Gestation Length Research Articles

Genetic correlation estimates between calving ease in primiparous cows and economically important traits in Nellore cattle.

This study aimed to estimate (co)variance components and genetic parameters for calving ease (CE) and their genetic correlations with growth, reproductive, carcass, and feed efficiency traits in Nellore cattle. Phenotypes for CE are scored in two categories: normal calving and assisted calving. The traits considered were probability of precocious calving, age at first calving, stayability, adjusted scrotal circumference at 365 days of age, accumulated cow productivity, age at puberty of males, gestation length, birth weight, adjusted weights at 210 and 450 days of age, adult cow weight, frame score, hip height, rib eye area, subcutaneous backfat thickness, rump fat thickness, intramuscular fat percentage, residual feed intake and dry matter intake. The estimation of genetic parameters was performed using a two-trait threshold-linear animal model, except for CE, stayability, and probability of precocious calving, which were evaluated through a two-trait threshold animal model. The direct (0.27) and maternal (0.19) heritability estimates for CE in heifers primiparous Nellore indicated that selecting for this trait is feasible. The selection to improve the female sexual precocity should consider CE during the selection and mating decisions to reduce calving problems. Genetic correlation estimates between CE and BW suggest that selecting low birth weight to reduce calving problems is not an appropriate strategy to improve calving ease in heifers Nellore. Therefore, adopting a multi-trait selection model with CE and BW in the Nellore breed would reduce calving difficulties, particularly in sexually precocious heifers, without impairing the growth, reproductive, feed efficiency conversion, and carcass indicator traits.

Lactation performances in primiparous Holstein cows following short and normal gestation lengths.

Despite decades of research, little is known regarding physiologic temporal limits for initiation of lactation in pregnant non-lactating cattle the aim of this study was to compare the lactation performances in primiparous Holstein cows after a short gestation length (GL) or abortion to those after a normal GL. The data were collected using an automated data collection system. The 94 herds evaluated were located in Belgium, France, Italy, the Netherlands and Germany. Data from a wide range of physiological cow-life events including birth and calving events, reproduction events (insemination, pregnancy checks, and abortions), and milking events were collected. The GL was defined as the interval between the last insemination and the subsequent calving (or abortion) within a range of 150-297 days. Animals were categorized into one of five categories based on GL quantiles (C-I to C-V). Lactation curve parameters including the scale, ramp, and decay were estimated using the Milkbot model. Then, the derived 305-day milk yield (M305-d), peak yield, and time to peak were compared between different GL categories. Of 13,732 lactations, 15 (0.11%) were found with a GL shorter than 210 days (ranging from 158 to 208 days). The 305-day milk yield was significantly lower in the C-I (7,566 ± 186) and C-II groups (7,802 ± 136 kg), compared to the C-III (8,254 ± 116 kg), C-IV (8,148 ± 119 kg), and C-V (8,255 ± 117 kg) groups. The same trends were found for the scale and peak yield of the lactation; the lowest scale were found for the C-I (31.5 ± 0.73) and C-II (32.8 ± 0.53) groups, and the highest were found for the C-III (34.5 ± 0.46), C-IV (34.9 ± 0.45), and C-V (35.0 ± 0.45) groups. Peak yield increased significantly from C-I (27.8 ± 0.66 kg) and C-II group (28.8 ± 0.48 kg) to the C-III (30.2 ± 0.42 kg) and further to the C-IV (30.6 ± 0.40 kg) and C-V (30.6 ± 0.41 kg) groups. Moreover, primiparous cows in the C-II GL category showed a higher milk yield persistency (decay of 1.30E-4 ± 3.55E-5) compared to those belonging to the C-IV (decay of 1.38E-4 ± 2.51E-5) and C-V (decay of 1.38E-4 ± 2.58E-5) group. In conclusion, results showed that primiparous cows with a shorter GL produced significantly less 305-day milk and peak yields, had a higher lactation persistency, and showed a lower upward slope of the lactation curve compared to those with a normal GL.

Climatic and calf-related risk factors associated with failure of transfer of passive immunity in Holstein calves in a hot environment.

