Vasopressin effectively suppresses male fertility.

Arginine vasopressin (VP) is neurohypophysial hormone has been implicated in stimulating contractile activity of the male reproductive tract in the testis. Higher levels of VP decrease sperm count and motility. However, very little is known about the involvement of VP in controlling mammalian reproductive process. The goal of this study was to confirm that effect of VP receptor (AVPR2) on sperm function in capacitation condition. Deamino [Cys 1, D-ArgS] vasopressin (dDAVP), an AVPR2 agonist that operates only on AVPR2, was used. Also, Mouse spermatozoa were incubated with various concentrations of dDAVP (10(-11)-10(-5) M) and sperm motility, capacitation status, Protein Kinase A activity (PKA), tyrosine phosphorylation, fertilization, and embryo development were assessed using computer-assisted sperm analysis, Combined Hoechst 33258/chlortetracycline fluorescence, Western blotting, and in vitro fertilization, respectively. AVPR2 was placed on the acrosome region and mid-piece in cauda epididymal spermatozoa, but the caput epididymal spermatozoa was mid-piece only. The high dDAVP treatment (10(-8) and 10(-5) M) significantly decreased sperm motility, intracellular pH and PKA substrates (approximately 55 and 22 kDa) and increased Ca(2+) concentration. The highest concentration treatment significantly decreased PKA substrate (approximately 23 kDa) and tyrosine phosphorylation (approximately 30 kDa). VP detrimentally affected capacitation, acrosome reaction, and embryo development. Treatment with the lowest concentration (10(-11) M) was not significantly different. Our data have shown that VP stimulates ion transport across sperm membrane through interactions with AVPR2. VP has a detrimental effect in sperm function, fertilization, and embryonic development, suggesting its critical role in the acquisition of fertilizing ability of mouse spermatozoa. These research findings will enable further study to determine molecular mechanism associated with fertility in capacitation and fertilization. It is also an important pivotal precondition to the progress of diagnostic test to identify infertility and to apply male contraception.

Effects of corn dried distiller's grains with solubles and enzyme premix supplements on growth performance, carcass characteristics and meat quality parameters in finishing pigs.

The objective of the present study was to investigate the effects of corn dried distiller's grains with solubles (DDGS) and enzyme premix (mannanase + phytase) supplementation on the growth performance, carcass and meat quality parameters in finishing pigs. Sixty hybrid pigs (L × LW × D) with initial weight of 63.92 ± 1.50 kg were used in a 3 × 2 factorial design with main effects of DDGS levels (0, 10 and 20%) and enzyme premix levels (0% vs. 0.14%). Average daily gain (ADG, P < 0.01) and average daily feed intake (ADFI, P < 0.05) were decreased due to an increased level of DDGS additive while the feed conversion ratio was improved (P < 0.05) by adding enzyme premix. The diet cost/gain (won/kg) was saved (P < 0.01) due to an increased level of DDGS additive. There were no significant differences in carcass characteristics and meat quality parameters of Longissimus dorsi muscle by DDGS level and enzyme premix. Palmitoleic acid, oleic acid and monounsaturated fatty acid (MUFA) decreased (P < 0.05) according to DDGS level. The results indicate that DDGS may be used in feeds for finishing pig as a replacement of corn and soybean meal without affecting their carcass characteristics and meat quality.

The effect of Eucommia ulmoides leaf supplementation on the growth performance, blood and meat quality parameters in growing and finishing pigs.

The aim of the present study was to investigate the effect of Eucommia ulmoides leaf (EUL) supplementation on the growth performance, blood and meat quality parameters in growing and finishing pigs. Ninety gilts (L x LW x D, 20 kg initialBW) were housed 10 per pen in a front-open building with three replicate pens per treatment. Experimental treatment was started from the beginning of the growing stage (20 +/- 3 kg) by supplementing EUL at 0(C), 3(T1) and 5% (T2) to the growing and finishing diet. Pigs were slaughtered by electrical stunning at 105 +/- 3 kg live weight. Average daily feed intake (ADFI, kg/day) decreased (P < 0.05) by addition of EUL in growth performance, average daily gain (ADG, kg/day) was lower (P < 0.05) in T1 and T2 than in C. In hematology, leukocytes (WBC, 10(3)/mm(3)) decreased (P < 0.05) in T1 and T2 than in C. Erythrocytes (RBC, 10(6)/mm(3)), hemoglobin (HGB, g/dL) and hematocrit (HCT, %) increased (P < 0.05) in T1 and T2 than in C. Platelet (PLT, 10(3)/mm(3)) was lower (P < 0.05) in T2 than in C and T1. In biochemical composition of serum, total protein (g/dL), r-GTP (micro/L), total cholesterol (mg/dL) and triglycerides (mg/dL) were lower (P < 0.05) in T1 and T2 than in C. On longissimus dorsi muscle, crude protein was higher (P < 0.05) in T1 than in C. Crude ash was higher (P < 0.05) in T1 and T2 than in C. Yellow to blue color scale (CIE b*) in meat color was higher (P < 0.05) in T2 than in C. CIE b* in back fat color was higher (P < 0.05) in T2 than in the other treatments. In sensory evaluation scores for fresh meat, the values of meat color, fat color, drip loss and marbling were not significantly affected by addition of EUL. In cooked meat, the values of chewiness and overall acceptability were higher (P < 0.05) in T1 and T2 than in C. The results indicate that the addition of EUL affected growth performance, blood parameters and meat quality parameters in growing and finishing pigs.

