ABSTRACT
OBJECTIVE: To investigate the effects of low-dose trace mineral proteinates on reproductive performance, mineral status, milk immunoglobulin contents and fecal mineral excretion of sows. METHODS: Eighty crossbred sows (Landrace×Large White) were randomly allocated to two groups in a 135-day trail, from breeding through 21 d postpartum. The two treatments were inorganic trace minerals (ITM): a basal diet+inorganic iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) at 90, 15, 25 and 90 mg/kg, respectively and organic trace minerals (OTM): a basal diet+proteinates of Fe, Cu, Mn, and Zn at 72, 12, 20, and 72 mg/kg, respectively. RESULTS: Compared with ITM, OTM significantly increased (p<0.05) the number of piglets with birthweight >1 kg, the litter weaning weight, and milk Fe, Cu contents. No significant differences (p>0.05) were observed on sow hair mineral contents or immunoglobulin M (IgM), IgG, and IgA contents in colostrum and milk. In comparsion to ITM, OTM decreased fecal Fe, Cu, Mn, and Zn contents of gestating sows (p<0.01) and Fe, Mn, and Zn in lactating sows (p<0.01). CONCLUSION: These results indicate that low-dose mineral proteinates can increase the number of piglets with birthweight >1 kg, the litter weaning weight and certain milk mineral concentrations while reducing fecal mineral excretion.
ABSTRACT
OBJECTIVE: The aim of this study was to evaluate the effects of compound organic acid calcium (COAC) on growth performance, hepatic antioxidant status and intestinal barrier of male broilers under high ambient temperature (32.7°C). METHODS: Nine hundred healthy one-d-old Cobb-500 male broiler chicks were randomly assigned into three groups with six replicates of 50 birds each. A basal diet supplemented with 0% (control), 0.4% and 0.8% COAC, respectively were fed to birds for 6 weeks. All treatments were under high ambient indoor temperature of 32.7°C, and had a constant calcium and available phosphorus ratio. RESULTS: The results showed that, compared with control, the average daily gain of broilers in 0.4% and 0.8% was significantly increased and the ratio of feed to gain in in 0.4% and 0.8% was significantly decreased at 1 to 21, 22 to 42 and 1 to 42 days of age (p<0.05). Compared with control, 0.8% COAC slightly decreased (p = 0.093) the content of malondialdehyde in liver at 42 days of age while 0.4% COAC significantly decreased (p<0.05) the activity of alkaline phosphatase. Furthermore, 0.4% COAC significantly enhanced the intestinal barrier function via increasing jejunal and ileal ocln transcription, promoting jejunal mucin 2 transcription at 42 days of age (p<0.05), and decreasing jejunal toll-like receptor 2 (TLR-2) and ileal TLR-15, inducible nitric oxide synthase compared with control group (p<0.05). Whereas, no significant differences on the transcription of interleukin-1ß in jejunum and ileum were observed among three treatments (p>0.05). Overall, heat stress caused by high natural environment temperature may induce the damage to hepatic antioxidation and intestinal barrier. CONCLUSION: Dietary inclusion of COAC can improve the tolerance of broilers to thermal environment through the modification of antioxidative parameters in liver and the mRNA expression of genes in intestinal barrier, resulting in an optimal inclusion level of 0.4%.
ABSTRACT
OBJECTIVE: The objective of this study was to investigate the effects of low doses of organic trace minerals (iron, copper, manganese, and zinc) on productive performance, egg quality, yolk and tissue mineral retention, and fecal mineral excretion of laying hens during the late laying period. METHODS: A total of 405 healthy hens (HY-Line White, 50-week-old) were randomly divided into 3 treatments, with 9 replicates per treatment and 15 birds per replicate. The dietary treatments included feeding a basal diet + inorganic trace minerals at commercial levels (CON), a basal diet + inorganic trace minerals at 1/3 commercial levels (ITM), and a basal diet + proteinated trace minerals at 1/3 commercial levels (TRT). The trial lasted for 56 days. RESULTS: Compared to CON, ITM decreased (p<0.05) egg production, daily egg mass, albumen height, eggshell strength, yolk Fe concentration, serum alkaline phosphatase activity and total protein, and increased (p<0.05) egg loss and feed to egg ratio. Whereas with productive performance, egg quality, yolk mineral retention, and serum indices there were no differences (p>0.05) between CON and TRT. The concentrations of Fe and Mn in the tissue and tibia were changed notably in ITM relative to CON and TRT. Both ITM and TRT reduced (p<0.05) fecal mineral excretion compared to CON. CONCLUSION: These results indicate that dietary supplementation of low-dose organic trace minerals reduced fecal mineral excretion without negatively impacting hen performance and egg quality.
