The effects of particle size, milling method, and thermal treatment of feed on performance, apparent ileal digestibility, and pH of the digesta in laying hens

Abstract

Various milling methods result in different particle size distributions and, in combination with mash and thermal treatment (expandate) of the feed, may have an impact on nutrient digestibility, pH of the digesta and subsequently the performance of an animal. Since this aspect has not been widely considered in laying hens, the objective of the present study was to investigate the effects of milling method, expansion, and particle size of feed on performance, apparent ileal nutrient digestibility, and pH of digesta in laying hens. Twelve variants of the same diet were produced. Four different milling techniques (hammer mill, roller mill, disc mill, and wedge-shaped disc mill) were used to grind the feed cereals. Coarse feed was obtained from all four mills. Additionally, fine feed was obtained from the hammer mill and the roller mill. Each of the six feed variants was offered as mash or expandate, resulting in a total of 12 treatments. The duration of the experimental period was 21 days. A total of 576 layers, each 19 weeks of age, were used in eight replicates. The statistical analysis for the four milling methods and two thermal treatments was performed using a 4×2 factorial arrangement. The effect of particle size was investigated using a 2×2×2 factorial arrangement including the coarse and fine particle sizes that were produced with the hammer mill and the roller mill as well as the mash and expandate. The animal performance and the pH of the digesta were not affected by the treatments. Ileal digestibility of starch was significantly improved by feeding mash compared to expandate (P=0.013) and by feeding coarse compared to fine feed (P=0.028). Based on this study, the tested milling methods can be used for the production of feed for laying hens without affecting performance and digestibility of nutrients.

Formas físicas de rações para aves

“…No entanto, existem divergências quanto à melhoria da absorção dos nutrientes quando as rações são somente expandidas, de acordo com Röhe et al (2014), existe a possibilidade de rações termicamente processadas resultar em utilização mais pobre de nutrientes, pois ao comparar rações fareladas e expandidas observaram aumento da superfície de contato das vilosidades do intestino e maior transporte de glicose ativo no jejuno de galinhas alimentadas com dietas fareladas. Ruhnke et al (2015) também não observaram diferenças no desempenho e na digestibilidade ileal dos nutrientes em galinhas alimentadas com rações expandidas ou fareladas. No entanto, para promover a melhoria do desempenho de aves o expander pode muitas vezes ser acoplado a uma peletizadora e assim promover a melhoria no desempenho de frangos de corte quando comprados com rações somente expandidas, ou peletizadas ou fareladas .…”

Influence of particle size of the cereal of the diet on egg production, egg quality, and the development of the gastrointestinal tract of brown-egg laying hens

“…The data available on the effects of coarse particle size on nutrient digestibility and FCR in poultry are contradictory with some research showing an improvement (Nir et al, 1994a,b;Röhe et al, 2014;Ruhnke et al, 2015) and some research showing no effects (Maclsaac and Anderson, 2007;Safaa et al, 2009). In experiment 2, FCR tended to increase in hens fed the 4-mm screen ground diets compared with the average FCR of the hens fed the other diets from 17 to 49 wk of age.…”

“…Also, a reduction in egg production and egg mass was observed in hens fed the 4-mm screen ground diet in some of the feeding periods. The available data on the effects of coarse particle size on nutrient digestibility and feed efficiency in poultry are contradictory with some research showing an improvement (Nir et al, 1994a,b;Röhe et al, 2014;Ruhnke et al, 2015) and some research showing no effects (Maclsaac and Anderson, 2007;Safaa et al, 2009). Coarsely ground diets have a stimulating effects of the development of the GIT, improving gizzard and pancreas weight (Röhe et al, 2014) and starch digestibility .…”

“…The interest on the effects of particle size of the diet on poultry growth, health, and production has increased in recent years, as the industry continues to search for new practices to optimize feed efficiency (Frikha et al, 2009b;Safaa et al, 2009;Svihus, 2010;Ruhnke et al, 2015). In addition, the renewed attention on this area is driven partly by the increasing interest in feeding whole grains to birds specifically broilers, to reduce the incidence of digestive problems in the absence of in feed antibiotics.…”

Diferentes estratégias do uso de sorgo para frangos de corte: desempenho e saúde intestinal

“…Por outro lado, o uso de Si100% levou a uma maior porcentagem da ordem Actinomycetales em comparação ao uso de Sm100%, tendo as demais dietas porcentagens similares. A forma do grão nos sete primeiros dias não influenciou a porcentagem desta ordem no intestino delgado, porém o uso de sorgo inteiro após esta idade aumentou a porcentagem de Actinomycetales (14,44%) em comparação ao uso de sorgo moído (6,80% (FRONTE et al, 2013;RUHNKE et al, 2015;XU et al, 2015). Do mesmo modo, estudos com grãos inteiros também encontraram influencia nestes parâmetros (AMERAH et al, 2011;SILVA et al, 2015;SINGH et al, 2014 (CAROLINO et al, 2014;FERNANDES et al, 2013;SILVA et al, 2015).…”