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This study was conducted to investigate the potential effects of active immunization against recombinant-derived goose inhibin-α (INH-α), anti-Müllerian hormone (AMH), and prolactin (PRL) fusion protein on broodiness onset and egg production in geese. The purified fusion proteins (INH-α, AMH, and PRL) were prepared using a prokaryotic expression system. Female Zhedong geese (10 mo old) were randomly assigned to one of 4 treatments and raised in separate pens. The geese were actively immunized with the recombinant goose INH-α, AMH, or PRL, respectively, and phosphate-buffered saline as control. The results showed the corresponding antibodies were produced when the geese were immune INH-α, AMH-, and PRL-recombinant proteins. The significantly higher luteinizing hormone contents were observed in the INH-α, AMH, and PRL recombinant protein-immunized geese, while the lower AMH hormone content only in PRL-immunized birds. AMH recombinant protein immunized geese had more large yellow follicles of ovary, while the INHα-treated birds with more other follicles compared with control geese. In addition, the geese receiving INH-α recombinant protein, the broodiness onset was about 6 d, which significantly shorter than did PBS immunization (16 d). The INHα- and PRL-immunization also resulted in 12.5 and 8.5 d shorter broody duration intervals compared to the control birds. Moreover, the lower new broodiness rate was observed in three recombinant proteins treated birds. Finally, the PRL recombinant protein-immunization resulted in an average increase of 1.34 eggs during a 40-d observation. Collectively, the data demonstrated that active immunization against recombinant proteins INH-α or AMH could promote LH hormone secretion, regulate follicle development and decrease the broodiness rate. Also, active immunization with a recombinant-derived goose PRL protein might improve egg laying performance.

Decreasing fertility in aging domestic roosters is a well-known phenomenon. Aging is manifested by a decrease in plasma testosterone level, testis function, and spermatogenesis, resulting in a low level of fertility. The roles of vasoactive intestinal peptide (VIP) and testicular inhibin in this aging process are not clear. The effects of active immunization against VIP, inhibin, or the combination of both hormones on the reproduction of aging White Leghorn (WL) roosters were assayed. In experiment 1a, 60 White Leghorn roosters (67 wk of age) were divided into 4 groups (n = 15/group). The first group was actively immunized against VIP, the second against inhibin, the third against VIP and inhibin, and the fourth served as a control. Active immunization against VIP decreased semen quality parameters, plasma steroid levels, and gene expression of gonadotropin-releasing hormone-I (GnRH-I), follicle-stimulating hormone (FSH), luteinizing hormone (LH), LH receptor, VIP, and prolactin (Prl). Immunization against inhibin increased some of the semen quality parameters and FSH mRNA gene expression but decreased inhibin gene expression. In experiment 1b, at 94 wk of age, we took the actively immunized against VIP group and the control group and divided them into 2 subgroups (n = 7 or 8): the first group was injected with 1 mg of ovine Prl (oPrl) daily for 7 d, and the second group served as a control. Administration of oPrl to previously VIP-immunized birds significantly elevated semen quality parameters. We suggest that VIP, Prl, and inhibin have an important effect on the reproductive axis in aging roosters. Active immunization against VIP-depressed reproductive activity and Prl administration restored their reproduction, indicating that both VIP and Prl are essential for reproduction in aging roosters. Immunization against inhibin improved FSH mRNA gene expression, suggesting a negative role of inhibin on FSH secretion in aging roosters. Not all semen quality parameters increased significantly after immunization against inhibin, even though FSH mRNA gene expression increased, suggesting interference in testicular function in aging roosters.

Lipid accumulation of avian adipocytes is mainly dependent upon the fatty acid transmembrane uptake process mediated by membrane proteins, such as fatty acid translocase (FAT/CD36), fatty acid transport protein 1, and caveolin-2. To examine the effects of FAT/CD36 on spatial-specific fat deposition, 60 broiler chickens were randomly allocated to 2 groups by sex. Each male or female group contained 2 subgroups (n = 14–15) inoculated by intramuscular injection with chicken FAT/CD36 or BSA (control) immunogens at 34, 49, and 63 d. The subcutaneous and visceral fat deposits were measured, as were levels of plasma triglyceride and free fatty acid. Serum antibody titer was measured by ELISA. The mRNA expression levels of fatty acid transport-related genes in the adipose tissue of the male broilers were investigated to reveal the relationships among various fatty acid transporters. The results showed that active immunization with FAT/CD36 could significantly decrease the visceral fat of the male broilers by up to 40%, but it had no effect on subcutaneous fat stores of male broilers or on either site of fat deposition in female broilers. The concentration of plasma free fatty acids increased in the experimental groups for both male and female broilers. After the FAT/CD36 immunization, very low density lipoprotein receptor mRNA expression was upregulated in both the subcutaneous and visceral fat of male broilers, whereas peroxisome proliferator-activated receptor γ, FAT/CD36, and acyl-CoA binding protein mRNA expression levels were upregulated only in the visceral fat of male broilers. These results indicated a novel role of chicken FAT/CD36 in fat deposition, with sex- and spatial-specific effects.

