The effects of pullet body weight, dietary nonpyhtate phosphorus intake, and breeder feeding regimen on production performance, chick quality, and bone remodeling in broiler breeders

Abstract

A 3 × 2 × 2 factorial experiment, consisting of 52 hens per treatment, was conducted to determine the effects of pullet BW, dietary nonphytate phosphorus (NPP), and feeding regimen on performance, progeny quality, and bone remodeling. Cobb 500 broiler breeder pullets were reared to 3 different growth curves: 20% under, Cobb standard, and 20% over. Body weights were recorded weekly and feed adjustments made accordingly. At 21 wk, 624 hens were fed one of 2 breeder diets differing only in the amount of dietary NPP: 0.15 or 0.40%. A normal feeding regimen was appropriate for the particular growth curve; an alternative regimen considered the 3 growth curves together as a flock. At 24, 26, and 29 wk, blood was collected from 5 hens per treatment every 4 h over a 24-h period. Plasma samples were analyzed for total alkaline phosphatase, tartrate-resistant acid phosphatase, parathyroid hormone-related peptide, Ca, and inorganic P. Eggs per hen housed were diminished in hens fed the low dietary NPP and by low pullet target weight. Hens fed low dietary NPP also had lower egg weights but better eggshell quality. Mortality was significantly higher in hens fed low dietary NPP. Breeder tibia relative strength and ash were also significantly lower in hens fed low dietary NPP, regardless of the quantitative amount. Progeny tibia ash was not affected by any treatment. Total alkaline phosphatase responded to pullet BW, however by wk 29, total alkaline phosphatase also became sensitive to dietary NPP. The NPP by pullet BW interaction for tartrate-resistant acid phosphatase levels became significant by 29 wk, and pullet BW was significant at wk 24. The NPP by pullet growth curve interaction was also critical for plasma inorganic P levels throughout the sampling period. In summary, both 0.15% dietary NPP and reared pullets 20% under standard BW negatively affect egg production but do not impair progeny productivity. Body composition appears to be a main contributor in bone remodeling mechanisms, especially during the transition into egg production.

The effect of rearing photoperiod on broiler breeder reproductive performance depended on body weight

“…No effects of rearing photoperiod on egg weight have been reported before. Previous studies showed that an increased 20 wk BW target did not affect egg weight (Fattori et al, 1991 ; Hocking et al, 2001 , 2002 ; Gous and Cherry, 2004 ; Robinson et al, 2007 ; Ekmay et al, 2012 ; van Emous et al, 2013 ), where others showed that a 20% increased BW at 20 wk of age increased egg weight by about 1 g (Renema et al, 2001a , 2001b ; Sun and Coon, 2005 ). We are currently unsure about the possible explanation of the described interaction.…”

“…Independent of photoperiod, higher than recommended BW at the end of rearing accelerated sexual maturity (age at first egg), whereas a lower than recommended BW delayed sexual maturity (Fattori et al, 1991 ; Renema et al, 2001a , b ; Hocking, 2004 ; Ekmay et al, 2012 ). However, other studies did not find the same result (Zuidhof et al, 2007 ; van Emous et al, 2013 ).…”

Effect of fibrous diet and vitamin C inclusion on uniformity, carcass traits, skeletal strength, and behavior of broiler breeder pullets

“…However, in chickens, elevated ALP activity has been predominantly related to increased osteoblastic activity and used as a marker for evaluating skeletal health and bone disease, such as skeletal growth, rickets, fracture repair, and osteomyelitis ( Lumeij and Westerhof, 1987 ). More recently, Ekmay et al. (2012) used ALP serological levels to assess broiler breeder growth and bone mineral deposition during transition into sexual maturity (24–26 wk of age).…”

Substitution of Soybean Meal by Shrimp Head Meal (Penaeus Monodon) in Poultry Ration for the Performance of Growing Pullets

“…Van Emouset al 2018reported that age at sexual maturity was not affected by differences in daily CP intake in broiler breeders. On the other hand, Ekmay et al (2012) described the relation between body weight and sexual maturity who reported that the age at sexual maturity decreased with the increasing of body weight in broiler breeders.…”