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Objective: The objective of this experiment was to determine the net energy (NE) content of full-fat rice bran (FFRB), corn germ meal (CGM), corn gluten feed (CGF), solvent-extracted peanut meal (PNM), and dehulled sunflower meal (SFM) fed to growing pigs using indirect calorimetry or published prediction equations. Methods: Twelve growing barrows with an average initial body weight (BW) of 32.4±3.3 kg were allotted to a replicated 3×6 Youden square design with 3 successive periods and 6 diets. During each period, pigs were individually housed in metabolism crates for 16 d, which included 7 days for adaptation. On d 8, the pigs were transferred to the respiration chambers and fed one of the 6 diets at 2.0 MJ metabolizable energy (ME)/kg BW0.6/d. Total feces and urine were collected and daily heat production was measured from d 9 to d 13. On d 14 and d15, pigs were fed at their maintenance energy requirement level. On the last day pigs were fasted and fasting heat production was measured. Results: The NE of FFRB, CGM, CGF, PNM, and SFM measured by indirect calorimetry method was 12.33, 8.75, 7.51, 10.79, and 6.49 MJ/kg dry matter (DM), respectively. The NE/ME ratios ranged from 67.2% (SFM) to 78.5% (CGF). The NE values for the 5 ingredients calculated according to the prediction equations were 12.22, 8.55, 6.79, 10.51, and 6.17 MJ/kg DM, respectively. Conclusion: The NE values were the highest for FFRB and PNM and the lowest in the corn co-products and SFM. The average NE of the 5 ingredients measured by indirect calorimetry method in the current study was greater than values predicted from NE prediction equations (0.32 MJ/kg DM). [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the performance and thermoregulatory responses during acclimation to high ambient temperature (Ta) of pigs from two lines selected for high (RFI) or low (RFI) residual feed intake with the hypothesis that RFI pigs producing less heat would better tolerate high Ta. Pigs (50 kg initial body weight; 17 per line among which 10 of them were catheterized) were individually housed in a climatic-controlled room where Ta was maintained at 24.2 ± 0.4 °C during 7 days and thereafter at 30.4 ± 0.7 °C during 14 days. Irrespective of Ta, RFI pigs had lower feed intake (ADFI) and similar average daily gain (ADG) than RFI pigs. Whatever the line, ADFI, ADG, and feed efficiency decreased with increased Ta. Overall, the Ta increase resulted in an increase in rectal temperature (RT), skin temperature (ST), and respiratory rate (RR) within the first 24-48 h and, subsequently, in a decrease followed by stabilization. The RT decrease during acclimation occurred 24 h earlier in RFI pigs than in RFI. Thyroid hormones and cortisol decreased at high Ta and it was similar in both lines. Based on performance and RT, ST, and RR responses, it seems that selection for low RFI tends to ameliorate pigs' tolerance to high Ta. Nevertheless, this selection does not induce significant differences between lines in endocrine and metabolite responses during thermal stress. [ABSTRACT FROM AUTHOR]

The conventional regression method for partitioning heat production (HP) in growing animals between HP associated with either maintenance or growth assumes maintenance HP to be independent of feeding level (FL). However, there are indications that this assumption is not correct and an alternative method is proposed in this study from a reanalysis of 3 trials. In trial 1, 73-, 152-, and 237-kg calves received one milk replacer at 77, 84, 92, and 100% of their ad libitum metabolizable energy (ME) intake. In trial 2, 70-kg barrows received one diet at 60, 80, and 100% of their ad libitum ME intake (2600 kJ ME/[kg body weight )BW)0.60. dl). In trial 3, 60-kg barrows received a basal diet 11700 kJ ME/(kg BW0.60.d)1 or 4 diets consisting of the basal diet plus 850 kJ ME/(kg BW0.60,d) of starch alone or starch with corn gluten, casein, or vegetable oil. In the 3 trials (n = 48, 18, and 28, respectively), HP and activity-related HP were measured on individuals pigs and calves in respiration chambers for 6 d (fed state) and fasting HP )FHP; at zero activity) was calculated as the asymptotic value of HP kinetics on d 7 (feed-deprived state). The FHP changed by 0.22 kJ in calves and 0.14 kJ in pigs/kJ ME intake change during the previous days. The efficiency of using ME for maintenance and growth [kmg; 1- (HP - FHP)/ME] was not affected by FL (calves: 84%, pigs in trial 2: 74%). In trial 3, kmgvaried between diets in connection with variations in efficiencies between nutrients (from 55% for corn gluten to 85% for lipid). This new method of representing partitioning of ME intake considers FHP as variable with FL, does not require estimates of maintenance ME requirements, includes efficiencies that depend on diet characteristics, and is not biased by metabolic adaptations of the animal to FL. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, policies encouraging the production of ethanol from corn or wheat have stimulated an increased production of distillers dried grains with solubles (DDGS) whose nutritional value for pigs is little described. Seventeen wheat DDGS samples were obtained from 7 different plants in Europe from July to September 2007. Each sample was analyzed and 10 representative samples were measured for amino acids (AA) content and their standardized ileal digestibility (SID) in pigs. Lightness score (L) of each DDGS was also measured. Our results indicate a rather stable crude protein content (32.6 to 38.9% DM basis; average: 36.1% DM basis) whereas lysine was the most affected AA with contents ranging between 0.82 and 3.00% of crude protein (CP; N*6.25). In addition, lysine SID was also variable (9 to 82%) with the lowest values observed in DDGS with low lysine level in CP. In fact, samples with low lysine content in CP and low SID of lysine had low lightness values (L<50) and a subsequent high occurrence of Maillard reactions. Consequently, both lysine content (R=0.63) and lysine SID (R =0.68) values were positively correlated with lightness and DDGS samples that were lighter in colour had higher total and digestible AA levels. Our data indicate that lysine SID can be accurately predicted from lysine content in CP with a quadratic model (R²=0.87) or a linear-plateau model (R²=0.80 with a breakpoint for lysine content in CP of 1.9% and SID at plateau of 68%). This also suggests that wheat DDGS with lysine content in CP lower than 1.9% should be avoided in pig diets. [ABSTRACT FROM AUTHOR]