Trade-offs in Energy Allocation During Lactation

SYNOPSIS. During lactation, mothers require energy to meet bothmaternal and offspring requirements. If a mother exports toomuch energy to dependent offspring (in milk), her weight lossmay be excessive and maternal risk may increase. Conversely,too little energy allocation to offspring may reduce the growthrate or induce mortality of dependent offspring. This paradigmwas evaluated in cotton rats (Sigmodon hispidus) supportingsmall (3 pup) and large (6 pup) litters from early to late lactation.Several types of evidence indicate that physiological constraintslimit the ability of mothers with large litters to provide resourcesto offspring. Mothers with large litters produced a dilute,energy-poor milk and their rates of food intake, weight lossand energy export per litter appeared to approach physiologicalmaxima. Whereas the energy exported to pups in small littersincreased from early to late lactation, the energy flow perpup in large litters was consistently low; consequently, offspringin large litters had low growth rates. An increase in eithermaternal food intake or weight loss (catabolism of maternaltissue) could have provided additional energy to offset thelow growth rate of pups in large litters. However, mothers withlarge litters did not substantially increase their food intakeor weight loss compared with mothers supporting small litters.These results indicate that the maternal support of offspringin large litters is limited. The pattern of energy allocationshown by cotton rats with large litters likely reflects a compromisebetween meeting maternal and offspring energy requirements (cf.,Parker and Macnair, 1979). The energy flow is greater than optimalfor the parent but less than optimal for the offspring. Lessmaternal-offspring conflict occurs in small than large littersbecause offspring in small litters maintain a high growth rateat a relatively low maternal cost. Yet, under favorable environmentalconditions, the reduction in maternal-offspring conflict hasno apparent fitness benefit.     

A Long Term Study on the Health Status and Performance of Sows on Different Feed Allowances during Late Pregnancy

The main objective of this study was to determine the total cell content, TCC, and the percentage of polymorphonuclear leucocytes, PMNLs, in colostrum and milk collected from sows during the first 22 days of lactation. The pH-values during the same sampling period were also determined. It should be emphasized that all the values obtained emanate from bacteriologically negative colostrum and milk. The potential influence of different levels of late gestation feeding regimes was also evaluated. The TCC-values obtained from milk samples during the first 3 weeks of lactation and exceeding the designated threshold of 10×106 cells/ml varied between 4% and 21%. Within the TCC-limitation of 10-19.99×l06 cells/ml neither the preceding nor the succeeding cell counts exceeded the threshold in 26.8%. TCC-values above 19.99×l06 cells/ml were preceded and succeeded by cell counts below the threshold in 58.8% and 58.8%, respectively. The TCC-levels below the threshold of 10×106 cells/ml, expressed as geometric least square means, increased significantly from day 1 to day 3 (1.23×l06 cells/ml versus 1.86×106 cells/ml) and decreased thereafter gradually to day 22 (1.38×106 cells/ml). When all values were included, the TCC-values increased in a similar pattern from day 1 to day 3 (1.38×106 cells/ml versus 3.18×106 cells/ml). The value on day 22 of lactation was still on a significantly elevated level compared with that of day 1 (2.10×106 cells/ml versus 1.38×106 cells/ml). The 2 different feeding regimes were not found to influence the TCC-values during the first 22 days of lactation. In the whole material the PMNL-values, expressed as percentages of the TCC, declined from approximately 60% on day 1 of lactation to between 40% and 50% for the remaining sampling period. This decline was comparable with the one seen in the cell class below the threshold of 10×106 cells/ml. In the 2 cell classes above 9.99×106 cells/ml, 78.0% and 88.8% of PMNLs on day 1 declined to about 40% on day 22. This might indicate an inflammatory response on day 1 but without any detectable bacteriological growth. The increase in lactation number, if lactation 1 was compared with the following lactations, revealed a significant rise (p<0.05) in TCC-level and percentage level of PMNLs. A stepwise and significant increase in pH-level occurred between days 1, 3 and 8 (6.18, 6.56, 7.03) followed by a significant decrease to day 22 (6.91) when pH-values from milk of all cell classes were included.     