The effect of fermented apple diet supplementation on the growth performance and meat quality in finishing pigs.

The objective of the present study was to investigate the effect of fermented apple diet (FAD) supplementation on the growth performance and meat quality in finishing Berkshires. The FAD was made from dropped apple mixed with rice bran and barley bran. Until 81 +/- 1 kg live weight at 133 +/- 1 days, the animals were fed a growing diet, after which experimental samples were fixed at 0, 2, 4 and 6% FAD as C, T1, T2 and T3 in the finishing diets. Growth performance, ADG, ADFI and feed efficiency were improved in T1 than other groups. In carcass parameters, carcass weight was higher (P < 0.05) in T1 than in other groups. In meat quality, moisture and crude protein contents decreased (P < 0.05) by addition of FAD. pH(24) and WHC were higher (P < 0.05) in T1 than other groups. In sensory evaluation, marbling of fresh meat and tenderness, juiciness, flavor and overall acceptability of cooked meat were improved by the addition of FAD. According to the results of our experiment, FAD can be used for improvement of meat quality parameters.

Reducing endogenous estrogen during development alters hormone production by porcine Leydig cells and seminiferous tubules.

High levels of estrogen produced by boar testes and the presence of estrogen receptors in both interstitial and tubular compartments are consistent with a direct role for estrogen in regulation of testicular cell function. This study investigated the importance of estrogen on hormone production by Leydig cells and seminiferous tubules in the developing boar. Thirty-six 1-week-old littermate pairs of boars were treated weekly with vehicle or 0.1 mg/kg BW Letrozole, an aromatase inhibitor, until castration at 2, 3, 4, 5, 6, 7, or 8 months. Tissue was collected and Leydig cells and seminiferous tubules were isolated. In a separate study, five untreated boars (ages 1.5-4 months) were castrated and Letrozole was added in vitro to Leydig cell and seminiferous tubule cultures. Leydig cells were cultured for 24h with and without porcine LH. Media were assayed for estradiol (E(2)) and testosterone (T) concentrations by RIA. Seminiferous tubules were cultured for 4h with and without porcine FSH; media were assayed for E(2) and immunoreactive inhibin (INH). In vivo aromatase inhibition decreased basal E(2) and increased basal T production by cultured Leydig cells. Basal seminiferous tubule production of E(2) but not INH was reduced. Decreasing estrogen synthesis in vivo did not alter LH-induced Leydig cell E(2) production or FSH-induced seminiferous tubule INH production. INH production decreased with advancing age regardless of treatment. In conclusion, in vivo aromatase inhibition altered baseline steroid production by cultured Leydig cells and seminiferous tubules but had little effect on response to gonadotropins.

Effect of exposure duration of ovaries and oocytes at ambient temperature on parthenogenetic development of porcine follicular oocytes.

This study was conducted to evaluate the effects of exposing porcine ovaries to 30-33 C during transportation for 4 h and subsequently room temperature (25 C) for 6 h of storage on in vitro maturation (IVM) and subsequent parthenogenetic development of oocytes collected from the ovaries. After IVM, oocytes having a tight oopalsm membrane and no signs of degeneration were exposed to Dulbecco's phosphate-buffered saline (DPBS) with 7% ethanol (v/v) for 7 min to induce parthenogenetic activation. Moreover, we also determined whether exposure of the collected oocytes to room temperature for 1, 2 and 4 h in DPBS or porcine follicular fluid (pFF) affected parthenogenetic development. When porcine ovaries were stored after transportation, oocytes collected from the stored ovaries showed a significantly higher rate of degeneration after 65 h of IVM (58.4%) and a significantly lower rate of cleavage after parthenogenetic activation (40.1%) than oocytes collected from ovaries immediately after transportation (38.9% and 47.4%, respectively). However, there was no significant difference in developmental rates to the morula and blastocyst stages between these two groups (14.4% and 14.3%, respectively). The duration of preservation, 1, 2, and 4 h, of oocytes in DPBS did not affect parthenogenetic development. In contrast, when preserved for 4 h in pFF, the developmental rates of the oocytes were significantly decreased. This suggested that some factor(s) in follicular fluid affects the developmental rate of oocytes with the passage of time in ambient conditions. These results suggest that even after 6 h storage of ovaries, oocytes having normal morphology after IVM have the same rate of parthenogenetic development as oocytes collected from ovaries just after 4 h of transportation, except for a lower cleavage rate, and that exposure of oocytes to room temperature for 4 h in DPBS does not affect their parthenogenetic developmental competence.