Barley sprouts and D-Aspartic acid supplementation improves fertility, hatchability, and semen quality in aging male broiler breeders by up-regulating StAR and P450SCC gene expressions

Abstract

At 50 wk of age, broiler breeder roosters exhibit a significant decline of fertility. Therefore, the aim of this study was to assess the impact of incorporating barley sprout (BS) powder, D-aspartic acid (DA), or their combination into the diet on fertility, hatchability, semen quality, and the relative expression of StAR and P450_SCC genes in aging broiler roosters. Aging (50 wk) male broiler breeders (n=32) were randomly assigned to one of four dietary treatments (2 × 2 factorial) with 2 levels of BS (0 or 2% basal diet) and DA (0 or 200 mg/kg/BW) for 12 wk. Roosters were individually housed under a 14-h light and 10-h dark cycle, with 150 g/d feed allocation and free access to fresh water, then euthanized. Throughout the study, the body weight of the broiler breeders was measured, along with various parameters related to semen quality, on a weekly basis. Additionally, artificial insemination was performed during the last 2 wk to evaluate reproductive endpoints. The results revealed that both BS and DA decreased (P < 0.01) body weight. Interestingly, the inclusion of BS, either alone or in combination with DA, resulted in a significant increase in total and forward sperm motility. Furthermore, it was demonstrated that the seminal concentration of malondialdehyde, a marker of oxidative stress, was significantly decreased by more than 20% in all groups compared to the control. The combination of both BS and DA led to the highest levels of circulating testosterone, as well as the functionality and membrane integrity of sperms. Additionally, it resulted in increased sperm concentrations, production, and penetration, ultimately leading to improved fertility rate and hatchability percentage. Moreover, a positive association between total motility and fertility was observed (P < 0.01). Furthermore, the combined supplementation of BS and DA up-regulated the relative mRNA expression of P450scc and StAR (P < 0.01). To summarize, dietary inclusion of BS, DA, or their combination have a potential to improve various aspects of reproductive performance in aging roosters.

Keywords: barley sprout; d-aspartic acid; elderly rooster; reproductive performance.

Figure 1

Weekly variation in sperm membrane functionality (The percentage of sperm with a swollen bubble around the curled flagellum in a hypo-osmotic solution) on roosters (50 wk of age; n = 8 per group) given dietary treatments for 12 successive weeks. Control (, a basal diet); barley sprout (, BS, 2% of basal diet); D-aspartic acid (, DA, 200 mg/kg/BW) and BS + DA (). ^a-dWithin a week show, groups without a common superscript differed (P < 0.05). Error bar = standard error of the mean.

Figure 2

Weekly variation in sperm membrane integrity on roosters (50 wk of age; n = 8 per group) given dietary treatments for 12 successive weeks. Control (, a basal diet); barley sprout (, BS, 2% of basal diet); D-aspartic acid (, DA, 200 mg/kg/BW) and BS + DA (). ^a-dWithin a week show, groups without a common superscript differed (P < 0.05). Error bar = standard error of the mean.

Figure 3

Weekly variation in sperm concentration on roosters (50 wk of age; n = 8 per group) given dietary treatments for 12 successive weeks. Control (, a basal diet); barley sprout (, BS, 2% of basal diet); D-aspartic acid (, DA, 200 mg/kg/BW) and BS + DA (). ^a-dWithin a week show, groups without a common superscript differed (P< 0.05). |Error bar = standard error of the mean.

Figure 4

Weekly variation in sperm total motility on roosters (50 wk of age; n = 8 per group) given dietary treatments for 12 successive weeks. Control (, a basal diet); barley sprout (, BS, 2% of basal diet); D-aspartic acid (, DA, 200 mg/kg/BW) and BS + DA (). ^a-dWithin a week show, groups without a common superscript differed (P< 0.05). Error bar = standard error of the mean.

Figure 5

Weekly variation in sperm forward motility on roosters (50 wk of age; n = 8 per group) given dietary treatments for 12 successive weeks. Control (, a basal diet); barley sprout (, BS, 2% of basal diet); D-aspartic acid (, DA, 200 mg/kg/BW) and BS + DA (). ^a-dWithin a week show, groups without a common superscript differed (P < 0.05). Error bar = standard error of the mean.

Figure 6

Means of sperm concentration (A), ejaculate volume (B), total motility (C), forward motility (D), plasma membrane functionality (E), plasma membrane integrity (F) in aging broiler breeder roosters (50 wk of age; n = 8 per group) fed by experimental treatments (Control, a basal diet; BS, 2% of basal diet; DA, 200 mg/kg/BW and BS + DA) for 12 successive weeks. Abbreviations: BS, barley sprout; DA, D-aspartic acid; D, diet (BS × DA); T, time (week). ^a-dMeans without a common letter differed (P < 0.05). Error bar = standard error of the mean.

Figure 7

Means of sperm MDA (A), abnormality (B), sperm production (C), and body weight (D) in aging broiler breeder roosters (50 wk of age; n = 8 per group) fed by experimental treatments (Control, a basal diet; BS, 2% of basal diet; DA, 200 mg/kg/BW and BS + DA) for 12 successive weeks. Abbreviations: BS, barley sprout; DA, D-aspartic acid; D, diet (BS × DA); T, time (week); MDA, seminal malondialdehyde. ^a-cMeans without a common letter differed (P < 0.05). Error bar = standard error of the mean.

Figure 8

Relative mRNA expression of StAR (left) and P450scc (right) and levels in aging broiler breeder roosters (50 wk of age; n = 8 per group)’ testes fed by experimental treatments (Control, a basal diet; BS, 2% of basal diet; DA, 200 mg/kg/BW and BS + DA) for 12 successive weeks. Abbreviations: P450scc, cholesterol side-chain cleavage enzyme; StAR, steroidogenic acute regulatory protein; BS, barley sprout; DA, D-aspartic acid. ^a-cMeans without a common letter differed (P < 0.05). Error bar = standard error of the mean.