Effect of initial sorting and amount of added fat on performance of growing-finishing pigs reared in a commercial facility

Swine research, 2005 is known as Swine day, 2005Two studies were conducted to determine whether the amount of dietary energy fed to pigs of different weight categories influenced growth performance, market weight, and economic return in a commercial grow-finish facility. In Experiment 1, a total of 1,032 pigs with initial weight of 67.7 lb were individually weighed, fitted with electronic ear tags, and sorted into ten, 5-lb weight categories. Pigs were then allotted to pens lighter and heavier then the barn mean or to pens remixed to create a normal distribution around the mean. To complete the 2 × 3 factorial, pigs were fed corn-soybean meal diets, with or without 6% choice white grease. For the overall trial, there were no fat × weight-category interactions (P>0.15). Pigs fed 6% added fat tended (P0.15) SD or CV of gain for the overall trial. For weight category, regardless of diet, heavy pigs grew faster (P<0.01, 1.83, 1.72, and 1.76 lb) than either the light or mixed pigs, respectively. In Experiment 2, 1,176 pigs with an initial weight of 77.4 lb were tagged and visually sorted into five weight categories. Pigs (28 per pen) were then allotted to pens lighter and heavier than the barn mean or remixed to create a normal distribution around the mean. To complete the 2 × 3 factorial, pigs were fed corn-soybean meal diets, with or without 6% choice white grease. For the overall trial, there were no fat × weight-category interactions (P>0.25). Pigs fed 6% added fat had greater (P0.61) in SD or CV for ADG during the overall study. For weight category, regardless of diet, heavy pigs grew faster (P<0.02, 1.96, 1.92, and 1.94 lb) than either the light or mixed pigs, respectively. Although no interactions existed for growth or carcass data, there was a fat × weight-category interaction (P<0.07) for the financial response of margin over feed cost (MOF). Heavy pigs in both studies had greater (P<0.01) MOF than either light or mixed pigs; when comparing 0 and 6% added fat within weight category, however, the increase in MOF was greater for light pigs fed added fat than for heavy pigs fed added fat. These studies indicate that adding 6% added fat does not increase variation within or across a population. Because adding fat to the diets of lightweight pigs improves their growth rate, dietary fat can be used selectively in the barn to increase the weight of the lightest 50% of the pigs

Determination of the apparent and true ileal amino acid digestibility and digestible and metabolizable energy of specialty protein sources intended for nursery pig diets

Two experiments were conducted to determine the apparent and true-ileal amino acid digestibility, and to determine the digestible energy and metabolizable energy values of rice protein concentrate, salmon protein hydrolysate, whey protein concentrate, and spray-dried animal plasma. The experimental ingredients were analyzed for essential and non-essential amino acids and crude protein so diets could be formulated. In Exp.1, pigs were fed each diet, and ileal digesta was collected and analyzed. Apparent and true digestibilities were then calculated. In Exp. 2, pigs were fed each diet and feces were collected, weighed, and sampled. Lab analyses were conducted for the determination of gross energy (GE) and digestible energy (DE). Then ME values were determined by calculation from the DE and CP concentrations of experimental diets. In Exp. 1, TID lysine, methionine, and threonine values were 86.6, 69.0, and 78.9% for rice protein concentrate; 89.7, 88.7, and 80.2% for salmon protein hydrolysate; 95.7, 93.9, and 88.4% for whey protein concentrate; and 95.4, 93.5, and 92.2% for spray-dried animal plasma, respectively. In Exp. 2, DE values for rice protein concentrate, salmon protein hydrolysate, whey protein concentrate, and spray-dried animal plasma were 2143, 1893, 2245, and 2062 kcal/lb, respectively. The ME values that were determined for the protein products were 1917, 1598, 1974, and 1805 kcal/lb, respectively

Effects of paylean (ractopamine⋅HCl) on finishing pig growth and variation

A total of 336 pigs were used in a 21-day trial to determine the effect of Paylean (9.0 g/ton Ractopamine·HCl) on finishing pig growth and variation. Pigs were allotted based on weight so that all pens had the same initial weight and degree of variation within the pen. Pigs fed Paylean had greater ADG and better feed efficiency than control-fed pigs (P<0.05). However, no differences in pen coefficient of variation were observed (P>0.70). The results suggest that adding Paylean to the diet improves finishing pig growth performance but does not affect weight variation within the pen

Evaluation of hemicell® on growth performance of late nursery pigs

A total of 276 pigs (initially 21.9 lb) was used to determine the effects of added Hemicell® on growth performance. Hemicell® is a patented fermentation product of Bacillus lentus. The active ingredient in the fermentation product is β-mannanase. However, other enzymes such as amylase, xylanase, cellulases, and α-galactosidase also are present. It is claimed that Hemicell® degrades β-mannan in feed, thus, removing its effects as an antinutritive factor in swine diets. Dietary treatments were arranged as a 2 x 3 factorial, with or without 0.05% Hemicell®, in diets with 3 levels of energy density (1,388, 1,488, 1,588 ME, kcal/lb). The 100 kcal increments were achieved by the addition of wheat bran or soy oil to a corn-soybean meal based diet. The addition of Hemicell® to the diets, regardless of energy level, did not lead to an improvement in growth performance in these late nursery pigs. Increasing energy density of the diet, however, resulted in an improved ADG and F/G