Non-offspring nursing by a nulliparous pregnant female just before first parturition in free-ranging Japanese macaques

A nulliparous pregnant Japanese macaque, Macaca fuscata, suckled her 1-year-old sister 44 days before her own parturition. Other Japanese macaque yearlings did not hold the nipples of this nulliparous female in their mouths. Although this non-offspring nursing before first parturition did not improve the rate of milk secretion, the nulliparous female may have improved her indirect fitness and her suckling behavior.     

Parity-related differences in suckling behavior and nipple preference among free-ranging Japanese macaques

Suckling behavior of primiparae in free-ranging Japanese macaques (Macaca fuscata) was compared with that of multiparae at Jigokudani Monkey Park, the Shiga Heights, Nagano Prefecture, Japan, from April 1984 to June 1994. The estimated rates of milk secretion in a single preferred nipple among primiparae were lower than those among multiparae from birth to 5 months of age. Milk secretion capabilities of primiparous mothers, hence, appear to be inferior to those of multiparous mothers. In nutritive sucking, although Japanese macaque infants preferred one single nipple, nipple preferences in primiparae were weaker than those in multiparae. With supplementary two-nipple use during sucking, however, the infants of primiparae appear to overcome a suckling flaw of their primiparous mothers. After infants were 5 months of age and after a drop (from approximately 10% to approximately 5%) in the rates of milk secretion, however, milk secretion rates in a single preferred nipple among primiparae were similar to those in multiparae and the supplementary two-nipple use in primiparous mother-infant dyads disappeared. Am. J. Primatol. 42:331–339, 1997. © 1997 Wiley-Liss, Inc.     

Enhancing captive breeding in giant pandas (Ailuropoda melanoleuca): maintaining lactation when cubs are rejected,and understanding variation in milk collection and associated factors

From 1997 to 2002, a female giant panda (Ailuropoda melanoleuca) was artificially stimulated and lactation was maintained, after her neonates were removed due to the female's inability to provide maternal care. Milk samples were collected and the amount of milk collected was quantified. The lactation curve of this animal was estimated based on the Gamma function: Y_t=at^be^−ct. The amount of milk collected showed significant, positive relationships with the number of days after parturition both in 1999 and in the whole study period from 1998 to 2002. This female's lactation curves fit the type I pattern of a typical mammalian lactation curve. Daily milk collection (g) during the first 30 days after parturition, and from 31 to 60 days after parturition, showed a consistent pattern with one peak at around 8:00 hr. More milk was collected during the latter period than during the former period. The amount of milk (g) collected on mucus excretion days was significantly less than that on days after mucus excretion had ended, yet no significant difference was found between milk collected one day before mucus days and on mucus days, or between milk collected one day before and one day after mucus days. Mucus excretion from the gastrointestinal tract significantly impacted the amount of milk collected. The results from this study may aid the captive propagation and conservation of giant pandas and other endangered and rare captive mammal species. Zoo Biol 28:331–342, 2009. © 2009 Wiley-Liss, Inc.     

Changes in maternal taurine levels in response to pregnancy and lactation

Taurine levels in various tissues and fluids of female rats were measured throughout pregnancy and lactation. The taurine concentration of liver markedly increased at days 19 and 21 of pregnancy to 188% of levels for nonpregnant, nonlactating control rats and then fell rapidly after delivery to reach only 30% of the control level by 3 days postpartum. Muscle and heart taurine concentrations were significantly negatively correlated with liver taurine levels. Brain taurine levels were low at days 14, 19 and 21 of pregnancy and day 14 of lactation. Urinary excretion of taurine decreased to 32% of control levels at day 21 of pregnancy and was negatively correlated with the hepatic taurine concentration over the course of pregnancy and lactation. The ratio of glycine- to taurine-conjugated bile acids was strongly negatively correlated with the hepatic taurine concentration. The milk taurine level was positively correlated with hepatic taurine concentration during lactation. The hepatic taurine pool appears to increase just before parturition and to rapidly decrease during the first few days of lactation when high levels of taurine are secreted in the milk. Our data suggests that the accumulation of taurine in the liver may be related to both a decreased renal clearance of taurine and a shifting of tauring from other tissues to the liver and that this enlarged pool of hepatic taurine may serve as a source of taurine for secretion in the early milk.     

