Effect Of Maternal Feed Restriction Research Articles

411 Awardee Talk: Fetal Programming and Molecular Characterization of the Skeletal Muscle Development in Ruminants

Abstract Three experiments were developed aiming to investigate the effects of maternal nutrition on the skeletal muscle development and metabolism of the offspring. The first study was designed to evaluate the protein restriction during mid-gestation on the skeletal muscle growth of beef cattle offspring. Our results revealed that maternal protein restriction at this stage of gestation caused a decreased number of muscle fibers in the offspring. The second and third studies aimed to elucidate the effects of maternal feed restriction during different stages of gestation on the transcriptome and proteome profile in the skeletal muscle of the newborn. In these experiments, pregnant goats were feed-restricted (at 50% maintenance requirements) either during the first or second half of gestation. Transcriptome analysis revealed that feed restriction at first half of gestation upregulated genes involved with the maintenance of satellite cells, and fatty acid oxidation in skeletal muscle of the newborn. On the other hand, restriction at the second half of gestation upregulated genes related with the balance of glucose metabolism, in addition to protective mechanisms against the oxidative stress in the skeletal muscle of the newborn. Through the proteomic analysis, we observed enriched biological processes (BP) and signaling pathways (SP) related with the energy-investment phase of glycolysis, in addition to the increase in the usage of glycogen and fatty acids storages in the skeletal muscle of the newborn due to feed restriction at the first half of gestation. We also observed that when feed restriction occurs at second half of gestation there is an enrichment in BP and SP associated with the energy-generation phase of glycolysis, and an enhancement in the biosynthesis of glutamine in skeletal muscle of the newborns. Overall, the results of these studies bring insights that help to develop nutritional strategies during early life development aiming to improve postnatal performance.

Effects of Maternal Nutrient Restriction and Melatonin Supplementation on Cardiomyocyte Cell Development Parameters Using Machine Learning Techniques.

Simple SummaryThe major objectives of this study were to examine the effects of maternal feed restriction and melatonin supplementation on fetal cardiomyocyte cell development parameters and predict binucleation and hypertrophy using machine learning techniques using pregnant beef heifers. Interestingly, major findings include evidence that compromised pregnancy in cattle leads to a reduction in the number of cardiomyocytes while melatonin treatment can mitigate some of these disturbances.The objective of the current study was to examine the effects of maternal feed restriction and melatonin supplementation on fetal cardiomyocyte cell development parameters and predict binucleation and hypertrophy using machine learning techniques using pregnant beef heifers. Brangus heifers (n = 29) were assigned to one of four treatment groups in a 2 × 2 factorial design at day 160 of gestation: (1) 100% of nutrient requirements (adequately fed; ADQ) with no dietary melatonin (CON); (2) 100% of nutrient requirements (ADQ) with 20 mg/d of dietary melatonin (MEL); (3) 60% of nutrient requirements (nutrient-restricted; RES) with no dietary melatonin (CON); (4) 60% of nutrient requirements (RES) with 20 mg/d of dietary melatonin (MEL). On day 240 of gestation, fetuses were removed, and fetal heart weight and thickness were determined. The large blood vessel perimeter was increased in fetuses from RES compared with ADQ (p = 0.05). The total number of capillaries per tissue area exhibited a nutrition by treatment interaction (p = 0.01) where RES-MEL increased capillary number compared (p = 0.03) with ADQ-MEL. The binucleated cell number per tissue area showed a nutrition by treatment interaction (p = 0.010), where it was decreased in RES-CON vs. ADQ-CON fetuses. Hypertrophy was estimated by dividing ventricle thickness by heart weight. Based on machine learning results, for the binucleation and hypertrophy target variables, the Bagging model with 5 Decision Tree estimators and 3 Decision Tree estimators produced the best results without overfitting. In the prediction of binucleation, left heart ventricular thickness feature had the highest Gin importance weight followed by fetal body weight. In the case of hypertrophy, heart weight was the most important feature. This study provides evidence that restricted maternal nutrition leads to a reduction in the number of cardiomyocytes while melatonin treatment can mitigate some of these disturbances.

