Effect of Dietary L-ascorbic Acid (L-AA) on Production Performance, Egg Quality Traits and Fertility in Japanese Quail (Coturnix japonica) at Low Ambient Temperature.

Environmental stress boosts the levels of stress hormones and accelerates energy expenditure which subsequently imbalance the body's homeostasis. L-ascorbic acid (L-AA) has been recognized to mitigate the negative impact of environmental stress on production performances in birds. The present investigation was carried out to elucidate the effect of different dietary levels of L-AA on production performance, egg quality traits and fertility in Japanese quail at low ambient temperature. Sixty matured females (15 wks) were equally divided into three groups (20/group) based on the different dietary levels of L-AA (0, 250 and 500 ppm) and coupled with an equal number of males (1:1) obtained from the same hatch. They were managed in uniform husbandry conditions without restriction of feed and water at 14 h photo-schedule. Except for feed efficiency, body weight change, feed consumption and hen-day egg production were recorded highest in 500 ppm L-AA supplemented groups. Among the all egg quality traits studied, only specific gravity, shell weight and thickness differed significantly (p<0.05) in the present study. Fertility was improved significantly (p<0.01) to a dose dependent manner of L-AA. The findings of the present study concluded that dietary L-AA can be a caring management practice at least in part to alleviate the adverse effect of cold induced stress on production performance in Japanese quail.

Influence of chicken native breeds on some physical and biochemical characteristics and short-term storage of semen.

1. The major objective of this study was to examine the influence of 24-h storage of semen at low temperature on semen characteristics and fertilising ability of spermatozoa in two native breeds (Kadaknath-KN, Aseel Peela-AP) and White Leghorn (WL) chicken. 2. Various physical and biochemical properties of freshly ejaculated semen of KN and AP were investigated. Fertility was examined in freshly-ejaculated as well as 24-h-stored (3°C) semen diluted (1:3) with Beltsville Poultry Semen Extender. 3. No significant difference was observed in sperm motility among the different breeds whereas live counts were higher in WL than the native breeds. Body weight, semen volume and sperm concentration were highest in AP, followed by KN and WL. A similar trend was observed in the percentage of dead and morphologically-abnormal spermatozoa. 4. The activity of acid and alkaline phosphatase in seminal plasma were higher in WL than KN, whereas the opposite trend was recorded for glutamic oxaloacetic and pyruvic transaminases. The cholesterol content of semen was highest in AP, followed by KN and WL. Cholesterol was much lower in seminal plasma compared with whole semen but there were no differences between breeds. Mean values of the methylene blue reduction time test were higher in WL than in the native breeds. 5. Fertility and hatchability, using freshly-diluted semen, were poorer in the native breeds than in WL. The pattern of fertility deteriorated further, especially in native fowls, when the birds were inseminated with 24-h-stored semen. 6. In conclusion, variation in physical and biochemical characteristics of semen in native breeds compared to WL correlated with poor fertility after short-term storage of semen.

Sexual maturation, serum steroid concentrations, and mRNA expression of IGF-1, luteinizing and progesterone hormone receptors and survivin gene in Japanese quail hens.

In avian species, sexual maturation represents the evidence of start laying, which is a consequence of the development of ovarian follicles. These follicles are the functional reproductive unit whose maturation and viability critically depends on endocrine, paracrine, and autocrine factors beyond the signals from the central nervous system. The present study was undertaken to investigate the correlation of sexual maturity with tissue growth, mRNA expression of certain genes, and serum steroid concentrations in Japanese quail hens. To carry out the present study, a total of forty Japanese quail hens (5 weeks) were housed individually under uniform husbandry condition with ad libitum quail layer ration and water at 14-hour photo schedule. On sixth week onwards, four birds were sacrificed at each time on 1, 3, 7, 10, 13, 16, 19, 22, 25, and 28 days. Serum was extracted aseptically to analyze the gonadal steroid hormones (estrogen and progesterone) and corticosterone to investigate the liaison with sexual maturation of the species. Expression analyses of four genes i.e., insulin-like growth factor-1, luteinizing hormone receptor, progesterone receptor, and survivin were carried out in the three largest ovarian yellow follicles. A significant (P < 0.05) increase in body weight gain and oviduct weight was recorded during the phase of sexual maturation. Smaller follicles revealed higher insulin-like growth factor-1 and survivin gene expression, whereas the reverse result was manifested in both the luteinizing and progesterone hormone receptors. In biochemical study, the gonadal steroids (estrogen and progesterone) were recorded higher at the first half of the experiment when a gradual decrease in corticosterone concentration was confirmed from the very beginning of this study. This result substantiated that sexual maturation in Japanese quail may be completed by the time of 8 weeks after its birth in support of the analyzed information studied in the current investigation.