Some aspects related to conception of the Japanese monkey (Macaca fuscata)

The season of birth, age of the first parturition, gestation period, and vaginal bleeding and mating after conception were surveyed with Japanese monkeys (Macaca fuscata). The analyses of the former two items were dependent on the birth records in the Ohirayama troop collected from 1957 to 1973, and the analyses of the latter two items were dependent on data obtained by a 48-hour mating in a laboratory. Birth in the Ohirayama troop converged into the months from March to July, especially from April to June. The age of the first parturition was three years and 11 months at the earliest, and nine years and two months at the latest. The monkeys giving their first birth at the age of five or thereabouts were most frequently observed (68.6%), and most of the monkeys had their first parturition from about the age of four years to about the age of six years. The gestation period calculated from 17 cases, which was defined as the period from the first day of a 48-hour mating to the day before parturition, was 173 ± 6.9 days ranging from 161 to 188 days. In 25 out of 28 cases, the vaginal bleeding was observed after conception. It began slightly later (between 16 and 24 days after mating) than the forecasted time of the next menstrual hemorrhage, and usually lasted longer than bleeding of the usual menses. Each of three female monkeys caged together with a male monkey 30 days after conception was observed to have copulated, and the male was observed to have ejaculated.     

Concurrent lactation and pregnancy: pregnant domestic horse mares do not increase mother-offspring conflict during intensive lactation

Lactation is the most energy demanding part of parental care in mammals, so parent-offspring conflict arises over milk provided by the mother. In some species females commonly become pregnant shortly after parturition of previous young. This further intensifies mother-offspring conflict due to concurrent pregnancy and lactation. In equids it has been well established that pregnant females wean their foals earlier than non-pregnant ones. Intensified mother-offspring conflict was presumed to associate with pregnancy also during the period of intensive lactation, i.e., before the weaning process starts. We investigated the effect of pregnancy on suckling behaviour characteristics as indicators of mother-offspring conflict in domestic horses. Contrary to expectation, here we provide evidence of a decreased mother-offspring conflict related to pregnancy in lactating females during first two trimesters of pregnancy. Pregnant mares provided longer suckling bouts and did not reject or terminate suckling of their foals more often than non-pregnant mares. Our results suggest that pregnant mares cope with parallel investment into a nursed foal and a foetus through enhancing nursing behaviour in early stages of pregnancy before the initially low requirements of the foetus increase. They compensate their suckling foal with the perspective of its early weaning due to ongoing pregnancy.     

Effect of Bromocryptine on hormones and milk secretion in Murrah buffaloes ( Bubalus bubalis)

An experiment was carried out on 10 advance pregnant Murrah buffaloes to determine the role of hormones in milk secretion around parturition. Experimental animals were administered with a single injection of bromocryptine, @ 100 μg/kg BW, for 5 days before expected calving, whereas control group buffaloes were injected with placebo injections. Blood samples collected before parturition (-5,-4,-3,-2,-1 days), on day of parturition (day-0) and on day 1, 2, 3, 4, 5, 10 and 15 post partum were analyzed for growth hormone (GH), insulin like growth factor-I (IGF-I) and prolactin (PRL) by radioimmunassay methods. Milk samples were collected daily for 5 days and on day 10 and 15 after parturition. Milk fat, protein, lactose, citric acid, non-esterified fatty acids (NEFAs) and somatic cell counts (SCCs) were determined in milk samples. Bromocryptine treatment significantly (P < 0.01) decreased pre partum PRL and increased GH levels (P < 0.01) on day of parturition in experimental buffaloes without influencing plasma IGF-I level. Milk yield was significantly lower (P < 0.01) in experimental than in control group. Further, effect of bromocryptine on milk yield was only for a week. Milk yield increased (P < 0.01) gradually and was similar to control group on day 15 post partum. Bromocryptine treatment significantly increased milk SCC (P < 0.01) and protein content (P < 0.01) but there was no effect of treatment on fat, lactose, citric acid, glucose, milk and plasma NEFA concentration. It was concluded that prepartum suppression of PRL by bromocryptine impairs milk secretion temporarily in ensuing lactation. The significant rise in GH level before parturition and on day of parturition suggests a role of it in milk secretion of buffaloes.     

