Nursing Period Research Articles

Intra-specific trophic variation in false killer whales (Pseudorca crassidens) from the southwestern South Atlantic Ocean through stable isotopes analysis

The false killer whale (Pseudorca crassidens) is a highly social top predator difficult to study in the wild because of its wide-ranging oceanic habits. Mass strandings offer good opportunities to gather ecological information about cetacean species. In this study we analyze a possible isotopic (δ13C and δ15N) variation in bone collagen among individual false killer whales that mass stranded on the south shore of the Strait of Magellan, Chile, in 1989, in relation to their ontogenetic classes, sex and total body length. We found an isotopic enrichment in δ13C and δ15N values from young and smaller to older and larger individuals, respectively. These isotopic shifts may reflect differences in foraging and diving capabilities, enabling older and larger individuals to feed more deeply in the water column and/or on larger prey. The lack of isotopic differences between females and males may suggests little evidence for sex-related resource partitioning in this group, as result of a possible coordination during feeding activities, e.g. food sharing as previous studies have found. We also found an important isotopic effect of lactation in both the carbon and nitrogen isotope composition of nursing calves, probably due to a prolonged nursing period (from 19 month to two years). This study integrate ecological information from several years to lifetime in relation to sex and total body length, obtaining information on possible changes linked to the development of foraging capabilities in false killer whale.

The Intrauterine and Nursing Period Is a Window of Susceptibility for Development of Obesity and Intestinal Tumorigenesis by a High Fat Diet inMin/+Mice as Adults

We studied how obesogenic conditions during various life periods affected obesity and intestinal tumorigenesis in adult C57BL/6J-Min (multiple intestinal neoplasia)/+ mice. The mice were given a 10% fat diet throughout life (negative control) or a 45% fat diet in utero, during nursing, during both in utero and nursing, during adult life, or during their whole life-span, and terminated at 11 weeks for tumorigenesis (Min/+) or 23 weeks for obesogenic effect (wild-type). Body weight at 11 weeks was increased after a 45% fat diet during nursing, during both in utero and nursing, and throughout life, but had normalized at 23 weeks. In the glucose tolerance test, the early exposure to a 45% fat diet in utero, during nursing, or during both in utero and nursing, did not affect blood glucose, whereas a 45% fat diet given to adults or throughout life did. However, a 45% fat diet during nursing or during in utero and nursing increased the number of small intestinal tumors. So did exposures to a 45% fat diet in adult life or throughout life, but without increasing the tumor numbers further. The intrauterine and nursing period is a window of susceptibility for dietary fat-induced obesity and intestinal tumor development.

Purple Grape Juice, an Important Flavonoids Source, Influence in Biochemical Parameters in Offspring of Wistar Rats

Our objective was to evaluate the effect of chronic gestational treatment and post-breast feeding with purple grape juice on the biochemical parameters in offspring of dams. We used 40 male offspring from 14 Wistar rats which received purple grape juice or water by gavage daily for 42 days at a dose of 7 microliters/g. The offspring were divided into groups of water or juice. All received daily purple grape juice or water by gavage for 30 days after completion of their nursing period at a dose of 7 microliters/g. At the end of the treatment period, the offspring were euthanized by decapitation with its truncal blood collected and subsequently separated the serum from the blood. The measurements were performed by automation or by manual dosing. Considering the gestational factor, grape juice was able to reduce levels of total cholesterol, triglycerides, urea, alanine aminotransferase (ALT), and not alter the levels of creatinine and aspartate aminotransferase (AST) in serum of the offspring. When considering the post-breast feeding factor, grape juice resulted in an improvement in HDL-C. We concluded that purple grape juice was able to produce a beneficial effect on certain biochemical parameters in offspring.

