Abstract A total of 962 pigs (Fast LW × PIC L02) × PIC 800; initially 26.5 ± 0.37 kg were used in a 116-d study to compare feeding strategies (phase feeding vs. diet blending) on growing-finishing pig growth performance and diet economics. Pens of pigs were randomly assigned to one of two treatments following a randomized complete block design with barn and initial body weight (BW) as blocking factors. There were 18-19 pigs per pen and 26 replications per treatment. Treatments included two feeding programs, a phase feeding strategy or complete diet blending with pre-defined mixing proportions of two diets to meet 100% of the standardized ileal digestible (SID) Lys curve requirement estimates for 23- to 114-kg pigs. The experimental period spanned from 23 to 114 kg BW with a common feeding period from 114-135 kg BW. Diets in phase feeding strategies were provided from 23-45, 45-79, and 79-114 kg. Pigs were fed on a feed budget set at 44, 82, and 104 kg of feed per pig for phases 1 to 3, respectively. Diets were corn-soybean meal based with 15% dried distillers grains (DDGS) except during the common period, when all pigs received the same DDGS-free diet. Feeding strategy did not influence BW or average daily gain (ADG) at any time during the study, except for BW at d 56 and ADG on d 28 to 56, where pigs in the phase feeding group had greater (P ≤ 0.013) BW and ADG compared to the diet blending group. For average daily feed intake (ADFI), pigs fed the diet blending strategy had lower (P ≤ 0.017) ADFI than those fed by phase feeding both during experimental and overall periods, but not during the common period. Pigs fed by diet blending had improved (P = 0.019) gain to feed ratio (G:F) and caloric efficiency (P = 0.007) compared to pigs fed the phase-feeding strategy during the experimental period but not overall. During the common feeding period (d 84 to 102), G:F of pigs previously phase fed was improved (P = 0.032) compared to pigs previously fed the diet-blending strategy. For diet economics, pigs fed the diet-blending strategy tended to have lower (P = 0.074) feed cost per pig and per kg of gain than those fed the phase-feeding strategy during the experimental period, but not during the overall period. Feeding strategy had no effect on total revenue or income over feed cost (IOFC) in either period. In conclusion, diet blending improved G:F by reducing ADFI without affecting ADG during the blending strategy feeding period. However, the inclusion of a common diet for the last 21 kg of BW growth diminished the G:F advantage, resulting in similar overall IOFC between the two feeding strategies.
Navales et al. (Wed,) studied this question.