Effect of Chromium Supplementation on Productive and Reproductive Performances and Some Metabolic Parameters in Late Gestation and Early Lactation of Dairy Cows

The objective of this study was to determine the effect of supplemental chromium as chromium-L-methionine (Cr-Met) on productive and reproductive performances and some metabolic parameters in late gestation and early lactation of dairy cows. Sixty multiparous Holstein dairy cows according to prior lactation, parity, body mass (682?±?33?kg), and expected calving date were divided equally (30 cows/treatment) and were randomly allocated to one of the two groups. One group received basal diet without Cr (control group) and another group received Cr-Met supplement added at manufacturer's recommended level (8?mg of "Cr"/head per day) from 21?days before expected calving date until 21?days of lactation. Supplemental Cr tended to increase milk yield (P?=?0.08) while percentage of lactose and lactose yield increased (P??0.05). Percentage of cyclic cows at 36?days postpartum and estrous behavior before AI was higher in the supplemented group.     

Clinical and Endocrinological Studies in Primiparous Post Partum Sows Effects of Lactation Length and Litter Size By

The object of this investigation was to determine the relationships between clinical findings and hormonal patterns in primiparous sows with different lactation length and litter size during lactation, weaning and to the first oestrus. Seven pairs of primiparous full sib sows were used to determine the effect of lactation length with normal litter size. One sow of each pair was assigned to nurse the piglets for 3 weeks (group A) while the other nusred for 5 weeks (group B). Another 8 primiparous sows (group C) were assigned to nurse 2–4 piglets during a 5-week lactation period. Oestrus detection was performed twice daily and laparoscopic examination every 2 weeks. If the sows did not come in oestrus within 3 weeks after weaning they were slaughtered. Peripheral plasma levels of progesterone, oestradiol-17β and LH were estimated by radioimmunoassays throughout the experimental period.     

Dietary Fish Oil Inhibits Pro-Inflammatory and ER Stress Signalling Pathways in the Liver of Sows during Lactation

Lactating sows have been shown to develop typical signs of an inflammatory condition in the liver during the transition from pregnancy to lactation. Hepatic inflammation is considered critical due to the induction of an acute phase response and the activation of stress signaling pathways like the endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR), both of which impair animal´s health and performance. Whether ER stress-induced UPR is also activated in the liver of lactating sows and whether dietary fish oil as a source of anti-inflammatory effects n-3 PUFA is able to attenuate hepatic inflammation and ER stress-induced UPR in the liver of sows is currently unknown. Based on this, two experiments with lactating sows were performed. The first experiment revealed that ER stress-induced UPR occurs also in the liver of sows during lactation. This was evident from the up-regulation of a set of genes regulated by the UPR and numerically increased phosphorylation of the ER stress-transducer PERK and PERK-mediated phosphorylation of eIF2α and IκB. The second experiment showed that fish oil inhibits ER stress-induced UPR in the liver of lactating sows. This was demonstrated by decreased mRNA levels of a number of UPR-regulated genes and reduced phosphorylation of PERK and PERK-mediated phosphorylation of eIF2α and IκB in the liver of the fish oil group. The mRNA levels of various nuclear factor-κB-regulated genes encoding inflammatory mediators and acute phase proteins in the liver of lactating sows were also reduced in the fish oil group. In line with this, the plasma levels of acute phase proteins were reduced in the fish oil group, although differences to the control group were not significant. In conclusion, ER stress-induced UPR is present in the liver of lactating sows and fish oil is able to inhibit inflammatory signaling pathways and ER stress-induced UPR in the liver.     

Serum Electrolyte and Mineral Variations During Pregnancy and Lactation in Nili-Ravi Buffalo

The aim of present study was to determine the changes of sodium, potassium, chloride, copper, and zinc in serum of Nili-Ravi buffalo during pregnancy and lactation. The study was carried out on 25 Nili-Ravi buffaloes during March 2008 to February 2009 at Buffalo Research Institute, Pattoki, District Kasur. Blood samples were taken from each buffalo during early pregnancy (Phase EP), i.e., between 1 and 3 months gestation, mid pregnancy (Phase MP), i.e., between 4 and 6 months gestation, late pregnancy (Phase LP), i.e., between 7 and 10 months gestation, and during lactation (Phase LT). Serum sodium, potassium, and chloride were determined on a clinical chemistry analyzer whereas copper and zinc were determined on an atomic absorption spectrophotometer. The mean serum sodium, potassium, and chloride concentrations varied non-significantly (P > 0.05) during pregnancy and lactation. With advancing pregnancy, copper increased and was significantly high (P < 0.05) during late pregnancy whereas during lactation copper concentrations dropped significantly (P < 0.05). The zinc concentrations increased non-significantly during early and mid pregnancy. There were significant differences (P < 0.05) in zinc concentrations during lactation compared with late pregnancy. This study demonstrates that concentrations of serum sodium, potassium, and chloride remain unchanged during pregnancy and lactation whereas serum copper concentrations increased and zinc concentrations decreased with advancing pregnancy because of the demand of the fetus at different periods of pregnancy.     

