The Relationships of Clutch Length and Egg Position on Ovarian Follicular Growth in Laying Hens

Abstract

To analyze characteristics of follicular rapid growth patterns in relation to clutch length and egg position in various clutch lengths, Sudan black and red were alternately injected intravenously into laying hens. The average growth period tended to decrease as clutch size increased, and this was accompanied by an increase in growth rate. The number of growing follicles and the total amount of daily yolk deposition in layers with short clutches were less than in layers exhibiting long clutches. The growth period tended to decrease as egg position advanced in clutches of 2 to 6 eggs. Follicular volume at ovulation also tended to be less in terminal (Ct) follicles in clutches of 2 to 5 eggs. Follicular growth rate was generaly reduced in the first egg of a clutch (Cl) and increased in the Ct follicles. Comparison of growth patterns between Ct and Cl follicles led to the detection of two growth patterns. In the first pattern, the growth period of the Ct follicle was equal to that of the Cl follicle and a one day skip was found between the transformation days of the two follicles; in the second pattern, Ct and Cl follicles entered into the rapid growth phase on consecutive days, but the Cl follicle took one day longer than the Ct follicle to reach ovulation.

Modelling the changes in the proportions of the egg components during a laying cycle

“…The weight of consecutive eggs within a sequence gradually decreases (Belyavin et al, 1987;Miyoshi et al, 1997). Similar patterns have been observed with yolk weights (Bastian and Zarrow, 1955;Zakaria et al, 1984;Zakaria, 1999) with the heaviest yolks occurring more frequently in the first two places of a sequence (Gilbert, 1972). Eggshell weight tends to be heaviest in the terminal egg of the clutch (Miyoshi et al, 1997), presumably because the lag in oviposition time is the longest for the last egg, which means a longer period of time is devoted to shell deposition.…”

Roles of Biotin in Growing Ovarian Follicles and Embryonic Development in Domestic Fowl

“…The ovaries of chickens are located anteriorly to the liver and suspended by the mesovarium, and white or yellow spherical follicles of various sizes aggregate in a grape pattern according to each growth stage (29)(30)(31)(32)(33). In the ovaries, the number of egg cells that can be macroscopically counted is 1,900 and the number that can be microscopically confirmed is more than 12,000.…”

Egg laying characteristics, egg weight, embryo development, hatching weight and post-hatch growth in relation to oviposition time of broiler breeders

“…In a young flock, hens have longer clutches and shorter intervals between ovulations (Zakaria et al, 1984a;Zakaria, 2001). Within a clutch, the rapid growth period of yellow growing follicles (YGF) decreases with advanced egg position (Zakaria et al, 1984b), whereas the yolk deposition in follicles during the rapid growth period is continuous until the ovulation occurs (Zakaria, 1999b;McLeod et al, 2014). On the other hand, the volume of terminal follicle in clutch tends to be less (Zakaria et al, 1984b;Zakaria, 1999b).…”

“…Within a clutch, the rapid growth period of yellow growing follicles (YGF) decreases with advanced egg position (Zakaria et al, 1984b), whereas the yolk deposition in follicles during the rapid growth period is continuous until the ovulation occurs (Zakaria, 1999b;McLeod et al, 2014). On the other hand, the volume of terminal follicle in clutch tends to be less (Zakaria et al, 1984b;Zakaria, 1999b). Furthermore, Tumova and Gous (2012) found that the eggs of broiler breeders were of a greater proportion of yolk comparing to eggs of layer hens.…”

“…Elf and Fivizzani (2002) found that the yolk of Leghorn hatched eggs had a significant greater initial level of androgen than other hormones. Furthermore, the first of clutch eggs (C1) contained heavier yolks (Robinson and Renema, 2003) whereas terminal follicle (Ct) of a clutch tended to be less (Zakaria et al, 1984b;Zakaria, 1999b). Transferring of different amounts of androgens to the eggs of a clutch is suggested to be a mechanism by which the hen can enhance the competitive ability (Groothuis et al, 2005) of later-hatched chicks (coincided with early chicks).…”