Impact of maternal feed rationing during pregnancy on meat quality attributes of rabbit offspring

Abstract Young rabbits does fed ad libitum diets often show parturition problems such as dystocia and abnormal presentation, resulting in reduced numbers of kits. This can be linked to excessive fatness of the does. Several studies have documented the effect of feed restriction on rabbits, but only limited information exist on the carryover effect of maternal feed restriction exerts on meat quality attributes of the offspring produced from such restriction. This study evaluated the influence of maternal feed restriction and vitamin E inclusion during pregnancy on meat quality of rabbit kits. Seventy-five rabbits, consisting of sixty 20-week-old does and 15 mature bucks, were used in the experiment. Treatments consisted of two levels of feed restriction (0 and 15 %) applied at three different periods during pregnancy (15 – 19, 20 – 24, or 25 – 29 days) with or without vitamin E dietary inclusions (0 and 300 mg/kg). The pregnant does were divided into twelve treatment groups, each containing five replicates of one rabbit each. The experiment was in a 2 × 3 × 2 factorial layout in a completely randomised design. After kindling (between days 28 – 31 of pregnancy) the resulting kits (a total of 180 kits) were arranged on treatment basis of their mothers and managed for a period of 56 days; that is 15 kits per treatment, each replicated 5 times (each replicate contained 3 kits). After 56 days of experiment, the data were collected on meat pH, total cholesterol, crude fat, crude protein, thermal shortening and refrigeration loss. Feed restriction during pregnancy with or without dietary vitamin E (no addition and 300 mg/kg) resulted in a significant (p < 0.05) influence on meat quality attributes of growing rabbits as total cholesterol (555.00 ± 6.06) decreased in the meat of rabbits whose mothers were feed-restricted during pregnancy. On the other hand, maternal feed rationing with or without vitamin E did not significantly (p > 0.05) affect the crude protein and thermal shortening of their slaughtered offspring. In conclusion, maternal feed rationing during pregnancy can be adopted as a feeding strategy in manipulating meat quality indicators of growing rabbits as total cholesterol concentrations decreased which is a good indicator that the meat is safer and better for consumers in order to prevent health-related challenges.

PSVII-5 Effect of maternal feed restriction at different stages of gestation on development of gastrointestinal tract of newborn goats

Abstract We assessed the effect of maternal feed restriction at different stages of gestation on growth and development of organs and small intestine of newborn goats. A total of 14 pregnant dams were randomly divided into one of the follow dietary treatments: Animals fed at 50% of maintenance requirement from 8-84 d of gestation and then fed at 100% maintenance requirement from day 85 of gestation to parturition (R-M, n = 6), and animals fed at 100% of maintenance requirement from 8-84 d of gestation and then fed at 50% maintenance requirement from day 85 of gestation to parturition (M-R, n = 8). At birth, newborns were slaughtered for collection of corporal components. No differences were observed among treatments for birth weight (P = 0.46). The weight of the complex reticulum-rumen-omasum tended to be heavier (P = 0.057) in the M-R group, when expressed per kg of body weight. The small intestine (P = 0.038) and total intestine (P = 0.038) were heavier in the offspring of the M-R group when expressed in kg of body weight. The M-R newborns had greater length of the small intestine (P = 0.043) and total intestine (P = 0.026). Maternal feed restriction did not influence the intestinal villi height (P = 0.406). However, newborn from R-M group had lower villus height:crypt depth ratio (P = 0.016), due to the tendency of the greater of crypt depth in these animals (P = 0.081). No differences among treatments were observed in mRNA expression of the MGAM and GLP-2R in the jejunum of the offspring (P > 0.12). Newborns of the M-R group tended to present greater mRNA abundance of the SLC5A1 (P = 0.091), SLC2A2 (P = 0.091), and OCLN (P = 0.061). In summary, restriction in the first half of gestation may be more detrimental to the performance and health of offspring throughout life due to increased impairment of intestinal development.

