An experiment was conducted to study the effect of dietary electrolytic balance (dEB) and addition of sodium bicarbonate to drinking water on carcass and meat quality of pigs. Sodium bicarbonate was used to adjust dEB to 140, 200 and 280 mEq/kg for T1, T2 and T, respectively. 144 Landrace*Duroc male pigs were allocated at 4 per pen and used until 105 kg liveweight. At the end pigs were kept in the same pens and diets for a week during which sodium bicarbonate rich water was supplied to a half of them. Therefore the experimental design was split in a factorial 2x3 and treated water was administered until slaughter. Forty-eight pigs were selected and sent to the slaughterhouse in order to evaluate the effect of experimental treatments on carcass and meat quality parameters. Enriched water significantly increase urine pH, hot and cold carcass weight and killing-out percentage (P<0.01). However did not affect fat or loin depth, lean meat percentage or chilling losses as well as meat quality parameters. pH of muscles Semimembranosus (SM) or Longissimus thoraccis (LT) measured at 45 min were not affected by dEB. However meat pH measured after 24 h statistically increased in both SM (P<0.01) and LT muscles (P<0.05). Pigs fed with low dEB showed a pH indicating meat with a tendency to become acid (5.5<pH<5.6) whereas meat from pigs of the other 2 groups has good ability to be consumed fresh or transformed. Electrical conductivity of SM muscle also indicated better meat quality of pigs fed medium and high dEB (P<0.05). Drip loss from the meat was also strongly reduced as a consequence of dEB (P<0.02). Meat from pigs fed low dEB lost the double of water than meat from pigs fed medium or high dEB. It can be concluded that dEB supplementation could positively affect meat quality parameters like pH 24h, electrical conductivity or drip losses. All these parameters were improved using finishing diets with a medium (200 mEq/kg) or high dEB (280 mEq/kg). Sodium bicarbonate in drinking water before slaughter did not seem to affect meat quality parameters. Nevertheless, it seems that it could improve carcass weight or killing-out percentage but those results need to be confirmed in other trials.

To assess this study, weaned piglets (at 28 days) received three dietary treatments until 39 days of age: (1) 12,5 mg alpha tocopheryl acetate/kg feed (2) 6,75 mg/l d-alpha tocopherol in drinking water (ratio 1:2) (3) 4,5 mg/l d-alpha tocopherol in drinking water (ratio 1:3). Alpha- Tocoferol accumulation was not significantly affected in any of the tissues analysed which would indicate a more efficient absorption of natural vitamin E in drinking water than the synthetic source in feed. Moreover, the lowest supplementation in drinking water (group 1:3) led to similar concentrations of vitamin E in tissues than the group supplemented with higher concentration (group 1:2). Consequently, when weaned piglets are fed under the minimum established requirements the minimum natural vitamin E supplementation to produce an equivalent tissues vitamin E concentration would be establish at 1:3 (water:feed).

The effects of mineral addition in feed or water on performance parameters and heart rate (HR) were evaluated in broilers at 28-35 d and  36 d under both chronic heat stress (CHS) and acute heat stress (AHS) in laboratory conditions. One-hundred ninety two broilers were used, distributed in 6 cages and 4 rooms, according to weight, with 8 animals per cage: four males and four females. For individual measurements, at 21 d, 2 males and 2 females out of 8 broilers were chosen and classified as: heavy male; light male; heavy female and; heavy female. For HR measurement, 48 broilers were used. The assay included 3 treatments (T): T1: A basal diet (BD); T2: BD plus mineral addition in feed; T3: a BD plus mineral addition in water. The experimental design was completely randomized with 4 repetitions/treatment. Composition of the mineral formula used was: NaHCO3 (0.83%); NH4Cl (0.07%); NaCl (0.30%), attaining a final balance of 240 mEq/kg. The following was measured: feed consumption (FC), water consumption (WC) body weight gain (BWG), feed conversion efficiency (FCE), body temperature (BT), HR, hyperventilation level (HL), blood pH, blood gases (BG), and blood electrolytes. The results were analyzed with ANOVA and mortality rate (MR) was evaluated through the Chi-square procedure. The results show that FC, BWG and FCE were similar for all T. The WC for T2 (300±23.0 mL/bird/period) and T3 (290±19.0 mL/bird/period) was higher (P=0,016) than for T1 (220±12 mL/bird/period). The lowest M (15.63 % vs 37.50%) was found in T3 vs T1 (P<0.001). The HR and HL were not affected by T during CHS and AHS. Tachycardia was the result of AHS due to higher environmental temperatures. Assessment of parameters such as cardiac output, blood pressure, stroke volume, total peripheral resistance, electrocardiogram wave morphology is advised to clarify cardiovascular function under heat stress. | Se evaluaron en ambiente semicontrolado, los efectos de adición de minerales en agua o alimento sobre parámetros productivos y frecuencia cardiaca (FC) en pollos de engorde de 28-35 d y 36 d bajo estrés calórico crónico (ECC) y estrés calórico agudo (ECA), respectivamente. Se usó un total de 192 pollos, según peso, distribuidos en 6 corrales y 4 salas, asignándose 8 pollos/corral: cuatro machos y cuatro hembras. A los 21 d, para las medidas individuales, de los 8 pollos se seleccionaron 2 machos y 2 hembras, identificándolos como macho pesado, macho liviano, hembra pesada y hembra liviana. Para FC, se escogieron 48 pollos. El ensayo incluyó 3 tratamientos (T): T1: Alimento balanceado (AB); T2: AB con adición mineral y T3: AB con adición mineral en agua. El diseño utilizado fue completamente al azar con 4 repeticiones/tratamiento. La composición del suplemento mineral fue: NaHCO3 (0,83%); NH4Cl (0,07%) y; NaCl (0,30%) con un balance electrolítico de 240 mEq/kg. Se evaluó consumo de alimento (CAL), consumo de agua (CAG), ganancia de peso (GP), conversión alimenticia (CA), temperatura corporal (TC), nivel dehiperventilación (NH), FC, gases y  electrólitos en sangre, y mortalidad (M). Los datos fueron analizados mediante ANAVAR. Se usó Chi cuadrado para calcular el porcentaje de mortalidad. Los resultados muestran que CAL, GP y CA fueron similares en todos los T. El CAG en T2 (300 ± 23,0 mL/pollo/período) y T3 (290±19,0 mL/pollo/período) fue mayor (P=0,016) que T1 (220±12 mL/pollo/período). La menor M (15,63 % vs 37,50 %) se produjo entre T3 vs T1 (P<0,001). Los T no afectaron NH ni FC durante ECC y ECA. En todos los T hubo taquicardia significativa (P<0,001) solamente en ECA, debido a mayores temperaturas ambientales. Se recomienda determinar gasto cardiaco, presión arterial, volumen de eyección, resistencia periférica total y morfología de ondas del electrocardiograma, para clarificar la función cardiovascular en condiciones de estrés calórico.