Assessment of the body development kinetic of broiler breeders by non-invasive imaging tools.

In order to determine the body composition of parental broilers during growth from hatching to adulthood (32 wk of age), we evaluated the kinetics of fattening, growth rate, reproduction parameters, and body composition of the animals by using non-invasive tools such as medical imaging (ultrasound and CT scan) and blood sample analysis. The use of CT scanner allowed us to monitor the development of the body composition (fatness, bone, muscle, ovary, and testis growth) of these same animals. These analyses were accompanied by biochemical blood analyses such as steroids, metabolites, and some adipokines concentration. Difference in the body composition between males and females appeared at 16 wk of age. From 20 wk of age, shortly before the onset of lay, the females had 1.6-fold more adipose tissues than males (P < 0.001) and 8-fold more elevated plasma triglycerides levels. In addition, females, from 16 wk of age, presented a weakened bone quality in comparison to males (P < 0.001). The ratio of the tibia volume/tibia length was 33.2% lower in female compared to male chicken at 32 wk of age (P < 0.001). However, the pectoral muscle had the same volume in both sexes. The production of steroids by gonad started at 16 wk of age for both sexes, and the testis and ovary development could be measured by imaging tools at 24 wk. The follicle development was correlated to the ovarian fat tissue (r = 0.80) and fatness. In conclusion, the use of CT scanner and ultrasound system has allowed investigate the body composition of live animals and actual parental breeds with to the aim of using them for genetic selection.

Is Meat of Breeder Turkeys so Different from That of Standard Turkeys?

The technological, nutritional, and sensorial quality of breasts and thighs with drumsticks of turkey male and female breeders was characterized by comparison with breasts and thighs with drumsticks of growing male and female turkeys from the Grademaker line (hybrid turkeys, n = 20 birds per sex and per physiological stage). The breeder turkeys were slaughtered at 397 and 410 days of age and 10.42 and 32.67 kg of body weight for the females and males, respectively. The standard turkeys were slaughtered at 75 and 103 days of age and 5.89 and 13.48 kg of body weight for the females and males, respectively. The differences observed between males and females on one hand and between standard and breeder turkeys on the other hand were mainly induced by differences in slaughter ages and sexual dimorphism on body weight. The meat of female breeders had characteristics close to those of female and male standard turkeys, whereas the meat of male breeders was clearly distinguishable, particularly by displaying lower tenderness and water holding capacity.

Use of computed tomography to determine body composition of heavy strain turkey hens (Meleagris gallopavo) from rearing to early laying.

Genetic selection has improved the growth performance of poultry, but also influenced other metabolic parameters and physiological functions such as reproduction. To counter the negative effects of this enhanced development, modifications of the environment or diet are frequently used. As all animals are not equally sensitive and do not respond in the same way, the evolution of the body composition has got to be better characterized with non-invasive tools to reach a higher flock homogeneity and improve production yield. Thus, we have analyzed turkey breeder hens' body composition using computed tomography scan and measurements of biochemical markers from 16 to 34 wk old. During rearing, body weight was strongly correlated to muscle, fat, and bone volumes (r > 0.75), and increased with hen age until sexual maturity (31 wk). These correlations did not maintain after photostimulation was initiated (29 wk). Muscle volume linear regression with hen age resulted in a R² value of 0.626 over the whole trial study. Bone volume was better fitted by a quadratic regression (R² = 0.7) and was proportional to calcium plasma level evolution, both increasing after 28 wk of age. Conversely, fat volume quadratic regression (R² = 0.5) was symmetrical to triglyceride levels, the first decreasing notably at sexual maturity, the other increasing massively after 28 wk. Egg, yolk, and albumen weights increased with hen age, as did yolk triglyceride levels. In conclusion, computed tomography allows to investigate turkey breeders' body composition and bring new data in the genetic selection strategy. In addition, the evolution of the fat deposition and bone changes have been monitored over time and could help to optimize breeders' diet strategy.