神农架川金丝猴初产雌性妊娠期异亲哺乳

<正>灵长类动物生长发育过程中,雌性往往承担着主要的育幼责任,因此,母亲是帮助灵长类婴儿尽早适应环境并独立生活的重要角色(F?rster and Cords, 2002; Xi et al., 2008; Briga et al., 2012)。对大多数群居型灵长类动物而言,母亲以外的成员也常常参与照料婴猴,该现象普遍存在于旧大陆猴中,     

Secretion of whey acidic protein and cystatin is down regulated at mid-lactation in the red kangaroo (Macropus rufus)

Milk collected from the red kangaroo (Macropus rufus) between day 100 and 260 of lactation showed major changes in milk composition at around day 200 of lactation, the time at which the pouch young begins to temporarily exit the pouch and eat herbage. The carbohydrate content of milk declined abruptly at this time and although there was only a small increase in total protein content, SDS PAGE analysis of milk revealed asynchrony in the secretory pattern of individual proteins. The levels of alpha-lactalbumin, beta-lactoglobulin, serum albumin and transferrin remain unchanged during lactation. In contrast, the protease inhibitor cystatin, and the putative protease inhibitor whey acidic protein (WAP) first appeared in milk at elevated concentrations after approximately 150 days of lactation and then ceased to be secreted at approximately 200 days. In addition, a major whey protein, late lactation protein, was first detected in milk around the time whey acidic protein and cystatin cease to be secreted and was present at least until day 260 of lactation. The co-ordinated, but asynchronous secretion of putative protease inhibitors in milk may have several roles during lactation including tissue remodelling in the mammary gland and protecting specific proteins in milk required for physiological development of the dependent young.     

Effects of stage of pregnancy on variance components,daily milk yields and 305-day milk yield in Holstein cows,as estimated by using a test-day model

Pregnancy and calving are elements indispensable for dairy production, but the daily milk yield of cows decline as pregnancy progresses, especially during the late stages. Therefore, the effect of stage of pregnancy on daily milk yield must be clarified to accurately estimate the breeding values and lifetime productivity of cows. To improve the genetic evaluation model for daily milk yield and determine the effect of the timing of pregnancy on productivity, we used a test-day model to assess the effects of stage of pregnancy on variance component estimates, daily milk yields and 305-day milk yield during the first three lactations of Holstein cows. Data were 10 646 333 test-day records for the first lactation; 8 222 661 records for the second; and 5 513 039 records for the third. The data were analyzed within each lactation by using three single-trait random regression animal models: one model that did not account for the stage of pregnancy effect and two models that did. The effect of stage of pregnancy on test-day milk yield was included in the model by applying a regression on days pregnant or fitting a separate lactation curve for each days open (days from calving to pregnancy) class (eight levels). Stage of pregnancy did not affect the heritability estimates of daily milk yield, although the additive genetic and permanent environmental variances in late lactation were decreased by accounting for the stage of pregnancy effect. The effects of days pregnant on daily milk yield during late lactation were larger in the second and third lactations than in the first lactation. The rates of reduction of the 305-day milk yield of cows that conceived fewer than 90 days after the second or third calving were significantly (P<0.05) greater than that after the first calving. Therefore, we conclude that differences between the negative effects of early pregnancy in the first, compared with later, lactations should be included when determining the optimal number of days open to maximize lifetime productivity in dairy cows.     

Short- and long-term effects of high milking frequency during the first 21 days of lactation on production and reproductive performance in high-lactating cows

