| Popis: |
The objective of this experiment was to evaluate the degree of compensatory gain in finishing hogs when fed increasing levels of lysine during the re-alimentation period after being fed a restrictive 97% corn diet for 3 or 6 weeks. One hundred and forty mixed-sex pens (DNA Genetics, Columbus, NE) with a starting body weight of 73.5 ± 2.2 kg were blocked by starting bodyweight and assigned to a 2:3:1 factorial. Twenty replicates of seven treatments were comprised of 2 restriction lengths [3 weeks (3W) vs. 6 weeks (6W)], and 3 lysine inclusion levels at re-alimentation (Lys:ME: 100%, 110%, or 120% of the genetic margin over feed curve), and a control that remained nutrient unrestricted. Pen weight and feed disappearance were recorded at trial day zero and every 3-weeks until market. Whole pens were marketed when the average met 130 kg to evaluate the full re-alimentation period. Data were analyzed by pen (SAS 9.4, Cary, NC) with the fixed effects of restriction length and lysine level nested within restriction length. Control pigs were market weight (130 kg) on d 49 while pigs fed corn diets for 3 weeks or 6 weeks were significantly slower to market (57 and 69 d, respectively; P < 0.01). Overall average daily gain was significantly different between the control, 3W, and 6W groups (Control: 1.17, 3W: 0.99, 6W: 0.82; P < 0.01). Furthermore, overall average daily gain was significantly influenced by the lysine inclusion level during re-alimentation (Control: 1.17, 3W/100%: 0.98, 3W/110%: 0.99, 3W/120%: 1.01, 6W/100%: 0.81, 6W/110%: 0.83, and 6W/120%: 0.84 kg/d; P < 0.03). In conclusion, the use of 97% corn diets significantly reduced average daily gain and increased days to market. However, the use of diets in which the Lys:ME was greater than genetic recommendations after a period of nutrient restriction, resulted in increased compensatory growth. |