Cloacal gland foam enhances motility and disaggregation of spermatozoa in Japanese quail (Coturnix japonica).

The adult male Japanese quail produces white foam from the cloacal gland, which is transferred to the female proctodeum during natural mating. The physiological role of foam on quail spermatozoa is still unclear. Therefore, attempts have been made to understand the effect of cloacal foam on motility and metabolism of quail spermatozoa. The profile of various biochemical constitutes in the foam extract was investigated. The addition of foam extract to neat semen completely disaggregated the clumps of spermatozoa leading to vigorous motility. The metabolic rate (MBRT) of the spermatozoa was significantly increased with the addition of foam extract. The foam extract was sub fractionated into seven different fractions by using the molecular cut off devices. Among all the seven sub-fractions from the foam extract, the addition of < 1 KDa sub-fraction contained lactate and has enhanced sperm motility and metabolism. Another fraction (3-10 KDa) has non-protein and non-heparin components which completely disaggregated the clumped quail spermatozoa. However, the remaining fractions did not show any effect on quail spermatozoa. It can be concluded from the present investigation that the lactate present in foam might be a fuel for sperm metabolism and motility. Furthermore, low molecular weight (3-10 KDa) components in the foam may responsible for sperm disaggregation.

Characterization of lactate dehydrogenase enzyme in seminal plasma of Japanese quail (Coturnix coturnix japonica).

Lactate dehydrogenase enzyme present in quail seminal plasma has been characterized. Polyacrylamide gel electrophoresis and subsequently with LDH specific staining of seminal plasma revealed a single isozyme in quail semen. Studies on substrate inhibition, pH for optimum activity and inhibitor (urea) indicated the isozyme present in the quail semen has catalytic properties like LDH-1 viz. H-type. Furthermore, unlike other mammalian species, electrophoretic and kinetic investigations did not support the existence of semen specific LDH-X isozyme in quail semen. The effect of exogenous lactate and pyruvate on sperm metabolic activity was also studied. The addition of 1 mM lactate or pyruvate to quail semen increased sperm metabolic activity. Our results suggested that both pyruvate and lactate could be used by quail spermatozoa to maintain their basic functions. Since the H-type isozyme is important for conversion of lactate to pyruvate under anaerobic conditions it was postulated that exogenous lactate being converted into pyruvate via LDH present in semen may be used by sperm mitochondria to generate ATP. During conversion of lactate to pyruvate NADH is being generated that may be useful for maintaining sperm mitochondrial membrane potential.

High doses of dietary zinc induce cytokines, chemokines, and apoptosis in reproductive tissues during regression.

In chickens, high levels of dietary zinc cause molting, and the reproductive system undergoes complete remodeling concomitant to feather replacement. In the present study, the expression profiles of cytokines and chemokines were investigated in the ovary and oviduct of control hens and of hens induced to molt by zinc feeding. The zinc-induced feed-intake suppression, the changes in corticosterone levels, the immune cell populations in the reproductive tract, and the apoptosis of reproductive tissues were analyzed. The expression of mRNAs for interleukin-6 (IL-6), interferon-gamma (IFN-gamma), the avian ortholog of mammalian IL-8 (chCXCLi2), and a chicken MIP-1beta-like chemokine (chCCLi2) in the ovary and of mRNAs for IL-1beta, IL-6, IFN-gamma, transforming growth factor-beta2, chCXCLi2, and chCCLi2 in the oviduct were upregulated significantly during zinc-induced molting. A simultaneous feed-intake reduction was observed with higher expression of cytokines and chemokines. The results of the present investigation also suggested that the upregulation of corticosterone was closely associated with the increased expression of cytokines and chemokines. An increase in apoptosis within reproductive tissue during tissue regression was also noted. We had previously observed the upregulation of these cytokines expression in an earlier study (molting by feed withdrawal). However, the pattern and the level of expression were different among these two methods. These findings indicate that cytokines might be a common mediator of tissue regression during molting induced by diverse methods, although the pattern of induction is different. Thus, a high dose of dietary zinc seems to induce reproductive regression via the upregulation of cytokines and chemokines, the suppression of feed intake, and the increase in serum corticosterone, resulting finally in the apoptosis of reproductive tissues.