Influence of particle size of the main cereal of the diet on egg production, gastrointestinal tract traits, and body measurements of brown laying hens

Abstract

The influence of the screen size used to grind the main cereal of the diet on egg production, gastrointestinal tract (GIT) development, and body measurements was studied in hens from 17 to 49 wk of age. Diets formed a 2 × 5 factorial with 2 main cereals (corn vs. barley) and 5 screen sizes of the cereal (4, 6, 8, 10, and 12 mm). Each treatment was replicated 5 times. No interactions between main cereal and screen size were observed for any of the traits studied. Cereal type and screen size did not affect feed intake, egg production, BW gain, or quality traits of the eggs. Eggs tended to be larger (P = 0.092) in hens fed the barley diet than in hens fed the corn diet. Also, feed conversion ratio tended to increase (P = 0.081) when the cereal of the diet was ground with a 4-mm screen as compared with the average of the other diets. At 49 wk of age, the relative weight (% BW) of the GIT and gizzard was greater (P < 0.05) in hens fed barley than in hens fed corn. An increase in the screen size increased linearly the relative weight of the GIT (P = 0.089), gizzard (P < 0.01), and liver (P = 0.056). None of the other GIT traits or body measurements was affected by the main cereal or the screen size. In summary, barley can substitute up to 45% of the corn in diets for laying hens without any adverse effect on egg production. Therefore, the use of one or other cereal will depend on their relative cost. An increase in screen size improved gizzard development but had little effect on hen productivity. Within the range studied, the size of the screen used for grinding the cereal had little effect on hen productivity, although the use of a 4-mm screen might increase feed conversion ratio and gizzard development.

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

“…On the other hand, the GMD and the GSD of the diets increased as the screen size used to grind the cereals increased. Similar results comparing these three cereals were reported by Perez-Bonilla et al (2014) and Herrera et al (2017), indicating that the structure of the feed depends not only on the size of the screen used but also on the characteristics of the grain.…”

“…The information available on the effects of main cereal of the diet on egg size is scarce. Herrera et al (2017) observed that egg size was greater in hens fed barley that in hens fed corn, in agreement with the data reported herein. In contrast, Coon et al (1988) and Pérez-Bonilla et al (2011) reported similar egg size in hens fed barley based diets than in hens fed corn based diets.…”

“…Probably, the higher level of supplemental fat of the barley diets, compared with that of the corn and wheat diets (4.9% vs. 1.8 and 1.6%, respectively) rather than the LNL content that was high and above 1.8% in all cases, was responsible for the increase in egg weight observed in hens fed barley. The results reported herein are consistent with data of Herrera et al (2017) who reported heavier eggs in hens fed diets based on barley containing 5.3% supplemental fat and 3.4% LNL than in hens fed diets based in corn containing 4.7% supplemental fat and 3.7% LNL. These results confirm that once the LNL requirement of the hens are reached (around 1.0 to 1.2% of the diet),…”

“…Egg production, egg mass, ADFI, and BW gain were not affected by the main cereal of the diet, consistent with most published research in which the wheat and barley diets were supplemented with an adequate combination of exogenous enzymes (Pérez-Bonilla et al, 2011;Herrera et al, 2017). However, hens fed barley produced heavier egg than hens fed corn or wheat.…”

“…Most studies indicate that when allowed to choose, hens show a clear performance for coarse particles (Isa Brown, 2009). Herrera et al (2017) reported that feed efficiency tended to improve when diets based on corn or barley were ground with a 6 to 12 mm screen compared with a 4-mm screen but no other production or egg quality traits were affected. The hypothesis of this research was that the size of the screen used to grind the main cereal of the diet could affect hen production, and effect that could depend on the type of cereal used.…”