Distinct and Dynamic Auxin Activities During Reproductive Development

Flowering plants have evolved sophisticated and complicated reproductive structures to ensure optimal conditions for the next generation. Successful reproduction relies on careful timing and coordination of tissue development, which requires constant communication between these tissues. Work on flower and fruit development over the last decade places the phytohormone auxin in a key role as a master of patterning and tissue specification of reproductive organs. Although many questions still remain, it is now clear that auxin mediates its function in flowers and fruits through an integrated process of biosynthesis, transport, and signaling, as well as interaction with other hormonal pathways. In addition, the knowledge obtained so far about auxin function already allows researchers to develop tools for crop improvement and precision agriculture.Flower and fruit development requires a precise patterning of organs and tissues, which also have to be coordinated for the successful fulfillment of the tasks inherited. The plant hormone auxin has received a lot of attention for its prominent role in organ positioning as well as in organ polarity formation and differentiation, and flowers and fruits make no exception to the dependency on auxin in these aspects. In addition, auxin appears to participate in the coordination of processes within, as well as between, floral organs, aiding for example in successful fertilization. In this article, we focus on the role of auxin in the establishment of the flower, and specifically in the development and dehiscence of the reproductive floral organs.     

The Structure of Bonobo Copulation Calls During Reproductive and Non‐Reproductive Sex

Copulation calls in primates are usually identified as sexually selected signals that promote the reproductive success of the caller. In this study, we investigated the acoustic structure of copulation calls in bonobos (Pan paniscus), a great ape known for its heightened socio‐sexuality. Throughout their cycles, females engage in sexual relations with both males and other females and produce copulation calls with both partners. We found that calls produced during sexual interactions with male and female partners could not be reliably distinguished in terms of their acoustic structure, despite major differences in mating behaviour and social context. Call structure was equally unaffected by the size of a female’s sexual swelling and by the rank of her mating partner. Rank of the partner did affect call delivery although only with male, but not female partners. The only strong effect on call structure was because of caller identity, suggesting that these signals primarily function to broadcast individual identity during sexual interactions. This primarily social use of an evolved reproductive signal is consistent with a broader trend seen in this species, namely a transition of sexual behaviour to social functions.     

Effects of Feeding Bt Maize to Sows during Gestation and Lactation on Maternal and Offspring Immunity and Fate of Transgenic Material

Background

We aimed to determine the effect of feeding transgenic maize to sows during gestation and lactation on maternal and offspring immunity and to assess the fate of transgenic material.

Methodology/Principal Findings

On the day of insemination, sows were assigned to one of two treatments (n = 12/treatment); 1) non-Bt control maize diet or 2) Bt-MON810 maize diet, which were fed for ∼143 days throughout gestation and lactation. Immune function was assessed by leukocyte phenotyping, haematology and Cry1Ab-specific antibody presence in blood on days 0, 28 and 110 of gestation and at the end of lactation. Peripheral-blood mononuclear cell cytokine production was investigated on days 28 and 110 of gestation. Haematological analysis was performed on offspring at birth (n = 12/treatment). Presence of the cry1Ab transgene was assessed in sows'' blood and faeces on day 110 of gestation and in blood and tissues of offspring at birth. Cry1Ab protein presence was assessed in sows'' blood during gestation and lactation and in tissues of offspring at birth. Blood monocyte count and percentage were higher (P<0.05), while granulocyte percentage was lower (P<0.05) in Bt maize-fed sows on day 110 of gestation. Leukocyte count and granulocyte count and percentage were lower (P<0.05), while lymphocyte percentage was higher (P<0.05) in offspring of Bt maize-fed sows. Bt maize-fed sows had a lower percentage of monocytes on day 28 of lactation and of CD4⁺CD8⁺ lymphocytes on day 110 of gestation, day 28 of lactation and overall (P<0.05). Cytokine production was similar between treatments. Transgenic material or Cry1Ab-specific antibodies were not detected in sows or offspring.

Conclusions/Significance

Treatment differences observed following feeding of Bt maize to sows did not indicate inflammation or allergy and are unlikely to be of major importance. These results provide additional data for Bt maize safety assessment.     