This retrospective observational study aimed to assess the effect of temperature-humidity index (THI) at calving and in the last trimester of pregnancy and calve-related factors affecting passive transfer of maternal immunoglobulin using Brix refractometry in Holstein calves. Blood samples from 4411 Holstein calves from a single large dairy farm in spring 2022 were used. A subset of data containing 6318 calvings was used to determine the effect of climatic conditions on the occurrence of agammaglobulinemia. Risk factors predictive of failure of passive transfer (FPT) were calculated using multiple logistic models. Females were 1.4 times more likely not to have FPT (56%; Brix% > 8 equivalent to ≥ 10g/L IgG) than males (47.2%). Calves born as singles increased the likelihood of not presenting FPT (52.6%) than calves born as twins (42.9%). Calves from cows with no dystocic delivery had a lower risk for FPT (odds ratio = 2.3) than calves from cows with dystocia. Agammaglobulinemia was 1.5 and 1.8 times more likely to occur in calves with THI ≥ 80 and ≥ 82 in the last trimester of gestation and at calving, respectively, than in calves not experiencing heat stress. Agammaglobulinemia was twice as likely to occur in male than in female calves. Calves with birth weight ≥ 37kg and gestation length ≥ 275kg were less likely to present agammaglobulinemia than lighter calves and calves with shorter gestation periods. This study raises questions for management practices in Holstein calves undergoing in utero heat stress and around calving to avoid agammaglobulinemia.

Fat and fatty acids - a scoping review for Nordic Nutrition Recommendations 2023.

Two de novo NNR2022 systematic reviews (SRs) as well as 21 qualified SRs (qSRs) were available. A literature search yielded an additional ~70 SRs, meta-analyses and biomarker papers. Diets lower in total fat are associated with reductions in body weight and blood pressure compared with diets higher in total fat in adults. Partial replacement of saturated fatty acid (SFA) with n-6 polyunsaturated fatty acid (PUFA) improves blood lipid profile, decreases the risk of cardiovascular disease (CVD), improves glucose-insulin homeostasis and may decrease the risk of total mortality. Long-chain n-3 PUFAs (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) decrease triglycerides and are associated with lower risk of CVD. Dietary PUFAs, both n-3 and n-6, may be associated with reduced risk of type 2 diabetes (T2D). There is inconclusive evidence to suggest that the type of dietary fat is associated with blood pressure, risk of hypertension or musculoskeletal health. Higher intake of total PUFA is associated with lower mortality from any cancer. Long-chain n-3 PUFA is associated with reduced risk of breast cancer, whereas biomarker levels of n-6 PUFA are associated with lower risk of any cancer. Intake of long-chain n-3 PUFA during pregnancy increases length of gestation and child birth weight and reduces the risk of preterm delivery, but there is inconclusive evidence to suggest that it may influence child neurodevelopment, growth or development of allergic disease. In studies with higher versus lower dietary cholesterol intake levels, total blood cholesterol increased or were unaffected by the dietary cholesterol, resulting in inconclusive results. Trans fatty acid (TFA), regardless of source, impairs blood lipid profile compared to unsaturated fat. In observational studies, TFA is positively associated with CVD and total mortality but whether associations differ by source is inconclusive. Ruminant TFA, as well as biomarker levels of odd-chain fatty acids, might be associated with lower risk of T2D.

Human placenta releases extracellular vesicles carrying corticotrophin releasing hormone mRNA into the maternal blood