Potentially adverse effects of diets containing transgenic plants are a concern for many consumers, particularly in Europe. For Bacillus thuringiensis-maize, several studies in livestock and poultry showed that the zootechnical data provide no indication for such adverse effects. These studies were all done in homeostatic situations; it remained open whether a deflection of the regulatory physiological systems might yield divergent dynamic responses in B. thuringiensis-maize-fed animals. We therefore tested the effect of an active immunization using BSA as antigen in a feeding regimen with or without B. thuringiensis-maize using quail as a model organism. Newly hatched Japanese quail were randomly allocated to 2 groups (n = 120 per group) fed with diets containing either B. thuringiensis-maize or isogenic maize of the same cultivar. The diets did not differ in concentrations of the mycotoxins deoxynivalenol and zearalenone, which were both far below guidance values. After 16 wk on the experimental diets, one-half of each group was immunized against BSA. The remaining birds were injected with saline. Thirty-six hours after the injection, half of the BSA-injected subgroup (n = 30) and half of the saline subgroup (n = 30) from B. thuringiensis-maize-and isogenic-fed birds were killed and blood samples were collected and analyzed for serum zinc levels, indicative for acute phase response. For determining IgY-mediated immune responses, eggs were collected every other week for 6 wk after the injections from the remaining birds and total IgY concentrations and BSA-specific IgY titers were measured in egg yolk. The BSA injections did not elicit significant decreases of serum zinc concentrations. The serum zinc levels were significantly higher in B. thuringiensis-maize-fed quail. Expectedly, total IgY as well as BSA-specific IgY titers increased with time in the BSA-immunized quail. The response of both variables to the BSA injection did not differ between the feeding groups. Our results indicate that feeding of B. thuringiensis-maize does not impair the immune system of Japanese quail and thus gives no indication for respective concerns

Injection of quail and breeder hens with a recombinant protein antigen (MBP-cINA521)--a fusion of the bacterical maltose-binding protein (MBP) and a fragment of the alpha-subunit of chicken inhibin (cINA521)--accelerates puberty and enhances lay. Herein, the effects of this immunogen on reproductive responses in broiler breeder males were assessed. Cockerels were subcutaneously injected with 0 (vehicular controls), 1, 3, or 5 mg of MBP-cINA521 at 13 wk of age and with one-half of these dosages (boosters) at 18 wk. Bird subsamples were weighed, blood sampled, and killed at 24, 28, and 39 wk of age to assess age and vaccination effects on BW, testes weight (TWT), TWT relative to BW (RTWT), TWTor = 20 g (TWT20; theoretical threshold TWT for maximum fertility), and plasma testosterone. Breeder males are sexually developing, reach peak sexual activity, and show age-related reproductive decline at these ages. Because vaccine gonadal effects at 24 wk appeared to be dramatic, the size of the left testis was also scored to see if size differences could be detected by mere visual inspection. Male fighting increasingly reduced sample sizes beyond 24 wk. Because mortality was unrelated to the treatments and to insure meaningful statistical comparisons, MBP-cINA521 data were pooled. Body weight (P0.04), testis score (P0.02), TWT (P0.03), RTWT (P = 0.06), and plasma testosterone (P = 0.08) were elevated in immunogen-treated males at 24 wk of age, and more (P0.05) MBP-cINA521-treated birds than controls achieved a TWT20 at this time. These variables did not differ by treatment at 28 wk. However, by 39 wk, treatment effects reemerged as follows: TWT (P0.04), RTWT (P = 0.06), and TWT20 (P0.01) were increased in vaccinated males who also showed nearly 3-fold higher levels of plasma testosterone. We conclude that immunoneutralization of inhibin accelerates puberty and retards age-related sexual senescence that typically occurs in broiler breeder males.