P.677 Serotonin transporter gene polymorphisms and confidence in adult relationships affect the number of followed people on Instagram

Maternal undernutrition during pregnancy impairs offspring behaviours and thereby their survival rate indirectly by decreasing lamb birth weight or by deteriorating milk production which in turn limits bonding of the dam with the neonate. This study was aimed to investigate the effect of maternal feed restriction during late pregnancy on performance and behaviours of ewes and their lambs. Twenty-four Ghezel ewes were allocated to the three experimental treatments including ad libitum intake (AL); restricted feed intake by 60 % (FR); and propylene glycol- supplemented restricted diet (FR + PG). AL and FR + PG ewes had higher circulating oestradiol (P < 0.001) but not progesterone (P < 0.0001) than FR ewes during late pregnancy and parturition. Prepartum undernutrition of FR ewes resulted in lower milk yield (P < 0.001) and higher milk fat percentage (P < 0.0001) than AL and FR+PG ewes during the initial three weeks of lactation. In the case of offspring behaviours, lambs born to ewes offered PG+FR treatment were quicker to kneel, stand up, reach to the udder, suck and play within the first 2 h of birth compared with those born to ewes offered FR and AL treatments (P < 0.0001). Lambs from FR+PG ewes had a higher birth weight (P < 0.05), weaning weight (P < 0.0001) and average daily gain (P < 0.0001) than those from the other groups. Concerning maternal behaviours, FR+PG ewes started grooming their lambs faster than ewes in other groups (P < 0.01). Moreover, it took more time for FR ewes to deliver their lambs or deliver their second lamb in multiple deliveries compared with those in the other groups (P < 0.01). The maternal recognition test revealed lambs born to AL and FR+PG ewes preferred to spend more time with their dams than did lambs born to FR ewes at 12 h of age (P < 0.0001). The results also showed that the time taken for the lambs to reach the contact zone or to reach their dam was substantially longer for lambs from FR ewes than those from AL and FR+PG ewes at 12 h and 24 h of age (P < 0.0001). There was a positive correlation between lamb birth weight and average daily gain (r= 0.36), weaning weight (r=0.64), survival rate (r=0.62). It can be concluded that although maternal under nutrition can adversely affect maternal and neonatal behaviours, supplementing glucogenic precursor as a strategy can alleviate the majority of physiological and behavioural abnormalities and might have beneficial outcomes for farmers.

Effect of late gestational feed restriction and glucogenic precursor on behaviour and performance of Ghezel ewes and their offspring

Maternal undernutrition during pregnancy impairs offspring behaviours and thereby their survival rate indirectly by decreasing lamb birth weight or by deteriorating milk production which in turn limits bonding of the dam with the neonate. This study was aimed to investigate the effect of maternal feed restriction during late pregnancy on performance and behaviours of ewes and their lambs. Twenty-four Ghezel ewes were allocated to the three experimental treatments including ad libitum intake (AL); restricted feed intake by 60 % (FR); and propylene glycol- supplemented restricted diet (FR + PG). AL and FR + PG ewes had higher circulating oestradiol (P < 0.001) but not progesterone (P < 0.0001) than FR ewes during late pregnancy and parturition. Prepartum undernutrition of FR ewes resulted in lower milk yield (P < 0.001) and higher milk fat percentage (P < 0.0001) than AL and FR+PG ewes during the initial three weeks of lactation. In the case of offspring behaviours, lambs born to ewes offered PG+FR treatment were quicker to kneel, stand up, reach to the udder, suck and play within the first 2 h of birth compared with those born to ewes offered FR and AL treatments (P < 0.0001). Lambs from FR+PG ewes had a higher birth weight (P < 0.05), weaning weight (P < 0.0001) and average daily gain (P < 0.0001) than those from the other groups. Concerning maternal behaviours, FR+PG ewes started grooming their lambs faster than ewes in other groups (P < 0.01). Moreover, it took more time for FR ewes to deliver their lambs or deliver their second lamb in multiple deliveries compared with those in the other groups (P < 0.01). The maternal recognition test revealed lambs born to AL and FR+PG ewes preferred to spend more time with their dams than did lambs born to FR ewes at 12 h of age (P < 0.0001). The results also showed that the time taken for the lambs to reach the contact zone or to reach their dam was substantially longer for lambs from FR ewes than those from AL and FR+PG ewes at 12 h and 24 h of age (P < 0.0001). There was a positive correlation between lamb birth weight and average daily gain (r= 0.36), weaning weight (r=0.64), survival rate (r=0.62). It can be concluded that although maternal under nutrition can adversely affect maternal and neonatal behaviours, supplementing glucogenic precursor as a strategy can alleviate the majority of physiological and behavioural abnormalities and might have beneficial outcomes for farmers.