Expression of adiponectin, chemerin and visfatin in plasma and different tissues during a laying season in turkeys.

BACKGROUND: In mammals, adipose tissue is able to secrete various hormones called adipokines including adiponectin (ADP), chemerin (Chem) and visfatin (Visf) which are involved in controlling energy metabolism as well as reproductive functions. Visf receptor is still unknown whereas ADP and Chem mainly act through AdipoR1, AdipoR2 and CMKLR1 and GPR1 receptors, respectively. No studies have yet demonstrated the presence of these three adipokines in peripheral tissues, ovarian cells or turkey plasma. Here, we investigated the expression (mRNA and protein) of ADP, Chem, Visf and their receptors in peripheral tissues and ovarian cells (granulosa and theca cells) from hierarchical follicles. Furthermore, we determined the plasma profile of ADP, Visf and Chem at different physiological stages: start, peak and end of the laying period in Meleagris gallopavo turkeys. This data was correlated with the metabolic data (plasma glucose, triglycerides, cholesterol and phospholipids). METHODS: Tissue and ovarian cells mRNA and protein expression levels were determined by RT-qPCR and immunoblot, respectively. Plasma adipokines were measured by chicken ELISA and immunoblotting. RESULTS: In turkeys, Chem is mainly expressed in the liver while ADP and Visf are mainly expressed in the abdominal adipose tissue and pectoral muscles,respectively. As in mammals, AdipoR1 and AdipoR2 expression levels (mRNA and protein) are highly present in muscle and liver, respectively, whereas the mRNA expression of CMKLR1 and GPR1 is ubiquitous. In ovarian cells, ADP, Visf, Chem and their receptors are more highly expressed in theca cells than in granulosa cells excepted for AdipoR1. Furthermore, we found that plasma levels of ADP, Chem and Visf were reduced at the end of the laying period compared to the start of this period. At the plasma levels, the levels of these adipokines are strongly negatively correlated with glucose and only plasma Chem is negatively correlated with cholesterol, triglycerides and phospholipids. CONCLUSIONS: In turkeys, ADP, Visf and Chem and their receptors are expressed in peripheral tissues and ovarian cells. Plasma concentration of ADP, Visf and Chem decrease at the end of laying period and only plasma Chem is negatively correlated with levels of cholesterol, triglycerides and phospholipids levels during the entire laying period.

Inactivation of AMPKα1 induces asthenozoospermia and alters spermatozoa morphology.

AMP-activated protein kinase (AMPK), a key regulator of cellular energy homeostasis, is present in metabolic tissues (muscle and liver) and has been identified as a modulator of the female reproductive functions. However, its function in the testis has not yet been clearly defined. We have investigated the potential role of AMPK in male reproduction by using transgenic mice lacking the activity of AMPK catalytic subunit α1 gene [α1AMPK knockout (KO)]. In the testis, the α1AMPK subunit is expressed in germ cells and also in somatic cells (Sertoli and Leydig cells). α1AMPK KO male mice show a decrease in fertility, despite no clear alteration in the testis morphology or sperm production. However, in α1AMPK(-/-) mice, we demonstrate that spermatozoa have structural abnormalities and are less motile than in control mice. These spermatozoa alterations are associated with a 50% decrease in mitochondrial activity, a 60% decrease in basal oxygen consumption, and morphological defects. The α1AMPK KO male mice had high androgen levels associated with a 5- and 3-fold increase in intratesticular cholesterol and testosterone concentrations, respectively. High concentrations of proteins involved in steroid production (3ß-hydroxysteroid dehydrogenase, cytochrome steroid 17 alpha-hydroxylase/17,20 lysate, and steroidogenic acute regulatory protein) were also detected in α1AMPK(-/-) testes. In the pituitary, the LH and FSH concentrations tended to be lower in α1AMPK(-/-) male mice, probably due to the negative feedback of the high testosterone levels. These results suggest that total α1AMPK deficiency in male mice affects androgen production and quality of spermatozoa, leading to a decrease in fertility.