Swine Day, 2002

Measuring emission rates of particulate matter from fan ventilated swine barns

Thu, 11 Feb 2010 22:35:34 GMT

Measuring emission rates of particulate matter from fan ventilated swine barns Predicala, B.Z.; Maghirang, R.G. Methods for measuring concentrations and emission rates of particulate matter (PM) from mechanically ventilated livestock buildings were evaluated in a laboratory facility and in a swine-finishing barn. Concentrations of PM were measured inside the room (room sampling) and at the exhaust duct (exhaust sampling). Concentrations at the exhaust duct were determined using high-volume traverse downstream of the exhaust fan, low-volume traverse downstream of the fan, and fixed sampling upstream and downstream of the fan. The traverse methods, which served as the reference, were conducted under isokinetic conditions; fixed sampling was done under both isokinetic and sub-isokinetic conditions. Compared to the traverse method, both room sampling and exhaust sampling under subisokinetic conditions overestimated PM concentrations. Fixed sampling under isokinetic conditions, on the other hand, did not differ significantly (P>0.05) from the high-volume traverse method. Thus, isokinetic fixed sampling can be an alternative to the more expensive and time-consuming high-volume PM traverse method to measure PM concentrations and emission rates at the exhaust.

Using heart girth to determine weight in finishing pigs

Thu, 11 Feb 2010 22:35:08 GMT

Using heart girth to determine weight in finishing pigs Groesbeck, C.N.; Goodband, R.D.; DeRouchey, J.M.; Tokach, M.D.; Dritz, S.S.; Nelssen, J.L.; Lawrence, K.R.; Young, M.G. 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 (R2=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.

Effects of increasing CA:P ratio in diets containing phytase on growth performance of grow-finish pigs

Thu, 11 Feb 2010 22:34:45 GMT

Effects of increasing CA:P ratio in diets containing phytase on growth performance of grow-finish pigs Hanni, S.M.; Tokach, M.D.; Nelssen, J.L.; Goodband, R.D.; Dritz, S.S.; Barker, M.R.; Groesbeck, C.N.; Keegan, T.P.; Lawrence, K.R.; Young, M.G.; James, B.W. We used 144 growing-finishing pigs (72 barrows and 72 gilts; initially 85 lb) to determine the effects of calcium to total phosphorus (Ca:P) ratio on growth performance. Pigs were housed in an environmentally regulated finishing building with two pigs per pen and nine pens per sex per treatment in a randomized complete block design. Pigs were blocked by initial weight and sex, and then allotted to one of four dietary treatments. The dietary treatments were corn-soybean meal-based diets fed in three phases. In each phase, diets consisted of a 1:1; 1.25:1; 1.5:1, and 2:1 Ca:P ratio. Diets were formulated to contain 0.44%, 0.39%, and 0.34% phosphorus from 70 to 130, 130 to 190, and 190 to 250 lb, respectively. All diets contained 0.05% phytase, providing 300 FTU/kg of feed. For the overall experiment, increasing Ca:P ratio decreased ADG (quadratic P<0.03) and ADFI (linear P<0.05). However, the greatest decrease in ADG and ADFI was observed when Ca:P increased from 1.5:1 to 2:1. Feed to gain was not affected by Ca:P ratio. These results suggest that in growing-finishing diets containing 300 FTU/kg phytase, a Ca:P ratio greater then 1.5:1 will decrease ADG and ADFI.

Phosphorus requirements of grow-finish pigs raised in a commercial environment

Thu, 11 Feb 2010 22:34:10 GMT

Phosphorus requirements of grow-finish pigs raised in a commercial environment Hastad, C.W.; Dritz, S.S.; Tokach, M.D.; Goodband, R.D.; Nelssen, J.L.; DeRouchey, J.M. We conducted three experiments to identify available phosphorus (aP) requirements of pigs reared in commercial facilities. In a pilot study (Exp. 1), 600 gilts (PIC, initially 95.2 lb) were randomly allotted to a low or high dietary P regimen in a 98-d study. Pigs were phase-fed six diets from 95 to 106, 106 to 150, 150 to 183, 183 to 212, 212 to 245, and 245 to 267 lb. Corresponding aP concentrations were: 0.30, 0.28, 0.27, 0.27, 0.24, and 0.19% (low) and 0.37, 0.33, 0.30, 0.28, 0.27, and 0.26% (high). No differences were observed (P > 0.10) in ADG and overall F/G was greater (P<0.07) for pigs fed the low aP regimen. In Exp. 2, 1,260 gilts (initially 74.5 lb) were randomly allotted to one of five dietary treatments in a 26-d study. Experimental diets contained 0.18, 0.22, 0.25, 0.29, or 0.32% aP, corresponding to 0.5, 0.6, 0.7, 0.8, or 0.9 g aP/Mcal ME. There were 28 pigs per pen and 9 pens per treatment. From d 0 to 14, increasing aP tended to increase (linear, P<0.03) ADG and F/G (quadratic, P<0.05) with the greatest response observed as aP increased from 0.18 to 0.22%. However, from d 0 to 26, no differences were observed for any growth traits (P>0.12). Pooled bending moment of the femur, 6th rib, and 3rd and 4th metatarsals increased with increasing aP (linear, P<0.01). Ash content of the rib and metatarsals numerically increased (P>0.10) with increasing aP. In Exp. 3, 1,236 gilts (initially 195.1 lb) were randomly allotted to one of five dietary treatments in a 28-d study. Experimental diets contained 0.05, 0.10, 0.14, 0.19, 0.23% aP, equivalent to 0.152, 0.277, 0.402, 0.527, or 0.652 g aP/Mcal ME. From d 0 to 14, increasing aP increased (linear, P<0.01) ADG and F/G. However, from d 0 to 28 increasing aP had no effect (P>0.17) on growth performance. Increasing aP increased (linear, P<0.05) bone ash and bending moment of the 3rd and 4th metacarpals. In commercial facilities, 74 to 121 lb pigs require approximately 0.22% aP to maximize ADG and F/G, whereas 195 to 240 lb pigs require approximately 0.19% aP. However, bone bending moment and ash continued to increase with increasing aP. These values correspond to 0.60 and 0.527 g aP/Mcal ME and 3.24 and 4.07 g/d of aP intake. Our results suggest percentage aP requirement estimates are similar to NRC (1998); however, because of the low feed intake of pigs in commercial facilities our study shows a lower requirement estimate on a g/d basis.