Digestion in and performance of intensively reared beef cattle fed diets with a majority of maize or barley, either ground or dry-rolled

Al Alami, Abdelmuhsen ; Gimeno, Antonio ; Schauf, Sofía ; Castrillo, Carlos ; Vega, Antonio, de (Universidad de Zaragoza)

Resumen: Barley is more extensively and more rapidly fermentable than maize, thus it is supposed to increase digestive disorders in ruminants. However, the effect of cereal type on animal performance and digestion may vary with processing degree. In the present experiment, the effect of dry-rolling or grinding barley and maize, as the main cereals in a concentrate containing a high proportion of starch with different rates of fermentation, on intensively reared beef cattle performance, diet digestibility, and feed intake amount and pattern, was studied. Thirty-six 3-month-old male calves were allocated to one of four diets consisting of barley straw (BS) and a concentrate with 60% cereals (barley and maize in proportions 75:25 or 25:75) presented dry-rolled or ground through a 3.5 mm sieve. The experimental period was divided into two phases of 10 weeks each: from start to 277 ± 3.6 kg live weight (LW; Growing), and from 289 ± 3.8 kg LW to slaughter (399 ± 4.6 kg; Finishing). For the Growing phase, there were no differences (p > 0.10) between the majority cereal in the concentrates, nor between their processing methods, in the daily intake of concentrate and BS, and in the animals’ final LW. With respect to Finishing, the interaction between cereal type and processing was significant (p < 0.05) for concentrate daily intake. As a result, animals consuming ground barley ate less concentrate than those fed rolled barley, whereas there were no differences between processing methods for animals fed maize-based diets. Animals consuming ground-barley concentrates consumed significantly more straw than those fed on dry-rolled-barley concentrates (p < 0.05 for Growing and p < 0.01 for Finishing) during the first four hours after feeding. No such differences appeared in animals consuming maize-based concentrates. Starch digestibility was higher in animals fed ground cereals vs. dry-rolled cereals during the Growing phase (p = 0.048), whereas NDF digestibility was also higher (p = 0.008) in animals fed ground cereals during the Finishing phase. The faeces from animals fed on rolled-maize concentrates showed a higher concentration of purine bases than the faeces of animals fed on rolled-barley concentrates (p = 0.016), although there were no differences for the ground cereals. Overall, the results reported indicated that replacing maize with barley in diets for feedlot beef cattle did not affect average daily gain, intake of straw or concentrate, or feed conversion ratios (total or considering just the concentrate); hence the inclusion of either cereal in greater proportions should be based on their market price and on the final cost of the compound feed (which may include different ingredients). The processing method of the cereals (grinding or dry-rolling) also had no influence on the above-mentioned variables, so the selection of the method should be based on their relative cost, exclusively in terms of feed efficiency.

La producción intensiva de carne de vacuno depende de un alto consumo de concentrados (hasta el 90 % de la ración total), lo que puede aumentar el riesgo de acidosis ruminal. Este riesgo está asociado con la tasa y el grado de fermentación del almidón, que a su vez depende del tipo de cereal y su procesamiento. En el presente estudio, se compararon dos cereales con diferentes tasas de fermentación del almidón (cebada vs. maíz en proporciones 75:25 o 25:75) y dos métodos de procesamiento (molienda vs. laminado en seco) para comprobar su efecto en la digestión de la dieta y el rendimiento del ganado de engorde alimentado con paja como fuente de fibra. En general, nuestros resultados mostraron que ni el tipo de cereal mayoritario ni su método de procesamiento influyeron en la ganancia diaria promedio, el consumo de paja o concentrado, ni en los índices de conversión alimenticia. Por lo tanto, la decisión sobre qué cereal debe incluirse en mayor proporción en el concentrado, o cuál debe ser su método de procesamiento, debe depender exclusivamente de sus costos relativos, buscando la rentabilidad óptima de las explotaciones.

Idioma: Inglés

DOI: 10.3390/ruminants6010001

Año: 2026

Publicado en: Ruminants 6, 1 (2026), 18
ISSN: 2673-933X

Financiación: info:eu-repo/grantAgreement/ES/MICINN/AGL2009-12026

Tipo y forma: Article (Published version)

Área (Departamento): Área Producción Animal (Dpto. Produc.Animal Cienc.Ali.)