Antisense versus proopiomelanocortin mRNA reduces vascular risk in a murine model of type-2 diabetes following stress exposure in early post-natal life

Mechanisms of vascular complications in type-2 diabetes patients and animal models are matter of debate. We previously demonstrated that a double-stress model applied to male mice during nursing period produces enduring hyperfunction of endogenous opioid and adrenocorticotropin (ACTH)-corticosteroid systems, accompanied by type-2 diabetes-like alterations in adult animals. Administration of the opioid receptor antagonist naloxone, or of an antisense oligodeoxynucleotide versus proopiomelanocortin mRNA, capable to block the pro-opiomelanocortin-derived peptides β-endorphin and ACTH, selectively prevent these alterations. Here, we investigated alterations produced by our stress model on aorta endothelium-dependent relaxation and contractile responses. Mice, stressed during nursing period, showed in the adulthood hormonal and metabolic type-2 diabetes-like alterations, including hyperglycemia, increased body weight and increased plasma ACTH and corticosterone levels. Ex vivo isolated aorta rings, gathered from stressed mice, were less sensitive to noradrenaline-induced contractions versus controls. This effect was blocked by nitric-oxide synthase-inhibitor l-NG-nitroarginine added to bath organ solution. Aorta rings relaxation caused by acetylcholine was enhanced in stressed mice versus controls, but following treatment with the nitric-oxide donor sodium nitroprusside, concentration-relaxation curves in aorta from stressed groups were similar to controls. Therefore, vascular response alterations to physiologic-pharmacologic stimuli were apparently due to nitric-oxide hyperfunction-dependent mechanisms. Aorta functional alterations, and plasma stress hormones enhancement, were prevented in mice stressed and treated with antisense oligodeoxinucleotide, addressed to reduce ACTH- and corticosteroid-mediated hyperfunction. This study demonstrates the key role of ACTH-corticosteroid axis hyperfunction for the triggering of vascular conditions in male adult rodents following postnatal stress in a type-2 diabetes model.

Jealous of mom? Interactions between infants and adult males during the mating season in wild squirrel monkeys (<i>Saimiri collinsi</i>)


 
 
 Squirrel monkeys (Saimiri collinsi) are seasonal breeders that live in large social groups in which females are dominant to males. Females have one infant per year, and the nursing period lasts six to eight months. Preliminary observations in the wild indicated that during the mating period (eight weeks: July and August in our population), the infants show agonism directed at males who approach their mothers. This directed sexual interference by infants has rarely been reported for neotropical primates. Our study reports observations in a natural population of Saimiri collinsi with the aim of describing the social behavior of infants during the breeding season, especially with regard to adult males in the group. Infants of both sexes were observed during three mating periods (2011, 2012, 2013), to test hypotheses about the possible function of infant harassment directed at adult males. The behavior of infants (variables: activity and nearest neighbor) was sampled by the focal animal method as well as ad libitum observations. We recorded 99 cases of agonism and 17 cases of tolerance between nearby males and infants via the all-occurrence method. Thus, 85% of interactions between adult males and infants involved agonism. These results suggest that infant interference can present a cost to adult males during the breeding season.
 
 

Duration of breastfeeding and serum PCB 153 concentrations in children

Polychlorinated biphenyls (PCBs) are toxic, persistent, and bioaccumulative chemicals which, because of their lipophilic properties, are abundant in human breast milk. Breastfed infants are therefore at risk of being exposed to considerable amounts of PCBs. The commonly used exposure estimations, based solely on breast milk PCB levels and duration of breastfeeding, may lead to exposure misclassification. To improve assessments of exposure to PCBs, we determined PCB 153 serum concentration, as a model substance for PCBs, at the critical time of weaning for each child in 305 breastfed infants from 5 single time point concentration measurements spread over 7 years and data on duration of breastfeeding, using an earlier developed model of the system type. We approximated the dependence of PCB 153 serum concentration, Ctbf, adjusted to cord serum concentration, C0, on nursing period, by a polynomial function Ctbf/C0=0.596+0.278t−0.0047t2 which reliably predicts exposure to PCB 153 of breastfed infants, important for assessment of dose-outcome relationships. Adjustment of current serum concentrations to cord serum concentration improved validity of exposure assessment.