The human placenta releases diverse extracellular vesicles (EVs), including microvesicles (100–1000 nm) and exosomes (30–150 nm), into the maternal blood for feto-maternal communication. Exosomes and microvesicles contribute to normal pregnancy physiology and major pregnancy pathologies. Differences in miRNA expressions and protein content in placental exosomes have been reported in complicated pregnancies. During human pregnancy, Corticotropin-Releasing Hormone (CRH) is produced and released by the placenta into the maternal blood. CRH is involved in regulating gestational length and the initiation of labour. CRH mRNA levels in the maternal plasma rise with gestation. High levels of CRH mRNA are reported to be associated with preeclamptic and preterm pregnancies. However, the underlying mechanism of placental CRH mRNA secretion remains to be elucidated. We hypothesise that the placenta releases CRH mRNA packaged within extracellular vesicles (EVs) into the maternal blood. In this study, placental EVs (microvesicles and exosomes) were isolated from human term healthy placentas via villus washes and from explant culture media by differential centrifugation and purified by density gradient ultracentrifugation using a continuous sucrose gradient (0.25–2.5 M). Western blotting using placenta- and exosome-specific markers and electron microscopy confirmed exosomes and microvesicles in the placental wash and explant media samples. Real-time quantitative RT-PCR data detected CRH mRNA in placenta-derived EVs from placental washes and explants. We also sorted placenta-secreted EVs in maternal plasma samples (≥37 weeks) by high-resolution flow cytometry using a fluorescent-labelled PLAP antibody. CRH mRNA was demonstrated in placental EVs obtained from maternal blood plasma. We therefore show that human placental EVs carry CRH mRNA into the maternal blood. Our study implies that measuring CRH mRNA in placental EVs in the maternal plasma could beused for monitoring pregnancy.

Estimation of genetic parameters for fertility traits in Chinese Holstein of south China.

Introduction: Chinese Holstein in South China suffer heat stress for a long period, which leads to evolutionary differences from Chinese Holstein in North China. The aim of this study was to estimate the genetic parameters of fertility traits for Chinese Holstein in South China. Methods: A total of 167,840 Chinese Holstein heifers and cows from Guangming Animal Husbandry Co., LTD farms were used in this study. The fertility traits analyzed were calving interval (CI), days open (DO), age of first service (AFS), age of first calving (AFC), calving to first insemination (CTFS), first insemination to conception (FSTC), gestation length (GL), non-return rate to 56days (NRR), and number of services (NS). Results: The descriptive statistics revealed that the same trait in heifers performed better than in cows, which was consistent with the other studies. The heritabilities of fertility traits in this study ranged from close to 0 (for NS of cows) to 0.2474 (for AFC of heifers). The genetic correlation of NRR between heifers and cows was 0.9993, which indicates that the NRR for heifers and cows could be treated as one trait in this population. Conclusion: The heritabilities of fertility traits in Chinese Holstein in south China were quite different from the heritabilities of fertility traits in North China. NRR56, NS, AFC, and CI were suggested to be included into the selection index to improve fertility performance of Chinsese Holstein of south China. The results of this study could provide genetic parameters for the animal breeding program of Chinese Holstein in the south of China.

Is oral consumption of dates (Phoenix dactylifera L. fruit) in the peripartum period effective and safe integrative care to facilitate childbirth and improve perinatal outcomes: a comprehensive revised systematic review and dose-response meta-analysis

BackgroundRecent reviews have reported inconclusive results regarding the usefulness of consuming dates (Phoenix dactylifera L. fruit) in the peripartum period. Hence, this updated systematic review with meta-analysis sought to investigate the efficacy and safety of this integrated intervention in facilitating childbirth and improving perinatal outcomes.MethodsEight data sources were searched comprehensively from their inception until April 30, 2023. Parallel-group randomized and non-randomized controlled trials published in any language were included if conducted during peripartum (i.e., third trimester of pregnancy, late pregnancy, labor, or postpartum) to assess standard care plus oral consumption of dates versus standard care alone or combined with other alternative interventions. The Cochrane Collaboration’s Risk of Bias (RoB) assessment tools and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) were employed to evaluate the potential RoB and the overall quality of the evidence, respectively. Sufficient data were pooled by a random-effect approach utilizing Stata software.ResultsOf 2,460 records in the initial search, 48 studies reported in 55 publications were included. Data were insufficient for meta-analysis regarding fetal, neonatal, or infant outcomes; nonetheless, most outcomes were not substantially different between dates consumer and standard care groups. However, meta-analyses revealed that dates consumption in late pregnancy significantly shortened the length of gestation and labor, except for the second labor stage; declined the need for labor induction; accelerated spontaneity of delivery; raised cervical dilatation (CD) upon admission, Bishop score, and frequency of spontaneous vaginal delivery. The dates intake in labor also significantly reduced labor duration, except for the third labor stage, and increased CD two hours post-intervention. Moreover, the intervention during postpartum significantly boosted the breast milk quantity and reduced post-delivery hemorrhage. Likewise, dates supplementation in the third trimester of pregnancy significantly increased maternal hemoglobin levels. The overall evidence quality was also unacceptable, and RoB was high in most studies. Furthermore, the intervention’s safety was recorded only in four trials.ConclusionMore well-designed investigations are required to robustly support consuming dates during peripartum as effective and safe integrated care.Trial registrationPROSPERO Registration No: CRD42023399626