Feed intake of the sow and playful creep feeding of piglets influence piglet behaviour and performance before and after weaning

Creep feed intake is variable and may be partly homeostatically and exploratory driven. We studied effects of maternal feed restriction and a ‘play-feeder’ on piglet behaviour and performance. 37 Litters received creep feed in a conventional (CON) or play-feeder (PL) and their sows were full-fed (FF) or restrictedly-fed (RES). Eaters were determined via rectal swabs. At weaning (d24) four piglets from the same treatment were grouped (n = 36 pens). RES hindered piglet growth by 41 g/d and enhanced time eating, creep feed intake and percentage of eaters at weaning versus FF. RES-PL had the largest proportion of moderate and good eaters. PL stimulated feeder exploration and attracted more piglets to the feeder than CON. Post-weaning, RES increased exploratory behaviours, feed intake between d0–5, and growth between d0–2, and reduced body lesions between d0–2 (within CON), drinking and ear biting. PL increased ingestive behaviours, feed intake and growth between d0–15, and BW at d15 post-weaning by 5%. PL also lowered the prevalence of watery diarrhoea, number of body lesions and piglets with ear (within FF) and tail (within RES) damage at d15 post-weaning. Treatments did not affect FCR. To conclude, RES and particularly PL (broader and for longer) result in less weaning-associated-problems.

Effect of maternal feed restriction in dairy goats at different stages of gestation on skeletal muscle development and energy metabolism of kids at the time of births

The aim was to determine effects of maternal feed restriction in dairy goats at gestational different stages on skeletal muscle development and energy metabolism in kids at birth. Six pregnant goats were fed 50% of total digestible nutrients (TDN) and crude protein (CP) (NRC, 2007) recommendations in the first half of gestation and then fed to 100% of the recommendations in the second half of gestation (treatment R-M). In the other group, eight pregnant goats were fed 100% of TDN and CP in the first half of gestation and 50% of a restricted diet the second half of gestation (treatment M-R). Birth weight, blood glucose concentration, muscle fiber number, and size of kids at birth were not affected by maternal feed restriction. The mRNA and protein abundance of myogenic, adipogenic and fibrogenic markers were not affected (P > 0.05) by maternal diet. With regard to values for variables in kid energy metabolism, mRNA abundance of the glycolic enzyme HKII was less (P = 0.03) in the M-R group. In conclusion, maternal feed restriction in the first or second half of gestation had no affect mRNA abundance on myogenic, adipogenic, and fibrogenic markers nor were there changes in skeletal muscle mesenchymal stem cell population of kids at the time of birth. There, however, may be detrimental effects on energy metabolism by reducing HKII gene expression in skeletal muscle of dairy goat kids at the time of birth.

Effect of maternal feed restriction on prenatal development in rats and rabbits – A review of published data

With respect to hazard classification for developmental toxicity under the CLP Regulation it is important to consider the possible influence of maternal toxicity. The aim of the present review was to characterize to which extent developmental effects could be caused by non-specific maternal toxicity. Such effects would not be relevant for classification. In prenatal developmental toxicity studies, the administration of high doses is given in the guideline. The associated non-specific systemic toxicity often affects the maternal body weight. Therefore, published results of studies in rats and rabbits, where maternal weight gain during gestation was inhibited by restricted feeding, were examined regarding developmental effects. In summary, maternal feed restriction resulted in a reduction of fetal body weight that was sometimes accompanied by delayed ossification in both species. Considering their magnitude these effects could be interpreted as secondary non-specific (i.e. not caused by a developmental toxicant) effects. Based on the limited number of available publications in total no further consequences on prenatal development by maternal feed restriction were observed.

Maternal feed restriction during pregnancy in Wistar rats: Evaluation of offspring using classical and immunoteratology protocols