Suckling induces a daily rhythm in the preoptic area and lateral septum but not in the bed nucleus of the stria terminalis in lactating rabbit does

Maternal behavior in the rabbit is restricted to a brief nursing period every day. Previously, we demonstrated that this event induces daily rhythms of Period1 (PER1) protein, the product of the clock gene Per1, in oxytocinergic and dopaminergic populations in the hypothalamus of lactating rabbit does. This is significant for the periodic production and ejection of milk, but the activation of other areas of the brain has not been explored. Here, we hypothesised that daily suckling would induce a rhythm in the preoptic area, lateral septum, and bed nucleus of the stria terminalis, which are important areas for the expression of maternal behavior in mammals, including the rabbit. To this end, we analysed PER1 expression in those areas through a complete 24-h cycle at lactation day 7. Does were scheduled to nurse during either the day at 10:00 h [zeitgeber time (ZT)03] or the night at 02:00 h (ZT19). Non-pregnant, non-lactating females were used as controls. In contrast to control females, lactating does showed a clear, significant rhythm of PER1 that shifted in parallel with the timing of nursing in the preoptic area and lateral septum. We determined that the maximal expression of PER1 at 8 h after scheduled nursing decreased significantly at 24 and 48 h after the absence of suckling. This effect was more pronounced in the lateral septum than in the preoptic area. We conclude that daily suckling is a powerful stimulus inducing rhythmic activity in brain structures in the rabbit that appear to form part of a maternal entrainable circuit.

Stocking density-dependent growth and survival of Asian red-tailed catfish (Hemibagrus wyckioides) fries: early nursing in cages

Asian red-tailed catfish (Hemibagrus wyckioides) were raised at five different stocking densities in cages (submerged and with a volume of 1 m3) suspended in a fish pond from July to August 2012. H. wyckioides fries (mean weight 0.8 ± 0.1 g) were stocked at densities of 25, 50, 100, 200, and 400 fish/m3. At the end of 56 days, the mean fish weights among the stocking densities of 25 and 50 fish/m3 were significantly lower than those of the 100, 200, and 400 fish/m3 density. The specific growth rates and final mean weights amongst fish reared in higher stocking densities of 100, 200, and 200 fish/m3 were higher than those of the low stocking densities of 25 and 50 fish/m3. Asian river catfish performed poorly at the lowest density. The results indicate an initial lower stocking threshold for Asian red-tailed catfish fries of above 100 fish/m3. The Asian red-tailed catfish fries reared in small cages placed in a pond reached the size 5–6.6 g within a 56-day nursing period.

Mother/Offspring Co-administration of the Traditional Herbal Remedy Yokukansan During the Nursing Period Influences Grooming and Cerebellar Serotonin Levels in a Rat Model of Neurodevelopmental Disorders

Neurodevelopmental impairment in the serotonergic system may be involved in autism spectrum disorder. Yokukansan is a traditional herbal remedy for restlessness and agitation in children, and mother-infant co-administration (MICA) to both the child and the nursing mother is one of the recommended treatment approaches. Recent studies have revealed the neuropharmacological properties of Yokukansan (YKS), including its 5-HT1A (serotonin) receptor agonistic effects. We investigated the influence of YKS treatment on behavior in a novel environment and on brain monoamine metabolism during the nursing period in an animal model of neurodevelopmental disorders, prenatally BrdU (5-bromo-2'-deoxyuridine)-treated rats (BrdU-rats). YKS treatment did not influence locomotor activity in BrdU-rats but reduced grooming in open-field tests. YKS treatment without MICA disrupted the correlation between locomotor behaviors and rearing and altered levels of serotonin and its metabolite in the cerebellum. These effects were not observed in the group receiving YKS treatment with MICA. These data indicate a direct pharmacological effect of YKS on the development of grooming behavior and profound effects on cerebellar serotonin metabolism, which is thought to be influenced by nursing conditions.

