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The transgenerational maternal effects of polycystic ovary syndrome (PCOS) in female progeny are being revealed. As there is evidence that a male equivalent of PCOS may exists, we ask whether sons born to mothers with PCOS (PCOS-sons) transmit reproductive and metabolic phenotypes to their male progeny. Here, in a register-based cohort and a clinical case-control study, we find that PCOS-sons are more often obese and dyslipidemic. Our prenatal androgenized PCOS-like mouse model with or without diet-induced obesity confirmed that reproductive and metabolic dysfunctions in first-generation (F1) male offspring are passed down to F3. Sequencing of F1–F3 sperm reveals distinct differentially expressed (DE) small non-coding RNAs (sncRNAs) across generations in each lineage. Notably, common targets between transgenerational DEsncRNAs in mouse sperm and in PCOS-sons serum indicate similar effects of maternal hyperandrogenism, strengthening the translational relevance and highlighting a previously underappreciated risk of transmission of reproductive and metabolic dysfunction via the male germline. CC BY 4.0© 2023 The Author(s)Correspondence: qiaolin.deng@ki.se (Q.D.), elisabet.stener-victorin@ki.se (E.S.-V.)We thank Zhiyi Zhao, Jacob Victorin, Sonja Edström, and Sara Pilström for technical assistance during animal work and molecular analysis; TSE Systems and the Metabolic Phenotyping Center at the Strategic Research program in Diabetes at the Karolinska Institutet; and the electron microscopy unit Emil at Huddinge University Hospital at the Karolinska Institutet. This work is supported by the Swedish Medical Research Council: project nos. 2018-02435 and 2022-00550 (E.S.-V.) and 2018-02557 and 2020-00253 (Q.D.); the Knut and Alice Wallenberg Foundation: 2019.0211 (Q.D.); Distinguished Investigator Grant – Endocrinology and Metabolism, Novo Nordisk Foundation: NNF22OC0072904 (E.S.-V.); the Diabetes Foundation:DIA2021-633 (E.S.-V.); the Novo Nordisk Foundation: NNF18OC0033992 and NNF19OC0056647 (E.S.-V.); the Strategic Research Program in Diabetes at the Karolinska Institutet (E.S.-V.); the Adlerbertska Research Foundation: GU 2019/86 (E.S.-V.); Karolinska Institutet KID funding: 2020-00990 (E.S.-V.); a Karolinska Instiutet faculty funded position (Q.D.); the Regional Agreement on Medical Training and Clinical Research between the Stockholm County Council and the Karolinska Institutet: 20190079 (E.S.-V.); O.E. och Edla Johanssons Stiftelse 2021 (S.R.); the Karolinska Institutet China scholarship council program (Q.L.); Magnus Bergvalls Stiftelse: 2020-03808 and 2021-04329 (S.R.); the Karolinska Institutet: 2020-02026 (S.R.); the National Fund for Scientific and Technological Development (FONDECYT): project no. 1151531 (T.S.P.); the FONDECYT: project no. 1201483 (B.E.); the National Commission for Scientific and Technological Research (CONICYT) (R.F.); HKH Kronprinsessan Lovisas förening för barnasjukvård (R.F.); and Stiftelsen Axel Tielmans minnesfond (R.F.)

Progestogens are frequently administered during early pregnancy to patients undergoing assisted reproductive techniques (ART) to overcome progesterone deficits following ART procedures. Orally administered dydrogesterone (DG) shows equal efficacy to other progestogens with a higher level of patient compliance. However, potential harmful effects of DG on critical pregnancy processes and on the health of the progeny are not yet completely ruled out. We treated pregnant mice with DG in the mode, duration, and doses comparable to ART patients. Subsequently, we studied DG effects on embryo implantation, placental and fetal growth, fetal-maternal circulation, fetal survival, and the uterine immune status. After birth of in utero DG-exposed progeny, we assessed their sex ratios, weight gain, and reproductive performance. Early-pregnancy DG administration did not interfere with placental and fetal development, fetal-maternal circulation, or fetal survival, and provoked only minor changes in the uterine immune compartment. DG-exposed offspring grew normally, were fertile, and showed no reproductive abnormalities with the exception of an altered spermiogram in male progeny. Notably, DG shifted the sex ratio in favor of female progeny. Even though our data may be reassuring for the use of DG in ART patients, the detrimental effects on spermatogenesis in mice warrants further investigations and may be a reason for caution for routine DG supplementation in early pregnancy.