Studies have revealed that impairment of the pregnant body weight reduces the fetal body weight and causes minor changes in skeletal development. The aim of the present study was to assess the effects of maternal feed restriction during pregnancy in offspring immune system development. Pregnant Wistar rats were distributed into 5 groups: 1 control in which dams received food ad libitum and 4 experimental groups in which dams were fed restricted amounts of rodent ration (16, 12, 9, or 6 g/rat/day) from the 6th to 17th gestation day. Teratogenicity was assessed using classical teratological evaluation and developmental immunotoxicology protocols. Maternal body weight gain, fetus weight, and placenta weight were reduced for feed-restricted females from the groups fed 12, 9, and 6 g/rat/day ( p < 0.05). No pup mortality was observed immediately after cesarean sections among the groups, and no visceral or skeletal malformations were detected. An immunoteratological study revealed an increase in the relative weight of the thymus and an increase in the phorbol myristate-acetate solution-induced hydrogen peroxide release by inflammatory cells in 21-day-old pups. Alterations in the delayed-type hypersensitivity response and the humoral immune response against sheep red blood cells were observed in pups from feed-restricted mothers. Feed restriction in Wistar rats during organogenesis did not promote structural malformations but resulted in offspring with lower birth weights and promoted significant changes in the immune responses of the rat pups.

666: Obesity as an independent risk factor for severe maternal morbidity (“near miss”) during delivery hospitalization

maternal morbidity (“near miss”) during delivery hospitalization Heather Lipkind, Katherine Campbell, David Savitz, Valery Danilack, Matthew Goldshore, Erika Werner Yale University, Obstetrics, Gynecology and Reproductive Science, New Haven, CT, Brown University, Public Health-Epidemiology, Providence, RI, The Johns Hopkins University School of Public Health, Population, Family and Reproductive Health, Baltimore, MD, The Johns Hopkins University School of Medicine, Gynecology and Obstetrics, Baltimore, MD OBJECTIVE: To examine the association between maternal obesity on “near miss” events during the delivery hospitalization. STUDY DESIGN: We used 1995-2003 NYC birth certificates linked to hospital discharge data to identify delivery hospitalizations with maternal diagnoses and procedures that indicated a possible life-threatening diagnosis or a life-saving procedure (near miss). We used indicators described in previous work by Callaghan et al (AJOG, 2008). Data were limited to singleton, live born neonates. Deliveries complicated by maternal death or where the pre-pregnancy weight was unknown were excluded. Women with a pre-pregnancy weight / 200 pounds were considered overweight/obese (obese) based on previous studies. Logistic regression was used to evaluate near miss events in obese women compared to non-obese women. RESULTS: For 1995-2003 there were 935,717 live singleton births in New York City in which pre-pregnancy weight was collected. 6.2% of these women had a pre-pregnancy weight / 200lbs and were classified as obese. Acute renal failure, eclampsia, hysterectomy, mechanical ventilation, pulmonary embolus and septicemia were independently associated with obesity (see table). Women who were obese had substantially higher adjusted odds of a near miss event (AOR 3.02; 95% CI 2.77-3.28) compared to non-obese women after adjusting for maternal socioeconomic and demographic characteristics. These odds was reduced but remained significantly elevated after controlling for maternal co-morbid medical conditions such as diabetes, hypertension, chronic cardiac disease and pulmonary disease (AOR 1.53; 95% CI: 1.40-1.68). CONCLUSION: This study shows that morbidity is increased in women with an elevated pre-pregnancy weight even after adjusting for comorbid conditions. It is important to understand contributors to lifethreatening maternal morbidity in order to improve obstetrical care. 667 Effect of feed restriction during gestation and lactation period on changes in hepatic lipid metabolism in 3-week-old male rat pups Hye Won Kim, Sangmi Lee, Mi Hye Park, Sun Hee Chun, Young Ju Kim School of Medicine, Ewha Womans University, Department of Obstetrics and Gynecology, Seoul, Republic of Korea, School of Medicine, Ewha Womans University, Department of Molecular Medicine, Seoul, Republic of Korea OBJECTIVE: We examined the effect of maternal feed restriction during gestation and lactation period on the hepatic lipid metabolism in 3-week-old male rat pups. STUDY DESIGN: Male and female Sprague-Dawley rats were mated after a one-week acclimation period with non-purified diet, and at day 10 of gestation, female rats were divided into two groups and given an ad libitum diet (AdLib) or 50% food restricted diet (FR). Pups were divided into three groups: 1) AdLib/AdLib, given AdLib throughout experimental period; 2) FR/AdLib, given FR during pregnancy and AdLib after delivery and 3) AdLib/FR, given AdLib during pregnancy and FR after delivery. On day 21 of lactation, male pups were killed by exsanguinations under anesthesia, and liver were removed immediately. The hepatic protein expression of sterol regulatory element binding protein 1 (SREBP1), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC ) and (ACC ) were measured by western blot analysis. RESULTS: As compared to the AdLib/AdLib group, liver weight was decreased in the AdLib/FR group (P 0.05) whereas the FR/AdLib group was not differed. The SREBP1 expression was higher in the AdLib/FR group than in the AdLib/AdLib and FR/AdLib groups (P 0.01). The FAS expression was lower in the FR/AdLib and AdLib/FR groups than in the AdLib/AdLib group (P 0.0001). The ACC expression was higher in the FR/AdLib group than in the AdLib/AdLib group (P 0.05). No ACC was detected in any groups. CONCLUSION: Our results suggest that maternal feed restriction during prenatal and early postnatal period could influence on changes of lipid metabolism in the liver of 3-week-old male pups. Moreover, these changes may independently affect to liver by when feed restriction has been occurred.

