This study was conducted to evaluate the effects of dietary supplementation with chitooligosaccharide (COS) on growth performance, blood characteristics, relative organ weight, and meat quality in broilers. A total of 480 broilers with an average initial BW of 45.04 g per chick were randomly allocated into 1 of the following 4 dietary treatments (20 broilers per pen with 6 pens per treatment): 1) CON (basal diet), 2) ANT (basal diet + 44 mg/kg of avilamycin), 3) COS0.2 (basal diet + 14 g/kg of COS), 4) COS0.4 (basal diet + 28 g/kg of COS). The experiment lasted for 5 wk and avilamycin was administered from d 0 to 21. Growth performance was measured on d 0, 21, and 35, and all other response criteria were measured on d 35. No change in feed conversion (G:F) was observed in response to any of the treatments throughout the experimental period (P > 0.05). However, BW gain and feed intake were greater (P < 0.05) in broilers provided with feed supplemented with COS than in those in the control group. In addition, broilers had significantly greater (P < 0.05) red blood cell and high-density lipoprotein cholesterol concentrations when they were provided with the COS0.4 diet, whereas the triglyceride concentration was lower (P < 0.05) in broilers in the COS0.2 treatment group. No other blood characteristics were affected by the treatments. Additionally, as the dietary COS concentration increased, the liver weight increased (P < 0.05). Conversely, as the concentrations of dietary COS increased, abdominal fat decreased (P < 0.05). Furthermore, meat yellowness decreased (P < 0.05) as the concentration of COS increased. Finally, the breast meat and abdominal fat of birds provided with feed supplemented with COS had a lower (P < 0.05) saturated fatty acid concentration but a greater concentration of total monounsaturated fatty acids (P < 0.05) than that of birds in the control. In conclusion, COS can improve the performance and breast meat quality of broilers while increasing the red blood cell and high-density lipoprotein cholesterol concentrations in blood. In addition, COS can induce a decrease in abdominal fat and improve meat quality.

Primary Audience: Nutritionists, Researchers, Veterinarians SUMMARYOrganic acids have been widely used as feed additives to replace antibiotics in livestock feeds. Data on the use of phenyllactic acid (PLA) are lacking. The effects of PLA on production performance, egg quality parameters, and blood characteristics in laying hens were studied in a 35-d experiment. A total of 240 ISA Brown 36-wk-old layers were divided into the following 4 treatments: 1) control (basal diet), 2) control + 0.1% PLA, 3) control + 0.2% PLA, and 4) control + 0.3% PLA. Although supplementing the diet with PLA did not affect ADFI and FE, it linearly improved egg production rate, eggshell breaking strength, and Haugh units. Egg weight, eggshell thickness, and egg yolk color were not significantly altered by supplementing the diet with PLA. White blood cell, red blood cell, total protein, and albumin concentrations were higher in the control + 0.1% PLA and control treatment groups (P < 0.05), whereas the groups fed the control + 0.2% PLA and control + 0.3% PLA diets had greater (P < 0.05) lymphocyte concentrations. In conclusion, PLA may exert some positive effects to the immune system and egg production over the short term. It may be beneficial to supplement the diets of laying hens with PLA in the absence of antibiotics. This experiment involved a small experimental sample and a short time, so the beneficial effects of PLA should be studied further in commercial farms over the long term.

This study was conducted to determine the effects of dietary supplementation with phenyllactic acid (PLA) on growth performance, intestinal microbiota, relative organ weight, blood characteristics, and meat quality in broilers. A total of 500 male broilers (BW = 46.3 g) were randomly allotted into 1 of the following 5 dietary treatments: 1) basal diet (CON), 2) basal diet + 44 mg/kg of avilamycin (ANT), 3) basal diet + 0.2% PLA (PLA0.2), 4) basal diet + 0.4% PLA (PLA0.4), 5) basal diet + 0.2% PLA + 44 mg/kg of avilamycin (PA). Chicks fed PLA had lower feed intake (FI) from d 0 to 7 (P < 0.05) than those fed CON and ANT. From d 21 to 35, BW gain was greater in ANT, PLA0.4, and PA diets than CON and PLA0.2 diets (P < 0.05), whereas the FI was lowest in the PLA0.4 diet. Feed efficiency was depressed (P < 0.05) by the antibiotics and PLA supplementation during d 0 to 7, whereas it was improved (P < 0.05) in the PLA and ANT diets during d 21 to 35, with the best value in PLA0.4.The population of Escherichia coli in the large intestine was lower in the ANT, PLA0.4, and PA groups than the CON and PLA0.2 groups (P < 0.05). The relative weights of gizzard, liver, spleen, bursa of Fabricius, breast, and abdominal fat were unaffected by any of the dietary supplementations. Treatment of PLA led to an increase (P < 0.05) in the concentrations of white blood cells and lymphocyte percentage. The yellowness of breast muscle decreased by ANT, PLA0.4, and PA treatment. In conclusion, PLA can improve growth performance when it is supplemented in finisher diet (d 21 to 35), whereas it can depress BW gain and FI in earlier days (d 0 to 7). In addition, PLA can also decrease the number of E. coli in the large intestine and improve the number of immune-related blood cells.

