Zinc oxide at low supplementation level improves productive performance and health status of piglets

Enhancement of protective vaccine-induced antibody titer to swine diseases and growth performance by Amino-Zn, yucca extract, and β-mannanase feed additive in wean-finishing pigs

The primary purpose of this research is to determine the effect of Amino-Zn (AZn), Yucca schidigera extract (YE), and β-mannanase enzyme supplementation on growth performance, nutrient digestibility, fecal gas emission, and immune response in pigs. A total of 180 crossbred pigs (6.57 ± 1 kg) were randomly assigned to one of three dietary treatments: CON-corn soybean meal (basal diet); TRT1-CON +1,000 ppm AZn + 0.07% yucca extract (YE) + 0.05% β-mannanase; and TRT2-CON +2,000 ppm AZn + 0.07% YE+ 0.05% β-mannanase for 22 weeks. Each treatment had 12 replicates with 5 pigs per pen. Pigs fed a diet supplemented with AZn, YE, and β-mannanase linearly increased (p < 0.05) BW and average daily gain at weeks 6, 12, 17, and 18. In contrast, the gain-to-feed ratio showed a linear increase (p < 0.05) from weeks 6 to 17 and the overall trial period. Moreover, the inclusion of experimental diets linearly decreased (p > 0.05) noxious gas emissions such as ammonia, hydrogen sulfide, acetic acid, carbon dioxide, and methyl mercaptans. The dietary inclusion of AZn, YE, and β-mannanase significantly increased the serological immune responses to Mycoplasma hyopneumoniae (MH) and foot-and-mouth disease virus (FMDV-O type) at the end of week 6 and porcine circovirus-2 (PCV-2) at week 19. Based on this result, we infer that the combination of AZn, YE, and β-mannanase supplement would serve as a novel in-feed additive to enhance growth performance and act as a boosting agent and immune stimulatory to increase the efficacy of swine vaccinations.

Alternative to ZnO to establish balanced intestinal microbiota for weaning piglets

A wide range of phytobiotic feed additives are available on the market claiming to have beneficial effects on the growth of the host animal and to promote the development of a balanced microflora. The present study investigated the effects of the phytobiotic-prebiotic mixture of curcumin, wheat germ, and chicory on the growth performance and on the intestinal microflora composition of weaning piglets. Post weaning diarrhea causes significant losses for the producers, most commonly it is prevented by feeding high doses of zinc oxide (ZnO). The effect of a phytobiotic-prebiotic feed additive (1 kg T^-1) was compared to a positive control (3.1 kg T^-1 ZnO) and to a negative control (no feed supplement) in an in vivo animal trial. There was no significant difference in the final body weight and average daily gain of the trial and positive control groups, and both groups showed significantly (P<0.05) better results than the negative control. The feed conversion ratio of the phytobiotic-prebiotic supplemented group was significantly improved (P<0.05) compared to both controls. Both phytobiotic-prebiotic mixture and ZnO were able to significantly reduce (P<0.05) the amount of coliforms after weaning, even though ZnO reduced the amount of coliforms more efficiently than the trial feed additive, it also reduced the amount of potentially beneficial bacteria. Metagenomic data also corroborated the above conclusion. In the trial and positive control groups, the relative abundance of Enterobacteriaceae decreased by 85 and 88% between 3 weeks and 6 weeks of age, while in the negative control group a slight increase occurred. Lactobacillaceae were more abundant in the trial group (29.98%) than in the positive (8.67%) or in the negative (22.45%) control groups at 6 weeks of age. In summary, this study demonstrated that a phytobiotic-prebiotic feed additive may be a real alternative to ZnO for the prevention of post weaning diarrhea and promote the development of a balanced gut system.