Genetic parameters, genetic trends and selection response for gestation length and traits used as selection criteria in Angus breed in Brazil

Context The knowledge of the genetic variability of gestation length and its correlations with other traits is relevant for selection decisions in beef cattle. Aims Genetic parameters and trends were estimated for gestation length (first (GL1), repeated measures range of 1–6 (GL)) and traits currently used as selection criteria (birth weight (BW), weight gain from birth to weaning (BWG), weight gain from weaning to yearling (WYG), scrotal circumference (SC), score of conformation (YC), score of precocity (YP), and score of muscling (YM)) in Brazilian Angus cattle. In addition, direct and correlated selection responses were predicted. Methods A series of single- and two-trait Bayesian analyses were performed on beef cattle data from 14 farms across different regions of Brazil, by using linear and threshold animal models. Key results A moderate heritability was estimated for GL1 (0.356 ± 0.058); however, the estimate for GL was low (0.189 ± 0.028) as was that for repeatability (0.204 ± 0.027). Lower accuracies of breeding values were obtained for GL than for GL1, ranging from 0.490 ± 0.161 to 0.687 ± 0.037. Direct heritability estimates for growth and body composition traits were low, except for SC and BWG (0.301 ± 0.060 and 0.241 ± 0.019 respectively). Genetic correlations of 0.558 ± 0.121 and 0.739 ± 0.131 were estimated between GL1 and BW, and between GL and BW respectively. The other traits studied were estimated to have weak or near-zero genetic correlations with gestation length traits. Positive and moderate genetic associations were estimated between BW and BWG, SC, and visual scores (ranging from 0.338 ± 0.095 to 0.458 ± 0.092), but a near-zero estimate was obtained with WYG (0.127 ± 0.150). Weight gains were more highly genetically correlated with visual scores than between themselves (BWG and WYG) and with SC. The SC was highly genetically correlated with visual scores (0.684 ± 0.054 to 0.714 ± 0.050). Genetic trends showed that all traits studied have been changing in a positive direction, being unfavourable for BW and GL. Higher genetic gains were expected from using direct selection than from using indirect selection for GL1. Conclusions Rapid growth is genetically associated with superior conformation, precocity and musculature, as well as a large scrotal circumference in males. However, selection decisions that heavily focus on these traits are likely to lead to more calving difficulties in the longer term. Implications Selection indices should incorporate traits that measure calving difficulty directly if relevant records are available. Currently, considering its practical implications in primiparous anoestrus, the first-gestation length could serve as a viable alternative for inclusion in selection indices. Due to the low repeatability of the gestation length, decisions to cull on the basis of only one or two records of GL are highly inaccurate.

A genome-wide association study reveals fetal genetic factor for gestation length on chromosome 21 in Japanese Black cattle.

Gestation length (GL) in cattle is associated with neonatal health and the subsequent reproductive performance of dams. We performed a genome-wide association study (GWAS) using 25,144 single nucleotide polymorphisms (SNPs) in 4373 animals to detect genetic variants associated with GL as a fetal trait in Japanese Black cattle in Gifu Prefecture. We identified four significant SNPs on chromosome 21 in moderate linkage disequilibrium (LD). The minor allele of the most significant SNP has the effect on -2.47 days GL with a 0.019 allele frequency. Of the 4373 animals, 140 heterozygotes and one homozygote with the minor allele were traced back to a heterozygous sire. The 7.2Mb LD region harbors three genes: gamma-aminobutyric acid type A receptor subunit beta3 (GABRB3), arrestin domain containing 4 (ARRDC4), and nuclear receptor subfamily 2 group F member 2 (NR2F2, also known as COUP-TFII). RNA expression analysis and its functions suggest that GABRB3, ARRDC4, and NR2F2 (COUP-TFII) are involved in glucose production via the hypothalamic-pituitary-adrenal axis during the fetal stress response at gestation period termination. These results suggest that an increase in the allele frequency of the associated SNPs has an impact on genetic improvement by shortening the GL in the population.