Long-term consequences of feed restriction during late pregnancy in goats on feeding behavior and emotional reactivity of female offspring

Feed restriction during pregnancy can have detrimental effects on offspring development both during the juvenile period and during adult life. Long-term effects of maternal feed restriction during the last third of pregnancy on growth, metabolism and behavior of female kids, with a focus on feeding behavior and emotional reactivity, were studied in goats. Female kids born to control (CONT, n=17) or born to feed restricted goats (REST, n=15) were artificially reared and monitored from birth to 24months of age. Maternal feeding restriction globally reduced live weight (P<0.001) and body condition score (P=0.02) of REST compared to CONT offspring. Females from the REST group had a higher daily feed intake (P=0.05) and tended to eat more rapidly (P=0.09) than females from the CONT group at 12months of age. One year later, REST goats still ate more than CONT goats (P=0.05). Glucose metabolism did not appear to be modified as no differences were observed in glucose or insulin responses to an intravenous glucose tolerance test. No differences in time budget were found at 12months of age. However, the HPA axis response to an ACTH injection was greater in REST than in CONT goats: higher peak cortisol concentration (P=0.02) and a greater area under the curve were found (P=0.01) at 14months of age. In conclusion, maternal feed restriction during late pregnancy modified both feeding behavior and the stress physiology of female offspring for up to 2years of age. However, the changes observed were small.

Short-term effects of maternal feed restriction during pregnancy on goat kid morphology, metabolism, and behavior1

Morphometric, metabolic, and behavioral modifications were studied in goat kids after maternal feed restriction during the last one-third of pregnancy. At birth, only kids from twin and triplet litters were studied [n=40 kids born to control dams (CONT) and n=38 born to restricted dams (REST)] and only males thereafter (n=13 CONT and 15 REST kids) until slaughter at 6 wk of age. Kids born to restricted goats had a smaller abdominal girth at birth (P<0.01) and tended to have a smaller body mass index (P=0.10) and a smaller density index (P=0.09) than kids born to CONT goats. Male REST kids had a lighter birth weight (P=0.03) than male CONT kids, but no differences (all P>0.10) were found for BW and morphometric measurements thereafter. Decreased NEFA concentrations suggested that male REST kids mobilized their body reserves less than CONT kids at birth (P<0.01). No modifications in drinking tests at 3 and 5 wk of age were observed, or in feeding behavior and emotional reactivity at 5 wk of age (all P>0.10). In conclusion, maternal feed restriction in the last one-third of pregnancy resulted in a decrease in birth size, but male kids rapidly caught up, and there were no changes in behavior, morphology, or metabolism during rearing.

Chronic maternal feed restriction impairs growth but increases adiposity of the fetal guinea pig.

