Pregnancy success results from the interaction of multiple factors, among them are folliculogenesis and early embryonic development. Failure during these different processes can lead to difficulties in conception. Alternatives to overcome these problems are based on assisted reproductive techniques. Extracellular vesicles are cell-secreted vesicles present in different body fluids and contain bioactive materials, such as messenger RNA, microRNAs (miRNAs), and proteins. Thus, our hypothesis is that extracellular vesicles from follicular fluid from 3–6 mm ovarian follicles can modulate bovine embryo development in vitro. To test our hypothesis follicular fluid from bovine ovaries was aspirated and small-extracellular vesicles (<200 nm) were isolated for further analysis. Additionally, small-extracellular vesicles (EVs) were utilized for functional experiments investigating their role in modulating messenger RNA, microRNA as well as global DNA methylation and hydroxymethylation levels of bovine blastocysts. EVs from 3–6 mm follicles were used for RNA-seq and miRNA analysis. Functional annotation analysis of the EVs transcripts revealed messages related to chromatin remodeling and transcriptional regulation. EVs treatment during oocyte maturation and embryo development causes changes in blastocyst rates, as well as changes in the transcription levels of genes related to embryonic metabolism and development. Supplementation with EVs from 3–6 mm follicles during oocyte maturation and early embryo development (until the 4-cell stage) increased the levels of bta-miR-631 (enriched in EVs from 3–6 mm follicles) in embryos. Interestingly, the addition of EVs from 3–6 mm follicles induced changes in global DNA methylation and hydroxymethylation levels compared to embryos produced by the standard in vitro production system. Our results indicate that the supplementation of culture media with EVs isolated from the follicular fluid of 3–6 mm follicles during oocyte maturation and early embryo development can partially modify metabolic and developmental related genes as well as miRNA and global DNA methylation and hydroxymethylation, suggesting that EVs play an important role during oocyte maturation and early embryo development in vitro.

a b s t r a c tThe aim was to evaluate growth, carcass traits, feed efficiency reranking, body composition, calpain system activity and meat quality in Nellore steers that were phenotypically ranked for high and low residual feed intake (RFI). Seventy-two Nellore steers (16-21 month-old, 334719 kg BW) had free access to a feedlot diet for 70 d (feeding period 1, P1). Daily dry matter intake (DMI), body weight gain (ADG) and ultrasound carcass traits were measured individually. The 12 lowest and the 12 highest RFI steers were classed as low-and high-RFI groups and were fed for a second feeding period (feeding period 2, P2). Spearman's rank correlation was performed for RFI and gain-to-feed ratio (G:F) measured over P1 and P2. The carcass traits, meat quality and calpain system activity were evaluated at slaughter, and body composition was determined. In P1, low-RFI steers had greater G:F (0.159 vs. 0.134; Po0.001), lower DMI (9.30 vs. 11.1 kg/d; Po0.0001), lower RFI (À 0.80 vs. 0.85 kg/d; Po0.0001), and tended to have lower rates of rump fat gain (4.48 vs. 6.05 mm; P¼ 0.06), but no differences were observed for ADG, BW, and other traits measured by ultrasound (P40.05). In P2, no differences between RFI classes were observed for G:F and DMI as a percentage of BW (P40.05), and small differences were observed for DMI (8.25 vs. 8.99 kg/d, Po0.05) and RFI (À 0.28 vs. þ0.29 kg/d, P¼0.06). The ranking correlations for RFI and G:F measured consecutively in P1 and P2 were low to moderate (r¼ 0.11-0.40). Low-RFI steers had lower requirements of metabolizable energy (ME) for maintenance (131 vs. 160 Mcal/kg EBW 0.75 d À 1 , Po0.05), but no differences were observed for fat and protein gain, retained energy and efficiency of ME use for gain (P40.05). No differences between low-and high-RFI steers were observed for carcass traits at slaughter; however, low-RFI steers had 8.1 kg less gastrointestinal fat than high-RFI steers. There were no RFI effects on meat shear force and the activities of m-calpain, m-calpain and calpastatin (P40.05). High-RFI steers had greater MFI in 1 d aged LM (53.9 vs. 40.8, Po0.05). The variation in feed efficiency between high-and low-RFI Nellore steers is related to differences in energy requirements and deposition of fat on internal organs. The ranking for feed efficiency is altered as cattle become older. The selection for improved RFI in Nellore cattle may reduce feed requirements for beef production without affecting meat tenderness and enzymatic activity of the calpain system.