We have demonstrated that inoculation of female Coturnix with an inhibin-based immunogen (MBP-cINA521) accelerated puberty and enhanced hen-day egg production (HDEP). Herein, MBP-cINA521, a fusion protein, which consists of the bacterial maltose binding protein (MBP) and a fragment of the infinity-subunit of chicken inhibin (cINA521), was tested for its ability to enhance production performance in broiler breeders. Pullets (Arbor Acres Classic Females; n = 60 birds/treatment group) were given (subcutaneously) 0, 1, 3, or 5 mg of MBP-cINA521 in Freund's complete adjuvant at 20 wk and 4 d of age. Booster immunizations (one-half of the primary dosages) were given at 23 wk of age. The vehicle for controls (CON; no booster) and MBP-cINA521-boosted birds was Freund's incomplete adjuvant. Blood samples were obtained at the end of the trial to assess immunological response to the antigen with a titer ELISA. The onset of puberty was assessed by calculation of the average ages at first lay (FIRST) and at 50% egg production (FIFTY). Cumulative percentage HDEP was determined weekly throughout the laying period (40 wk). Egg weight (EWT) and specific gravity (SG) assessments were made periodically during the trial. Body weight gain (BWG) and mortality (MORT) data were also collected. Significant injection treatment differences (P0.01) in inhibin antibody titers were detected according to the following order: low dose = intermediate dosehigh doseCON. A dose of MBP-cINA521 capable of accelerating puberty and increasing overall egg lay was identified. FIRST and FIFTY responses were decreased (P0.05) in birds given the intermediate dose (3.0 mg) of MBP-cINA521 when compared to the CON. FIFTY responses were also lower (P0.05) than CON responses in those birds given the highest dose (5.0 mg) of the inhibin antigen. Cumulative HDEP was also higher (P0.05), beginning at 3 wk of lay and weekly thereafter (P0.05, for the remaining 40 wk), in birds given the intermediate immunogen dosage when compared to the CON. By Week 40, an average increase of 9.5% HDEP was realized in birds given 3.0 mg of MBP-cINA521. MORT rates were similar in the CON and in the two lowest MBP-cINA521 treatment groups but were higher (P0.05) in those birds given 5.0 mg of the antigen. EWT, SG, and BWG measurements were unaffected by treatment with the inhibin vaccine. In agreement with our findings in quail, immunoneutralization of inhibin enhanced production performance in breeder hens.

Active immunization of turkey hens against vasoactive intestinal peptide (VIP) has been shown to inhibit incubation behavior and to increase egg production in second-cycle hens. The objective of this study was to compare the effect of VIP immunization on first- and second-cycle turkey hens during a 27-wk production period. First- (25-wk-old) and second- (54-wk-old) cycle hens were intermixed, distributed among 16 pens, and subjected to a photoperiod of 6 h of light and 18 h of darkness for 10 wk. The first-cycle hens were divided into two groups: keyhole limpet hemocyanin (KLH)-immunized controls (n = 16) and VIP-immunized (n = 18). Second-cycle hens were divided into four groups: 1) unimmunized controls (n = 19), 2) KLH-immunized controls (n = 18), 3) VIP-immunized (n = 19), and 4) VIP-preimmunized (immunized during first cycle; n = 16). Each hen received four antigen injections beginning the day of photostimulation (4-wk intervals), except for the preimmunized hens, which received three injections beginning 4 wk after photostimulation. The maximum titer of VIP antibodies in first-cycle, second-cycle, and preimmunized hens was 17.2+/-2.2, 20.9+/-2.9, and 21.7+/-3.2%, respectively. After photostimulation, plasma prolactin of first- and second-cycle control hens peaked between 484 +/-105 and 630+/-118 ng/mL. In contrast, prolactin changed very little in VIP-immunized turkeys. The average number of daily nest visits was less in first- and second-cycle VIP-immunized hens (1.68+/-0.23 and 1.09+/-0.15 visits per hen per day, respectively) than in their respective KLH-immunized controls (2.47+/-0.36 and 2.65+/-0.45 visits per hen per day). Expression of incubation behavior was 50.0 and 52.6% in first- and second-cycle control hens, respectively, upon termination of the study. In contrast, only 11.1% first-cycle and 5.2% second-cycle VIP-immunized turkeys exhibited the hormonal and behavioral characteristics of incubating hens. Average weekly egg production of first- and second-cycle VIP-immunized turkeys was similar (3.58+/-0.19 vs. 3.63+/-0.14 eggs per hen per wk). First- and second-cycle control hens laid 2.63+/-0.25 and 2.41+/-0.20 eggs per hen per wk, respectively. The present results show that comparable egg production was attained in first- and second-cycle hens by active immunization with VIP.