This study was conducted to evaluate the effect of dietary administered delta-aminolevulinic acid (ALA) and vitamin C on the hematological profiles and performance of sows and sucking pigs and to determine if iron status could be improved by dietary administration of ALA. Seven days before parturition, 120 sows (Landrace x Yorkshire) were randomly assigned within parities to 1 of 4 dietary treatments. The lactation treatments were arranged as a 2 x 2 factorial with 2 ALA concentrations (0 or 10 mg/kg of feed, as fed) and 2 vitamin C concentrations (0 or 500 mg/kg of feed, as fed). After farrowing, daily feed allowance increased gradually, and sows had ad libitum access to feed by wk 2. Sows provided diets with ALA tended to consume more feed (P < 0.10) than sows fed diets that did not contain ALA. Conversely, backfat losses were less in sows that received the diets with ALA compared with those received the nonsupplemented diets (P < 0.05). Supplementation with ALA and vitamin C resulted in improved hematological profiles (total protein, albumin, and IgG) in sows (P < 0.05). The iron status in the blood and milk were also improved by ALA supplementation (P < 0.05). Moreover, the BW at weaning and the ADG during the sucking period increased in response to supplementation of ALA and vitamin C (P < 0.05). The blood iron status of piglets was also improved by ALA supplementation (P < 0.05). In conclusion, dietary supplementation of ALA can increase the blood iron status of sows and sucking pigs, as well as the iron transfer efficiency from sows to piglets through elevated milk iron concentrations.

Ninety weanling pigs in Exp. 1 (6.27 +/- 0.73 kg; 21 d of age) and 96 growing pigs in Exp. 2 (21.73 kg +/- 1.29 kg; 56 d of age) were used in two 42-d experiments to evaluate the effect of phenyllactic acid (PLA) on growth performance, apparent total tract digestibility (ATTD) of DM and N, fecal pH value, microbial shedding, and blood profiles. In Exp. 1, the 3 dietary treatments were 1) negative control (NC), 2) positive control (PC), NC + antibiotics, and 3) PLA, NC + 0.5% PLA. In Exp. 2, dietary treatments were 1) control diet (CON), 2) PLA-0.1, CON + 0.1% PLA, 3) PLA-0.2, CON + 0.2% PLA, and 4) PLA-0.3, CON + 0.3% PLA. In Exp. 1, pigs fed the PC and PLA diets had greater ADFI during the overall period (P < 0.05) and tended to have greater ADG and G:F from d 7 to 21 (P < 0.10) than those fed the NC diet. The ATTD of DM was greatest in pigs fed the PLA diet on d 20 and 41, and N digestibility on d 20 was greater in pigs fed the PLA diet (P < 0.05) than those fed the NC diet. The numbers of white blood cell and lymphocyte concentrations on d 42 were increased (P < 0.05) by the inclusion of antibiotics and PLA in the diet. In Exp. 2, G:F tended to increase when PLA was added (quadratic, P < 0.10). The ATTD of DM did not differ among treatments, but there was a tendency (quadratic, P < 0.10) for N digestibility to increase as PLA levels increased. The lymphocyte percentage on d 42 increased linearly as dietary PLA increased (P < 0.05). Additionally, the white blood cell counts on d 42 tended to increase as PLA levels increased (P < 0.10). In both experiments, there was no effect of treatment on the fecal pH or presence of Lactobacillus, but the number of Escherichia coli in feces on d 41 decreased in response to the addition of PLA [P < 0.05 and 0.001 (linear) in Exp. 1 and 2, respectively]. In conclusion, PLA can decrease the number of E. coli, and this novel dietary acid may have potential to stimulate the immune system for both weanling and growing pigs. Thus, it could be a good candidate as an alternative to antibiotics in pig diets.