Pre- and Postnatal Predator Cues Shape Offspring Anti-predatory Behavior Similarly in the Bank Vole

Prey animals can assess the risks predators present in different ways. For example, direct cues produced by predators can be used, but also signals produced by prey conspecifics that have engaged in non-lethal predator-prey interactions. These non-lethal interactions can thereby affect the physiology, behavior, and survival of prey individuals, and may affect offspring performance through maternal effects. We investigated how timing of exposure to predation-related cues during early development affects offspring behavior after weaning. Females in the laboratory were exposed during pregnancy or lactation to one of three odor treatments: (1) predator odor (PO) originating from their most common predator, the least weasel, (2) odor produced by predator-exposed conspecifics, which we call conspecific alarm cue (CAC), or (3) control odor (C). We monitored postnatal pup growth, and we quantified foraging and exploratory behaviors of 4-week-old pups following exposure of their mothers to each of the three odour treatments. Exposure to odors associated with predation risk during development affected the offspring behavior, but the timing of exposure, i.e., pre- vs. postnatally, had only a weak effect. The two non-control odors led to different behavioral changes: an attraction to CAC and an avoidance of PO. Additionally, pup growth was affected by an interaction between litter size and maternal treatment, again regardless of timing. Pups from the CAC maternal treatment grew faster in larger litters; pups from the PO maternal treatment tended to grow faster in smaller litters. Thus, in rodents, offspring growth and behavior are seemingly influenced differently by the type of predation risk perceived by their mothers.

Change in the Physiological and Biochemical Aspects of Tomato Caused by Infestation by Cryptic Species of Bemisia tabaci MED and MEAM1

Infestation by Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes damage to tomatoes with production losses of up to 100%, affecting the physiological and biochemical aspects of host plants. The objective of this study was to analyze the influence of infestation of cryptic species of B. tabaci MED and MEAM1 on the physiological and biochemical aspects of tomato. Tomato plants ‘Santa Adélia Super’ infested with B. tabaci (MED and MEAM1), and non-infested plants were evaluated for differences in gas exchange, chlorophyll - a fluorescence of photosystem II (PSII), and biochemical factors (total phenols, total flavonoids, superoxide dismutase—SOD, peroxidase—POD, and polyphenol oxidase—PPO). Plants infested with B. tabaci MED showed low rates of CO2 assimilation and stomatal conductance of 55% and 52%, respectively. The instantaneous carboxylation efficiency was reduced by 40% in MED and by 60% in MEAM1 compared to the control. Regarding biochemical aspects, plants infested by MED cryptic species showed high activity of POD and PPO enzymes and total phenol content during the second and third instars when compared to control plants. Our results indicate that B. tabaci MED infestation in tomato plants had a greater influence than B. tabaci MEAM1 infestation on physiological parameters (CO2 assimilation rate (A), stomatal conductance (gs), and apparent carboxylation efficiency (A/Ci)) and caused increased activity of POD and PPO enzymes, indicating plant resistance to attack. In contrast, B. tabaci MEAM1 caused a reduction in POD enzyme activity, favoring offspring performance.

Maternal and paternal age effects on male antler flies: a field experiment

In many species, parental age at reproduction can influence offspring performance and lifespan, but the direction of these effects and the traits affected vary among studies. Data on parental age effects are still scarce in non-captive populations, especially insects, despite species such as fruit flies being models in laboratory-based aging research. We performed a biologically relevant experimental manipulation of maternal and paternal age at reproduction of antler flies (Protopiophila litigata) in the laboratory and tracked the adult lifespan and reproductive success of their male offspring released in the wild. Increased paternal, but not maternal, age somewhat increased sons’ adult lifespan, while parental ages did not influence sons’ mating rate or reproductive senescence. Our results indicate that while parental age effects do exist in an insect in the field, they may be beneficial in such a short-lived animal, in contrast to results from most wild vertebrates and laboratory invertebrates.

195 Maternal Impact on Fetal Muscle and Adipose Tissue Development

Tissues and organs are actively developing during the fetal stage, which is sensitive to nutritional alteration and exerts long-term impacts on offspring performance. Both muscle and adipose tissue are derived from the dermomyotome during the early embryonic stage, and their common origins provide an opportunity to promote myogenic instead of adipogenic differentiation, which enhances the lean/fat ratio of offspring. In previous studies with sheep and cattle, we found that maternal nutrient deficiency reduces fetal myogenesis and the lean/fat ratio of offspring. Stress is common in animals during pregnancy, and we examined the impacts of maternal stress induced by dexamethasone on fetal muscle and adipose development. We found that maternal stress impairs fetal muscle and brown adipose tissue (BAT) development. Mechanistically, we found that maternal stress suppresses mitochondrial biogenesis during fetal muscle and BAT development by elevating DNA methylation in the promoter of peroxisome proliferator-activated receptor-gamma coactivator α (PGC-1α), which persists in offspring muscle and BAT, generating lasting effects on the functions of muscle and adipose tissue. In short, available data clearly show that maternal nutrition and other physiological factors have profound impacts on fetal development, which programs offspring performance. Understanding related mechanisms are important for effective and precise management of animals during gestation in order to enhance production efficiency of offspring.

