Is relaxing broiler breeder growth restriction cost-effective?

M. Afrouziyeh, M.J. Zuidhof, V.L. Carney, Is relaxing broiler breeder growth restriction cost-effective?, Poultry Science, 2023, 103082, ISSN 0032-5791, https://doi.org/10.1016/j.psj.2023.103082.

broiler breeder, budget, progeny, Research Showcase 2023

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Broiler breeders have high growth potential, which needs to be passed onto their broiler offspring, yet, breeders need to produce fertile eggs, which requires optimum body condition. Broiler breeders are feed restricted to control excessive growth. There is a growing body of evidence that the intensity of feed restriction has increased in broiler breeders over the past decades, raising welfare concerns. The economic projections of various relaxed growth restrictions should be considered in designing strategic growth trajectories. In this regard, partial budgeting allows us to understand how a decision will affect the profitability of an enterprise. One of the important questions associated with relaxing growth restriction in broiler breeder pullets is how the resulting performance in hatching egg production will compensate for the concomitant increase in feed intake and cost. This research evaluated the economic projection of various relaxed growth trajectories for hatching egg producers and supply chain sectors.

Approach

Ross 708 pullets (n=40) were placed in a pen containing 2 precision feeding (PF) stations from hatch to 43 wk of age. The pullets were randomly assigned to 10 growth trajectories. The birds in the High g1 groups were raised heavier by 10% than their Standard g1 counterparts during the prepubertal phase. The pubertal phase inflection point coefficient (I2) was advanced by 0, 5, 10, 15, and 20% creating inflection points at 22.29, 21.16, 20.05, 18.94, and 17.82 wk of age, respectively. The growth trajectories were: Scenario 1 (Ross 708 target) = Standard g1, I2-0%; Scenario 2 = Standard g1, I2-5%; Scenario 3 = Standard g1, I2-10%; Scenario 4 = Standard g1, I2-15%; Scenario 5 = Standard g1, I2-20%; Scenario 6 = High g1, I2-0%; Scenario 7 = High g1, I2-5%; Scenario 8 = High g1, I2-10%; Scenario 9 = High g1, I2-15%; Scenario 10 = High g1, I2-20%. Two progeny trials varied in maternal age (MA = 35 and 42 wk) were conducted to evaluate the intergenerational effects of two degrees of maternal prepubertal BW gain (MW) and five earlier maternal pubertal growth inflection points (MI) on offspring growth and development. An average of 12 chicks per maternal treatment, were placed in four controlled pens and individually fed commercial diets via PF stations until 35 days. Individual bird BW and feed intake were recorded by the PF system. The economic projections of switching broiler breeder target growth from the breeder-recommended target growth to 9 alternative growth scenarios were investigated using a partial budget analysis in Canadian dollars. In the partial budget analysis for the broiler sector, differential chick cost estimated in the broiler breeder partial budget, broiler 35 d live BW, and cumulative feed consumption were included in the broiler margin calculation.

Analysis of Results

The partial budget for the hatching egg sector predicted that increasing prepubertal BW gain by 10% along with advancing the pubertal growth inflection by 15 or 20% resulted in a greater margin over feed and pullet cost compared to the breeder-recommended growth trajectory (scenarios 9 and 10 vs. scenario 1). If a hatching egg producer switched from the breeder-recommended BW target scenario to scenario 9, the model-predicted margin over pullet and feed cost until 42 wk of age would increase by $0.52/hen; the increase in profitability would be $1.97/hen for scenario 10. For every week of earlier pubertal growth, ADFI decreased by 1.3 g/d/wk for the Standard g1 hens and increased by 1.2 g/d/wk for the High g1 birds, egg production increased by 0.33 egg/hen for the High g1 treatment and decreased by 0.27 egg/hen and for the Standard g1 treatment; egg mass increased by 0.916 g/d for the High g1 treatment and decreased by 0.29 g/d for the Standard g1 treatment. 35 d BW of broilers from 42-wk old hens were greater than that of broilers from 35-wk old hens (1,955 vs. 1,903 g, respectively), which increased revenue for the 42-wk old hens’ offspring cohort compared to that of the 35-wk old hens. Furthermore, FCR of chicks from older breeders (42 wk) was lower than that of the ones of younger mothers (35 wk). In the partial budget analysis for the broiler sector, the margin over feed and chick cost estimated for maternal scenario 1 (breeder-recommended scenario) from 35-wk old hens was used as a reference to compare the margin of other maternal growth scenarios. All maternal growth scenarios increased margin over feed and chick cost compared to that of the breeder-recommended maternal growth scenario (scenario 1), except for scenario 6 from 35-wk old hens.

Application

The current paper investigated the economic aspects of implementing the growth curves using the partial budget analysis. Increasing prepubertal BW gain by 10% and advancing the pubertal growth phase by 20% (scenario 10) could increase margin over feed and chick cost for the hatching egg producers by CDN$1.97/hen. For broiler chicken supply chain as a whole, the highest differential margin over feed and chick cost was for maternal growth scenario 10 from 42-wk old hens. The latter margin over feed and chick cost was greater than that of breeder-recommended maternal growth (from 35-wk old hens) by $0.1053/kg live chicken under the current economic situation.

Abstract

Broiler breeders are subjected to feed restriction programs to control excessive growth. However, current levels of feed restriction and concomitant growth restriction are becoming severe, raising welfare and suboptimal reproductive performance concerns in underfed breeders. To circumvent the issue, our previous studies investigated the effects of new strategic growth curves, with various degrees of relaxed growth restrictions, on broiler breeders and their progeny’s performance. The broiler breeder study was conducted with 40 Ross 708 broiler breeder pullets reared on one of ten target growth trajectories using a precision feeding (PF) system. The growth trajectories were designed with 2 levels of the amount of prepubertal BW gain and 5 levels of pubertal growth timing. The prepubertal BW gain (g₁) was estimated from the breeder-recommended standard BW gain (Standard g₁) target, or 10% higher (High g₁). The pubertal growth timing (I₂) was advanced such that it happened at I₂-0% = 22.29 wk, I₂-5% = 21.16 wk, I₂-10% = 20.05 wk, I₂-15% = 18.94 wk, I₂-20% = 17.82 wk of age. Two broiler experiments with different maternal ages (35 and 42 wk) were conducted as the extension of the breeder experiment to evaluate the intergenerational effects of a reduced degree of maternal pre-pubertal phase growth restriction and earlier maternal pubertal phase growth on offspring growth and development. The current paper investigated the economic aspects of implementing the growth curves using the partial budget analysis. Increasing prepubertal BW gain by 10% and advancing the pubertal growth phase by 20% (scenario 10) could increase margin over feed and chick cost for the hatching egg producers by CDN$1.97/hen. For broiler chicken supply chain as a whole, the highest differential margin over feed and chick cost was for maternal growth scenario 10 from 42-wk old hens. The latter margin over feed and chick cost was greater than that of breeder-recommended maternal growth (from 35-wk old hens) by $0.1053/kg live chicken under the current economic situation.