Effects of Farrowing Induction on Some Farrowing Characteristics in the Pig − A Review

Abstract Several farrowing induction programs have been used to increase the proportion of sow farrowing during the work period and the rate of farrowing supervision, as well as to promote the success of cross-fostering and the practice of all-in all-out in swine production. The present overview aimed to evaluate the effects of farrowing induction on farrowing duration, birth interval, birth weight, dystocia/birth assistance, and stillbirth in pigs. The results showed that via different routes of administration, either natural or synthetic prostaglandins alone or in combination mostly with uterotonic drugs, including oxytocin and carbetocin, have been used for the induction of farrowing. Sometimes other drugs, such as dexamethasone, estradiol, xylazine, ergometrine, and AGN190851, were added. Vulvar and perinatal routes reduced the intramuscular dose of prostaglandins by 50% to 75%, while equal effects remained. A split dose of prostaglandin 6 h apart should be used because it may enhance complete luteolysis. Additionally, if uterotonic drugs are used following prostaglandin injection, they should be injected after the birth of the first piglets at the earliest timepoint to ensure full opening of the cervix. These two practices decrease the farrowing duration, the birth interval, and dystocia. Induction should not be conducted more than 2 days earlier than the expected farrowing date in order to keep the stillbirth rate and birth weight unaltered. This review also revealed that certain factors, such as the rate of farrowing supervision, natural differences in piglets’ birth weights, litter size, gestation length, and treatment with altrenogest before induction, may be confounding factors that possibly alter the effect of induction programs on certain farrowing characteristics.

Associations of Organophosphate Ester Flame Retardant Exposures during Pregnancy with Gestational Duration and Fetal Growth: The Environmental influences on Child Health Outcomes (ECHO) Program.

Widespread exposure to organophosphate ester (OPE) flame retardants with potential reproductive toxicity raises concern regarding the impacts of gestational exposure on birth outcomes. Previous studies of prenatal OPE exposure and birth outcomes had limited sample sizes, with inconclusive results. We conducted a collaborative analysis of associations between gestational OPE exposures and adverse birth outcomes and tested whether associations were modified by sex. We included 6,646 pregnant participants from 16 cohorts in the Environmental influences on Child Health Outcomes (ECHO) Program. Nine OPE biomarkers were quantified in maternal urine samples collected primarily during the second and third trimester and modeled as -transformed continuous, categorized (high/low/nondetect), or dichotomous (detect/nondetect) variables depending on detection frequency. We used covariate-adjusted linear, logistic, and multinomial regression with generalized estimating equations, accounting for cohort-level clustering, to estimate associations of OPE biomarkers with gestational length and birth weight outcomes. Secondarily, we assessed effect modification by sex. Three OPE biomarkers [diphenyl phosphate (DPHP), a composite of dibutyl phosphate and di-isobutyl phosphate (DBUP/DIBP), and bis(1,3-dichloro-2-propyl) phosphate] were detected in of participants. In adjusted models, DBUP/DIBP [odds ratio (OR) per ; 95% confidence interval (CI): 1.02, 1.12] and bis(butoxyethyl) phosphate (OR for high vs. ; 95% CI: 1.06, 1.46), but not other OPE biomarkers, were associated with higher odds of preterm birth. We observed effect modification by sex for associations of DPHP and high bis(2-chloroethyl) phosphate with completed gestational weeks and odds of preterm birth, with adverse associations among females. In addition, newborns of mothers with detectable bis(1-chloro-2-propyl) phosphate, bis(2-methylphenyl) phosphate, and dipropyl phosphate had higher birth weight-for-gestational-age -scores ( for detect vs. ); other chemicals showed null associations. In the largest study to date, we find gestational exposures to several OPEs are associated with earlier timing of birth, especially among female neonates, or with greater fetal growth. https://doi.org/10.1289/EHP13182.

Reconsidering the developmental origins of adult disease paradigm: The 'metabolic coordination of childbirth' hypothesis.

