Energy metabolism in the weanling pig : effects of energy concentration and intake on growth, body composition and nutrient accretion in the empty body

Dietary energy is the largest single cost in pork production. Accurate and current understanding of energy metabolism is crucial to production efficiency. The overall objective of this thesis was to evaluate the effects of dietary energy concentration and energy intake on growth, nutrient deposition rates and energy utilization in weaned pigs. In experiment 1, the optimum total lysine:DE ratio for weaned pigs was estimated at 4.27 and 4.46 g/Mcal for pigs growing from 7.5 to 12.8 kg and 7.5 to 22.5 kg BW, respectively. Experiment 2 determined if a more predictable growth, nutrient deposition and energy utilization in the weaned pig is achieved with NE or with DE. ADG either remained similar or was depressed with increased NE compared to the control (P 0.05) but increased with feeding level (P 0.05) but both LD and LD:PD ratio increased (interaction, P < 0.001). These data suggest that when amino acid:energy ratio is optimal, increasing dietary energy concentration increased energy intake but does not improve PD and overall body weight gain of weaned pigs. However, body lipid content and LD were increased. Finally, NE offers an advantage over the DE in predicting the body composition and nutrient deposition rates rather than in overall BW gain

Effects of feeding flaxseed to sows during late gestation on lactation and litter performance

A study was conducted to investigate the effect of supplemental fat from flaxseed (FL) on fatty acid (FA) profile, chemical composition, energy value of colostrum and milk, and litter performance. On day 107 of gestation a total of 59 large white sows were selected, blocked by parity and randomly allotted to one of three diets, 15% flaxseed (FL), 10% fullfat soybean (SB) or a control commercial (CO) diet containing corn and soybean meal. Diets were isocaloric and isonitrogenous but differed in fat content and FA composition. Colostrum and milk were collected soon after farrowing and on day 7, respectively, for fatty acid and chemical analysis. Dietary treatments did not affect sow feed consumption, weight loss, number of live pig born and weaned per litter. Similarly, pig birth weights, and day 7, 14, and 21 weights did not differ among treatment groups. FL significantly (p < 0.05) increased linolenic (LNA C18:3co3) and decreased palmitic (C16:0) and oleic (C18:1) acids in colostrum. FL also significantly (p < 0.001) increased LNA and arachidonic acid (C20:4) in milk, while it decreased myristic (C14:0), palmitic and palmitoleic (C16:1) acids. Chemical analysis showed no significant differences in total solids (TS) and energy value of colostrum while a significant (p < 0.05) increase in TS, fat concentration and energy value was observed in milk from FL. A total of 335 piglets were used in the plasma study of lipid metabolites. Triglyceride (TG), cholesterol, HDL cholesterol and glucose were not affected by dietary treatment (p > 0.05). Feeding FL to sows during late gestation and lactation enriches sow milk and piglets with LNA