We examined short- and long-term effects of high milking frequency (HMF) for the first 21 days of lactation. The study included 122 Israeli Holstein cows – 32 pregnant heifers, 40 cows in second lactation and 50 cows in >second lactation. Heifers were paired according to predicted transmitting ability and cows according to energy-corrected milk (ECM) production, age, days in milk and expected calving date. Thin cows (body condition score <2.75) were not included. One cow from each pair was arbitrarily allocated to a control group milked three times daily (3× milking cows) and the counterpart to an experimental group milked six times daily for the first 21 days of lactation and then three times daily for the rest of the lactation (6× milking cows). During the first 21 days of lactation, 6× milking cows produced 9.3 kg more milk (26.5%) and 7.16 kg more ECM (19%) than the 3× milking cows. The higher milk production persisted throughout the entire lactation (305 days), as reflected by treatment×age interaction showing higher milk production for the first and second (7%) but not >second lactation cows relative to their control counterparts (−0.37%); ECM production was also higher in 6× milking first and second lactation (7.6% and 5%, respectively) but not for >second lactation cows. Furthermore, HMF had long-lasting effects, expressed as significantly higher milk production through the succeeding lactation in the previous first lactation cows (10%); a tendency toward significance in the second lactation cows relative to the controls (4.7%), but a deleterious effect on the >second lactation cows, reflected by lower milk production (−5.25%) than in controls; similar patterns were found for the ECM. For the entire 305 days of lactation, fat and protein yields were higher for first and second lactation cows, whereas protein yield for >second lactation cows was lower in the 6× milking v. control group. Given that HMF during the first 21 days of first or second lactation increases milk and ECM yields throughout the concurrent and successive lactation with no adverse effect on energy balance, mastitis, metabolic diseases or reproduction, it seems to be economically beneficial. However, caution should be paid for >second lactation cows due to absence of significant effect in the entire of the first HMF applied lactation and the deleterious effect in the succeeding lactation.     

Association between age at first calving,year and season of first calving and milk production in Holstein cows

The effects of first calving (FC) in Holstein heifers on their first lactation, second lactation and lifetime milk production were examined from an initial database of 459 743 animals that first calved between 1 January 1990 and 31 July 2010 in Wallonia, Belgium. The FC age class (18 to 22, 22 to 26, 26 to 30, 30 to 34, 34 to 38 and 38 to 42 months), the FC season and FC year class (1990 to 1994, 1995 to 1999, 2000 to 2004 and 2005 to 2010) were considered when analysing the first and second lactation data. Lifetime data were similarly analysed, but did not include animals that calved after 2005 because many of them were still lactating. Only 24% of animals had their FC before 26 months of age. Animals that first calved between 22 and 26 months of age had more lactations and productive days during their life. They also had higher first and second lactation milk production and lifetime milk production. Summer or autumn FC improved first lactation, second lactation and lifetime milk production, as well as production per day of lactation, compared with winter or spring FC. Compared with animals that calved for the first time in 1990 to 1994, animals with a FC in 2000 to 2004 had a longer calving interval (0.5 months), fewer lactations per animal (−0.6) and fewer days in their lifetime lactation (a reduction of 144 days). As a result, the animals’ lifetime production did not increase between 1990 to 1994 and 2000 to 2004, although milk production per day of lactation (22.85v. 20.49 l/day) and per day of life (11.49v. 10.78 l/day) improved. Milk fat content was lower in 2000 to 2004 than in 1990 to 1994, but protein content remained relatively constant, probably because of the cows’ higher production level and increased dietary concentrate supplementation.     

Lactation in the Japanese monkey (Macaca fuscata): Yield and composition of milk and nipple preference of young

Changes in the yield and chemical composition of milk, together with those in the nipple preferences and suckling behavior of infants, were followed in three lactating Japanese monkeys rearing single infants under laboratory conditions at monthly intervals for six months after their paturition. Milk accumulating in the mammary glands during a 4-hr separation of the infant was collected by milking under anesthesia with the aid of a physiological dose of oxytocin. The stage of full lactation appeared to last for about two or three months after parturition. The milk at this stage contained 14.0% of total solids, 4.2% of lipids, 1.6% of proteins, and 6.2% of lactose, and the concentrations of Na, Cl, and K in the milk water were 7.4, 15.1, and 5.9 mM, respectively. From the 9th or 13th week of lactation onwards, according to the individual, the milk composition changed appreciably and the time during which the young left hold of the mother's nipple also increased. The weaning of young in the Japanese monkey appears to begin during the 3rd or 4th month of age. The milk production then wanes and almost ceases by the end of the 6th month. The nipple preference of the young was generally established completely by the 3rd, or the 8th at latest, week of age. However, no difference in either the yield or composition of the milk secreted was found between the mammary glands of the preferred and non-preferred sides. Without regard to the apparent nipple preference, infants seem to ingest milk from the mother's breasts of both sides. Accurate estimation of the rate of milk production could not be achieved, but the rate was expected to be 150–200 g/day at the height of lactation based on the relation between the mother's body weight and the milk production rates of other primate species. A disparity was noted between the observed and estimated values for the milk yield, and a diurnal fluctuation in the milk secretion of the Japanese monkey was inferred. This study was conducted through the official system of the Primate Research Institute, Kyoto University, for cooperative research work with other institutions.     