Novel zinc sources as antimicrobial growth promoters for monogastric animals: A review

The essentiality of zinc for animals has been recognized over 80 years. Zinc is an essential trace element that is a component of many enzymes and is associated with the various hormones. Apart from the nutritional function, zinc has antimicrobial property and often be supplemented in diets in the quantities greater than which is required to meet the nutritional requirement, especially for weaning pigs. This review will focus on the application of pharmacological zinc and its mechanisms which may be responsible for the effects of zinc on performance and health of monogastric animals. Various novel sources of zinc in non-ruminant animal production will also be discussed. These should assist in more precisely formulating feed to maximize the production performance and to maintain the health condition of monogastric animals.

Comparative effect of potentiated zinc oxide and antibiotic growth promoters on intestinal morphometry and nutrient digestibility in broiler chickens

The comparative effects of potentiated zinc oxide (pZnO) and antibiotic growth promoters (AGP) supplementation on intestinal morphometry and nutrient digestibility in broiler chickens were studied. Four hundred straight-run Cobb 500-day-old broiler chicks were randomly allotted to four dietary treatments replicated 10 times with 10 birds per replicate. Dietary treatments were as follows: T1: basal diets without AGP (negative control; NC), T2: basal diets with 500 g/t maduramicin 10 g and 500 g/t zinc bacitracin 150 (positive control; PC), T3: NC added with 150 g/t pZnO, and T4: PC added with 150 g/t pZnO in a 2 × 2 factorial design in RCBD. At days 18 and 35, 10 birds were randomly selected per treatment for morphometry of the duodenum, jejunum, and ileum. At day 38, eight birds per treatment were used for the nutrient digestibility study. Results showed significant interaction effects (P < 0.05) of AGP and pZnO supplementation on day 35 intestinal morphometry of duodenum's villi height and villi height: crypt depth, and ileum's crypt depth; apparent COD_GE, AME, CP, DM, and EE. Significant differences (P < 0.05) with pZnO supplementation were only observed on feed intake and FCR of birds fed with pZnO at days 8-14 and fecal quality at days 0-7. Results of present study suggested that pZnO has the potential to replace AGPs without negatively affecting the intestinal morphometry, digestibility, and growth performance of broiler chickens.

The Effects of Dietary Porous Zinc Oxide Supplementation on Growth Performance, Inflammatory Cytokines and Tight Junction's Gene Expression in Early-Weaned Piglets

This study was conducted to investigate the effect of dietary porous ZnO supplementation on the growth performance, inflammatory cytokines and tight junction's gene expression in weaned piglets. A total of 192 weaned piglets were randomly allocated to 4 experimental groups (n=48/group) and fed, during 14 d, with one of the following dietary treatments: 1) basal diet (NC); 2) basal diet with 3,000 mg/kg of conventional ZnO (PC); 3) basal diet with 750 mg/kg of porous ZnO (low inclusion porous ZnO, LP-ZnO); 4) basal diet with 1,500 mg/kg porous ZnO (high inclusion porous ZnO, HP-ZnO). Results showed that dietary supplementation with regular ZnO or porous ZnO (750 and 1,500 mg/kg) improved average daily gain (ADG), feed to gain ratio (F/G) and jejunum morphology, while decreasing diarrhea incidence. Compared with the NC group, porous ZnO at both doses (750 or 1,500 mg/kg) increased serum alkaline phosphatase (ALP), immunoglobulin G (IgG) and insulin-like growth factor 1 (IGF-1) concentrations, but decreased serum glucose (GLU). Moreover, the mRNA expression of anti-inflammation cytokine (TGF-β), tight junction (Occludin, ZO-1) in the jejunum by different ZnO administration were significantly increased compared with the NC group, while mRNA expression of pro-inflammatory (IL-8), membrane channels that transport water (AQP3) and miR-122a were significantly decreased. It can be concluded that porous ZnO even at low dose (750 mg/kg) can be an effective alternative to pharmacological (3,000 mg/kg) conventional ZnO in reducing diarrhea, promoting the growth performance, increasing anti-inflammatory cytokines and tight junctions, reducing pro-inflammatory cytokines of weaned piglets.

