Early induction of luteolysis in a timed AI protocol increases reproductive performance in beef cows.

The aim of this study was to produce a longer proestrus by early administration of prostaglandin F2α (PGF) in a timed artificial insemination (TAI) protocol in non-suckling Bos taurus (Angus crossbreed) beef cows. On day 0, cows (n = 489) were treated with an intravaginal 1 g progesterone (P4) device and 2 mg of estradiol benzoate. On day 7, cows were randomized into two groups: PGF7(n = 244; 500 µg of sodium cloprostenol 24 h before P4 device removal) or PFG8 (n = 245; 500 µg of sodium cloprostenol at P4 device removal). On day 8, P4 device was removed and cows received 0.5 mg of estradiol cypionate. All cows were submitted to TAI on day 10 (48-50 hours after P4 device removal). Cows treated with PGF on day 7 had greater expression of estrus (91.3 vs 79.1 %; P = 0.0011), regardless of CL presence at beginning of the protocol. Cows from PGF7 group had lower circulating P4 concentrations on day 8 in comparison with PGF8 treated cows (1.86 vs 2.99 ng/mL; P < 0.001). However, preovulatory follicle diameter did not differ among treatments at TAI (11.9 vs 11.8 mm; P = 0.7881). Pregnancy per TAI (P/TAI) was greater for PGF7 (63.9 vs 50.6 %; P = 0.0114) than PGF8 treated cows. In cows with follicles <8.5 mm at TAI, expression of estrus (33.3 vs 26.6 %; P = 0.6427) and P/TAI (40 vs 26.6 %; P = 0.3657) were low in both PGF7 and PGF8 treated cows, respectively. In cows with medium follicle size (8.5 to 11.9 mm) PGF7 treated cows had greater expression of estrus (90.5 vs 80 %; P = 0.033) and P/TAI (62.2 vs 49 %; P = 0.053). In cows with follicles >12 mm, expression of estrus was greater for PGF7 than PGF8 treated cows (99.1 vs 93.3 %; P = 0.045), however P/TAI did not differ (68.2 vs 59 %; P = 0.149). In cows with P4 < 1.99 ng/mL on day 8, expression of estrus was similar between PGF7 and PGF8 treated cows (92.6 vs 90.4 %; P = 0.53), and P/TAI tended to be greater for PGF7 than PGF8 treated cows (63 vs 52.1 % P = 0.076). However, in cows with P4 > 2 ng/mL PGF7 cows had higher expression of estrus (89 vs 67.5 %; P = 0.0005) and P/TAI (64.8 vs 48.7 %; P = 0.021) than PGF8. Thus, increasing the proestrous period by inducing luteolysis 24 hours earlier than removing the P4 intravaginal device enhanced fertility in non-suckling cyclic beef cows by increasing expression of estrus and P/TAI.

Effects of holes in plastic film on the storage losses in total mixed ration silage in round bales.

The ensilage of total mixed ration (TMR) is a technology designed to help farmers with limitations to provide a balanced diet for their herds. Our aim was to evaluate the conservation of TMR ensiled in round bales with or without holes in the wrapping plastic film. Eight round bales of a corn silage-based TMR of 1,000 kg (370 kg DM/m3) were prepared. Ten days (d) after ensiling, four bales were randomly punctured with two holes of 25 cm2 each in opposite sides of the bale. The temperature in the center of the bales was recorded during the storage using dataloggers. After 60 d of storage, bales were weighted to assess dry matter (DM) recovery. Silages were sampled for measuring DM content, chemical composition, pH, lactic acid, and microbial counts. The temperature of the sliced bale face was assessed by infrared thermography. The holes in the plastic affected the DM content, DM recovery, and pH, whereas lactic acid, microbial counts, and temperature were not affected by treatments. The holes in the sealing plastic film should be avoided. However, holes of 25 cm2 each were not capable of causing expressive losses in TMR silage stored in 1,000 kg bales.

Chemical composition, fermentative losses, and microbial counts of total mixed ration silages inoculated with different Lactobacillus species.