Educational game of medication administration: a validation study

This is a methodological research, which aimed to determine the validity of an educational technology (ET) in the form of educational game of medicine administration, according to the judges and audience, using the theoretical stage of Pasquali model. Data were collected between September 2011 and May 2012 in two stages: 1) application and validation of TE by forty students of the 4th period of Nursing, at the Fluminense Federal University (target audience); 2) observation and validation of TE by 8 teachers (judges). The questionnaires were organized in Likert scale, with items distributed in blocks and analyzed quantitatively. The game was validated, since it has over 80% approval by the two groups, and may therefore be used as a TE in the discipline of Fundamentals of Nursing. The results were positive, demonstrating that students and teachers are more interested in content taught when most dynamic technologies are used in the classroom.

Treatment of Crohn's disease in pregnant women: drug and multidisciplinary approaches.

Inflammatory bowel disease affects a substantial number of women in their reproductive years. Pregnancy presents a number of challenges for clinicians and patients; the health of the baby needs to be balanced with the need to maintain remission in the mother. Historically, treatments for Crohn's disease (CD) were often discontinued during the pregnancy, or nursing period, due to concerns about teratogenicity. Fortunately, observational data has reported the relative safety of many agents used to treat CD, including 5-aminosalicylic acid, thiopurines, and tumor necrosis factor. Data on the long-term development outcomes of children exposed to these therapies in utero are still limited. It is most important that physicians educate the patient regarding the optimal time to conceive, discuss the possible risks, and together decide on the best management strategy.

Development of the circadian clockwork in the kidney.

The circadian molecular clock is an internal time-keeping system composed of centrally synchronized tissue-level pacemakers. Here, we explored the ontogeny of the clock machinery in the developing kidney. Pregnant rats were housed at 12-12 h light-dark cycles. Offsprings were killed at 4-h intervals on embryonic day 20 and at postnatal weeks 1, 4, and 12. Canonical clock gene (Clock, Bmal1, Rev-erbα, Cry1, Cry2, Per1, Per2) and kidney-specific clock-controlled gene (αENaC, SGK1, NHE3, AVPR2) expression was profiled by RT-PCR. To investigate the role of nutritional cues, the feeding pattern was modified postpartum. Clock, Rev-erbα, Per2, αENaC, SGK1, NHE3, and AVPR2 showed circadian expression at the end of intrauterine development. By 1 week, all genes oscillated with a distinct acrophase shift toward the time of peak feeding activity. Daily 4-hour withdrawal of mothers induced a 12-hour phase shift of Clock and Bmal1 expression, while disrupting oscillations of the other genes. After weaning, oscillation phases shifted back toward the adult pattern, which was fully expressed at 12 weeks. Thus, functional circadian molecular clockwork evolves in the late fetal and early postnatal kidney. During the nursing period, oscillations are entrained by nutritional cues. The coupling of the circadian expression of tubular regulators of fluid and electrolyte excretion to the feeding-entrained clockwork may be important to maintain homeostasis during this critical period.

When the Nose Must Remain Responsive: Glutathione Conjugation of the Mammary Pheromone in the Newborn Rabbit

In insects, xenobiotic-metabolizing enzymes were demonstrated to regulate pheromones inactivation, clearing them from the olfactory periphery and keeping receptors ready for stimulation renewal. Here, we investigate whether similar processes could occur in mammals, focusing on the pheromonal communication between female rabbits and their newborns. Lactating rabbits emit in their milk a volatile aldehyde, 2-methylbut-2-enal, that elicits searching-grasping in neonates; called the mammary pheromone (MP), it is critical for pups which are constrained to find nipples within the 5 min of daily nursing. For newborns, it is thus essential to remain sensitive to this odorant during the whole nursing period to display several actions of sucking. Here, we show that the MP is enzymatically conjugated to glutathione in newborn olfactory epithelium (OE), in accordance with the high mRNA expression of glutathione transferases evidenced by quantitative reverse transcription-PCR. This activity in the nose is higher than in the liver and in OE of newborns compared with weanlings (no more responsive to the pheromone). Therefore, the results pinpoint the existence of a high level of MP-glutathione conjugation activity in the OE of young rabbits, especially in the developmental window where the perceptual sensitivity toward the MP is crucial for survival.