In uncomplicated pregnancies, birthweight is inversely associated with adult non-communicable disease (NCD) risk. One proposed mechanism is maternal malnutrition during pregnancy. Another explanation is that shared genes link birthweight with NCDs. Both hypotheses are supported, but evolutionary perspectives address only the environmental pathway. We propose that genetic and environmental associations of birthweight with NCD risk reflect coordinated regulatory systems between mother and foetus, that evolved to reduce risks of obstructed labour. First, the foetus must tailor its growth to maternal metabolic signals, as it cannot predict the size of the birth canal from its own genome. Second, we predict that maternal alleles that promote placental nutrient supply have been selected to constrain foetal growth and gestation length when fetally expressed. Conversely, maternal alleles that increase birth canal size have been selected to promote foetal growth and gestation when fetally expressed. Evidence supports these hypotheses. These regulatory mechanisms may have undergone powerful selection as hominin neonates evolved larger size and encephalisation, since every mother is at risk of gestating a baby excessively for her pelvis. Our perspective can explain the inverse association of birthweight with NCD risk across most of the birthweight range: any constraint of birthweight, through plastic or genetic mechanisms, may reduce the capacity for homeostasis and increase NCD susceptibility. However, maternal obesity and diabetes can overwhelm this coordination system, challenging vaginal delivery while increasing offspring NCD risk. We argue that selection on viable vaginal delivery played an over-arching role in shaping the association of birthweight with NCD risk.

Risk factors during admission on mortality of newborns in neonatal care units

Background Neonatal mortality is defined as the death of live born within the first 28 days of life. It represents a great burden on the health and community. Many risk factors are associated with neonatal mortality. Aim Evaluate perinatal admission risk factors and their relation to neonatal mortality in newborns admitted to neonatal care units participating in the Egyptian Neonatal Network (EGNN). Patients and methods This retrospective study included 4621 newborns admitted to Neonatal Care Units participating in the Egyptian Neonatal Network over 3 years (2014–2016). The record of the cases was revised to determine the maternal characteristics, the incidence of neonatal mortality, and the associated risk factors associated with mortality. Results Among the studied factors, increased gravidity, parity, and number of live children and lower gestational age, birth and, admission weight, length, and HC, are associated with increased neonatal mortality in neonatal intensive care unit (NICUs) (P value<0.001). Conclusion Determination of risk factors in neonatal death can help to identify sick neonates who are more likely to die in NICUs and provide on-time care. Help doctors to tell parents what possibly happened to their babies. And used as a tool to compare the outcome of different NICUs and evaluate their performance.

Autophagy in the corpus luteum correlates with tissue growth in pregnant rats.

The developmental activation of the corpus luteum (CL) structurally and functionally is critical for the temporally regulated establishment, maintenance, and termination of pregnancy in rats. In this study, we have investigated the possible involvement of autophagy in the regulation of the CL during pregnancy in rats. The expression ratio of microtubule-associated protein light chain 3 (LC3)-II/-I, a widely used indicator of autophagic activity, in the CL remained relatively stable until day 15 of pregnancy. Subsequently, it progressively increased until day 21, and then declined until day 3 postpartum. This fluctuation was closely associated with the tissue weight of the CL rather than progesterone (P4) production activity. Light and electron microscopy revealed the presence of immunoreactive LC3 aggregates and irregularly shaped autolysosome-like microstructures in the cytoplasm of luteal cells during late pregnancy. Notably, a bolus intrabursal injection of the autophagy inhibitor bafilomycin A1 on day 15 of pregnancy resulted in a significant reduction in luteal cell size and disrupted the normal alteration of circulating P4 levels. Consequently, treatment with this inhibitor increased the likelihood of the varied timing (both advanced and delayed) of delivery and led to reduced body weight in neonates when compared with the vehicle-treated control group. Our findings suggest that autophagy in the rat CL contributes to luteal tissue growth, influences P4 production, and thereby fine-tunes the regulation of gestation length in rats.

