Particle size affects short-term preference behavior of brown-egg laying hens fed diets based on corn or barley

Abstract

We studied the influence of particle size of the main cereal of the diet on preference behavior by laying hens. Diets formed a 2 × 5 factorial with 2 main cereals (corn vs. barley) and 5 grinding sizes of the cereal (4, 6, 8, 10, and 12 mm screen). Each treatment was replicated 5 times (10 hens each). After a fasting period of 8 h, hens received their respective experimental diets from 06.00 to 14.00 hours. The geometric mean diameter (GMD) and the geometric standard deviation of the residuals in the feeder were determined every 2 hours. In addition, CP, ash, and Ca contents of the feeds were determined at the start and at the end of the experimental period. The experimental design was completely randomized with data analyzed as repeated measures with particle size and cereal as main effects. The GMD of the original feeds increased with increases in screen size and was greater for the barley than for the corn diets. The difference in GMD between the original diets and the residuals measured at 2 h intervals decreased as the experiment progressed (P < 0.001 for the interaction). Crude protein, ash, and Ca concentrated in the coarse fraction of the original diets and of the uneaten feed, an effect more pronounced for the minerals. Independent of the coarseness of the feed sieve, ash and Ca contents were higher in the uneaten feed at 14.00 h than in the original diets. Hens showed a clear preference for coarse particles irrespective of the concentration of CP, ash, or Ca in the different fractions of the diets. Data showed that birds under-consumed Ca during the morning, a period in which the requirements for mineral deposition are low. In summary, hens showed a significant preference for coarser particles, an effect that was more evident when the cereals were ground coarse. Hens, however, did not show any preference for consuming those feed fractions with greater CP, ash, or Ca contents.

Effect of beak trimming at hatch and the inclusion of oat hulls in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract traits of brown-egg pullets from hatch to 15 weeks of age

“…Feed particle size was greater in the original diets than in the feed residuals that remained in the feeders 24 h after the offer, confirming that pullets have a preference for coarse particles, as shown in previous studies with broilers ( Portella et al, 1988b ; Xu et al, 2015 ) and laying hens ( Portella et al, 1988a ; Safaa et al, 2009 ; Herrera et al, 2018 ). The data reported herein, however, suggest that the preference response observed might be a combination of the predilection of the pullets for coarse particles and the rejection to consume fine particles.…”

“…The data reported herein, however, suggest that the preference response observed might be a combination of the predilection of the pullets for coarse particles and the rejection to consume fine particles. In fact, the percentage of coarse particles (average of the 4 treatments) decreased from 53.8% in the original feeds to 39.3% in the refusals, whereas the percentage of fine particles increased from 23.0% in the original feeds to 30.6% in the feed refusals, data that suggest that pullets might reject to consume fine particles, as suggested by Herrera et al (2018) in laying hens. In this respect, Portella et al (1988a) reported that hens discriminate against feed particles smaller than 850 µm.…”

Influence of the energy and digestible lysine contents of the diet on performance and egg quality traits of brown-egg laying hens from 19 to 59 weeks of age

“…(2008b) , and Herrera et al. (2017 , 2018 ) reported that the increase in EW observed with increases in the level of supplemental fat was independent of the LNL content of the diet. Moreover, Bouvarel et al.…”

“…Highly concentrated energy diets, however, are costly and might reduce feed efficiency for egg production, because part of the energy ingested is directed to fat deposition and BW gain ( Perez-Bonilla et al., 2012a ). On the other hand, high energy diets usually contain more linoleic acid ( LNL ) and supplemental fat than low energy diets ( Grobas et al., 2001 ; Safaa et al., 2008b ; Herrera et al., 2018 ) resulting often in an increase in egg size ( Harms and Waldroup, 1963 ; DeGroote, 1972 ; Grobas et al. 1999b ; Wu et al., 2005 ).…”

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

“…Consequently, finely ground diets might reduce voluntary FI (Safaa et al, 2009;Lohmann, 2016;Herrera et al, 2017Herrera et al, , 2018 and therefore, egg size and egg production (Isa Brown, 2009). In the current research, however, the size of the screen used to grind the cereals had little effect on hen production or egg quality traits.…”