Temporal proteomic analysis reveals defects in small-intestinal development of porcine fetuses with intrauterine growth restriction

The fetus/neonate with intrauterine growth restriction (IUGR) has a high perinatal mortality and morbidity rate, as well as reduced efficiency for nutrients utilization. Our previous studies showed alterations of intestinal proteome in IUGR piglets both at birth and during the nursing period. Considering the potential long-term impacts of fetal programming and substantial increases in amounts of amniotic fluid nutrients from mid-gestation in pigs, the present study involved IUGR porcine fetuses from days 60 to 110 of gestation (mid to late gestation). We identified 59 differentially expressed proteins in the fetal small intestine that are related to intestinal growth, development and reprogramming. Our results further indicated increased abundances of proteins and enzymes associated with oxidative stress, apoptosis and protein degradation, as well as decreased abundances of proteins that are required for maintenance of cell structure and motility, absorption and transport of nutrients, energy metabolism, and protein synthesis in the fetal gut. Moreover, IUGR from middle to late gestation was associated with reduced expression of intestinal proteins that participate in regulation of gene expression and signal transduction. Collectively, these findings provide the first evidence for altered proteomes in the small intestine of IUGR fetuses, thereby predisposing the gut to metabolic defects during gestation and neonatal periods.

Estimation of External Radiation Dose to Caregivers of Patients Treated with Radioiodine after Thyroidectomy

Due to the remarkable increase in thyroid cancer cases, the number of patients treated with radioiodine (I) shows a sharply increasing trend in recent years. Accordingly, radiation exposure of other people, particularly caregivers or comforters, after release of patients from hospitals is getting more attention than ever. In the present study, empirical equations are proposed for estimation of doses to caregivers. Only patients administered with therapeutic amounts of ¹³¹I after thyroidectomy were considered. External radiation doses to 70 caregivers or family members were measured using thermoluminescence dosimeters (TLDs). The mean, external, effective dose to caregivers, during a nursing period of 5-9 d after patient quarantine for 3-4 d in the hospital, was 0.12 ± 0.10 mSv. This is only 2.5% of the dose limit recommended by the International Commission on Radiological Protection for caregivers. By analyzing those individual doses to the caregivers, values of a factor affecting caregiver doses, K, are obtained for use in estimation of caregivers' doses. The factor reflects the degree of engagement of the caregiver to the patient, and hence it is named the "engagement factor." The mean value of the engagement factor in this study was 1.3 ± 0.88. With the help of the engagement factor, the total external dose to a caregiver can be estimated as 1.1 × Q₀ × e⁻⁰·⁰⁵(Tr) mSv, where Q₀ is the administered activity of ¹³¹I (GBq) and T(r) is the patient's release time (h) after admistration of radioiodine. Based on the dose estimation model developed in this study, by comparing the cost of extended quarantine against that incurred by release of the patient, including the burden of radiation exposure of caregivers or family members, the reasonableness of current quarantine periods was revisited. It was found that the dichotomous policy (i.e., hospitalizing patients administered ¹³¹I over 1.1 GBq for a period of 3-4 d compared with treating other patients administered below 1.1 GBq as outpatients) is unjustifiable; this is particularly true for those treated with a few GBq. Based upon the dose estimation model presented herein, tables suggesting an appropriate quarantine period depending upon the activity of the administered ¹³¹I are provided for use as reference in deciding when to release patients treated with therapy levels of ¹³¹I after thyroidectomy.

Experimental Nonalcoholic Steatohepatitis Induced by Neonatal Streptozotocin Injection and a High-Fat Diet in Rats.

