Dietary crude protein levels during growth phase affects reproductive characteristics but not reproductive efficiency of adult male Japanese quails.

OBJECTIVE: The objective was to evaluate the influence of different dietary crude protein (CP) levels during the growth phase on reproductive characteristics and reproductive efficiency as well as the body development of adult male Japanese quail. METHODS: Three hundred one-day-old male quails were distributed into five treatments with diets containing different CP levels (18%, 20%, 22%, 24%, and 26%) in a completely randomized design, with six replicates of ten birds each. The CP diets were applied only during the growth phase (1 to 35 days). At 36 days of age, the birds were transferred to 30 laying cages with three males and nine females each, and all birds received the same diet formulated to meet production-phase requirements until 96 days of age. RESULTS: The growth rate of the birds increased linearly (p<0.01) with increasing dietary CP, but the age of maximum growth decreased (p<0.05). At growth maturity, all birds had the same body weight (p>0.05). At 35 days of age, higher weight gain was obtained (p<0.05) with diets containing 22% CP or higher. No effects on feed conversion were observed in this phase. The increase in dietary CP enhanced (p<0.01) nitrogen intake and nitrogen excretion but did not affect (p>0.05) nitrogen retention. Testis size, seminiferous tubular area, number of spermatogonia, and germinal epithelial height at 35 days of age increased linearly (p<0.05) with dietary CP, while the number of Leydig cells decreased (p<0.01). The Sertoli cell number at 60 days of age increased linearly (p<0.01) with dietary CP. Dietary CP levels did not affect cloacal gland size, foam weight, foam protein concentration, semen volume, or flock fertility at 90 days of age. CONCLUSION: Dietary CP concentration affected body and testicular development in male Japanese quails but did not affect reproductive efficiency.

Chlorogenic acid improves the quality of boar semen processed in Percoll.

This study aimed to evaluate if the addition of chlorogenic acid (ChA) to semen extenders improves the quality of cooled boar semen processed in Percoll. The experimental design was randomized blocks (ejaculates) in a 2×3 factorial (with or without Percoll, and three antioxidant systems: a negative control, without supplementation, a positive control - vitamin E, and ChA), totaling six treatments and 12 repetitions. ChA and vitamin E (VE) were added at 4.5 mg/ml and 400 µg/ml in extender, respectively. At 0, 48 and 72h of storage at 15ºC, 80 ml insemination doses each containing 2.0 billion sperm cells were submitted to centrifugation in Percoll. The use of Percoll impaired (P<0.01) all motility patterns but decreased (P<0.01) the number of abnormal cells at 0, 48 and 72h of storage. Both VE and ChA improved (P<0.05) the total motility after Percoll processing, but only in semen stored for 48h. The same effect was not observed (P>0.05) in semen stored for 72h. ChA improved (P<0.05) the total motility of the semen stored for 72h, but this effect was not observed (P>0.05) when the semen was processed in Percoll. The antioxidants had no effect (P>0.05) on the viability and integrity of the acrosome, but ChA reduced (P<0.05) the number of abnormal cells at 0h, while VE increased the number of abnormal cells in semen stored for 72h, independent of the use of Percoll. There was no effect (P>0.05) of antioxidants or Percoll on the concentration of malondialdehyde in seminal plasma. The use of Percoll had no effect (P>0.05) on the cholesterol efflux, but ChA increased (P<0.05) this parameter at 0h and reduced (P<0.05) in the semen stored for 72h not processed with Percoll. In conclusion, the addition of ChA to semen extenders improved the quality of boar semen processed or not in Percoll.

Histological characteristics of the gonads of pig fetuses and their relationship with fetal anatomical measurements.

The objective was to evaluate the histomorphometric characteristics of the testis and ovaries of pig fetuses at different gestational ages, as well as their correlation with some fetus measurements. Forty-four fetuses were separated for gender (male and female) and gestational age (50, 80 and 106days of gestation). After slaughter, fetuses had their body length, head and thoracic perimeters measured and their gonads submitted to histomorphometric analyses. The gonadal characteristics at different gestational ages were statistically compared, correlations with the fetal measurements were performed and equations to predict the gonadal characteristics from the fetal measurements were obtained. The testis weight logarithmically increased along pregnancy, whereas ovary weight increased in a linear manner. The cordonal length and number of Sertoli cells were positively correlated with the fetal measurements, being higher at 106days gestation, while the nuclear volume of these cells were negatively correlated. The total number of follicles was higher at day 80 and 106 of pregnancy. The number of oogonia decreased along the pregnancy, however, their nucleus size was increased. The number of follicles and volume of oogonia were positively correlated with the fetal measurements, while the number of oogonia was negatively correlated. Equations were obtained for the prediction of gonadal characteristics of fetuses. We concluded that in pigs testis cell proliferation, ovary development and histological organization was more pronounced during the final third of pregnancy. Fetal weight and size were strongly related to gonadal development, and can be used to estimate the histological characteristics of gonads.

Supplementing Maturation Medium With Insulin Growth Factor I and Vitrification-Warming Solutions With Reduced Glutathione Enhances Survival Rates and Development Ability of in vitro Matured Vitrified-Warmed Pig Oocytes.

The present study sought to determine whether in vitro maturation (IVM) of pig oocytes in a medium supplemented with insulin growth factor-I (IGF-I) and subsequent vitrification with or without reduced glutathione (GSH) affect their quality and developmental competence, and the expression of genes involved in antioxidant, apoptotic and stress responses. In Experiment 1, cumulus-oocyte complexes were matured in the absence or presence of IGF-I (100 ng·mL-1) and then vitrified-warmed with or without 2 mM of GSH. Maturation rate was evaluated before vitrification, and oocyte viability, DNA fragmentation and relative transcript abundances of BCL-2-associated X protein (BAX), BCL2-like1 (BCL2L1), heat shock protein 70 (HSPA1A), glutathione peroxidase 1 (GPX1) and superoxide dismutase 1 (SOD1) genes were assessed in fresh and vitrified-warmed oocytes. In Experiment 2, fresh and vitrified-warmed oocytes were in vitro fertilized and their developmental competence determined. Whereas the addition of IGF-I to maturation medium had no effect on oocyte maturation, it caused an increase in the survival rate of vitrified-warmed oocytes. This effect was accompanied by a concomitant augment in the relative transcript abundance of HSPA1A and a decrease of BAX. Furthermore, the addition of GSH to vitrification-warming media increased survival rates at post-warming. Likewise, the action of GSH was concomitant with an increase in the relative abundance of GPX1 and a decrease of BAX transcript. Blastocyst rates of vitrified-warmed oocytes did not differ from their fresh counterparts when IGF-I and GSH were combined. In conclusion, supplementing maturation medium with 100 ng·mL-1 IGF-I and vitrification-warming solutions with 2 mM GSH improves the quality and cryotolerance of IVM pig oocytes, through a mechanism that involves BAX, GPX1 and HSPA1A expression.