The objective of this study was to evaluate the effects of Lactobacillus inoculants on fermentation, losses, and aerobic stability of a total mixed ration (TMR) silage. A TMR, formulated to meet the requirements of dairy cows producing 25 kg of milk/d, was applied with the following treatments prior to ensiling: 1) Control (CON), 2) Lactobacillus buchneri (105 cfu/g of fresh forage; LB), and 3) Lactobacillus plantarum (105 cfu/g of fresh forage; LP). TMR silages were ensiled for 15 and 60 d in silos equipped with an apparatus for determination of gravimetric DM, gas, and effluent losses. The experiment was performed in a complete randomized design with a 3 × 2 factorial arrangement of the treatments, with 5 replicates per treatment. Chemical changes, microbial counts, fermentation profile, and aerobic stability were measured after opening the silos. Data were submitted to ANOVA, and means were compared by Tukey and T-test and statistical significance was declared at P ≤ 0.05. After 15 d of ensiling, the inclusion of inoculant decreased NDF (P < 0.05) and butyric acid concentrations (P < 0.05) in TMR. LP had the lowest aerobic stability (P < 0.05) and the greatest loss of DM (P < 0.03). Ensiling for 60 d increased ammonia nitrogen (NH3-N), lactic acid bacteria (LAB), aerobic stability, and concentrations of lactic and acetic acid (P < 0.01) and lowered (P < 0.02) total fermentation losses compared to 15 d across all treatments. After 60 d of ensiling, LP lowered pH to the greatest extent. Treatment had no effect on concentrations of DM, CP, ADF, ash, and EE, as well as in vitro DM digestibility. In conclusion, inoculants containing LP or LB did not improve fermentation profile, did not prolong the aerobic stability, nor reduced losses. Furthermore, the 15-d ensiling period was insufficient for adequate bacterial activity.

Optimizing timed AI protocols for Angus beef heifers: Comparison of induction of synchronized ovulation with estradiol cypionate or GnRH.

This study compared estradiol cypionate (ECP) or GnRH as ovulation inducers at the end of a timed AI (TAI) protocol in Angus heifers. On day 0, heifers (n = 415), between 22 and 24 months of age, were treated with an intravaginal 1 g progesterone (P4) insert and 2 mg of estradiol benzoate. On day 8, heifers had P4 removed, received 500 µg cloprostenol, and were randomized into two groups: ECP [n = 214; 0.5 mg of ECP on day 8] or GnRH [n = 201; 25 µg of GnRH analog licerelin acetate on day 10]. All heifers received TAI on day 10; 48-50 h after P4 insert withdrawal. Estrus was determined by removal of tail paint. Ovaries of heifers were evaluated by ultrasound on day 0 to determine CL presence (with CL = 213, without CL = 202) and on day 10 to measure preovulatory follicle size. Heifers were divided into three categories based on preovulatory follicle diameter: <8.5 mm (smaller than deviation), 8.5-10.9 mm, or ≥11 mm. Pregnancy diagnosis was performed 32 days after TAI. Heifers treated with ECP had greater expression of estrus than GnRH-treated heifers (93.9% vs 67.7%; P < 0.0001), regardless of CL presence at beginning of protocol. Heifers with CL at beginning of protocol had larger preovulatory follicle diameter (10.4 mm vs 9.6 mm; P = 0.0058) and greater pregnancy per AI (P/AI; 61.0% vs 50.5%; P = 0.032) than heifers without CL at day 0. In heifers with CL at day 0, GnRH treatment increased P/AI compared to ECP treatment (68.0% vs 54.9%; P = 0.0498). Expression of estrus was greater in ECP-treated than GnRH-treated heifers that had small (<8.5 mm; 77.1% vs 5.6%; P < 0.001) or medium-sized (8.5-10.9 mm; 98.4% vs. 61.7%) follicles, but not in heifers with large follicles (≥11 mm; 97.9% vs 98.3%). The P/AI was very low in both treatments for heifers with follicles <8.5 mm (ECP-14.3% vs GnRH-16.7%). In heifers with medium-sized follicles (8.5-10.9 mm), ECP treatment tended to increase P/AI compared with GnRH-treated heifers (62.9 vs 46.7%; P = 0.074). In contrast, P/AI was greater for GnRH-treated than ECP-treated heifers with large preovulatory follicles (≥11 mm; 79.7% vs 60.4%; P = 0.032). Thus, the optimal inducer of ovulation in a TAI protocol for beef heifers appears to depend on the presence of a CL at beginning of protocol (GnRH > ECP if CL present) and size of the preovulatory follicle, with ECP increasing expression of estrus and tending to increase fertility in heifers with medium-sized follicles but GnRH increasing fertility in heifers having large preovulatory follicles.