Evaluation of the combined effects of different dose levels of Zinc oxide with probiotics complex supplementation on the growth performance, nutrient digestibility, faecal microbiota, noxious gas emissions and faecal score of weaning pigs

This study was conducted to assess the effects of different dose levels of zinc oxide (ZnO) combined with probiotics complex supplementation on the growth, performance, nutrient digestibility, faecal lactobacillus and Enterobacteria counts, noxious gas emissions and faecal score of weaned piglets. A total of 180 crossbred weaning pigs ([Yorkshire × Landrace] × Duroc; 6.61 ± 1.29 kg [mean ± SE]; 28 days old) were used in a 42-day trial. All pigs were randomly allotted to 1 of 4 treatment diets based on initial BW and sex (9 replicate pens/treatment; 2 gilts and 3 barrows/pen). Dietary treatment groups were as follows: CON, basal diet +ZnO 3,000 ppm; BZS, basal diet +ZnO 2,100 ppm +0.1% SynerZymeF10; BZS1, basal diet +ZnO 1,200 ppm +0.1% SynerZymeF10; BZS2, basal diet +ZnO 300 ppm +0.1% SynerZymeF10. During the phase 3, decreasing the ZnO concentration led to a linear reduction in ADG (p = 0.044), and the ADG was lower (p < 0.05) in BZS2 compared with CON treatment during the whole experimental period. The effects of dietary ZnO with probiotics complex were not detected (p > 0.05) on nutrient digestibility, Lactobacillus and E. coli counts, faecal gas emissions and faecal scores. In conclusion, the diet supplementation of ZnO (1,200 ppm) with probiotics complex has been shown to have comparable efficacy to ZnO (3,000 ppm) diet on growth performance, nutrient digestibility, faecal microbiota, noxious gas emissions and faecal score of weaning pigs.

Comparative effects of low zinc oxide dose with or without probiotics relative to high zinc oxide dose on the performance, nutrient digestibility, blood metabolites, and noxious gases emission in weaned piglets

The objective of this study was to assess the effects of low-dose zinc oxide (ZnO) supplemented with or without probiotic complex compared with pharmacological ZnO (3000 mg kg−1) on the performance, digestibility, blood metabolites, fecal Lactobacillus and enterobacteria counts of weaned piglets. One-hundred and twenty crossbred piglets were randomly allocated to three treatments based on their initial body weight (BW). Treatments consisted of corn–soybean-meal-based basal diet supplemented with 3000 mg kg−1 ZnO as positive control (ZH), basal diet supplemented with 300 mg kg−1 ZnO as negative control (ZL), and ZL + 0.1% probiotic complex (ZLP). At the end of the experiment, fecal samples were collected by direct rectal massage to determine nutrient digestibility, Lactobacillus and enterobacteria counts, and gas emission, whereas blood samples were taken via jugular venipuncture for determination of blood metabolites. The BW of piglets at week 6, and the average daily gain (ADG) at week 6 and during overall period were higher (P < 0.05) in pigs fed ZH diet compared with those fed ZL diet. The supplementation of ZLP increased the ADG during week 6 and overall making it comparable with ZH diet (P < 0.05). However, other parameters described above were comparable with ZH in pigs fed ZLP diet.

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

In recent years, zinc oxide nanoparticles (ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles (NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods. Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, non-toxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal's body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.

The effects of dietary supplementation with porous zinc oxide on growth performance, intestinal microbiota, morphology, and permeability in weaned piglets