The effects of active immunization against inhibin on production performance in female Japanese quail (Coturnix coturnix japonica) were assessed in two separate trials using an MBP-cINA521 fusion protein as an immunogen. The fusion protein, MBP-cINA521, consisted of the bacterial maltose binding protein (MBP) and a truncated form of the mature alpha-subunit of chicken inhibin (cINA521). MBP-cINA1521 was constructed by: 1) excising a 521-bp PstI fragment from a chicken inhibin alpha-subunit cDNA (cINA6; gift of P. A. Johnson), 2) cloning this fragment, which encodes all but the first 11 amino acid residues of the mature alpha-subunit, into the pMal-c2 vector of the MBP fusion expression system, and 3) expressing the fusion protein (MBP-cINA521) from the Escherichia coli and purifying it using affinity chromatography. In each trial, quail were randomly and equally assigned to one of two injection treatments as follows: 1) MBP-cINA521 in Freund's adjuvant, or 2) Freund's adjuvant (vehicular controls; CON). All immunizations were given subcutaneously and Freund's complete and incomplete adjuvant were used for primary and booster injections, respectively. In Trial 1, birds were given a primary challenge of 0.2 mg MBP-cINA521 per bird at 25 d of age, followed by booster immunizations (0.1 mg MBP-cINA521 per bird) at 33, 40, 47, 54 and 61 d of age and every 35 d thereafter. The CON birds received vehicular immunizations at the same time intervals. In Trial 2, birds treated with MBP-cINA521 received a primary challenge of 0.2 mg MBP-cINA521 per bird at 26 d of age, followed by booster immunizations (0.1 mg MBP-cINA521 per bird) using the same schedule as that used in Trial 1, with the exception that no boosters were given after 61 d of age. The CON birds received vehicular immunizations at the same time intervals. Collection of production performance data was initiated coincident with the laying of the first egg in each trial (i.e., beginning at 41 and 44 d of age for Trials 1 and 2, respectively) and continued for 30 1-wk periods of lay. Combined data from Trials 1 and 2 indicated that the mean +/- SE age at first egg lay was markedly decreased (P < 0.005) in MBP-cINA521-treated quail (53.4 +/- 0.9 d of age) when compared to the CON (57.6 +/- 1.3 d of age). Likewise, the mean +/- SE age at 50% egg production was reduced (P < 0.03) in quail immunized against inhibin (65.4 +/- 2.1 d of age) when compared to the CON (77.6 +/- 4.7 d of age). Total hen-day egg production was also higher (P < 0.05, Trial 1; P < 0.01, Trial 2) in MBP-cINA521-treated quail (88.7 +/- 1.4%, Trial 1; 90.1 +/- 1.2%, Trial 2) than in the CON birds (81.9 +/- 2.9%, Trial 1; 73.6 +/- 6.5%, Trial 2). Collectively, these findings provide evidence that inhibin immunoneutralization accelerated puberty and enhanced hen-day egg production during a 30-wk period of egg lay in Japanese quail.

Juvenile turkey hens were actively immunized against vasoactive intestinal peptide (VIP) prior to photostimulation to evaluate its effect on enhancing egg production. VIP antibody titers were generated in the VIP immunized hens and a greater rate of egg production per hen was observed compared to controls. In addition, the first egg laying cycle was extended for an additional 7 wk without a significant decline in egg production. Over a 27-wk period, 116 settable eggs per hen were produced from the VIP immunized hens as compared to 102 and 90 eggs for the keyhole limpet hemocyanin and saline control groups, respectively. Based on the increased egg production and the extension of the first egg laying cycle, this experiment demonstrates that VIP immunization of turkey hens is potentially economically relevant.

Seven 31-week-old White Leghorn hens were immunized with estradiol-17-6-(0-carboxymethyl) oxime-bovine serum albumin (.5 to 1 mg/hen; 1- to 7-week intervals for 44 weeks). Six control hens of similar egg shell quality received only bovine serum albumin. Within 35 weeks of immunization, four of the estradiol-17β(E2) antigen-treated birds developed significant titers of antibodies to E2 based on a four- to fivefold increased binding of tritiated labeled E2 to plasma; two hens had low titers (twofold increase), and one had none. Forty-eight weeks after the first injection, the specific gravity (1.0768) and percent shell (8.32) of the four high-titer birds were lower (P The six positively immunized hens laid a total of 29 soft-shell eggs out of a total of 1,626 eggs as compared with 7 out of a total of 1,658 eggs laid by the six control birds. No significant increase in plasma binding was observed for the nonphenolic steroid hormones such as progesterone, corticosterone, and testosterone. It was concluded that the effect of immunization on egg shell quality was due to neutralization of estrogen activity.