The present study was conducted to investigate the effects of dietary inorganic and/or organic based trace mineral premix in full or half doses in broiler breeders" diet on hatchability, fertility, post hatch performance, and carcass parameters of broiler progeny. A total of 220 Ross-308, 36 wkold broiler breeders were divided into 4 dietary treatments (100% inorganic, 50% organic + 50% inorganic, 50% organic, and 100% organic trace mineral premix) with 5 replicates of 10 females and 1 male in each pen having similar body weight and egg production. The results of this experiment showed that inclusion of trace minerals source type in broiler breeders" diet did not have a significant effect on hatching egg characteristic. The results, however, showed that diets containing full (100%) or half (50%) doses of organic and/or inorganic minerals in broiler breeder hens" diet have a significant effect on fertility rate (P

Ionizing radiation is known to cause DNA damage, yet the mechanisms underlying potential transgenerational effects of exposure have been scarcely studied. Previously, we observed effects in offspring of zebrafish exposed to gamma radiation during gametogenesis. Here, we hypothesize that these effects are accompanied by changes of DNA methylation possibly inherited by subsequent generations. We assessed DNA methylation in F1 embryos (5.5 hours post fertilization) with whole genome bisulfite sequencing following parental exposure to 8.7 mGy/h for 27 days and found 5658 differentially methylated regions (DMRs). DMRs were predominantly located at known regulatory regions, such as gene promoters and enhancers. Pathway analysis indicated the involvement of DMRs related to similar pathways found with gene expression analysis, such as development, apoptosis and cancers, which could be linked to previous observed developmental defects and genomic instability in the offspring. Follow up of 19 F1 DMRs in F2 and F3 embryos revealed persistent effects up to the F3 generation at 5 regions. These results indicate that ionizing radiation related effects in offspring can be linked to DNA methylation changes that partly can persist over generations. Monitoring DNA methylation could serve as a biomarker to provide an indication of ancestral exposures to ionizing radiation.

At the end of 2013, strong wind destroyed spruce stands on large areas of Kościeliska Valley in Tatra Mts. in Poland. In 2015–2017, 304 bark samples were collected from 106 spruces; 25 cm × 25 cm large samples were taken from 2 or 4 sections of infested trees in July/August each year. The infestation density, sex ratio, length of maternal galleries, number of progeny and impact of natural enemies were recorded. The infestation density in individual years was 0.79–0.86 mating chambers per dm2, the average length of maternal gallery (55.2–56.6 mm) did not differ between years, The average number of progeny per female from 3-year pooled data was 18.22, the highest in 2015 (27.4) then collapsed to 15.5–16.8. The gallery systems with 2 females, in which the reproduction success was the highest, dominated (62.6%). The frequency of parasitoids or entomopathogens was very low (2–20% mortality rate in 19 bark samples). Possible reasons of relatively low reproduction success regardless generally favourable breeding conditions and its collapse after first year, such as high infestation density and low survival rate of larvae because of climatic conditions (drought), are discussed. Taking into account the described population features, very intense tree mortality and mechanisms known from the other wind events, further development of the outbreak can be expected in this area.