Nonalcoholic steatohepatitis (NASH) has become a major concern in clinical hepatology. To elucidate the disease mechanisms and to develop a treatment, the advent of an appropriate experimental model is crucial. Pregnant Sprague-Dawley rats were fed a high-fat diet from gestational day 16. Two days after birth, the neonates were injected subcutaneously with streptozotocin (STZ) (180, 200, or 256 mg/kg). The mothers were fed a high-fat diet during the nursing period. After being weaned (4 weeks of age), the juvenile rats were fed the same high-fat diet. The survival rates at the time of weaning were 25.6% (180 mg/kg STZ), 22.8% (200 mg/kg STZ), and 19.4% (256 mg/kg STZ). The mean body weight of NASH rats was approximately 20% less than that of normal rats. Serum levels of glucose, alanine aminotransferase, and hyaluronic acid increased in NASH rats. Histologically, typical features of steatohepatitis such as ballooning, inflammatory cell infiltration, and perivenular and pericellular fibrosis were observed. In an indocyanine green loading test, the blood half-life was significantly longer in NASH rats (5.04 ± 2.14 vs. 2.72 ± 0.72 min; p < 0.05), which was suggestive of an impaired hepatobiliary transportation function. Concomitantly, biliary ICG concentrations in NASH rats stabilized in a delayed fashion compared with normal rats. In addition, the amount of bile excreted in NASH rats was significantly lower than that in normal rats (4.32 ± 0.83 vs. 7.66 ± 1.05 mg/min; p < 0.01). The rat NASH model presented here mimics the clinical features of the disease and will be a helpful tool for medical and bioscience research.

Impact of rearing mangement on health in domestic rabbits: a review

High mortality in rabbit rearing is not only an economical problem but also an animal welfare issue. Without doubt, certain common rearing practices are the main reasons for the high mortality rates. In this review, we point out different and commonly used management practices, which neither represent adequate housing conditions for the animals’ behavioural requirements nor correspond to their nutritional needs, and discuss possibilities to reduce the risk of disease. (1) Usually the doe is forced to build the nursery nest in the cage or in a box with a permanently open entrance, often not protected from the light. This can lead to perinatal mortality due to disturbed maternal behaviour, such as failure to build a proper nest, depositing the kits outside the nest, or infanticide. (2) Continuous housing of the doe with the kits does not conform to this species’ pattern of unusually limited maternal care. Stimulated by olfactory and acoustic signals emanating from the nest, the doe disturbs the inactivity of the kits by her frequent entries to the nest or attempts to close the entrance. Cooling of the kits caused by maladaptive maternal behaviour under such unnatural conditions is one of the most important causes of mortality and morbidity during the nursing period. (3) When the doe is left to nurse the kits for longer than four weeks, which does not conform to the reproductive biology of the rabbit, kit morbidity is caused by the following factors: (a) Prolonged mother-offspring contact increases the risk of the kits becoming infected with pathogens such as coccidiosis, EPEC and pasteurellosis persisting in the doe. (b) Pre-disposition of the kits to bacterial enteropathies is encouraged by the retarded development of the enzymatic system, delayed establishment of a stable gut flora (due to the use of wood shavings or straw as nest material) and by consumption of the doe’s feed. (c) The increased energy demands of lactation as well as mastitis due to excessive and prolonged suckling by the kits decrease the fertility and the lifespan of the doe. (4) Feed with a high non-fibre carbohydrate content (compared to green forage) promotes bacterial enteropathies when given before the development of the kits’ digestive functions is completed. In addition, the risk of the outbreak of such diseases is enhanced by intestinal coccidiosis and unstable gut flora. (5) In contrast to housing rabbits on perforated floors, the use of cages with deep litter increases the risk of enteropathies.

Providing elevated ‘getaway bunks’ to nursing mink dams improves their health and welfare