Farrowing Induction in Swine with Prostaglandin: Effect on Farrowing Traits and Piglet Performance

The variation of gestation length in sows leads to difficulties performing farrowing supervision in commercial farms. The present study determined the efficacy of prostaglandin F2alpha (PGF2α) administration on induction of farrowing in pig. The sows (n=50) were randomly divided into two groups. In group-1, sows (n=25) were injected with placebo intramuscularly (one mL sterile water) on 113th day of gestation at 8.00 am in the morning. In group-2 (n=25), cloprostenol sodium (250 mcg) was injected intramuscularly on 113th day of gestation at 8.00 am in the morning. The parameters recorded during the experiment were gestation length, farrowing duration, total number of piglets born per litter (NTB), number of piglets born alive per litter (NBA), number of stillborn per litter, mummified foetuses per litter, birth interval (min), number of piglets alive at day 3 of lactation and piglet mortality (%) till day 3 of lactation. Gestation length was significantly (p<0.05) shorter in Group-2 compared to Group-1. Similarly, the interval from PGF2α administration to onset of farrowing was significantly (p<0.05) shorter as compared to natural farrowed sows. Farrowing duration did not differ significantly (p>0.05) between two groups. There was no effect of PGF2α administration on NTB, NBA, stillbirths, mummified fetuses. The numbers of alive piglets at day 3 of lactation were also similar between two groups (p>0.05). The PGF2α administration also resulted in increased proportion of sows that farrowed on day 114 of gestation. In conclusion, PGF2α administration on day 113 of gestation could be an option for controlled farrowing in sow without any adverse effects.

Oocyte competence is comparable between progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) and GnRH-antagonist protocols: A matched case-control study in PGT-A cycles

ObjectiveTo outline oocyte competence after progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) compared to conventional GnRH-antagonist protocol. Study designRetrospective matched case-control study involving advanced-maternal-age women undergoing ICSI with PGT-A. 89 NETA-PPOS were matched with 178 control patients based on maternal age and ovarian reserve biomarkers. Both groups underwent recombinant-FSH OS with GnRH-agonist ovulation trigger and collected ≥1 MII. In the study group, NETA (10 mg/day) was administered orally starting from day2 of the menstrual cycle. Euploid blastocyst rate per cohort of metaphase-II oocytes (EBR per MII) was the primary outcome. All other embryological and clinical outcomes were reported. Gestational age, birthweight and length were also assessed. ResultsThe EBR per MII was comparable among PPOS and control (13.9 % ± 19.3 % versus 13.3 % ± 17.9 %; the sample size allowed to exclude up to a 10 % difference). Blastocysts morphology and developmental rate were similar. No difference was reported for all clinical outcomes among the 61 and 107 vitrified-warmed euploid single blastocyst transfers respectively conducted. The cumulative live birth delivery rate per concluded cycles was also comparable (24.7 % versus 21.9 %). Neonatal outcomes were analogous. ConclusionsOocyte competence after NETA-PPOS and standard OS is comparable. This evidence is reassuring and, because of its lower cost and possibly higher patients’ compliance, supports PPOS administration whenever the patients are indicated to freeze-all (e.g., fertility preservation, PGT-A, oocyte donation). More data are required about follicle recruitment, oocyte yield, gestational and perinatal outcomes. Randomized-controlled-trials are advisable to confirm our evidence.

Fish Oil Supplementation as an Omega-3 Fatty Acid Source during Gestation: Effects on the Performance of Awassi Ewes and Their Offspring.