A study with a 2 × 2 factorial arrangement was conducted to determine the effects of 2 dietary crude protein levels, high (CPh) or low (CPl), supplemented with free amino acids (AA), and 2 ages at photo stimulation (PS)—early (21 wk; PSe) or late (23 wk; PSl)—on reproduction traits of broiler breeders and progeny performance. Diets were isocaloric, and calculated CP content of the CPl diets was 15 g/kg lower than the CPh diets during all phases. A total of 480 female and 64 male Ross 308 breeders of 20 wk of age were used. Total egg production was similar between CPl and CPh birds during phase 1 and 2 but was reduced by 2.8 eggs for CPl birds during phase 3. For the overall laying period, CPl birds tended (P = 0.075) to produce 4.7 fewer total eggs. Hatchability of set eggs was similar between CPl and CPh birds during phases 1 and 2 but tended (P = 0.064) to be lower for CPl birds in phase 3. PSe birds showed an advanced age at sexual maturity and age at peak production of 4.6 and 5.3 d, respectively, resulting in 2.5 more total eggs during phase 1. During phase 1, PSe birds showed an almost 5% increased fertility. Chick production in phase 1 was higher for PSe birds resulting in a tendency (P = 0.071) to higher overall chick production of almost 8 chicks. Progeny from early PS breeders showed an overall significant lower feed conversion ratio (FCR). It was concluded that egg and chick production during phases 1 and 2 were not affected by dietary CP level, but egg and chick production was reduced for CPl birds during phase 3. On the other hand, PSe birds showed an increased number of chicks. It is possible to decrease CP level of breeder diets with comparable reproduction from 22 to 46 wk; however, this is questionable for phase 3. For maximal chick production, early PS is recommended.

Despite the increasing use of oregano ( Origanum vulgare L.) essential oil for therapeutic purposes, pre- and postnatal development of animals offspring exposed to this oil has not yet been evaluated. In line with previous concerns of genotoxicity, in this study adult rats were exposed to different doses of oregano essential oil (3, 9 and 27% vol/vol) during pre-mating, mating, gestation and lactation. Prenatal screening included fetal development and uterine inspection, where the reproductive rate of females such as breeding, pregnancy, delivery, viability and post-implantation loss rate were measured. Postnatal evaluation of rat offspring included motor development, neuroendocrine and behavioral assessment. Body weight of rat dams and signs of dystocia were evaluated daily. Development of physic characteristics and reflex tests of puppies were also assessed. Additionally, these rats, when adults, were submitted to sexual and open field behavioral tests. The main differences among the groups were observed in the indices of mating, pregnancy and post-implantation loss (P

Introduction: The effect of in vitro fertilization (IVF) on neurodevelopmental outcome is unclear. Probably, IVF does not affect traditional measures of neurological development in infancy, but little is known on long-term effects. Recently a new video-based instrument to evaluate neuromotor development was developed. The Infant Motor Profile (IMP) evaluates neuromotor condition in infants in terms of the quality of spontaneous motor behaviour. The IMP does not only assess traditional neuromotor domains, such as performance, symmetry and movement fluency, but also two novel domains: variation and variability. Movement variation denotes the size of the child's movement repertoire. Previous studies demonstrated that reduced movement variation is associated with early lesions of the periventricular white matter and - more generally - reflects the integrety of cortical connectivity. In addition, reduced variation during infancy is associated with neurodevelopmental disorders in later life and reduced intelligence at school age. Variability denotes the child's ability to select from the repertoire of movements the strategy that suits the situation best. In this prospective, assessor-blinded cohort study, we address the question whether ovarian hyperstimulation and/or the in vitro procedure affect movement variation during infancy. Material and Methods: Singletons born following IVF with conventional controlled ovarian hyperstimulation (COH-IVF, n = 68), following IVF in a modified natural cycle (MNC-IVF, n = 57) and following natural conception born to subfertile couples (Sub-NC, n = 90) were assessed with the IMP at 4, 10 and 18 months. The assessment resulted in a total IMP score and 5 domain scores: variation (i.e. the size of movement repertoire), variability (i.e. the ability to select motor strategies), symmetry, fluency and performance. Primary outcome was the domain score variation. Outcome variables were analyzed with a mixed effects model. Results: The mixed model indicated an overall effect of treatment on variation (p Conclusions: The preliminary data suggest that ovarian hyperstimulation may be associated with reduced movement variation in infancy. These findings stress the need to carefully monitor neurodevelopment in IVF offspring.