Milk and its derivatives are important foods that contribute to daily nutrient requirements and improve consumers’ health. This study evaluated the effects of supplementing the diet of lactating dairy cows with sunflower oil (SFO), selenium, and vitamin E on the milk’s fatty acid profile and fat oxidative stability as well as the acceptability of the milk by consumers. For this purpose, 32 Jersey dairy cows were allocated to four treatment groups for 60 days, as follows: C (control diet); A (3.5 mg/kg DM (dry matter) organic selenium + 2000 IU vitamin E/cow per day); O (4% SFO DM); OA (equal doses of A and O treatments). The inclusion of SFO decreased the contents of 10:0, 10:1, 11:0, 12:0, 12:1, 14:0, and 9c-14:1 fatty acids as well as odd- and branched-chain fatty acids (13:0, iso 13:0, anteiso 13:0, 15:0, iso 15:0, and 17:0). There was also a tendency for 8:0 and 16:0 fatty acid concentrations to decrease when SFO was included in the cows´ diet. SFO decreased the concentration of 10:0 to 15:0 fatty acids in milk. The sum of the conjugated linoleic acids (CLAs), conjugated alpha-linolenic acid intermediates (CLnAs; 18:3 ω6 + 18:3 ω3), and 22:0 fatty acids in milk tended to increase, and there were significant increases in 18:0 and 9c11t-18:2 with SFO. In terms of the effects of SFO on the health-related lipid indices, the atherogenicity index tended to decrease and h/H tended to increase. When cows were supplemented with antioxidants, the concentration of 20:2 fatty acids decreased, the 6 + 7 + 8 + 9t-18:1, 16t-18:1, 20:0, 22:2, and 24:0 fatty acid concentrations increased, and there was a trend for the 22:1 ω9 fatty acid concentration to increase with antioxidants plus oil. There was a tendency for ω6 fatty acids and ω6/ω3 to increase with milk treated with antioxidants plus oil. The oxidative stability of milk was not influenced by the presence of SFO or antioxidants in the diet of dairy cows. Consumers desired the color and mouthfeel of the milk that was treated with SFO. Cows fed with 4% sunflower oil produced milk with an improved fatty acid profile for human nutrition, containing a higher CLA content and an improved ratio of hypocholesterolemic and hypercholesterolemic fatty acids, without increasing the milk’s susceptibility to oxidation. The milk was also rated as being more acceptable by consumers.

Quatorze bezerros com quatro meses de idade, foram distribuídos em dois tratamentos, sendo um controle e um com suplementação de 0,4 mg de cromo orgânico por kg/M.S de ração basal. A ração basal foi constituída de 52% de feno de coastcross e 48% de concentrado à base de fubá de milho e soja extrusada, e foi oferecida ao animais durante 98 dias. Foi efetuado o controle diário da ingestão de alimentos. Na última semana foi realizado um teste de tolerância à glicose, com os animais em condições de conforto térmico. Para os grupos controle e tratado , o ganho em peso (1,330 e 1,320 kg/dia), a eficiência alimentar (0,24 e 0,25 kg) e a conversão alimentar (4,13 e 4,07 kg), foram semelhantes. Apesar de o grupo tratado apresentar tendência de eliminar a glicose mais rapidamente, os grupos não diferiram entre si.

Apoptosis and necrosis are two distinct forms of cell death that can occur in response to different agents and stress conditions. In order to verify if the oxidative stress induced by dietary selenium and vitamin E deficiencies can lead muscle cells to apoptosis, one-day-old chicks were reared using diets differing in their vitamin E (0 or 10 IU/kg) and selenium (0 or 0.15 ppm) supplementation. Chick skeletal muscle tissue was obtained from 28-day-old animals and used to verify apoptosis occurrence based on caspase activity detection and DNA fragmentation. Antioxidant deficiency significantly increased caspase-like activity assessed by the hydrolysis of fluorogenic peptide substrates (Abz-peptidyl-EDDnp) at lambda exc = 320 nm and lambda em = 420 nm. Proteolytic activation was not accompanied by typical internucleosomal DNA fragmentation detected by field inversion gel electrophoresis. Although the general caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone (Z-VAD-fmk) (0 to 80 muM) did not block caspase-like activity when preincubated for 30 min with muscle homogenates, the hydrolyzed substrates presented the same cleavage profile in HPLC (at the aspartic acid residue) when incubated with the purified recombinant enzyme caspase-3. These data indicate that oxidative stress causes caspase-like activation in muscle cells and suggest that cell death associated with exudative diathesis (dietary deficiency of selenium and vitamin E) can follow the apoptotic pathway.