Selection for food conversion in broilers: Direct and correlated responses to selection for body‐weight gain, food consumption and food conversion ratio

Pym, R. A.; Nicholls, PJ

doi:10.1080/00071667908416551

Cited by 106 publications

(50 citation statements)

References 24 publications

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“…Improvement in FCR is due to the population's genetic structure, and to a certain extent, diet and environmental conditions (Varkoohi et al, 2010). Improved FCR for a certain body weight could be partially due to lower maintenance costs and lower fat deposition of birds with higher growth rate (Pym, 1979).…”

Section: Resultsmentioning

confidence: 99%

Effect of selection for body weight in Japanese quails(Coturnix coturnix Japonica) on some production traits

Taşkın

Karadavut

Tunca

et al. 2016

IJAR

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The aim of the study was to identify quails which have different body weight for some production traits such as egg production, egg characteristics, daily feed consumption and feed conversion ratio (FCR). The selection was based on body weight in Japanese quail over two generations using 150 quails (120 female and 30 male). These groups consisted of Low Body Weight (LBW), High Body Weight (HBW) and control. Average body weights for females at the end of five weeks were 182.3±0.5, 159.5±0.34, and 141.7±0.55 for LBW, HBW and control groups respectively. There were significant differences between females and males in body weight across the generations. Significant differences were observed for total egg production and egg width for Group X Generation's interactions. Also, statistically significant differences were found for egg quality parameters such as yolk index, yolk height, yolk diameter, albumin length, and albumin width among generations. As a result, body weight is a very important factor in selection studies and it also increases the efficiency of the selection program with other selection features.

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Section: Resultsmentioning

confidence: 99%

Effect of selection for body weight in Japanese quails(Coturnix coturnix Japonica) on some production traits

Taşkın

Karadavut

Tunca

et al. 2016

IJAR

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show abstract

“…Intensive selection pressures placed on broiler performance traits, such as increased body weight and growth rate, have resulted in broilers with an increased appetite and therefore also increased voluntary feed intake per day (Siegel and Wisman 1966;Pym and Nicholls 1979;Havenstein et al 1994aHavenstein et al , 2003bO'Sullivan et al 1992b;Schmidt et al 2009;Howie 2010Howie , 2011) (see also section 5). As well as genetic selection, exogenous factors which influence many physiological and behavioural processes can be carefully controlled to increase feed intake and pre-ingestion efficiency.…”

Section: Feed Intake Digestion and Absorptionmentioning

confidence: 99%

Breeding for efficiency in the broiler chicken: A review

Tallentire

Leinonen

Kyriazakis

2016

Agron. Sustain. Dev.

171

120

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Artificial selection of broiler chickens for commercial objectives has been employed at an unprecedented magnitude over the recent decades. Consequently, the number of days, total feed and in turn energy, required to raise a broiler to slaughter weight, have decreased dramatically. Feed provision is the poultry industry's biggest environmental hotspot; hence, understanding the interactions between the birds' genetic change and their energy use efficiency forms the necessary starting point for quantifying and predicting and thereby mitigating the future environmental impact of the poultry sector. This review assesses the consequences of artificial selection on the following traits: digestive efficiency, body composition and utilisation of metabolisable energy for growth and metabolic activity. The main findings were (1) the digestive system has been subjected to much physical change due to selection in the recent decades, but this has not led to any apparent change in digestion efficiency. (2) Both the energy intake per day and the metabolic heat production rate have increased in the recent decades whilst (3) the efficiency of utilising energy for growth has also increased; this is due to an increased growth rate, so that broilers reach slaughter weight more quickly and therefore need to allocate less energy overall to metabolic processes, with the exception of growth. (4) There may have been a reduction in the tendency to waste feed through spillage and carry out energetically expensive behaviors. There is a discrepancy in the literature with regards to the influence of selection on body composition and its contribution to feed efficiency. In this review, two scenarios are demonstrated, whereby body composition either has or has not altered via artificial selection. Understanding the effects of artificial selection on the traits that relate to the feed efficiency of the broilers will contribute towards the reduction of the environmental impacts that arise from such systems.

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“…The domestic chicken raised for meat purposes (broiler) has been intensely selected over generations for increased body weight at early ages, derived primarily from the major correlated response of increased voluntary feed consumption (Pym & Nicholls 1979). Contemporary generations of this model display extreme hyperphagia, which results in obesity and attendant health problems similar to the human population (e.g.…”

Section: Introductionmentioning

confidence: 99%

Evidence of a role for neuropeptide Y and monoamines in mediating the appetite-suppressive effect of GH

Wang

Day

Zhou

et al. 2000

Journal of Endocrinology

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Among the many responses to GH administration is suppression of voluntary feed intake (FI) in some species, attributed to improvement in the efficiency of nutrient utilization and, therefore, reduced need for ingested substrates. Commercial broiler chickens have been genetically selected for generations for rapid growth, realized largely via the major correlated response of increased voluntary feed consumption. Neuropeptide Y (NPY) and monoamines play very important roles in the central regulation of feeding. Preliminary studies from our laboratory suggest that the appetite-suppressive effect of GH may be independent of its actions as a repartitioning agent, and may involve alterations in NPY expression at the pre-translational level. The purpose of this investigation was to explore the dose-response nature of the appetite-suppressive effect of GH in juvenile broilers, and the possible involvement of NPY and monoamines in this process.A GH dose-response study was conducted using 8-week-old female broilers infused i.v. with GH in a pulsatile pattern for 7 days at 0, 10, 50, 100 or 200 µg/kg body weight per day. Hypothalamic NPY and epinephrine (EP) concentrations decreased in a dose-related manner with GH. At the highest dosage, voluntary FI decreased 19% (P<0·05) and hypothalamic NPY mRNA decreased approximately 50% in the infundibular nuclei and midline region (P<0·0001). In contrast, birds pairfed to the high-GH dosage group did not differ from controls, verifying that changes in NPY and monoamines were not secondary to reduced FI. We conclude that hypothalamic NPY and EP are likely candidates to explore further as mediators of the appetite-suppressive effect of GH.

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Selection for food conversion in broilers: Direct and correlated responses to selection for body‐weight gain, food consumption and food conversion ratio

Cited by 106 publications

References 24 publications

Effect of selection for body weight in Japanese quails(Coturnix coturnix Japonica) on some production traits

Effect of selection for body weight in Japanese quails(Coturnix coturnix Japonica) on some production traits

Breeding for efficiency in the broiler chicken: A review

Evidence of a role for neuropeptide Y and monoamines in mediating the appetite-suppressive effect of GH

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