Study question: Evaluating the effects and underlying causal relationships of ovarian hyperstimulation, the in vitro procedure and the combination of both on cognitive and behavioural development in 4-year-olds. Summary answer: Our preliminary results suggest that ovarian hyperstimulation, the in vitro procedure and the combination of both are not associated with cognitive and behavioural development in 4-year-olds. The child's cognitive and behavioural development largely depend on parental characteristics such as level of education and maternal age. What is known already: Long-term follow-up of health and development of IVFoffspring is important since the use of assisted reproduction techniques (ART) is steadily increasing. Results of long-term studies on cognitive and behavioural development in IVF-children vary, partly due to difficulties in interpretation of direct and indirect underlying causal relationships between ART, subfertility- and parental- and child aspects. The present study focuses on cognitive and behavioural development of 4-year-old IVF-offspring and underlying causal relationships. Study design, size, duration: A prospective follow-up study, in which 195 4-year-old singletons were assessed. They were born to subfertile couples (n = 195) following IVF with controlled ovarian hyperstimulation (COH-IVF, n = 63), IVF in the modified natural cycle (MNC-IVF, n = 53) and natural conception (Sub-NC, n = 79). The attrition rate since birth was 9.3%. Participants/materials, setting, methods: Cognitive development was evaluated with the Kaufman Assessment Battery for Children; behavioural development was evaluated with the Child Behavior Checklist. Primary cognitive outcome parameter was the total intelligence quotient (IQ); behavioural outcome parameter was the total problem T-score. Regression analyses, causal inference search algorithms and structural equation modelling were applied. Main results and the role of chance: The total IQ score [mean (sd)] for COH-IVF, MNC-IVF and Sub-NC children was 106.1 (11.8), 105.2 (13.3) and 108.9 (10.7), respectively and did not differ significantly between the three groups. Similarly, behavioural scores did not differ between the three groups. The causal models suggested that ovarian hyperstimulation and the in vitro procedure did not affect cognitive and behavioural outcome. Rather, cognitive and behavioural outcome were associated with parental characteristics such as maternal age and educational level. Limitations, reason for caution: The prospective design of our study and small post-natal attrition rate reduced potential selection bias based on the child's development or health. The assessors were blind to the mode of conception. However, our results cannot be generalized to multiples, as we studied singletons only. Wider implications of the findings: Our study contributes to the understanding of the relation between ART-aspects and cognitive and behavioural development. Long-term monitoring of development and growth of children born after ART remains of importance, especially since in society maternal age at child birth, and with that subfertility and the use of ART are steadily increasing.

This study aimed to examine the mechanisms involved in the transgenerational increase in Daphnia magna sensitivity to waterborne depleted uranium (DU) under controlled laboratory conditions. Daphnids were exposed to concentrations ranging from 2 to 50 μg L-1 over two successive generations. Genotoxic effects were assessed using random amplified polymorphic DNA and real time PCR (RAPD-PCR). Effects on life history (survival, fecundity and somatic growth) were monitored from hatching to release of brood 5. Different exposure regimes were tested to investigate the specific sensitivity of various life stages to DU. When daphnids were exposed continuously or from hatching to deposition of brood 5, results demonstrated that DNA damage accumulated in females and were transmitted to offspring in parallel with an increase in severity of effects on life history across generations. When daphnids were exposed during the embryo stage only, DU exposure induced transient DNA damage which was repaired after neonates were returned to a clean medium. Effects on life history remained visible after hatching and did not significantly increase in severity across generations. The present results suggest that DNA damage might be an early indicator of future effects on life history. © 2013 Elsevier Inc.

For a comprehensive survey of the structure and dynamics of the Dutch Phytophthora infestans population, 652 P. infestans isolates were collected from commercial potato fields in the Netherlands during the 10-year period 2000–2009. Genotyping was performed using 12 highly informative microsatellite markers and mitochondrial haplotypes. In addition, for each isolate, the mating type was determined. STRUCTURE analysis grouped the 322 identified genotypes in three clusters. Cluster 1 consists of a single clonal lineage NL-001, known as “Blue_13”; all isolates in this cluster have the A2 mating type and the Ia mitochondrial haplotype. Clusters 2 and 3 display a more elaborate substructure containing many unique genotypes. In Cluster 3, several distinct clonal lineages were also identified. This survey witnesses that the Dutch population underwent dramatic changes in the 10 years under study. The most notable change was the emergence and spread of A2 mating type strain NL-001 (or “Blue_13”). The results emphasize the importance of the sexual cycle in generating genetic diversity and the importance of the asexual cycle as the propagation and dispersal mechanism for successful genotypes. Isolates were also screened for absence of the Avrblb1/ipiO class I gene, which is indicative for virulence on Rpi-blb1. This is also the first report of Rpi-blb1 breakers in the Netherlands. Superimposing the virulence screening on the SSR genetic backbone indicates that lack the Avrblb1/ipiO class I gene only occurred in sexual progeny. So far, the asexual spread of the virulent isolates identified has been limited.