Beef cow weight variations during gestation and offspring performance: a meta-analysis

The objective of this meta-analysis was to evaluate the effects of weight loss or weight gain of beef cows during the second and/or third trimester of gestation on the postnatal performance of the progeny. The variation in cow weight during the gestational period was calculated to standardize the treatments, being them: severe loss (SL = cows that lost more than 10% of weight); moderate loss (ML = cows that lost from 0 to 10% of weight) and weight gain (WG = cows that gained weight). The intensity of the cow weight variation effect was calculated as the mean difference (MD) with a 95% confidence interval and heterogeneity determined using the Q test and the I2 statistic. A meta-analysis of random effects was conducted for each indicator separately with the means of the control and experimental groups. Calves from WG cows were higher for birth weight (P = 0.0094); weight adjusted to 205 days (P = 0.0127) and average daily gain during pre-weaning (P < 0.0001) in relation to calves from ML cows. The W205 of calves from SL cows was 11.6 kg lower than the progeny from ML cows. The post-weaning performance of the progeny tended (P = 0.0868) to be higher in the progeny of WG cows than ML ones. The weight gain of beef cows during gestation improves the pre- and post-weaning performance of the progeny, with more evident effects in the early months of life of the offspring.

220 Effects of Actisaf HR+ SC47 Live Yeast Probiotic Fed at Two Levels to Sows on Offspring Performance Before and After Weaning

750 sows (PIC line 42) were used to evaluate the effects of ActiSaf HR+ SC47 live yeast probiotic (AS) on sow and litter performance when fed to sows and their weaned piglets (PIC line 42 x 359). 250 multiparous sows per treatment (average parity 3.6) were fed the control diet without a live yeast probiotic (NC) or a diet with 250 mg/kg AS from breeding through lactation (LY1) or 250 mg/kg AS during gestation and 500 mg/kg AS during lactation. Weaned pigs from these sows were subsequently fed 4-phase nursery diets containing 0 (wNC) or 1 g/kg AS from d 0–10 after weaning followed by 500 mg/kg AS (wLY) from d 10–42 after weaning. This provided a 3x2 nursery trial design. During lactation, number of pigs born; born live varied by treatment (P &lt; 0.05). After weaning, wLY fed pigs had lower BW on d 12, 23; d 0–12 ADG, ADFI, lower d 0–42 ADFI and $/kg gained (P &lt; 0.05). Pigs fed wLY after weaning also tended towards lower d 42 BW and d 0–42 ADG (P &lt; 0.06; Table 1). Conversely, weaned pigs from sows fed LY1 or LY2 had higher ADG and ADFI from d 0–12 and d 0–42 after weaning (P &lt; 0.05) versus pigs from sows fed NC. Pigs from sows fed LY1 or LY2 also had higher BW at d 12, 23, and 42 after weaning than pigs from sows fed NC. Pigs from sows fed LY1 and LY2 tended to have lower nursery $/kg gain (P &lt; 0.06) than pigs from sows fed NC. No significant interactions were observed. Feeding ActiSaf HR+ SC47 live yeast probiotic to gestating and lactating sows improved their weaned pigs’ growth performance and tended to improve piglet cost of production after weaning.

508 Late-Breaking: Heritability and Validation of Sow Uterine Prolapse in the United States

Uterine prolapse impacts animal welfare and reduces sow farm profitability. In general, the incidence of uterine prolapse is higher in the United States than in other countries. Some suspected causes of uterine prolapse include water quality, vitamin deficiency, mycotoxins, and genetics. The objectives of this study were to: 1.) estimate the heritability of uterine prolapse; and 2.) to validate estimated breeding values (EBVs) for uterine prolapse in an independent, related population. Prolapse records collected from purebred females at a commercial multiplier (n = 16,434) and nucleus farm (n = 4,096) were used for training and validation, respectively. Phenotypes were recorded as the presence/absence of uterine prolapse at the sow level. Heritability estimates were derived from the training dataset by fitting year-season of insemination and parity at removal of the sow as fixed effects and animal as a random effect. Using the same model, validation was performed by regressing corrected offspring performance on sire EBV in the validation dataset. A pedigree- and a genomics-based relationship matrix were used for parameter estimation and the validation analysis, respectively. Incidence of uterine prolapse was heritable at 0.15 ± 0.02 and 0.22 ± 0.02 when analyzed using a linear vs. threshold model, respectively. Regression of corrected offspring performance on sire EBV resulted in a slope parameter of 0.40 (95%-CI; 0.27 - 0.54, including the expected value of 0.5), indicating that sire EBV is predictive of uterine prolapse among his offspring. In conclusion, these results show that uterine prolapse is lowly-to-moderately heritable, and therefore, mainly due to environmental factors. Higher incidence of uterine prolapse within the United States vs. other geographic locations confirms the existence of a strong environmental component. Genetic selection can be used to address genetic factors, but identifying/mitigating environmental triggers remains critical to reducing the incidence of uterine prolapse within the U.S. swine industry.