Effect of combined aerobic and resistance training in body composition of obese postmenopausal women

The aim of this study was to investigate the effects of a 16-week program of combined aerobic and resistance training on the body composition of postmenopausal women who are obese. The participants were divided into two groups: training group (TG, n = 37) and non-trained control group (CG, n = 18). The trunk fat, fat mass, percentage of fat mass and fat-free mass were estimated using DXA. Three nonconsecutive 24-hour dietary recalls were conducted. The training protocol consisted of 50 minutes of resistance training followed by 30 minutes of aerobic training. After the 16-week training program, differences were observed in trunk fat (CG= 0.064 x TG= -0.571 Kg; p-value = .020), fat mass (CG= -0.088 x TG= -1.037 Kg; p-value = .020) and fat-free mass (CG= -0.388 x TG= 1.049 Kg; p = .001). Therefore, a 16-week program of systematic combined aerobic and resistance training in obese postmenopausal women was effective in improving fat-free mass and decreasing both whole and abdominal adiposity.

O objetivo deste estudo foi investigar os efeitos de 16 semanas de treinamento aeróbio e resistido combinados na composição corporal de mulheres na pós-menopausa. As participantes foram divididas em dois grupos: grupo treinamento (GT, n = 37) e grupo controle (GC, n = 18). A gordura de tronco, massa gorda, percentual de gordura e massa livre de gordura foram estimadas pelo DEXA. O recordatório alimentar de 24 h foi realizado três dias não consecutivos para controle alimentar. O protocolo de treinamento consistiu de 50 minutos de treinamento resistido seguido por 30 minutos de treinamento aeróbio. Após 16 semanas de treinamento diferenças foram observadas na gordura de tronco (GC= 0,064 x GT= -0,571 Kg; p-valor= 0,020), massa gorda (GC= -0,088 x GT= -1,037 Kg; p-valor= 0,020) e massa livre de gordura (GC= -0,388 x GT= 1,049 Kg; p-valor=0,001). Assim, 16 semanas de treinamento aeróbio e resistido combinado em mulheres obesas na pós-menopausa é efetivo em aumentar a massa livre de gordura e reduzir adiposidade total e abdominal.

El objetivo de este estudio fue investigar los efectos de 16 semanas de entrenamiento aeróbico y de resistencia combinada en la composición corporal en mujeres posmenopáusicas obesas. Los participantes fueron divididos en dos grupos: grupo de entrenamiento (GE, n = 37) y control (C, n = 18). La grasa del tronco, la masa grasa, porcentaje de masa grasa y masa libre de grasa se ​​ utilizó el DXA. El recordatorio de 24 horas se realizó tres días no consecutivos para el control de los alimentos. El protocolo de entrenamiento consistió en 50 minutos de entrenamiento de resistencia, después 30 minutos de entrenamiento aeróbico. Después de 16 semanas de entrenamiento, no se observaron diferencias en la grasa del tronco (C= 0,064 x GE= -0,571 Kg; p-valor= 0,020), la masa grasa (C= -0,088 x GE= -1,037 Kg; p-valor = 0,020 Kg) y libre de grasa (C= -0,388 x GE= 1,049 Kg; p= 0,001). Así, 16-semana de entrenamiento aeróbico y de resistencia combinada en las mujeres posmenopáusicas con obesidad es eficaz en la mejora de la masa libre de grasa y la disminución de la masa grasa y la adiposidad abdominal.

The 18S rRNA from Odontophrynus americanus 2n and 4n (Amphibia, Anura) reveals unusual extra sequences in the variable region V2.

The nucleotide sequence of the rDNA 18S region isolated from diploid and tetraploid species of the amphibian Odontophrynus americanus was determined and used to predict the secondary structure of the corresponding 18S rRNA molecules. Comparison of the primary and secondary structures for the 2n and 4n species confirmed that these species are very closely related. Only three nucleotide substitutions were observed, accounting for 99% identity between the 18S sequences, whereas several changes were detected by comparison with the Xenopus laevis 18S sequence (96% identity). Most changes were located in highly variable regions of the molecule. A noticeable feature of the Odontophrynus 18S rRNA was the presence of unusual extra sequences in the V2 region, between helices 9 and 11. These extra sequences do not fit the model for secondary structure predicted for vertebrate 18S rRNA.