Effects of low-dose organic trace minerals on performance, mineral status, and fecal mineral excretion of sows

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.

Effects of compound organic acid calcium on growth performance, hepatic antioxidation and intestinal barrier of male broilers under heat stress.

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%.

Low-dose of organic trace minerals reduced fecal mineral excretion without compromising performance of laying hens.

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.

Effects of High-Dose of Copper Amino Acid Complex on Laying Performance, Hematological and Biochemical Parameters, Organ Index, and Histopathology in Laying Hens.

The objective of the study was to evaluate the maximum tolerance limit of amino acid copper complex (Cu-Lys-Glu) for laying hens by measuring their laying performance, hematological and serum biochemical parameters, organ index, and histopathology. A total of 450 18-week-old Beijing White layers were randomly allocated to 5 groups (90 birds per group) with 6 replicates of 15 birds each. After a 2-week acclimation on a basal diet (analyzed copper content 8.63 mg/kg), the birds were fed diets supplemented with 0 (control), 15, 75, 150, and 300 mg Cu/kg as Cu-Lys-Glu for 10 weeks. Results showed that, compared with the control group, dietary supplementation with 15, 75, and 150 mg Cu/kg as Cu-Lys-Glu did not affect (P > 0.05) laying performance, whereas hens receiving with 300 mg Cu/kg significantly decreased (P < 0.001) the laying rate as compared with the control. No significant differences (P > 0.05) were observed among the hens receiving 0, 15, 75, and 150 mg Cu/kg as Cu-Lys-Glu in hematological and serum biochemical parameters, organ indexes, and histopathological changes. However, hens receiving 300 mg Cu/kg significantly increased (P < 0.05) the concentrations of mean corpuscular volume (MCV), albumin (ALB), total bilirubin (TBILI), alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (UN), and creatinine (CRE), as well as caused severe microscopic histopathological changes in the liver and kidney. In conclusion, 150 mg Cu/kg as Cu-Lys-Glu is identified as no-side-effect supplementation level in laying hens after daily administration for 70 days.

[Effect of Temperature on the Activity Kinetics of Nitrobacter].

A sequencing batch reactor (SBR) was operated in this study to investigate the effect of temperature on the kinetics of Nitrobacter activity among nitrite oxidizing bacteria. At the beginning of the experiment, the NO2--N concentration in the influent was changed to enrich Nitrobacter. Then, the sludge with enriched Nitrobacter was employed to determine the variation of the specific nitrite oxidation rate (SNiOR) during the nitrite oxidation process in batch tests. Metagenomics species annotation and abundance analysis showed that Nitrobacter accounted for 40.3% of the total bacterial population. The variation of SNiOR in the nitrite oxidation process was investigated under different NO2--N concentrations. The effect of temperature on the kinetics of Nitrobacter was investigated using the Monod model. Furthermore, the kinetics model of the effect of temperature on Nitrobacter activity was fitted for statistical analysis. The results showed that SNiOR reached its maximum at 30℃, which was 1.31 g·(g·d)-1. Statistical analysis showed that the Monod equation could describe the effect of substrate concentration on Nitrobacter activity under different temperature conditions. Calculating the temperature coefficient (θ) in different temperature intervals based on the Phelps equation, showed that when the system temperature is lower than 25℃ or higher than 30℃, the reaction rate is more sensitive to temperature changes.

[Effect of Free Nitrous Acid on the Activity of Nitrifying Bacteria in Different Sludge Concentrations Under Anoxic Conditions].

This study investigated the inhibitory effect of free nitrous acid (FNA) on the activity of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) under anoxic conditions with different mixed liquid suspended solids (MLSS). Sequencing batch reactors were used to study the changes in the activity of AOB and NOB in nitrifying activated sludge based on four different MLSS (8398, 11254, 15998, and 19637 mg·L-1), after treatment, under anoxic conditions with FNA (at an initial concentration of 1.3 mg·L-1) for 48 h. The results showed that the pH increased by approximately 0.9, but the concentration of NO2--N did not decrease significantly. With over-aeration, the concentration of NH4+-N gradually degraded to 0 mg·L-1, and the removal rate of NH4+-N gradually increased to a maximum of 4.4-6.8 mg·(L·h)-1 which time used was shorter with the increase of the inhibition MLSS. The nitrite accumulation rate was more than 92% when the sludge concentration was 8398, 11254, 15998, and 19637 mg·L-1 and with over-aeration for 0-396 h, 0-396 h, 0-372 h, and 0-168 h, respectively. When aerated for 468 h, 468 h, 444 h, and 264 h, the NO2--N concentration and NAR decreased to 0, and NO3--N concentrations increased to their highest with the values of 42.6, 49.9, 42.9, and 47.9 mg·L-1 respectively.

[Synergetic Inhibitory Effect of Free Ammonia and Aeration Phase Length Control on the Activity of Nitrifying Bacteria].

Three sequencing batch reactors (SBRs) labeled with R(Ahead), R(Exact) and R(Exceed) were employed to investigate the synergetic inhibition effect of free ammonia (FA) and length of aeration phase on the activity of ammonia-oxidizing bacteria ( AOB) and nitrite- oxidizing bacteria (NOB) after shortcut nitritation was achieved in the systems. The experiments were conducted under the conditions of three FA concentrations (0.5, 5. 1, 10.1 mg · L⁻¹) combined with three kinds of aeration time (t(Exact): the time when ammonia oxidation was completed; t(Ahead): 30 min ahead of the time when ammonia oxidation was completed; t(Exceed): 30 min exceeded when the time ammonia oxidation was completed). It was found that short-cut nitrification could be successfully established in three reactors with a FA level of 10.1 mg · L⁻¹. Meanwhile, the speed of achieving nitritation was in the sequence of R(Ahead) > R(Exact) > R(Exceed) with operational cycles of 56, 62 and 72, respectively. Compared to AOB, NOB in the three reactors was observed to be more sensitive to FA, resulting in AOB activity higher than NOB activity throughout the whole experimental period. Moreover, there was great difference in the activity coefficient ( η) between AOB and NOB. The activity coefficients of AOB were in the order of η(RExact) > η(RExceed) > η(RAhead) with the values of 104.4%, 100% and 85.8%, respectively. Nevertheless, the activity coefficients of NOB were in the order of η(RExceed) > η(RExact) > η(RAhead) with the values of 71.2%, 64.9% and 50.2%, respectively.