medica veterinaria

AGUA, SALES, DEGRADABILIDAD, RUMEN

Arch. Med. Vet. 39, Nº 3, 2007
COMUNICACION

Efecto de concentraciones elevadas de sales totales y sulfatos en agua de bebida
sobre la degradabilidad ruminal in vitro de Thinopyrum ponticum
Effect of drinking water with high concentrations of total salts and sulphates
on in vitro ruminal degradability of Thinopyrum ponticum
M L Coriaa, J P Fayb*, S BCseha, b, M A Brizuelaa, c
aFacultad

bEstación

de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Argentina.
Experimental Agropecuaria Balcarce, Instituto Nacional de Tecnología Agropecuaria. (INTA), Argentina.
cComisión de Investigaciones Científicas, Provincia de Buenos Aires, Argentina.

SUMMARY
The objective of this study was to find out the effect of high concentrationsof total salts (ST) and sulphates (Sulf) in drinking water on the
degradability of tall wheatgrass (Thinopyrum ponticum). Six trials repeated at different moments using rumen fluid from a steer fed on either alfalfa
hay (diet A) or alfalfa hay plus grass pasture (diet B) were performed. Drinking water was obtained from a watering place located in the same
paddock of the pasture. Rumen fluidand tall wheatgrass were incubated at 39 ºC in artificial saliva prepared with drinking water. Six treatments
were evaluated in flasks fitted with graduated syringes. The flasks contained 60 ml of ruminal inoculum and 1 g of tall wheatgrass except in
treatment 1 (T1). Treatments were T1: without forage; T2: control; T3: ST (3,000 mg/l); T4: ST (7,000 mg/l); T5: Sulf (1,500 mg/l) y T6: Sulf(7,000
mg/l). Salts used were: sulphates and chlorides of sodium, potassium, calcium and magnesium. To estimate the ruminal degradability of tall wheatgrass,
gas production as a function of incubation time was evaluated by measuring the gas accumulated in the syringes during 50 h. The pH of the incubates
of each treatment at the beginning and at the end of the trials was also recorded. Data wereanalysed using ANOVA and means were compared using
Dunnett’s test. Effects of block (diet), treatment, hour, and interactions of hour x block and hour x treatment on gas production were detected
(P < 0.05). In both diets, A and B, ST7.000 was the treatment that most affected the degradative activity of rumen microorganisms, followed in diet A
by Sulf7,000 and in diet B by ST1,500. Somesignificant differences of pH were found between treatments, and between initial and final values. It was
concluded that high concentrations of salts, particularly of ST, decrease the degradative activity of rumen microbes after 50 h of digestion.
Palabras clave: agua, sales, degradabilidad, rumen.
Key words: water, salts, degradability, rumen.

INTRODUCCION
La relación entre la calidad del agua debebida y la
nutrición de vacas lecheras ha sido tratada detalladamente
en una publicación reciente (Beede 2005).
Si bien es conocido el efecto negativo que el consumo de agua de mala calidad tiene sobre los bovinos
(Solomon y col 1994, Bremer 20021, Willms y col 2002),
son escasos los trabajos que se han publicado para conocer el efecto de altas concentraciones de sales totales y
sulfatossobre la microbiota ruminal de esos animales
(Alves de Olivera y col 1996).
Los minerales, además de desempeñar funciones muy
importantes asociadas directamente con la salud y producción de los rumiantes, cumplen un rol fundamental
en el metabolismo de los microorganismos ruminales y,

Aceptado: 09.01.2007.
* Casilla 276, 7620 Balcarce, Argentina; pfay@balcarce.inta.gov.ar
1
Bremer J.2002. Better water makes more milk. http.//www.
iowafarmertoday.com. 2 pp.

por ende, en la utilización del alimento. Con respecto a
este metabolismo, los minerales intervienen en los dos
procesos más importantes que se llevan a cabo en el
retículo-rumen: la degradación de la fibra del forraje y la
síntesis de biomasa microbiana.
Entre las sales contenidas en el agua, los sulfatos son
más...