RESUMEN
The effects of oxidized ß-carotene (OxBC) were determined upon the growth performance of swine through their full growth cycle under commercial production conditions in Vietnam. Five hundred 28-day-old-weaned barrows and gilts were used in a 140-day complete wean-to-finish feeding trial. Animals were randomized by weight, and each pen contained 20 pigs with the same ratio of barrows to gilts. There were five dietary treatment groups with five replicate pens per treatment: Control basal diet, no antibiotics or OxBC; Basal diet with antibiotics; no OxBC; Basal diet supplemented with 2, 4, or 8 mg OxBC/kg of diet, no antibiotics. Growth performance parameters were calculated for each production stage (Starter: Days 1−28, Grower: Days 29−84, Finisher: Days 85−140) and for the overall study (Days 1−140). OxBC and antibiotics each improved growth rate, feed efficiency, and body weight compared to the unsupplemented control (p < 0.001). Animals receiving 4 and 8 mg/kg OxBC performed better than animals on antibiotics (p < 0.001). In Starter pigs, OxBC reduced the occurrence of diarrhea dose-dependently (2, 4, and 8 mg/kg) and more so than did antibiotics (p < 0.001). These findings support the concept that oxidized ß-carotene can facilitate swine growth and health in the absence of in-feed antibiotics.
RESUMEN
Two studies were conducted to determine the impact of an absorption enhancer containing a combination of lysophospholipids, monoglycerides and synthetic emulsifiers (LEX) on apparent ileal digestibility, metabolizable energy (ME), and growth performance of growing pigs. In the digestibility study, 12 male crossbred [Duroc x (Large White x Landrace)] pigs with an initial body weight (BW) of 30 kg were randomly allocated to two dietary treatments: (1) a positive control (PC) receiving standard diets formulated to 3100 kcal ME/kg, and (2) a negative control formulated with −100 kcal ME/kg and −2.5% AA content vs. PC and supplemented with LEX at 500 g/t. Apparent ileal digestibility of essential AA was significantly increased for lysine, methionine, threonine, histidine, isoleucine and phenylalanine in the LEX treatment (p < 0.05). Average uplift in AA digestibility as a percent of the PC was +1.88%; with greatest improvement for histidine (+4.22%). LEX supplementation effectively compensated energy deficiency of low-density diet and provided additional ME improvement compared to the PC diet (p < 0.05). A second study was conducted to evaluate LEX dose response on the growth performance of pigs fed a low nutrient density diet. Total 450 cross-bred pigs (240 males (castrated) and 210 females) [Duroc x (Large White x Landrace)] with an average initial BW of 7.19 kg were randomly allocated into 4 dietary treatments: (1) a positive control (PC) formulated with standard specifications, (2) a negative control formulated with −100 kcal ME/kg and −2.5% AA content vs. the PC (NC), (3) NC + LEX at 250 g/t (NC + 250) and (4) NC + LEX at 500 g/t (NC + 500). Results showed significant improvement with LEX supplementation on the final BW, average daily gain (ADG) and feed conversion ratio (FCR) of pigs of >50 kg body weight. Across the study, NC + 500 significantly increased ADG vs. PC and NC, and significantly reduced FCR compared to all other treatments. FCR of negative control diets improved by 9 and 15 points with the supplementation of 250 g/t and 500 g/t of LEX, respectively (p < 0.05). FCR in the NC + 250 diet was statistically similar vs. PC, which was significantly reduced compared to the NC. Taken together, these studies demonstrate that the addition of an absorption enhancer containing a combination of lysophospholipids, monoglycerides and synthetic emulsifiers can improve growth performance in growing pigs, driven by increased nutrient digestibility and retention.