Changes in plasma progesterone and prolactin concentrations during the annual cycle and the role of prolactin in the maintenance of lactation and luteal development in the Antarctic fur seal (Arctocephalus gazella)

Progesterone in Antarctic fur seals was undetectable from 1-2 days before parturition to 4-6 days after parturition. There was a rapid increase in progesterone to 20 ng/ml between 6 and 10 days post partum and this increase coincided with peak concentrations of oestradiol-17 beta at the time normally associated with oestrus and mating in this species. Newly formed corpora lutea were present in the ovaries by Day 9 post partum even though the seals had been isolated in an enclosure and not mated. Thereafter, progesterone remained detectable, but at a low concentration (5 ng/ml) throughout embryonic diapause. A similar pattern was observed in unmated females which suggests they enter a period of pseudopregnancy. Progesterone increased to 35 ng/ml between late February and mid-March, indicating activation of the corpus luteum at the end of diapause, and then declined slowly through the remainder of gestation. Plasma prolactin, measured against a human prolactin standard, was elevated from 1-2 days before parturition and peaked at 0-3 days post partum. It then declined slowly throughout the post-partum period and remained at a low level throughout embryonic diapause. Prolactin concentration declined to undetectable at the end of diapause and before the end of lactation. Reduction of prolactin secretion by injections of bromocriptine from Days 3 to 5 post-partum terminated lactation. Mothers, which normally leave their pups to feed at sea on about Day 7 post partum, did not continue to lactate beyond Day 7 although this did not appear to be associated with reduced prolactin secretion. Bromocriptine treatment appeared to prevent the post-ovulatory surge of progesterone although there was no long-term effect of bromocriptine on progesterone secretion during the early stages of embryonic diapause/pseudopregnancy. This study has shown that prolactin is an important hormone for maintaining early lactation in the fur seal and it probably also has a role in the control of ovulation and luteal development. Prolactin does not appear to be implicated in the control of lactation cycles in fur seals. Changes in plasma progesterone during the annual cycle show that the pattern in fur seals resembles that of some carnivores with embryonic diapause.     

Milk carbohydrates of marsupials. II. Quantitative and qualitative changes in milk carbohydrates during lactation in the tammar wallaby (Macropus eugenii)

Milk was collected at various stages of lactation from a group of tammar wallabies, M. eugenii, in which parturition had been synchronized. The milk carbohydrate was determined by a phenol-sulfuric acid method which had been modified to give equal colour yields for galactose and glucose. The mean carbohydrate content increased gradually during the first 6 months of lactation to a peak of 13 g hexose/100 ml of milk, but then fell rapidly to much lower values, over the following 2 months. Throughouth lactation, galactose was the predominant monosaccharide constituent of acid hydrolysates of the milk carbohydrate. Glucose, glucosamine, galactosamine and sialic acid were the only other monosaccharides present. Qualitative changes were investigated by gel filtration and thin-layer chromatography. During the first 6 months post partum the milk carbohydrate was composed of a variety of oligosaccharides including lactose, but from 8 months onwards it consisted mainly of free monosaccharides. Between 6 and 8 months an intermediate pattern was observed, i.e. a mixture of lower oligosaccharides and free monosaccharides. In two animals which suckled both a new-born pouch young and a young at foot, the mammary gland supplying the new-born secreted milk which was rich in oligosaccharides, whereas that supplying the young at foot produced milk in which the carbohydrates were mainly free monosaccharides, and which had a much lower carbohydrate content.     