Prevalence of Reproductive Abnormalities Among Women with Familial Partial Lipodystrophy

ObjectiveTo compare the risk of having polycystic ovary syndrome (PCOS) or ovarian cysts among women with genetically confirmed familial partial lipodystrophy (FPLD) with that in the general population of healthy women.MethodsTwenty-five women with FPLD who were 18 to 80 years old were interviewed regarding a history of PCOS or ovarian cysts (composite primary outcome) as well as for secondary outcomes of interest including menstrual irregularities, hirsutism, gynecologic surgical procedures, and fertility or obstetric complications. From the 2005 National Ambulatory Medical Care Survey, 3,326 women, aged 18 to 80 years (control subjects), were assessed for the presence of the primary outcome based on appropriate International Classification of Diseases, Ninth Revision, Clinical Modification codes.ResultsFour of the 25 patients with FPLD (16%) had a history of PCOS or ovarian cysts, in comparison with 14 of the 3,326 control subjects (0.42%), resulting in an age- and body mass index-adjusted odds ratio of 40.6 (95% confidence interval, 12.1 to 136.7; P < .0001) among the patients with FPLD. Furthermore, 5 women with FPLD (20%) required at least 1 oophorectomy during their lifetime, and 6 (24%) had had hysterectomies at a young age (≤ 55 years).ConclusionWomen with genetically confirmed FPLD have an increased risk for PCOS and ovarian cysts, as well as early hysterectomies, in comparison with the general population. Therefore, timely involvement of gynecologists in the care of these patients is warranted. (Endocr Pract. 2008;14:1126-1132)     

Impact of Maternal Selenium Supplementation from Late Gestation and Lactation on Piglet Immune Function

Biological Trace Element Research - The present work aimed at assessing passive, innate, and acquired immunity in piglets from sows supplemented with either organic or inorganic selenium (Se). A...     

Effect of Different Iodine Nutrition on Cerebellum Pcp-2 in Rat Offspring During Lactation

The thyroid functions of breastfed infants, as well as (indirectly) the development of their central nervous system, are dependent on the iodine status of the lactating mother. Purkinje cell protein-2 is a cell-specific marker of the cerebellum Purkinje cell and is a suitable indicator for observing the postnatal development of the cerebellum after birth. We measured the Purkinje cell protein-2 mRNA and protein levels in the rat cerebellum in the critical postnatal (14 days after birth) and maturation periods (28 days after birth) to determine the effect of different nutritional iodine levels on cerebellum growth in the offspring during lactation. We found that severe iodine deficiency resulted in thyroid dysfunction in lactating rats and their offspring on both 14 and 28 days, showing maternal total T₄ 16.7 ± 12.0 vs 36.4 ± 15.0, P < 0.05 (14 days) and 22.6 ± 18.7 vs 53.4 ± 9.4, P < 0.01 (28 days), and neonatal total T₄ 10.6 ± 2.3 vs 16.4 ± 4.7, P < 0.01(14 days) and 12.8 ± 2.9 vs 16.7 ± 3.4, P < 0.05 (28 days), respectively. The Purkinje cell protein-2 mRNA and its protein levels in offspring rats were significantly reduced that showed Purkinje cell protein-2 mRNA 1.12 ± 0.04 vs 2.25 ± 0.53, P < 0.05 (14 days) and 1.74 ± 0.94 vs 8.69 ± 2.71, P < 0.01 (28 days). However, mild iodine deficiency and excessive iodine maintained almost normal thyroid function in maternal and neonatal rats and normal Purkinje cell protein-2 mRNA and protein levels in offspring’s cerebellum. We conclude that severe iodine deficiency could significantly reduce Purkinje cell protein-2 mRNA and its protein levels, indicating that the cerebellum development was retarded, but mild iodine deficiency and excessive iodine could maintain them at an approximately normal level by the mother’s and offspring’s compensations, especially by the mother’s mammary glands.     

Reproductive Hierarchies Among Workers of the Slave-making Ant,Chalepoxenus muellerianus

In queenright colonies of the slave-making ant, Chalepoxenus muellerianus, workers formed dominance hierarchies through ritualized food begging and antennation bouts, but did not lay eggs. Within a few hours of the experimental removal of the queen, the frequency of dominance displays increased drastically and the interactions became considerably more violent. During the observation period, the dominant workers almost incessantly attacked subordinate slave-makers and slaves by antennation and biting. The aggression rate decreased after approximately 3–4 wk. Within a single colony, several high-ranking workers were observed laying eggs, although typically only one or a few top-ranking individuals became fully fertile Directly after eclosion, young workers engaged in aggressive interactions with other young workers and high-ranking old workers, but did not dominate the top-ranking egg-layers. Callows achieved ranks immediately below the top-ranking worker.