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This study was conducted to assess the effect of different total dissolved solids (TDS) levels (265, 2610, 3154, and 3448 ppm) in drinking water obtained from natural sources on the performance and immune response of broilers against sheep red blood cells (SRBC) and Newcastle disease (ND) vaccine under hot, arid environmental conditions. Each water treatment was given to a group of 100 Ross 308 broiler chicks. Each group of chicks was divided into five replicates in a cage house system. All chicks were injected with SRBC at 8 days of age when drinking water treatments started. Water intake increased significantly with the increase of TDS level. Feed efficiency and bodyweight gain were affected negatively only under the highest TDS level (3448 ppm). The highest weight gain was observed at the 2610 ppm TDS level. Plasma total protein and albumin concentration showed a significant increase at the two highest levels of TDS (3154 and 3448 ppm) in drinking water. Heterophil/lymphocyte ratio was significantly elevated by the increase of the TDS level in drinking water. At 21 days of age the chicks consuming drinking water with TDS of 2610 and 265 ppm recorded a significantly higher (P < 0.05) ND antibody titer than the other two groups. At 28 and 35 days of age chicks consuming drinking water containing 2610 ppm of TDS recorded a significantly higher (P < 0.05) ND antibody titer than the group consuming water containing TDS of 265 ppm. Higher levels of antibody titer against SRBC were recorded in birds consuming drinking water with TDS of 2610 and 265 ppm at 7 and 10 days post injection than the other two groups. However, at 10 days post injection birds consuming drinking water with 2610 ppm TDS recorded higher antibody titer than birds consuming 265 ppm TDS drinking water. In conclusion, 265 and 2610 ppm of TDS in drinking water did not negatively affect broiler productive performance, while levels of 3154 and 3448 ppm may negatively affect broiler growth. The study suggests that a TDS level of 2610 ppm has a better effect on broiler performance, in terms of weight gain and immune response in hot and arid environmental conditions, compared with a TDS level of 265-ppm level.

Abstract:Mixture theory provides a continuum framework to model a multi-phase system. The basic assumption is, at any instant of time all phases are present at every material point and momentum and mass balance equations are postulated. This paper reviews the recent developments in mixture theory and focuses on the applications of the theory in particular areas of biomechanics, composite manufacturing and infiltration into deformable porous materials. The complexity based upon different permeability and stress functions is also addressed. The review covers the literature presented in the past fifty years and summarizes applications of mixture theory in specific areas of interest, for the sake of brevity, only necessary details are provided rather than complete modeling and simulation.

Forty-five Hisex commercial layers and forty-five local Saudi breed layers were used to determine the acceptable limit of short-term water restriction in the late phase of production, when the problem of high feed and water consumption is expected. The experiment was performed under hot and arid environmental conditions when the layers were at fifty weeks of age. Layers from each breed were randomly assigned in groups of five into nine floor pens. The average environmental temperature was 37.2-38.6°C, and the relative humidity was between 20 to 37%. The trial was divided into 3 periods; control (1 week), water restriction (2 weeks) and rehydration (1 week). During the restriction period, layers from each breed were divided into three groups that received 20, 40, and 0% restriction of drinking water relative to their consumed water during the control period. During the study, feed and water consumption, body weight, changes in body weight, egg production, primary antibody response to SRBC, and rectal temperature were evaluated. Water restriction did not result in any clear effect on feed intake in either breed, however, commercial layers tended to consume less feed compared to the local breed. Body weight declined with water restriction during the first week of restriction in the commercial breed regardless of rate of restriction, but it was delayed until the second week in the local breed. Water restriction of 40% decreased egg production in both breeds but with a delay of 1 week in the local breed. Antibody level to SRBC was not affected by water restriction in the commercial line while it was highly affected in the local breed. A water restriction of 20% is considered to be an acceptable limit under the current experimental conditions without a negative effect on egg production in both breeds and considering the immune status of the local breed. Whereas, 40% restriction had a negative effect on egg production, and varied effects in the other traits in both breeds.

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