The life cycle of Toxocara vitulorum in Asian buffalo (Bubalus bubalis)

A procedure for labelling hatched Toxocara vitulorum larvae with 75 selenium is described. Labelled larvae are infective when administered into the small intestine and portal vein of buffalo of all ages. Only very young calves are infected after oral administration. The labelled larvae are used with an enhanced fluorographic autoradiographic procedure to study the dynamics of the infection in non-pregnant and pregnant buffalo. Larvae penetrate the wall of the small intestine between 2 and 8 h after administration. Most larvae go straight to the liver via the portal vein but a few enter the mesenteric lymph nodes. Over the next 90 h some larvae migrate to the lung and a few to muscle, brain, kidney and peripheral lymph nodes. Most remain in the liver. Over the next 3-7 weeks the larvae grow by about 10% and no moulting is observed. In a pregnant host larvae grow to 500-600 microns in liver and lung 1-8 days before parturition and migrate to the mammary gland around the time of parturition. In the mammary gland they grow to about 1200 microns and pass into the milk during the 7 days after parturition.     

Concentrations of serum cortisol, progesterone, estradiol-17 beta, cholesterol and cholesterol ester in the doe during the reproductive stadium, in the fetal serum, in the amniotic fluid and in the milk of rabbits, as well as correlations between these parameters

1. Serum progesterone, estradiol-17 beta and cortisol, as well as cholesterol and cholesterol ester concentrations in pregnant and lactating rabbits (New Zealand white hybrids, n = 9), were measured. These parameters were also studied in the amniotic fluid, the milk and the fetal serum (28-day old fetuses). 2. Serum progesterone and estradiol-17 beta were significantly enhanced during gestation, while the content of cortisol showed a marked elevation at the end of pregnancy. The concentrations of these hormones decreased before parturition. 3. Serum cholesterol and cholesterol ester concentrations markedly decreased in the second half of gestation (74 and 76%, respectively) and elevated after parturition and in the first week of lactation.     

Southern elephant seal,Mirounga leonina: composition of milk during lactation

An analysis of milk constituents during various stages of lactation in the southern elephant seal Mirounga leonina was carried out. Forty-six milk samples were taken from 30 females throughout lactation during 1985, 1987, 1990 and 1991 on Stranger Point, King George Island, South Shetland Islands. Total nitrogen (TN), non-protein nitrogen (NPN), sugar, fat, ash and water were measured, and from some of these data true protein and energy content were calculated. The results showed a high degree of variation in water and fat concentrations among samples at different stages of lactation. During the first 20 days the fat content of milk increased from about 12 to approximately 52%, while water content fell from 70 to 33%. The composition of milk changes rapidly during the first days post-partum. Protein, minerals and sugar appear to remain stable after the fourth day of lactation. Milk samples contain significant levels of sugars; thin layer chromatography indicates the presence of lactose and glucose together with other unidentified components. There is evidence of a striking change in composition of the milk in the later part of lactation; the progressive increase in the fat:water ratio is abruptly reversed just prior to weaning.     

Use of Stochastic Simulation to Evaluate the Reduction in Methane Emissions and Improvement in Reproductive Efficiency from Routine Hormonal Interventions in Dairy Herds

This study predicts the magnitude and between herd variation in changes of methane emissions and production efficiency associated with interventions to improve reproductive efficiency in dairy cows. Data for 10,000 herds of 200 cows were simulated. Probability of conception was predicted daily from the start of the study (parturition) for each cow up to day 300 of lactation. Four scenarios of differing first insemination management were simulated for each herd using the same theoretical cows: A baseline scenario based on breeding from observed oestrus only, synchronisation of oestrus for pre-set first insemination using 2 methods, and a regime using prostaglandin treatments followed by first insemination to observed oestrus. Cows that did not conceive to first insemination were re-inseminated following detection of oestrus. For cows that conceived, gestation length was 280 days with cessation of milking 60 days before calving. Those cows not pregnant after 300 days of lactation were culled and replaced by a heifer. Daily milk yield was calculated for 730 days from the start of the study for each cow. Change in mean reproductive and economic outputs were summarised for each herd following the 3 interventions. For each scenario, methane emissions were determined by daily forage dry matter intake, forage quality, and cow replacement risk. Linear regression was used to summarise relationships. In some circumstances improvement in reproductive efficiency using the programmes investigated was associated with reduced cost and methane emissions compared to reliance on detection of oestrus. Efficiency of oestrus detection and the time to commencement of breeding after calving influenced variability in changes in cost and methane emissions. For an average UK herd this was a saving of at least £50 per cow and a 3.6% reduction in methane emissions per L of milk when timing of first insemination was pre-set.