Introduction: The effect of in vitro fertilization (IVF) on neurodevelopmental outcome is unclear. Probably, IVF does not affect traditional measures of neurological development in infancy, but little is known on long-term effects. Recently a new video-based instrument to evaluate neuromotor development was developed. The Infant Motor Profile (IMP) evaluates neuromotor condition in infants in terms of the quality of spontaneous motor behaviour. The IMP does not only assess traditional neuromotor domains, such as performance, symmetry and movement fluency, but also two novel domains: variation and variability. Movement variation denotes the size of the child's movement repertoire. Previous studies demonstrated that reduced movement variation is associated with early lesions of the periventricular white matter and - more generally - reflects the integrety of cortical connectivity. In addition, reduced variation during infancy is associated with neurodevelopmental disorders in later life and reduced intelligence at school age. Variability denotes the child's ability to select from the repertoire of movements the strategy that suits the situation best. In this prospective, assessor-blinded cohort study, we address the question whether ovarian hyperstimulation and/or the in vitro procedure affect movement variation during infancy. Material and Methods: Singletons born following IVF with conventional controlled ovarian hyperstimulation (COH-IVF, n = 68), following IVF in a modified natural cycle (MNC-IVF, n = 57) and following natural conception born to subfertile couples (Sub-NC, n = 90) were assessed with the IMP at 4, 10 and 18 months. The assessment resulted in a total IMP score and 5 domain scores: variation (i.e. the size of movement repertoire), variability (i.e. the ability to select motor strategies), symmetry, fluency and performance. Primary outcome was the domain score variation. Outcome variables were analyzed with a mixed effects model. Results: The mixed model indicated an overall effect of treatment on variation (p Conclusions: The preliminary data suggest that ovarian hyperstimulation may be associated with reduced movement variation in infancy. These findings stress the need to carefully monitor neurodevelopment in IVF offspring.

Study question: Evaluating the effects and underlying causal relationships of ovarian hyperstimulation, the in vitro procedure and the combination of both on cognitive and behavioural development in 4-year-olds. Summary answer: Our preliminary results suggest that ovarian hyperstimulation, the in vitro procedure and the combination of both are not associated with cognitive and behavioural development in 4-year-olds. The child's cognitive and behavioural development largely depend on parental characteristics such as level of education and maternal age. What is known already: Long-term follow-up of health and development of IVFoffspring is important since the use of assisted reproduction techniques (ART) is steadily increasing. Results of long-term studies on cognitive and behavioural development in IVF-children vary, partly due to difficulties in interpretation of direct and indirect underlying causal relationships between ART, subfertility- and parental- and child aspects. The present study focuses on cognitive and behavioural development of 4-year-old IVF-offspring and underlying causal relationships. Study design, size, duration: A prospective follow-up study, in which 195 4-year-old singletons were assessed. They were born to subfertile couples (n = 195) following IVF with controlled ovarian hyperstimulation (COH-IVF, n = 63), IVF in the modified natural cycle (MNC-IVF, n = 53) and natural conception (Sub-NC, n = 79). The attrition rate since birth was 9.3%. Participants/materials, setting, methods: Cognitive development was evaluated with the Kaufman Assessment Battery for Children; behavioural development was evaluated with the Child Behavior Checklist. Primary cognitive outcome parameter was the total intelligence quotient (IQ); behavioural outcome parameter was the total problem T-score. Regression analyses, causal inference search algorithms and structural equation modelling were applied. Main results and the role of chance: The total IQ score [mean (sd)] for COH-IVF, MNC-IVF and Sub-NC children was 106.1 (11.8), 105.2 (13.3) and 108.9 (10.7), respectively and did not differ significantly between the three groups. Similarly, behavioural scores did not differ between the three groups. The causal models suggested that ovarian hyperstimulation and the in vitro procedure did not affect cognitive and behavioural outcome. Rather, cognitive and behavioural outcome were associated with parental characteristics such as maternal age and educational level. Limitations, reason for caution: The prospective design of our study and small post-natal attrition rate reduced potential selection bias based on the child's development or health. The assessors were blind to the mode of conception. However, our results cannot be generalized to multiples, as we studied singletons only. Wider implications of the findings: Our study contributes to the understanding of the relation between ART-aspects and cognitive and behavioural development. Long-term monitoring of development and growth of children born after ART remains of importance, especially since in society maternal age at child birth, and with that subfertility and the use of ART are steadily increasing.