Farmed mink infants (Neovison vison) remain with their mothers beyond natural weaning age. This benefits their welfare, but can stress their mothers and contribute to illness (e.g. ‘nursing sickness’). European studies have explored augmenting cages with structures allowing mothers to get away from their infants (‘kits’); these show that if provided with high, shelf-like structures permitting rest away from kits, dams utilise them. Here, we assessed the benefits of providing an elevated ‘getaway bunk’ – a wire-mesh half-cylinder attached to the cage ceiling – to 80 Black dams on an Ontario farm. Controls comprised nursing females without bunks (n=80), and barren females given bunks (n=40). Behaviour was observed daily over kit ages 23–42 days. Mothers were removed from litters at 42 days (typical for North American farms), at which time health and production parameters were recorded. Mothers used bunks approximately half as much as barren dams, but their bunk-use increased as kits aged, up to c. 7% scans (c. 30min per observation day). Seasonal changes in temperature did not explain this pattern. Bunks increased maternal rest (from 78.9 to 82.3% of scans; c. 16min per observation day), and increased the time spent with teats inaccessible to kits by a similar amount. Dams with bunks showed approximately one third less stereotypy (3.7% scans, compared to 5.4% in bunkless controls): a reduction most evident when kits were aged 30–42 days, when infants transition from milk to water and solid food; and, although apparently not protected from nursing sickness, at the end of lactation they were less likely to have swollen, red and/or crusty teats (which thermal imaging also showed were significantly hotter), suggesting less mastitis. Such benefits seemed particularly strong in multiparous dams: effects of bunks on teat health and stereotypy as a proportion of activity (not scans) were significant in older dams but not first-time mothers when analysed separately. Kits’ suckling opportunities and time spent nursing were not significantly reduced by the bunks, however; nor did bunks compromise kit survivorship or weights at 42 days. Elevated bunks can thus enhance mink mothers’ welfare during the nursing period, seemingly without serious drawbacks for their kits. Unexpectedly, however, all study dams had very high mortality (>20%; more than triple that of non-experimental animals on the farm), suggesting that repeated live observation, or being housed close to barren dams, may elevate risks of nursing sickness.

Reproductive performance in pigs reared under organic conditions compared with conventionally reared pigs

BackgroundTo achieve a competitive reproductive performance in organic pig farming is a major challenge for this farming practise. Practices and research data regarding conventional pig production are not always applicable to organic production, why field studies are needed to identify differences in performance between organic and conventional pig farms in order to identify areas for improvement.ResultsPerformance data for one year was collected from 5 organic herds that had more than 30 sows in production and used a computerized recording system, and data from five nearby conventional farms with more than 30 sows and the same recording system were used as a comparison. In total data from 4697 farrowings were analyzed. In the organic pig herds, there were a higher total number of piglets born per litter (p=0.001), a higher number of piglets stillborn per litter (p<0.001), but a tendency (p<0.06) to lower number of weaned pigs per litter and longer nursing period (p<0.001) and farrowing interval (p<0.001).ConclusionsThe reproductive performance was lower in the organic herds and the variation in reproductive performance among the organic herds was larger than among the conventional ones, suggesting options for improvement in the organic herds.

Fish oil supplementation for two generations increases insulin sensitivity in rats

We investigated the effect of fish oil supplementation for two consecutive generations on insulin sensitivity in rats. After the nursing period (21 days), female rats from the same prole were divided into two groups: (a) control group and (b) fish oil group. Female rats were supplemented with water (control) or fish oil at 1 g/kg body weight as a single bolus for 3 months. After this period, female rats were mated with male Wistar rats fed on a balanced chow diet (not supplemented). Female rats continued to receive supplementation throughout gestation and lactation periods. The same treatment was performed for the next two generations (G1 and G2). At 75 days of age, male offspring from G1 and G2 generations from both groups were used in the experiments. G1 rats did not present any difference with control rats. However, G2 rats presented reduction in glycemia and lipidemia and improvement in in vivo insulin sensitivity (model assessment of insulin resistance, insulin tolerance test) as well as in vitro insulin sensitivity in soleus muscle (glucose uptake and metabolism). This effect was associated with increased insulin-stimulated p38 MAP kinase phosphorylation and lower n-6/n-3 fatty acid ratio, but not with activation of proteins from insulin signaling (IR, IRS-1 and Akt). Global DNA methylation was decreased in liver but not in soleus muscle. These results suggest that long-term fish oil supplementation improves insulin sensitivity in association with increased insulin-stimulated p38 activation and decreased n-6:n-3 ratio in skeletal muscle and decreased global DNA methylation in liver.