Hybrid rye may replace a portion of barley or wheat in diets for growing and finishing pigs with minimal impact on growth performance or carcass characteristics, but at very high inclusion rates in finishing diets, feed intake may be reduced if hybrid rye replaces wheat. However, limited published data exist for effects of feeding hybrid rye to growing-finishing pigs in place of corn. Therefore, an experiment was conducted to test the hypothesis that average daily gain (ADG) and carcass characteristics will not differ when hybrid rye partially replaces corn in diets for growing-finishing pigs.

Experimental Procedures

A total of 128 pigs with an initial body weight of approximately 24 kg were randomly allotted to 4 dietary treatments. Four pigs were housed per pen, and there were 8 replicate pens per treatment. There were 3 phases during the growing-finishing period (grower = day 1 – 35; early finisher = day 35 – 70; late finisher = day 70 – 97). A corn-soybean meal control diet was used in each phase, and 3 additional diets were formulated for each phase by replacing 33, 66, or 100% of the corn in the control diet with hybrid rye (Table 1). Individual pig weights were obtained at the beginning of the experiment and at the conclusion of each phase, and feed allowance was recorded daily. At the conclusion of the experiment, one pig per pen was harvested to measure carcass and meat characteristics.

Results

In the grower phase, ADG and average daily feed intake (ADFI) decreased (linear, P < 0.05) as the inclusion of hybrid rye in the diet increased (Table 2). In the early finishing phase, G:F tended to increase (linear, P < 0.10) with greater dietary inclusion of hybrid rye, likely as a result of compensatory gain following the reduced growth observed in phase 1. In the late finishing phase, gain:feed (G:F) increased and then decreased (quadratic, P < 0.05) with more hybrid rye in the diet. For the overall 97-day experiment duration, ADG, ADFI, and G:F did not differ among treatments. Diet did not impact most carcass characteristics, but loin (visual) and backfat (instrumental) color were lighter (linear, P < 0.05) with greater inclusion of hybrid rye (Table 3). Organ weights increased (linear, P < 0.05) with increased dietary hybrid rye.

Key Points

• In phase 1, pigs fed hybrid rye consumed less feed, which resulted in reduced ADG.
• Adapting pigs to hybrid rye early in life and in a stepwise manner may prevent the initial reduced feed intake observed in the present experiment.
• Hybrid rye may replace up to 100% of corn in growing and finishing pig diets without reducing overall growth performance or carcass quality. However, feed intake may be reduced at high inclusion rates in the late finishing phase due to gut fill.
• Organ weights were heavier for pigs fed hybrid rye, likely as a result of greater dietary fiber and total nitrogen in hybrid rye compared with corn.

Table 1. Ingredient composition of experimental diets in which either 0, 33, 66, or 100% of corn was replaced with hybrid rye

¹Other ingredients included limestone, dicalcium phosphate, crystalline amino acids, salt, and vitamin-mineral premix.

Table 2. Growth performance of pigs fed experimental diets in which either 0, 33, 66, or 100% of corn was replaced with hybrid rye¹

¹Least square means for dietary treatments represent 8 observations. 

Table 3. Carcass characteristics and loin quality of pigs fed experimental diets in which either 0, 33, 66, or 100% of corn was replaced with hybrid rye¹

¹Least square means for dietary treatments represent 7 to 8 observations.

²National Pork Producers Council color, 1 = palest and 6 = darkest.

³National Pork Producers Council marbling, 1 = least amount of marbling and 6 = greatest amount of marbling.

⁴L*, a*, and b* measure darkness, redness, and yellowness, respectively. No differences were observed for loin or backfat a* or b*.