Effect of water-to-feed ratio on feed disappearance, growth rate, feed efficiency, and carcass traits in growing-finishing pigs.

The optimum proportion of water for preparing liquid feed to maximize growth and optimize feed efficiency (FE) in growing-finishing pigs is not known. The aim of the current study was, using an automatic short-trough sensor liquid feeding system, to identify the water-to-feed ratio at which growth was maximized and feed was most efficiently converted to live-weight. Two experiments were conducted in which four commercially used water-to-feed ratios were fed: 2.4:1, 3.0:1, 3.5:1, and 4.1:1 on a dry matter (DM) basis (the equivalent of 2:1, 2.5:1, 3.0:1, and 3.5:1 on a fresh matter basis). Each experiment comprised 216 pigs, penned in groups of 6 same sex (entire male and female) pigs/pen with a total of 9 pen replicates per treatment. The first experiment lasted 62 days (from 40.6 to 102.2 kg at slaughter) and the second experiment was for 76 days (from 31.8 to 119.6 kg at slaughter). Overall, in Exp. 1, FE was 0.421, 0.420, 0.453, and 0.448 (s.e. 0.0081 g/g; P < 0.01) for pigs fed at 2.4:1, 3.0:1, 3.5:1, and 4.1:1, respectively. Overall, in Exp. 2, average daily gain was 1,233, 1,206, 1,211, and 1,177 (s.e. 12.7 g/day; P < 0.05) for pigs fed at 2.4:1, 3.0:1, 3.5:1, and 4.1:1, respectively. At slaughter, in Exp. 1, dressing percentage was 76.7, 76.6, 76.7, and 75.8 (s.e. 0.17%; P < 0.01) for 2.4:1, 3.0:1, 3.5:1, and 4.1:1, respectively. There were no differences between treatment groups for DM, organic matter, nitrogen, gross energy, or ash digestibilities. These findings indicate that liquid feeding a diet prepared at a water-to-feed ratio of 3.5:1 maximizes FE of growing-finishing pigs without negatively affecting dressing percentage. Therefore, preparing liquid feed for growing-finishing pigs at a water-to-feed ratio of 3.5:1 DM is our recommendation for a short-trough liquid feeding system.

Effect of wet/dry, fresh liquid, fermented whole diet liquid, and fermented cereal liquid feeding on feed microbial quality and growth in grow-finisher pigs.

Fermented liquid feeding has proved beneficial for weaner pigs; however, there is limited research on its effect on the growth and feed conversion efficiency (FCE) of grow-finisher pigs. Microbial decarboxylation of amino acids is associated with whole diet fermentation, while wet/dry and liquid feeding reportedly improve growth compared with dry feeding. The objective of this study was to determine the effect of wet/dry feeding and fresh, fermented whole diet, and fermented cereal liquid feeding on pig growth, feed efficiency, and carcass quality in grow-finisher pigs. Pigs were allocated to one of four dietary treatments in two experiments: 1) Single-space wet/dry feeders (WET/DRY), 2) Fresh liquid feeding (FRESH), 3) Fermented cereal liquid feeding where the cereal fraction (38% barley, 40% wheat) of the diet was fermented prior to feeding (FERM-CER), and 4) Fermented whole diet liquid feeding where the whole diet was fermented prior to feeding (FERM-WH). In exp. 1, pigs were fed the experimental diets for 68 d prior to slaughter (29.8 kg ± 0.92 SE to 102.3 kg ± 0.76 SE). Overall, average daily gain (ADG) was 1,094, 1,088, 1,110, and 955 g/d (SE = 13.0; P < 0.001) and FCE was 2.26, 2.37, 2.40, and 2.88 (SE = 0.031; P < 0.001) for treatments one through four, respectively. Pigs fed FERM-WH were lighter at slaughter than pigs fed the other three treatments (P < 0.001). In exp. 2, pigs were on treatment for 26 d prior to slaughter (85.3 kg ± 1.69 SE to 117.5 kg ± 0.72 SE). Overall, ADG in exp. 2 was 1,103, 1,217, 1,284, and 1,140 g/d (SE = 27.9; P < 0.01) and FCE was 2.78, 2.99, 2.95, and 3.09 g/g (SE = 0.071; P = 0.05), for treatments one through four, respectively. There were no significant differences observed between treatments for apparent total tract digestibility of dry matter, organic matter, nitrogen, gross energy, or ash. Higher lactic acid bacteria counts and lower Enterobacteriaceae counts and pH were observed in FERM-CER and FERM-WH compared with WET/DRY and FRESH. Ethanol concentrations were almost 4-fold higher in FERM-CER troughs than FRESH troughs and 5-fold higher in FERM-WH than FRESH troughs. To conclude, FERM-WH resulted in poorer growth and FCE compared with WET/DRY, FRESH, and FERM-CER, probably due to amino acid degradation and a loss in gross energy found in FERM-WH.

The effect of feed form and delivery method on feed microbiology and growth performance in grow-finisher pigs.

There is no generally accepted optimal feed form and delivery method for feeding finisher pigs. The objective of this study was to compare the effect of feed form (meal and pellet) and delivery method (liquid, dry, and wet/dry) on feed microbiology and growth, gain-to-feed ratio (G:F), and carcass quality of finisher pigs. Two batches of pigs were used, each with six pen replicates per treatment. In each batch 216 pigs (32.7 kg; ± 0.48 SE) housed in same-sex (entire male or female) pens of six pigs per pen were on treatment for ~62 d prior to slaughter. The experiment was a 2 × 3 factorial arrangement with two factors for diet form (meal and pellets) and three factors for feed delivery (dry, wet/dry, liquid). The treatments were 1) meal from dry feeder, 2) meal from wet/dry feeder, 3) meal from liquid system, 4) pellet from dry feeder, 5) pellet from wet/dry feeder, and 6) pellet from liquid system. Pig growth performance was determined, blood samples collected at slaughter for hematological analysis and microbiological and proximate analysis of feed performed. A significant feed form × delivery interaction was found for G:F. During the overall period G:F was 0.446, 0.433, 0.423, 0.474, 0.459, and 0.418 g/g (SE = 0.0080; P < 0.01) for treatments 1 through 6, respectively. When feed was pelleted, G:F was improved when feed delivery was dry or wet/dry compared to meal but when the delivery was liquid, pelleting did not affect G:F. There were no interactive effects for overall average daily gain (ADG). Overall ADG was 1,114 and 1,156 g/d (SE = 16.9; P < 0.01) for pigs fed diets in meal and pellet form, respectively and 1,080, 1,114, and 1,210 g/d (SE = 18.4; P < 0.001) for dry-, wet/dry-, and liquid-fed pigs, respectively. Carcass weight was 76.6 and 79.0 kg (SE = 0.55; P < 0.001) for pigs fed in meal and pellet form, respectively, while it was 74.7, 77.3, and 81.5 kg (SE = 0.60; P < 0.001) for pigs delivered dry, wet/dry, and liquid diets, respectively. Lactic acid bacteria (P < 0.05) and yeast (P < 0.01) counts in troughs were greater for the liquid than the dry diet in both meal and pelleted form. There was also evidence of lysine degradation in the liquid diet but this did not impact pig growth. Feeding the diet in pelleted vs. meal form led to lower hemoglobin and greater white blood cell and neutrophil counts (P < 0.05). To conclude, wet/dry feeding of a pelleted diet is recommended to maximize growth rate while optimizing G:F in grow-finisher pigs.