Do dietary buffers improve growth performance or nutrient digestibility or decrease stomach ulcers in finishing pigs?

The effects of supplemental buffers in finely ground diets were determined in two experiments. In Exp. 1, 128 pigs (123 lb average initial body wt) were fed a cornsoybean meal-based diet (488 μm mean particle size for corn) for 66 d. Treatments were a control and 1, 2, or 3% added sodium bicarbonate (NaHCO3). Average daily gain, dressing percentage, and plasma urea N concentration decreased as the concentration of NaHCO3 in the diet was increased. However, the reduction in average daily gain occurred only at the 2 and 3% additions. Feed intake, feed/gain, backfat thickness, stomach ulceration score, stomach keratinization score, and blood gases (pH and HCO3) were not affected by treatment. In Exp. 2, 120 pigs (121 lb average initial body wt) were fed a pelleted wheat-soybean meal-based diet (355 μm mean particle size for the wheat) during a 64-d growth assay. Treatments were: 1) control; 2) 1% added NaHCO3; and 3) 1% added potassium bicarbonate (KHCO3). Average daily gain, feed intake, feed/gain, backfat thickness, stomach keratinization score, plasma urea N concentration, and digestibilities of dry matter and nitrogen were not affected by treatment. However, addition of NaHCO3 and KHCO3 tended to decrease the incidence of ulcers and increased the digestibility of gross energy. These data indicate that a 1% addition of either NaHCO3 or KHCO3 may help to reduce the severity of gastric ulcers in finishing pigs without adversely affecting growth performance or nutrient digestibility

Effects of hammermills and roller mills on growth performance, nutrient digestibility, And stomach morphology in finishing pigs

The effects of particle size and mill type used to grind corn were determined with 128 pigs (122 lb average initial body wt). Treatments were corn ground in a hammermill and a roller mill to 800 and 400 μm. The roller mill was more efficient than the hammermill when grinding the corn, with less energy consumption and greater production rate per horsepower hour. For the 800 μm treatments, greater uniformity of particle size was achieved with the roller mill than the hammermill; however, at the 400 μm treatments, corn ground with the hammermill was slightly more uniform. Pigs fed corn ground to 400 μm had 7% greater efficiency of gain, and had greater digestibilities of dry matter, nitrogen, and energy than pigs fed corn ground to 800 μm. Mill type did not affect growth performance, but pigs fed corn ground in the roller mill had greater digestibilities of dry matter, nitrogen, and energy and excreted 18% less dry matter and 13% less nitrogen as feces than pigs fed corn ground in a hammermill. There were interactions among mill type and particle size, with digestibilities much greater for the diet with corn ground to 800 μm in the roller mill compared to the hammermill, but only small advantages in nutrient digestibility for diets with corn ground to 400 μm in the roller mill. Mill type did not affect rate or efficiency of gain, but pigs fed diets with roller-milled corn had greater digestibilities of nutrients and, thus, lower excretions of nutrients in feces

Reduction of corn particle size in lactation diets improves sow and litter performance

One hundred primiparous sows were used to determine the effects of corn particle size in lactation diets on sow and litter performance. Sows were fed com-soybean mealbased diet with the com ground to 1,200, 900, 600, or 400 JLm. Particle size of corn had no influence on sow weight or backfat loss, or piglet survivability. However, feed intake and digestibilities of DM, N, and GE were increased (6, 5, 7, and 7%, respectively) as particle size was reduced from 1,200 to 400 JLm. The combination of increased feed intake and improved digestibilities resulted in increased intake of digestible nutrients. DE intake was increased 14% (13.72 to 15.60 Mcal/d) as com particle size was reduced from 1,200 to 400 JLm. Intakes of digestible DM and N were also increased (11 and 14%, respectively). The increased intake of digestible nutrients resulted in a 11% increase in litter weight gain. Reducing particle size increased severity of keratinization and lesions in the esophageal region of the stomach although all treatment averages were low to moderate, and the change was not associated with reduced sow performance. In conclusion, our data indicate that nutrient intake of sows and litter weight gains can be increased by grinding corn for lactation diets to particle sizes of 600 to 400 JLm

Does diet form (pelleted vs meal) affect optimum particle size of corn for finishing pigs?

One hundred and sixty pigs, with an average initial wt of 121 lb, were used in an experiment to determine the effects of diet form and particle size on growth performance and nutrient digestibility. The pigs were fed corn-soybean meal-based diets with the corn milled to particle sizes of 1,000, 800, 600, or 400 p,m. The diets were fed in meal and pellet forms. In general, reducing particle size increased electrical energy required for milling and decreased production rate. Milling to 400 p,m, as opposed to 600 JLm, required twice as much electrical energy and reduced production rate by 50%. Reducing particle size of the corn from 1,000 to 400 p,m resulted in a 4% increase in DE of the diets and 6% decrease in ADFl. The net result was similar DE intakes, with 22% less daily fecal excretion of DM, 25% less daily fecal excretion of N, and 7% greater efficiency of gain when particle size was reduced from 1,000 to 400 /Lm. Pelleting the diets resulted in 3% greater ADG and 6% greater efficiency of gain. Also, pelleting increased digestibilities of DM, N, and GE by 5 to 7 %. Stomach keratinization and lesions increased with reduced particle size and pelleting, but performance was not affected. In conclusion, particle size reduction and pelleting improved efficiency of gain and decreased daily excretion of DM and N in the feces, with some increase in ADG because of pelleting

Effects of mill type (hammer vs roller) and particle size uniformity on growth performance, nutrient digestibility, and stomach morphology in finishing pigs

Two experiments were conducted to determine the effects of mill type and particle size uniformity on finishing pigs. In Exp. 1, 120 pigs, with an average initial weight of 105 lb, were fed corn-soybean meal-based diets for 57 d. The corn was milled so that all diets had an average mean particle size of 800 11m (± 20), yet differed in particle size uniformity (Sgw). To obtain the most uniform treatment (1.9 Sgw), corn was milled through a roller mill. The intermediate treatment (2.3 Sgw) was obtained by milling corn through a hammermill. The least uniform treatment (2.7 Sgw) was obtained by blending coarsely and finely ground corn. Growth performance of pigs was not affected by Sgw of the diet. However, digestibilities of DM, N, and GE increased as Sgw was reduced. In Exp. 2, 128 pigs, widl an average initial weight of 150 lb, were fed diets with corn milled to 450 JLm (± 7) in a hammermill or a roller mill. The hammermilled corn had an Sgw of 1.8 and the rollermilled corn had an Sgw of 2.0. The diets were fed in meal or pelleted form. There were no interactions among mill type and diet form. Digestibilities of DM and N were greater for the hammermilled treatments, but no growth performance differences were due to mill type. Pelleting increased ADG 9% and improved efficiency of gain by 5 %. Pelleting also increased the severity of stomach lesions. In conclusion, at 800 and 450 p.m, mill type did not affect growth performance. However, nutrient digestibilities were improved by decreasing variability in particle size, a response that merits further investigation