K.R. Lawrence

Using heart girth to determine weight in finishing pigs

Heart girth and body weight were measured on 100 growing-finishing pigs (50 to 273 lb) at the KSU Swine Teaching and Research Center. Heart girth, in inches, was measured using a cloth measuring tape. The tape was placed directly behind the front legs and then wrapped around the heart girth and read directly behind the shoulders. Heart girth was strongly correlated (R=0 .98) with body weight, with the following regression equation: pig weight = 10.1709 × Heart girth 205.7492. The 95% confidence interval shows the projected weight to be ±10 lb of the actual weight of the pig. To validate our equation we weighed and measured heart girth on 40 pigs from a commercial breeding farm and a group of 165 pigs at the 2002 Swine Classic Youth Exposition. At the commercial breeding farm, the actual measured body weights fit within the 95% confidence interval from their projected weights, based on the regression equation. The average residual (difference between predicted and actual weight) of the 40 pigs was -0.70 lb with a range of ± 4 lb. The actual weights of pigs at the Swine Classic averaged 16 lb greater than their predicted body weights with a range of ±8.5 lb. The actual weights failed to fall within the 95% confidence interval for the developed regression equation. This was probably due to shrink during transportation to the show and limited feed and water. Heart girth as a means of determining body weight is a viable device for 4-Hers and producers, but it is important to use only on pigs with continuous access to feed and water.

Particle size, mill type, and added fat influence flow ability of ground corn.

We conducted three experiments to determine effect of particle size, mill type, and added fat on flow characteristics of ground corn. In Experiment 1, corn was ground with either a hammer mill or a roller mill to produce six samples with different particle sizes. The particle size for the corn ground with a roller mill ranged from 1,235 to 502 microns with standard deviation ranging from 1.83 to 2.03. Particle size for corn ground with a hammer mill ranged from 980 to 390 microns with standard deviation ranging from 2.56 to 2.12. All samples were dried 12 hours to equalize moisture content. Soy oil was then added at 0, 2, 4, 6, and 8% to each sample.

Effects of extruded-expelled soybean meal and solvent extracted soybean meal level of growth performance of weanling pigs

Summary A total of 350 weanling pigs (initially 15.7 lb) were used to evaluate the effects of soybean meal source and level on growth performance of early weaned pigs. Dietary treatments included a control diet containing no soybean meal, or diets containing 20% or 40% of either solvent extracted soybean meal (SBM) or extruded-expelled soybean meal (EESOY). The SBM and EESOY were analyzed for trypsin inhibitor (0.7 mg TI/g and 1.8 mg TI/g, respectively) to ensure quality, and actual crude protein values (46.9% and 48.3% as-fed, respectively) were used in diet formulation. From d 0 to 14, increasing EESOY decreased ADG and ADFI (linear, P 0.05) were found between soybean meal sources throughout the trial. The results of this study suggest extrudedexpelled soybean meal processed properly and fed in diets immediately after weaning did not improve growth performance of nursery pigs relative to conventional solvent extracted soybean meal. When EESOY or SBM was included at 40% in diets fed immediately after weaning, growth performance of weanling pigs was poorer than if fed at lower levels (20%). Feeding properly processed EESOY resulted in similar growth performance compared to feeding SBM.

Evaluation of Hemicell® on growth performance of late nursery pigs.

Summary 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.

Use of dried distiller’s grains with soluble for swine diets

Two experiments were conducted to determine the energy value of DDGS. In Experiment 1, 360 pigs (each initially 38.5 lb) were used in a 22 d growth assay. Treatments consisted of five corn-soybean meal-based diets with added wheat bran or soy oil to provide five different energy densities ranging from 1,390 to 1,604 Kcal/lb ME. The objective was to use responses to the wide range of energy densities to calculate an energy value for two sources of DDGS.