In this paper, we estimate levels of inbreeding with parental relatedness and contribution inferred from microsatellites in groups of Common sole that reproduce by natural mating. We present results on spawning patterns during one entire reproductive season of wild Common sole, Solea solea, kept in two broodstock groups (28 animals in broodstock A; 20 animals in broodstock B) under semi-natural conditions. Batches of eggs were collected daily and incubated separately. First, we performed a parentage analysis on parents and samples of 24 newly hatched larvae from all batches, using 10 polymorphic microsatellite markers. As expected, contribution of parents to offspring was highly skewed. In both broodstocks, five or less parental pairs produced more than half of the total progeny. Natural spawning and unequal contributions of parents to offspring resulted in significant deviations from Hardy–Weinberg equilibria. Furthermore, few alleles were lost and levels of heterozygosity in offspring population increased. Next, we calculated relatedness between parents that mated successfully based on estimates of molecular similarity. Mean coefficients of coancestry in offspring were determined using parental relatedness and contributions. Levels of coancestry in progeny were substantially high. These results show that due to different parental contributions, natural mating in groups can result in significant inbreeding in future generations despite of limited loss of alleles and high levels of heterozygosity in first generation progeny. This shows that using loss of alleles and levels of heterozygosity alone can be misleading for estimation of genetic diversity.

Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA) are natural constituents found in human milk, fish oil or egg yolk. Until recently, infant formulas, though providing the essential fatty acid precursors for these PUFAs, did not contain preformed ARA or DHA. In this study the safety of SUNTGA40S as source of ARA, not only for use in infant formulas but also for nutritional products or food supplements, was evaluated in a subchronic study in Wistar rats, preceded by a 4-week pretreatment period of parental (F0) rats and exposure of the F0 dams throughout mating, gestation and lactation. SUNTGA40S was administered at dietary levels of 0.5%, 1.5% and 5% (wt/wt) adjusted with corn oil to 5.76% added fat. An additional group received 3.65% (wt/wt) SUNTGA40S in conjunction with 2.11% (wt/wt) high DHA Tuna oil, providing an ARA:DHA ratio of 2.7:1. High-fat and low-fat controls received basal diet with or without 5.76% corn-oil supplement. The content, stability and homogeneous distribution of the test substances in the diet were confirmed under study conditions. The administration of SUNTGA40S, with or without DHA oil, did not affect health, growth, fertility or reproductive performance of the parental rats, nor pup characteristics (condition, weight gain, viability, number per litter or sex ratio). In the subchronic study with the offspring (F1) rats, no significant differences were found in condition, neurobehavioural observations, ophthalmoscopy, growth, urinalysis or macroscopic and microscopic findings between the test groups and the low-fat or the high-fat controls. In males of the 5% SUNTGA40S and the SUNTGA40S/DHA group, red blood cell counts, haemoglobin concentration and packed cell volume were lower and reticulocytes were slightly higher than in the high-fat and low-fat control groups. Cholesterol, triglycerides and phospholipids in plasma were lower than in the high-fat controls in both sexes in the 5% SUNTGA40S and the SUNTGA40S/DHA group and (for triglycerides only) in the 1.5% SUNTGA group. Due to the administration of extra dietary fat, food intake and prothrombin time (males only) were lower and alkaline phosphatase activity was higher in all the high-fat groups, including the corn-oil controls, as compared to the low-fat controls. The weight of the spleen was higher in males of the 5% SUNTGA40S and the SUNTGA40S/DHA group compared to both the low-fat and the high-fat controls. The effects noted in this study at high dose levels of SUNTGA40S are consistent with previously reported physiological responses to dietary intake of high PUFA containing oils. The present results provide evidence that SUNTGA40S is a safe source of arachidonic acid. Except during lactation when the intake in dams doubled, 5% Suntga40S in the diet was equivalent to an overall intake of approximately 3 g/kg body weight/day in F0 and F1 animals. © 2005 Elsevier Ltd. All rights reserved.

