Relation between Feed Particle Size Distribution and Plumage Condition in Laying Hens on Commercial Farms.

Ruben Schreiter,Klaus Damme,Markus Freick

doi:10.3390/ani11030773

Abstract

Simple SummaryFeather pecking is a serious problem in laying hen husbandry, which can lead to feather damage, performance losses and economic disadvantages. In this context, feed has been identified as an important factor, whereby scientific knowledge is primarily available on the effect of ingredients but hardly on the feed structure. In this study, feed samples from feather pecking and non-feather pecking herds from production farms were analyzed for their nutrient contents and feed particle sizes. More coarser (>2.00 mm) and fewer medium and finer feed particles (≤1.60 mm) were found in the feed of the flocks affected by feather pecking. The coarser components contained lower levels of nutrients important for preventing feather pecking (e.g., methionine, sodium). The study demonstrated that a feed structure that is too coarse can be considered a risk factor for feather pecking.In this cross-sectional study, 103 complete feed samples from laying hen herds affected by plumage damage as an indirect measure for severe feather pecking (affected herds; AH, n = 37) and control herds without plumage damage (control herd; CH, n = 66) of commercial German farms were examined by dry sieve and nutrient analysis. AH showed higher percentages of particles >2.50 mm (mean ± SD, CH: 11.0 ± 8.5%, AH: 24.9 ± 14.3%) and 2.00–2.50 mm (CH: 11.2 ± 5.3%, AH: 15.7 ± 5.7%), but lower proportions of fractions 1.01–1.60 mm (CH: 22.9 ± 4.9%, AH: 17.8 ± 5.7%), 0.51–1.00 mm (CH: 25.5 ± 8.2%, AH: 16.0 ± 6.8%) and ≤0.50 mm (CH: 15.4 ± 5.0%, AH: 11.0 ± 4.8%) (p < 0.001). Diets of AH had a higher geometric mean diameter (GMD) compared to CH (AH: 1470.8 ± 343.9 μm; CH: 1113.3 ± 225.7 μm) (p < 0.001). Contents of crude ash (CH: 130.3 ± 18.8 g/kg, AH: 115.9 ± 24.3 g/kg), lysine (CH: 8.2 ± 1.0 g/kg, AH: 7.7 ± 1.2 g/kg), methionine (CH: 3.4 ± 0.5 g/kg, AH: 3.2 ± 0.6 g/kg) and sodium (CH: 1.7 ± 0.4 g/kg, AH: 1.3 ± 0.4 g/kg) were lower in AH (p ≤ 0.041). In a logistic regression model, animal age (p = 0.041) and GMD (p < 0.001) were significant factors on the occurrence of plumage damage.

Highlights

Severe feather pecking (SFP) and cannibalism in laying hens are undesirable allopecking behaviors that lead to plumage damage and skin/toe injuries, affecting animal welfare, performance, and profitability [1,2]
Significant differences between the particle size fractions were present for all analyzed traits of energy and nutrient contents (Table 2)
Particles ≤1.00 mm had lower energy contents with higher levels of crude ash, crude fiber, lysine, methionine, calcium, sodium and magnesium compared to fractions >2.00 mm (p < 0.001)

Summary

Introduction

Severe feather pecking (SFP) and cannibalism in laying hens are undesirable allopecking behaviors that lead to plumage damage and skin/toe injuries, affecting animal welfare, performance, and profitability [1,2]. Within the multifactorial causes of SFP, animal nutrition plays a crucial role along with factors of husbandry, management, environmental enrichment, and genetics [3,4,5,6]. In addition to nutrient composition, feed structure is a major factor affecting digestibility, animal health, and performance of poultry [7,8]. Given its importance to animal health and productivity, a balanced intake of structured feeds is considered important for optimal nutrition [11]. In this regard, chickens prefer larger feed particles [9,12]. Higher feed intake with coarser feed was observed in some reports [13], but not in all studies [7,14]

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