The optimal true ileal digestible lysine and threonine requirement for nursery pigs between 25 and 55 lb

A total of 360 pigs (initially 22.2 lb and 31 d of age) was used in a 21-d growth assay. This trial was conducted as a combination of two separate trials in order to simultaneously examine both the true ileal digestible lysine and true ileal digestible threonine requirement and determine the appropriate threonine:lysine ratio. The first part of the trial consisted of five treatments with increasing dietary lysine (1.0. 1.1, 1.2, 1.3 and 1.4% true digestible lysine). The second part consisted of five treatments with increasing dietary threonine (0.66, 0.72, 0.78, 0.84 and 0.91% true ileal digestible threonine). The highest level of both lysine and threonine (1.4% and 0.91% respectively) served as a positive control, and this diet was combined as one treatment to give a total of nine treatments. Average daily gain increased to 1.3% true ileal digestible lysine, and then plateaued, while ADG increased to 0.78% true ileal digestible threonine, suggesting a threonine:lysine ratio of 60% for ADG. Increasing dietary lysine improved F/G linearly through 1.4% true ileal digestible lysine, while F/G improved up to a level of 0.84% true ileal digestible threonine. Using a level of 1.4% true ileal digestible lysine, a threonine:lysine ratio of approximately 60% is implicated for F/G.

Effects of increasing extruded soy-protein concentrate on growth performance of nursery pigs.

Two hundred and forty barrows and gilts (initially 13.0 lb and 18 ± 2 d of age at weaning) were blocked by initial weight and were allotted randomly to one of five dietary treatments. There were eight replications (pens) per treatment, with six pigs per pen. Pigs were fed experimental diets from d 0 to 14 after weaning that included a control diet containing 40% soybean meal and diets containing 7.1, 14.3, 21.4, or 28.6% extruded soy-protein concentrate. From d 14 to 28, all pigs were fed a similar diet to determine if any carry-over effects existed from the treatment diets.

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 ratio of total sulfur amino acid to lysine on finishing-pig growth performance.

The objective of this study was to characterize the growth response to total sulfur amino acids (TSAA) and lysine simultaneously to estimate the true-ileal-digestible (TID) TSAA-to-lysine ratio in early finishing pigs. One hundred and twenty-six pigs were used in a 27-d growth study. Pigs (73 to 134 lb) were blocked by sex and weight and were allotted to one of nine dietary treatments with five TID lysine (0.79, 0.87, 0.94, 1.02 and 1.10%) and five TID TSAA (0.53, 0.57, 0.61, 0.66 and 0.70%) concentrations. The highest lysine (1.10%) and TSAA (0.70%) concentrations were combined to form one treatment used in both the lysine and TSAA titrations. In diets evaluating increasing TID lysine, methionine & cysteine ratios were 64 to 66% of lysine; and in diets evaluating increasing TSAA, diets were formulated to 1.10% TID lysine. Increasing TID lysine increased ADG (linear, P 0.05) were observed in ADFI. Increasing TSAA had no effect (P<0.05) on ADG or F/G, but pigs fed the diet containing 0.70% TSAA had numerically greater ADG than did pigs fed lower rates. As TSAA concentration increased to 0.61%, feed efficiency numerically improved (P = 0.16). Using a TID lysine requirement of 1.02% and TID TSAA requirement of 0.61% suggests a TSAA-to-lysine ratio of 60%. The surface response analysis suggests a similar TSAA-tolysine ratio of 59% for overall F/G.

Interactive effects between pantothenic acid and ractopamine HCl (Paylean®) on growth performance and carcass characteristics of growing-finishing pigs.

Summary were randomly selected from the 156 initial pigs and were moved into individual stainless- steel metabolism creates. Pigs remained on their respective PA treatments, with or without RAC (10 ppm), for 8 d, were moved out of the collection chambers, and were fed the same diets from d 8 to 28. There were no PA × RAC interactions (P<0.05) observed. Added PA had no effect (P<0.05) on N excretion, N retention, or biological value (BV). Fecal N excretion was greater (P<0.01) for pigs fed RAC, compared with that of the pigs not fed RAC, but urinary N decreased (P<0.01) for the pigs fed RAC, resulting in no difference in total excreted N. Adding RAC increased (P<0.04) BV. No PA (P < 0.05) response was observed for ADG or F/G, and RAC increased (P<0.001) ADG and F/G from d 0 to 28.