The development of new feed additives has improved poultry performance. Potassium Diformate (KD) is one of the most recent product used in the animal production, especially in pork industry, however for poultry few data are available up to now. Two trials were done, with the objective to evaluate KD effect on broiler breeder productive and reproductive performance. The experiments were carried out at the Poultry Science Laboratory, Federal University of Santa Maria, RS, Brazil. For Trial 1, was used Cobb Breeder from 46th to 54th weeks old were used. Second Trial, Ross Breeder was with 41th to 49th weeks old were used. Birds were submitted to diets with increasing levels of KD. The parameters measured with brioler were: body weight, body weight gain, egg production, egg weight and specific gravity, relative weight of egg shell, yolk and albumen. At hatchery, measured parameters were percentage of alive hatched chick, hatchability, day-old chick weight, percentage of first and second grade chick, and embriodiagnosis. With the progeny, body weight, weight gain, feed intake and feed efficiency were recorded. A complete randomized design was used. For Trial 1, three treatments were used (0; 0.15 and 0.30% of KD), with four replicates with 45 female and 5 males per floor pen. For Trial 2, four treatments were used (0; 0.1; 0.2 and 0.3% of KD) with five replicates. Each replicate was composed by 23 females and two males by floor pen. Data were submitted to ANOVA and regression analysis. When statistically different (P< 0.5), Tukey test was used for mean comparison. Based on the current experiments, it can be concluded that KD fed to broiler breeder, resulted in negative effect on hatchery parameters, however positive effect on progeny performance were observed. Doing to the exploratory character of the trials, more research should be done, elucidating KD applicability and mode of action on broiler breeder. O desenvolvimento de novos aditivos para rações tem contribuído na melhoria da produtividade das aves, como o Diformiato de Potássio (DK), que têm demonstrado eficiência no desempenho de suínos, entretanto, existem poucos estudos na área avícola. Foram conduzidos dois experimentos com objetivo de avaliar os efeitos do DK sobre o desempenho produtivo e reprodutivo de matrizes de corte. Os experimentos foram conduzidos no Laboratório de Avicultura da Universidade Federal de Santa Maria, RS. Foram utilizadas matrizes de corte da linhagem comercial Cobb da 41a a 49a semanas de idade, para o Experimento 1 e, linhagem Ross da 46a a 54a semanas de idade para o Experimento 2. As matrizes foram submetidas aos tratamentos com adição de DK às dietas. Foi avaliado peso corporal, ganho de peso corporal, taxa de postura, gravidade específica, peso médio de ovos, e, peso percentual de clara, gema e casca. No incubatório foram avaliados percentagem de nascimento, eclodibilidade, peso de pintos, percentagem de pintos de primeira e segunda, e embriodiagnóstico. Nas progênies foram avaliados, peso corporal, ganho de peso corporal, consumo de ração e conversão alimentar. O delineamento experimental foi inteiramente casualizado. Para o Experimento 1, utilizouse três tratamentos (0,00%, 0,15% e 0,30% de DK) com quatro repetições de 45 fêmeas e 5 machos por unidade experimental. Para o experimento 2, utilizou-se quatro tratamentos (0,0%, 0,1%, 0,2% e 0,3% de DK) com cinco repetições de 23 fêmeas e 2 machos por unidade experimental. Os dados foram submetidos à análise de variância e análise de regressão. Onde ocorreram diferenças ao nível de 5% de significância, foi aplicado o teste de Tukey para comparação de médias. Nas condições em que foram realizados os experimentos, conclui-se que a adição de DK na alimentação de matrizes de corte implicou em efeitos negativos a nível de incubatório, entretanto, promoveu efeitos positivos no desempenho zootécnico de progênie. Contudo, em virtude do trabalho realizado ser inédito, se faz necessário mais estudos para elucidar a aplicabilidade e os mecanismos de ação do DK que possam beneficiar ou prejudicar o desempenho produtivo e reprodutivo de matrizes de corte.