Francisca Avilés Nova

On-farm evaluation of the effect of coffee pulp supplementation on milk yield and dry matter intake of dairy cows grazing tropical grasses in central Mexico

Tropical grasses are the primary nutrient resource for cattle production in the tropics, and they provide low-cost nutrients to cattle. However, its production is constrained by seasonal changes and quality; hence, appropriate usage of relatively inexpensive agricultural by-products is important to profitable livestock production. The objective of the study was to evaluate the effect of supplementing coffee pulp to dairy cows grazing tropical grasses on milk yield and forage intake. Four multiparous crossed Holstein–Brown Swiss–Zebu cows of similar weight and milk yield were used. The effect of 10%, 15% and 20% inclusion of coffee pulp in dairy concentrates on milk yield and forage intake was analysed using a 4 × 4 Latin square design. Results showed that there were no significant effects (P > 0.05) in grass dry matter intake, milk yield, milk composition body weight and body condition score due to the inclusion of coffee pulp in the dairy concentrates. It is concluded that coffee pulp can be included at levels of 20% in the concentrate without compromising significantly (P > 0.05) milk yield, milk composition and grass dry matter intake. It also was concluded that cost of concentrate is reduced in 20% by the inclusion of coffee pulp.

COMPARACIÓN ENTRE DOS MÉTODOS DE VENTILACIÓN EN LA COMPOSICIÓN QUÍMICA DE COMPOST DE ESTIÉRCOLES PECUARIOS

Este trabajo comparo el efecto de dos metodos de ventilacion en la composicion quimica de cuatro compost de estiercoles pecuarios. Para cada tipo de estiercol mezclado se realizo un experimento de compostaje. En cada experimento (Exp) se ensayaron dos metodos de ventilacion: manual con pala (Vm) y con tubos de policloruro de vinilo perforados (Vt). El Exp 1 se denomino compost estiercol bovino (CBo + Vm, CBo + Vt), el Exp 2 compost estiercol caprino (CCa + Vm, CCa + Vt), el Exp 3 compost estiercol equino (CEq + Vm, CEq + Vt) y el Exp 4 compost estiercol ovino (COv + Vm, COv + Vt). Durante el proceso se analizaron temperatura, potencial de hidrogeno (pH), conductividad electrica (CE), materia organica (MO), carbono organico (C), nitrogeno total (N), relacion carbono/nitrogeno (C/N), fosfato (PO 4 ), potasio (K), magnesio (Mg), sulfato (SO 4 ), calcio (Ca), sodio (Na), hierro (Fe), manganeso (Mn), boro (B), zinc (Zn) y cobre (Cu). Para cada experimento se utilizo un diseno completamente aleatorizado con tres repeticiones. En las variables de composicion quimica se realizo un analisis de varianza de un factor utilizando el programa Minitab y las medias se compararon con la prueba de Tukey (p 0.05). El producto proveniente de CEq + Vt presento menor relacion C/N (p = 0.049). Los metodos de ventilacion no influyeron en las caracteristicas quimicas de los compost de estiercol bovino, caprino y ovino, sin embargo, en el compost de estiercol equino al colocar tubos en las pilas de compostaje, se favorecio la degradacion de la MO y redujo la relacion C/N. Se concluye que los dos metodos de ventilacion se recomiendan en los CBo, CCa y COv. Y el metodo de ventilacion con tubos se recomienda en el CEq.