Despite the importance of hedonic reactions in pig's intake, feed palatability has been typically inferred from preference or acceptance measures. However, these measures are influenced by factors beyond palatability, such as energy density and hunger. The aim of this study was to evaluate palatability responses in pigs to sweet and umami taste at different inclusions levels. Pigs (24 per experiment) were video recorded while exposed in pairs to different sucrose (Exp. 1) or monosodium glutamate (MSG, Exp. 2) solutions over seven consecutive 10 min tests (one concentration per day). In both experiments, palatability was estimated through consumption patterns (consumption time per approaches, CT/A), facial expressions (snout openings and tongue protrusions), and consumption during a brief 2 min period. Data were analyzed by sucrose or MSG concentration. Sucrose concentration affected total intake, producing an inverted-U function and a quadratic relationship with sucrose concentration (P = 0.012). In contrast, CT/A and snout openings showed a dose effect (P < 0.005) with a direct correlation between sucrose concentration and CT/A (R = 0.23, P = 0.033) but not for openings (R = 0.18, P = 0.105) where a quadratic relationship appears (P < 0.001). Tongue protrusions and brief consumption time were not affected by sucrose concentration (P = 0.144 and 0.205, respectively). MSG concentration affected consumption, CT/A, snout openings, and brief consumption time (P < 0.001), with significant (P < 0.001) positive correlations (R = 0.59, 0.56, 0.56, and 0.68), respectively. As with rats, CT/A appears to provide a novel and interesting measure reflecting the palatability of preferred ingredients in pigs. However, brief consumption time and orofacial reactions show less similarity between pigs and rodents. Thus further studies are necessary both to better understand the measurement methods themselves and relationship between hedonic reactions and simple consumption in pigs.

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The present study was supported by the Program U-INICIA VID 2013 from Universidad de Chile, the Chilean Government research project "FONDECYT Iniciación Nº 11140576 and the Nutrition and Welfare group (SNIBA) of the Universitat Autònoma de Barcelona. We thank David Solà-Oriol and Francisco Pérez for their experiment collaboration.

The objective of this work was to evaluate the comparative P bio-avalability of different sources of phosphate based on their effects on animal performance, bones mineralization and mineral retention in broilers. To achieve this goal, two experiments were conducted. In Experiment 1, twenty diets were prepared including five different phosphorus sources, either mono-calcium phosphate (MCP) or 4 different batches of di-calcium phosphate, to supplement non phytic P (NPP) levels at 3.0, 3.5, 4.0 and 4.5 g/kg in the diets. In Experiment 2, three treatments were used: the low MCP diet was deficient in NPP (3.1 g/kg for the starter phase and 2.8 g/kg for the grower phase); the high MCP diet and the high TCP (tri-calcium phosphate) diet included adequate levels of NPP (4.4-4.7 g/kg for the starter phase and 4.2-4.3 g/kg for the grower phase). Phytase was not added to experimental diets. Results of Exp. 1 indicated that an increase of NPP in the diet from 3.0 to 4.0 g/ kg increased weight gain and feed intake between d 1 and d 21 (Trial 1). Alternatively, tibia weight and ash percentage at d 21 responded up to the level of 4.5 g/kg and showed significant difference with birds of the 4.0 g/kg NPP group. In Trial 2, chickens fed with the high MCP and TCP had improved growth performances and bone mineralization. No differences were observed on the P availability among different mineral P sources. A level of 4.5 g/kg, NPP is recommended when phytase is not included to maximize both performance and bone mineralization in broiler chickens up to d 21.Additional keywords: mineralization; digestibility; calcium; phosphorus sources. Abbreviation used: BW (body weight); CP (crude protein); DCP (di-calcium phosphate); DM (dry matter); FI (feed intake); G: F (gain feed ratio); MCP (mono-calcium phosphate); ME (metabolic energy); NPP (non phytic phosphorus); TCP (tri-calcium phosphate); WG (weight gain).

During the incubation period, the Ca-to-P weight (mg/mg) ratio in the yolk increases from 0.26 on day 0 to 0.92 on day 17.5 and to 2.9 at hatch. Moreover, the absolute Ca content in the yolk increases by 41%, whereas P content decreases by 87%, from day 0 to the day of hatching. Thus, at hatch and during the first days after hatching, there are high reserves of Ca relative to P in the residual egg yolk, risking hypercalcemia and hypophosphatemia. A growth performance study was conducted to explore the effects of reducing dietary Ca content in the prestarter phase (0–4 D) on BW and bone mineral deposition during the first days after hatch and at market weight (day 37). Four prestarter (0–4 D) diets were formulated to have 0.4, 0.6, 0.8, and 1.0% Ca content. After the prestarter phase, all birds were fed with the same commercial diets based on a 3-phase feeding program (starter, grower, and finisher). Growth performance (BW, ADG, ADFI, and feed conversion ratio [ FCR ]) was monitored throughout the study, and blood and tibia bone samples were collected on specific days. On day 4, BW and ADG decreased with dietary Ca contents higher than 0.6% ( P < 0.05), but there were no differences in BW on day 14 onward ( P > 0.10). For the overall study (0–37 D), there were no differences in ADG and ADFI, but the FCR decreased with lower Ca contents ( P < 0.05). On day 4, there were no differences in blood plasma Ca concentration, but P concentration increased in the group treated with diet containing 0.4% Ca compared with the groups treated with diets containing 0.6 and 0.8% Ca ( P < 0.05). Tibia ash content decreased in the group treated with diet containing 0.4% Ca ( P < 0.05) compared with all other treatments at the end of the prestarter phase. Tibia ash content and tibia breaking strength, on day 37, were not different among the treatments ( P > 0.10). In conclusion, during the prestarter phase, BW increased with dietary Ca contents lower than 0.6%, most likely improving Ca–P balance; bone mineral deposition was reduced in this period. On feeding with a diet containing higher Ca content, bone mineral content was rapidly recovered.