Small size at birth has been associated with an increased risk of central obesity and reduced lean body mass in adult life. This study investigated the time of onset of prenatally induced obesity, which occurs after maternal feed restriction, in the guinea pig, a species that, like the human, develops substantial adipose tissue stores before birth. We examined the effect of maternal feed restriction [70% ad libitum intake from 4 wk before to midpregnancy, then 90% until day 60 gestation (term approximately 69 days)] on fetal growth and body composition in the guinea pig. Maternal feed restriction reduced fetal (-39%) and placental (-30%) weight at 60 days gestation and reduced liver, biceps muscle, spleen, and thymus weights, relative to fetal weight, while relative weights of brain, lungs, and interscapular and retroperitoneal fat pads were increased. In the interscapular depot, maternal feed restriction decreased the volume density of multilocular fat and increased that of unilocular fat, resulting in an increased relative weight of interscapular unilocular fat. Maternal feed restriction did not alter the relative weight of perirenal fat or the volume density of adipocyte populations within the depot but increased unilocular lipid locule size. Maternal feed restriction in the guinea pig is associated with decreased weight of major organs, including liver and skeletal muscle, but increased adiposity of the fetus, with relative sparing of unilocular adipose tissue. If this early-onset obesity persists, it may contribute to the metabolic and cardiovascular dysfunction that these offspring of feed-restricted mothers develop as adults.

Effect of maternal feed restriction during pregnancy on glucose tolerance in the adult guinea pig

Maternal nutrient restriction and impaired fetal growth are associated with postnatal insulin resistance, hyperinsulinemia, and glucose intolerance in humans but not consistently in other species, such as the rat or sheep. We therefore determined the effect of mild (85% ad libitum intake/kg body wt) or moderate (70% ad libitum intake/kg body wt) maternal feed restriction throughout pregnancy on glucose and insulin responses to an intravenous glucose tolerance test (IVGTT) in the young adult guinea pig. Maternal feed restriction reduced birth weight (mild and moderate: both P < 0.02) in male offspring. Moderate restriction increased plasma glucose area under the curve (P < 0.04) and decreased the glucose tolerance index (K(G)) (P < 0.02) during the IVGTT in male offspring compared with those of mildly restricted but not of ad libitum-fed mothers. Moderate restriction increased fasting plasma insulin (P < 0.04, adjusted for litter size) and the insulin response to IVGTT (P < 0.001), and both moderate and mild restriction increased the insulin-to-glucose ratio during the IVGTT (P < 0.003 and P < 0.02) in male offspring. When offspring were classed into tertiles according to birth weight, glucose tolerance was not altered, but fasting insulin concentrations were increased in low compared with medium birth weight males (P < 0.03). The insulin-to-glucose ratio throughout the IVGTT was increased in low compared with medium (P < 0.01) or high (P < 0.05) birth weight males. Thus maternal feed restriction in the guinea pig restricts fetal growth and causes hyperinsulinemia in young adult male offspring, suggestive of insulin resistance. These findings suggest that mild to moderate prenatal perturbation programs postnatal glucose homeostasis adversely in the guinea pig, as in the human.

Maternal-foetal adaptation to mid pregnancy feed restriction in single-bearing ewes

In two experiments, restriction of feed to levels below maintenance for periods of up to 4 weeks was imposed on groups of ewes bearing single foetuses at 79, 87 or 95 days post coitus. In the first experiment, carried out at pasture, measurements were made of concentration of ovine placental lactogen (oPL) and progesterone in ewe plasma. Effects on lamb birth weight and gestation length were also examined. The second experiment investigated the effect of maternal feed restriction of (i) feed intake, (ii) maternal oPL, (iii) maternal plasma glucose concentration, (iv) lamb birth weight and (v) gestation length. In the first experiment, there were no significant effects of feed restriction on lamb birth weight or gestation length, although foetal growth rate had been reduced in some treatment groups. There were significant interactions between time of sampling and treatment for oPL and progesterone concentration. Control group ewes had lower oPL (P&lt; 0.001) and progesterone (P &lt; 0.05) concentrations than restricted ewes at the end of feed restriction, but higher oPL (P &lt; 0.001) and progesterone (P &lt;0.05) concentrations at 144 days post coitus. In the second experiment, lamb birth weight and gestation length were not significantly affected by maternal feed restriction (birth weight: restricted 4.94 kg, control 4.87 kg av. s.e.m. 0.17 kg; gestation length: restricted 148.3 days, control 147.0 days, av. s.e.m. 0.76 days). Feed restriction was associated with increased (P &lt; 0.05) oPL and decreased glucose (P &lt; 0.05) concentration in plasma. Maternal feed intake was significantly higher (P &lt;0.05) in the restricted group in the week preceding lambing. These results strongly suggest that continuation of maternal feed intake over the last week of pregnancy is the major contributor to maintenance of 'normal' lamb birth weight in previously feed restricted ewes.