Effect of feed withdrawal and dietary energy source on muscle glycolytic potential and blood acid-base responses to handling in slaughter-weight pigs1

Abstract

The effects of dietary energy source and feed withdrawal on muscle glycolytic potential (GP) and blood acid-base responses to handling were investigated in slaughter-weight pigs (initial BW 94.7 ± 1.01 kg). Crossbred pigs (n = 96; 48 barrows, 48 gilts) were used in a randomized complete block design with a 4 × 2 × 2 factorial arrangement of treatments: l) diet [control, high fat (10% supplemental fat), low-digestible carbohydrate (20% total starch), and high-fat/low-digestible carbohydrate (10% supplemental fat and 20% total starch)]; 2) feed withdrawal (0 and 36 h); and 3) sex (barrow and gilt). Diets were fed for 28 d before the feed withdrawal treatment was applied, at the end of which all pigs were individually moved through a 12.20-m-long × 0.91-m-wide passageway for 16 laps (195 m total distance), with the assistance of an electric goad (2 times per lap). Longissimus muscle biopsies were collected at the beginning of the feeding and feed withdrawal periods and immediately after and 4 h after the handling procedure. Venous blood was collected 2 h before and immediately after the handling procedure to measure acid-base responses. At the end of the feeding period, pigs fed the control and high-fat diets were heavier (P < 0.001) than those on the low-digestible carbohydrate and the high-fat/low-digestible carbohydrate diets (129.8, 130.9, 114.0, and 122.1 kg, respectively; SEM 1.91). Diet, feed withdrawal, and sex did not affect (P > 0.05) blood acid-base responses to handling. Muscle GP at the end of the feeding period and 4 h posthandling was least (P < 0.05) for pigs fed the high-fat diet and similar for the other 3 diet treatments. Pigs subjected to 36 h compared with 0 h of feed withdrawal had less GP (P < 0.05) immediately after and 4 h after the handling procedure. There was an interaction between diet and feed withdrawal treatments for changes in GP from the start of feed withdrawal to 4 h posthandling. The reduction in GP was greater (P < 0.05) for fasted than for fed pigs receiving the control and high-fat diets, but was similar (P > 0.05) for fasted and fed pigs receiving the 2 low-digestible carbohydrate diets. In conclusion, neither dietary energy source nor fasting affected blood acid-base responses to handling; however, fasting-induced changes in LM GP were diet dependent.

Effects of Dietary Energy Sources on Post Mortem Glycolysis, Meat Quality and Muscle Fibre Type Transformation of Finishing Pigs

“…The reduction of ADFI in the present study may be attributed to the poor palatability [ 1 ] and early satiety [ 17 ] induced by the high fibre diet. Similarly, Bertol et al, [ 18 ] also reported that pigs fed high fibre diets had less feed intake compared with those fed corn and soybean-based diets. Although the higher soybean oil in diet can improve feed efficiency [ 19 ] and decrease heat increment [ 20 ], in this study, diet C did not prevent the reduction of ADG, nor was it beneficial to FCR.…”

“…These data were contrary to the results of Rosenvold et al, [ 1 ], who reported that pigs fed diets with lower level of digestible carbohydrate (compared with a standard diet) reduced muscle glycogen contents. Additionally, the insulin resistance induced by high fat feeding can reduce glucose uptake and glycogen synthesis in muscle [ 18 ]. Thus, the muscle glycogen content should not be unchanged by the low starch high fat diet in the current study.…”

Can the monitoring of animal welfare parameters predict pork meat quality variation through the supply chain (from farm to slaughter)?1

“…The difference in live weight between AWIRS and CON pigs (Table 2) also may be a source of variation in the easiness to handle between these pigs. Bertol et al (2011) also reported that heavier pigs needed more handler interventions during handling than lighter pigs.…”

Welfare of pigs at slaughter

“…Current guidelines do not recommend ramps steeper than 20°t o be used for fixed ramps (Warriss et al, 1991) or than 25°for adjustable ramps. However, as market pigs have become heavier and difficult to move (Bertol et al, 2005(Bertol et al, , 2011Rocha et al, 2016), recent works recommend the maximum ramp slope to be reduced to 15° (Grandin, 2012;Faucitano and Goumon, 2018).…”