The effect of reducing dietary calcium in prestarter diets (0–4 D) on growth performance of broiler chickens, tibia characteristics, and calcium and phosphorus concentration in blood

Abstract

During the incubation period, the Ca-to-P weight (mg/mg) ratio in the yolk increases from 0.26 on day 0 to 0.92 on day 17.5 and to 2.9 at hatch. Moreover, the absolute Ca content in the yolk increases by 41%, whereas P content decreases by 87%, from day 0 to the day of hatching. Thus, at hatch and during the first days after hatching, there are high reserves of Ca relative to P in the residual egg yolk, risking hypercalcemia and hypophosphatemia. A growth performance study was conducted to explore the effects of reducing dietary Ca content in the prestarter phase (0–4 D) on BW and bone mineral deposition during the first days after hatch and at market weight (day 37). Four prestarter (0–4 D) diets were formulated to have 0.4, 0.6, 0.8, and 1.0% Ca content. After the prestarter phase, all birds were fed with the same commercial diets based on a 3-phase feeding program (starter, grower, and finisher). Growth performance (BW, ADG, ADFI, and feed conversion ratio [ FCR ]) was monitored throughout the study, and blood and tibia bone samples were collected on specific days. On day 4, BW and ADG decreased with dietary Ca contents higher than 0.6% ( P < 0.05), but there were no differences in BW on day 14 onward ( P > 0.10). For the overall study (0–37 D), there were no differences in ADG and ADFI, but the FCR decreased with lower Ca contents ( P < 0.05). On day 4, there were no differences in blood plasma Ca concentration, but P concentration increased in the group treated with diet containing 0.4% Ca compared with the groups treated with diets containing 0.6 and 0.8% Ca ( P < 0.05). Tibia ash content decreased in the group treated with diet containing 0.4% Ca ( P < 0.05) compared with all other treatments at the end of the prestarter phase. Tibia ash content and tibia breaking strength, on day 37, were not different among the treatments ( P > 0.10). In conclusion, during the prestarter phase, BW increased with dietary Ca contents lower than 0.6%, most likely improving Ca–P balance; bone mineral deposition was reduced in this period. On feeding with a diet containing higher Ca content, bone mineral content was rapidly recovered.

Determination of the standardized ileal digestible calcium requirement of male Arbor Acres Plus broilers from hatch to day 10 post-hatch

“…For example, the Ca content of the yolk increases by 71% from embryonic d 0 to 17.5 ( Hopcroft et al, 2019 ). Previous authors reported no difference in daily FI or daily gain of broilers fed 0.40, 0.60, or 0.80% total Ca from hatch to d 4 post-hatch, whereas further increases in total dietary Ca significantly decreased daily intake and gain ( Mansilla et al, 2020 ).…”

“…Response variables that are the most sensitive to Ca and P concentrations in the diet are bone ash, growth performance, and Ca and P digestibility. Growth rate and efficiency are optimized at concentrations of Ca that are suboptimal for bone mineralization ( Bedford and Rousseau, 2017 ; Lagos et al, 2019 ; Mansilla et al, 2020 ). In the current experiment, there was no effect of graded levels of SID Ca on body weight gain and the linear impact of dietary SID Ca on FCR or the AID of P or Ca suggest the requirement is greater than or less than that tested in the current experiment for these parameters.…”

Process optimization in poultry feed mill

“…They are used for pellet materials that either contain ground crops like sand and dirt or with a high mineral such as cattle feed materials. Greater care should be considered when adjusting the rollers with the shell fitted 16 .…”

Process optimization in Poultry Feed Mill

“…Close ends allows the feed material to be trapped on the face of the die. Close end roller shell assist in a greatly die face wear by holding back on the natural characteristics of some of the feed formulations; it works to the grooves of each side of die face [10]. The close-end shells are available in different depths and widths and suits many applications but is generally used with poultry feed manufacturing for a well-conditioned, high-grain rations.…”

“…When adjusting the rollers, greater care should be considered with this shell tted. If adjusted too tight towards die face, the surface of the tungsten of shell will cause rapid wear [10].…”