The primary aim of this research was to assess the impact of supplementing fish oil into the diet of pregnant Awassi ewes on various aspects of the dam's productive performance, offspring birth weight, colostrum yield and quality, milk production and composition, postpartum offspring performance, and the composition of fatty acids in milk. In this study, two different fat sources, namely palm oil (PO) and fish oil (FO), were utilized, with both being included at a rate of 2.4% of dietary dry matter (DM) during the initial 65 days of gestation (early gestation stage), and then at 2.1% DM from day 65 of gestation until lambing (late gestation stage). The study subjects were Awassi ewes with a body weight (BW) averaging 57 ± 1.5 kg and an age of 3.5 ± 1.2 years. These ewes were randomly assigned to one of four dietary treatments: (i) a diet containing only palm oil from day 0 to day 150 of pregnancy (PO, n = 15); (ii) a diet containing palm oil from day 0 to day 65 of pregnancy, followed by a diet containing fish oil from day 66 to day 150 of pregnancy (POFO, n = 16); (iii) a diet containing fish oil from day 0 to day 65 of pregnancy, followed by a diet containing palm oil from day 66 to day 150 of pregnancy (FOPO, n = 16); (iv) a diet containing only fish oil from day 0 to day 150 of pregnancy (FO, n = 16). Within each treatment, ewes were housed in three replicates, with each replicate further divided into three subgroups. The first two subgroups each contained eight ewes, while the third subgroup contained nine ewes. In addition, each treatment contained 10 primiparous and 15 multiparous ewes. The results indicated that the POFO treatment led to significant increases (p < 0.05) in birth weight, gestation length, and colostrum IgG concentration. However, it also resulted in a decrease (p < 0.001) in colostrum production and a reduction (p < 0.001) in the percentage of milk fat and milk protein. Furthermore, the milk from the POFO treatment exhibited higher levels of polyunsaturated fatty acids (PUFAs) (p < 0.001) compared to the PO and FOPO treatments, while the milk saturated fatty acids (SFA) were lower (p < 0.001). In conclusion, the addition of fish oil at a rate of 2.1% DM during the late pregnancy period showed promise for enhancing birth weight, colostrum IgG concentration, and the PUFA content in the milk.

16 Stillbirth, gestation length, and birth weights from Jersey calves originated from artificial insemination vs in vitro embryo transfer

16 Stillbirth, gestation length, and birth weights from Jersey calves originated from artificial insemination vs in vitro embryo transfer

The evolution of human altriciality and brain development in comparative context.

Human newborns are considered altricial compared with other primates because they are relatively underdeveloped at birth. However, in a broader comparative context, other mammals are more altricial than humans. It has been proposed that altricial development evolved secondarily in humans due to obstetrical or metabolic constraints, and in association with increased brain plasticity. To explore this association, we used comparative data from 140 placental mammals to measure how altriciality evolved in humans and other species. We also estimated how changes in brain size and gestation length influenced the timing of neurodevelopment during hominin evolution. Based on our data, humans show the highest evolutionary rate to become more altricial (measured as the proportion of adult brain size at birth) across all placental mammals, but this results primarily from the pronounced postnatal enlargement of brain size rather than neonatal changes. In addition, we show that only a small number of neurodevelopmental events were shifted to the postnatal period during hominin evolution, and that they were primarily related to the myelination of certain brain pathways. These results indicate that the perception of human altriciality is mostly driven by postnatal changes, and they point to a possible association between the timing of myelination and human neuroplasticity.

Genome-wide association study for reproduction traits in Colombian Creole Blanco Orejinegro cattle.

The profitability of the beef cattle production system relies heavily on reproductive traits. Unfortunately, certain traits, such as age at first calving (AFC), calving interval (CI), and gestation length (GL), can pose challenges in traditional breeding programs because of their low heritability (0.01-0.12) and sex-limited characteristics. Another important aspect is the conservation of the genetic resources of animals adapted to the Colombian regions, which implies the preservation and rational use of the creole breeds in the country market. Therefore, this study aimed to identify genomic regions in the creole cattle breed Blanco Orejinegro (BON) that influence the reproductive traits in females. The dataset comprised 439 animals and 118,116 single-nucleotide polymorphisms' (SNPs) markers. The GS3 program was used to identify the SNP effects employing the BAYES Cπ methodology. The number of SNPs with effect for AFC was 25, 1527 for CI, and 23 for GL. Some of the genes found associated with reproductive and growth traits as well as immune response and environmental adaptation ECE1, EPH, EPHB2, SMARCAL1, IGFBP5, IGFBP2, FCGRT, EGFR, MUL1, PINK1, STPG1, CNGB1, TGFB1, OXTR, IL22RA1, MYOM3, OXTR, CNR2, HIVEP3, CTPS1, CXCL8, FCGRT, MREG, TMEM169, PECR, and MC1R. Our results evidenced a high contribution of the genetic architecture of the Colombian creole cattle breed Blanco Orejinegro that may impact should be included in implementing genetic improvement and conservation programs.