rapid establishment of mutual attachment between mother goats (does) and their kids offers the possibility to investigate an aspect of mother–young affiliation that is not present in many laboratory species.

Incontinentia Lactis: Physiology and Anatomy Conducive to Milk Leakage in Dairy Cows

Incontinentia lactis is a possible predisposing factor for an elevated level of intramammary infection. The goal of the present study was to investigate possible causes of incontinentia lactis in dairy cows. Two farms that differed in breed composition, but that had similar average milk yields were studied: herd A, 28 kg/d, 31 Red Holstein cows; and herd B, 26 kg/d, 16 Brown Swiss cows. Herd A was classified into 2 groups: incontinentia lactis (ILA group) and control, whereas herd B was exclusively a control herd. Milk samples that represented foremilk and the main milk fraction were collected during 4 milking sessions. In addition, milk leakage samples from the ILA group were collected at different time intervals from 0 to 5h before milking. Measurements of the teat, milk flow, fractions of cisternal and alveolar milk, intramammary pressure, and blood oxytocin pattern also were obtained. The ILA cows did not have differences in fat content between milk leakage and cisternal milk fraction. Milk fat content, however, increased during milking in response to continuous milk ejection (1.95, 1.99, and 4.61% for milk leakage, cisternal, and main milk samples, respectively). Teat canals were 9% shorter in the ILA cows, which showed greater milk yield, peak, and average flow rates. Quarter cisternal milk yield of ILA cows tended to be greater (0.50 vs. 0.23 and 0.28kg for ILA and controls from herds A and B, respectively), whereas percentages of cistern milk and alveolar milk did not differ from controls. The greater pressure in the ILA group, both before and after manual udder stimulation (ILA: 4.0 and 6.4 kPa; control: 2.0 and 5.0 kPa, respectively), could be an important cause for the leakage. Nevertheless, the increase in IMP that occurred after udder preparation affirms that milk ejection occurred in response to the tactile teat stimulation, but not before the onset of leakage. Blood oxytocin concentration in ILA cows was low until the start of udder preparation and increased in response to the milking stimulus (reaffirming the hypothesis that milk leakage occurred in the absence of milk ejection). In conclusion, milk losses by leakage are likely due to the large amount of cisternal milk, which creates pressure and causes leakage, in the absence of milk ejection.

Effects of restricted nursing on milk production and collection, kid growth and plasma prolactin and growth hormone concentrations in dairy goats

The milk production of dairy goats under various regimes of mother-young contact from day 4 post partum were studied during the first 2 months of lactation, together with the prolactin (PRL) and growth hormone (GH) responses to udder stimulation. In the control group, 13 goats and their kids were left in permanent contact and did not undergo milking. In two additional groups, goats were machine milked once a day in the morning (at 0800 h) and kids were allowed 10 hours (from 1000 to 2000 h; 10H group, n = 11) or 5 h (from 1000 to 2000 h; 5H group, n = 11) of mother-young interaction per day. In the last group (MO, n = 10), mothers were permanently separated from their kids on day 4 post partum and milked once a day. Milk production during a 24-h period at 37 days post partum performed by controlled nursing and weighing of the kids (groups with kids) or by two machine milking 12 h apart (milking only group) revealed a higher production in the three groups with some mother-young contact than in the MO group. Total milk collected by milking over the 2 months of the study did not differ between the three groups that underwent milking. Kid weights at 2 months were 3.4 to 4.8 kg. lighter in the groups that underwent milking than in the control group. Hormonal profiles were significantly affected by restricted mother-young contact, with highest pre-stimulation concentrations of PRL and GH in the 5H group. Restricting mother-young contact from the first week postpartum can permit an early collection of milk without major effects on kid growth, when compared with one daily milking in goats totally separated from their young.

Development of a Biotin-streptavidin Amplified Enzyme Immunoassay for Oxytocin and its Application During Milk Ejection and the Reproductive Cycle in the Mithun (Bos frontalis)

Oxytocin is a key hormone involved in milk ejection. It plays a key role in regulation of reproductive cyclicity in female mammals by taking part in the process of luteolysis. Determination of oxytocin is, therefore, important for studying the control of its secretion and its role in reproduction of the mithun. A simple and sufficiently sensitive enzyme immunoassay (EIA) for oxytocin determination in mithun plasma using the biotin-streptavidin amplification system and second antibody coating technique was therefore developed. Biotin was coupled to oxytocin and used to bridge between streptavidin-peroxidase and the immobilized oxytocin antiserum in a competitive assay. The EIA was conducted directly in 200 microl of unknown mithun plasma. Standards prepared in hormone-free plasma were used. The lowest detection limit was 0.5 pg/ml plasma. Plasma volumes for the EIA (50, 100, and 200 microl) did not influence the shape of standard curve, even though a drop in OD450 was seen with higher plasma volumes. A parallelism test was carried out to compare endogenous mithun oxytocin with a bovine oxytocin standard. The former showed good parallelism with the bovine standard curve. For biological validation of the assay, plasma oxytocin was measured in the blood samples collected before, during, and after milking in three mithun cows and in six non-lactating cyclic mithuns during the entire estrous cycle. A sharp release of oxytocin shortly after udder stimulation was observed. A high level of oxytocin was maintained during milking, falling sharply thereafter. The mean plasma oxytocin concentration was different on different days of the estrous cycle (P < 0.001). Two peaks of oxytocin were recorded, one at day 6 and another at day 18 of the estrous cycle. In conclusion, a simple, sufficiently sensitive and direct EIA procedure has been developed for the first time to determine plasma oxytocin levels in mithuns. Apart from being non-radioactive, the EIA procedure described here also utilizes a highly stable biotinalyted hormone which has a shelf life of several years, unlike the short shelf life of iodinated tracer used in RIA procedures.