The objective of this experiment was to evaluate the effects of dietary supplementation with porous zinc oxide (HiZox) on growth performance, intestinal microbiota, morphology, and permeability in weaned piglets. A total of 128 weaned piglets [(Landrace × Yorkshire) × Duroc] with an average body weight (BW) of (6.55 ± 0.25 kg; 21 d of age) were randomly assigned to four dietary treatments: (1) a corn-soybean basal diet; (2) basal diet + 3,000 mg/kg conventional ZnO; (3) basal diet + 200 mg/kg HiZox; (4) basal diet + 500 mg/kg HiZox. The experiments lasted for 28 days. Incremental HiZox in the diet increased ADG (linear p = 0.015; quadratic p = 0.043) and ADFI (linear p = 0.027; quadratic p = 0.038), and the diarrhea index decreased linearly and quadratically (p < 0.01) as HiZox supplemented increased. Furthermore, supplementation with HiZox increased the amounts of Lactobacillus spp. (p < 0.05) in the ileum and cecum in comparison with that of control treatment or 3,000 mg/kg ZnO treatment, while decreased the populations of Escherichia coli, Clostridium coccoides, and Clostridium. leptum subgroup (p < 0.05) in the ileum and cecum relative to those in control treatment. The addition of HiZox increased the villus height and villus-to-crypt ratio (VC) of duodenum, jejunum, and ileum (p < 0.05), while decreased the crypt depth of jejunum (p < 0.05) and tended to reduce the crypt depth of duodenum (p < 0.10) compared with the control treatment. Piglets fed with 500 mg/kg HiZox had lower serum D-lactate and diamine oxidase (DAO) than those fed with basal control diet or 3,000 mg/kg ZnO diet (p < 0.01). The results suggested that supplementation with HiZox modulated intestinal microbial composition and improved intestinal morphology, which may exert protective effects on the integrity of the mucosal barrier function of weaned piglets, was as efficacious as pharmaceutical doses of ZnO in enhancing growth performance, indicating that the HiZox may be a promising alternative to pharmaceutical doses of ZnO.

Effect of zinc oxide sources and dosages on gut microbiota and integrity of weaned piglets

Zinc oxide (ZnO) supplied at pharmacological dosage in diets of weaned piglets improves growth performance. However, it causes environmental contamination and induces bacterial antibiotic resistance, yet this practice is debated. The effects on gut microbiota and integrity in weaned piglets of conventional ZnO at nutritional and pharmacological dosage (110 and 2,400 mg/kg Zn, respectively) were compared to an alternative ZnO source at 110 and 220 mg/kg Zn. Each of the four treatments was applied to four pens (two piglets/pen; weaning age, 20 days) for 15 days, and piglets were sampled on day 15 to determine indices of gut integrity. Feeding conventional ZnO at 2,400 mg/kg Zn reduced coliforms and Escherichia coli in distal small intestine as compared to conventional ZnO at 110 mg/kg (-1.7 and -1.4 log₁₀ cfu/g, respectively), whereas the alternative ZnO reduced only coliforms, irrespective of dosage (-1.6 to -1.7 log₁₀ cfu/g). Transepithelial electrical resistance of distal small intestinal mucosa was higher for pigs fed the alternative ZnO source as compared with groups fed 110 mg/kg Zn of conventional ZnO, in line with a trend for higher gene expression of claudin-1 and zona occludens-1. Interestingly, the alternative ZnO source at 110 and 220 mg/kg Zn increased intestinal alkaline phosphatase gene transcript as compared to conventional ZnO at 110 mg/kg Zn, whereas the alternative ZnO source at 110 mg/kg Zn exhibited higher Zn concentrations in mucosa (2,520 μg/g) as compared to conventional ZnO at 110 mg/kg Zn (1,211 μg/g). However, assessing alkaline phosphatase activity, no significant effects were found. In conclusion, the alternative ZnO reduced digesta Enterobacteriaceae numbers and improved gut integrity, albeit similar or better, depending on the dosage, to the effects of pharmacological dosage of conventional ZnO.

Effects of zinc supplementation on Shiga toxin 2e-producing Escherichia coli in vitro

Swine edema disease is caused by Shiga toxin (Stx) 2e–producing Escherichia coli (STEC). Addition of highly concentrated zinc formulations to feed has been used to treat and prevent the disease, but the mechanism of the beneficial effect is unknown. The purpose of the present study was to investigate the effects of highly concentrated zinc formulations on bacterial growth, hemolysin production, and an Stx2e release by STEC in vitro. STEC strain MVH269 isolated from a piglet with edema disease was cultured with zinc oxide (ZnO) or with zinc carbonate (ZnCO₃), each at up to 3,000 ppm. There was no effect of zinc addition on bacterial growth. Nonetheless, the cytotoxic activity of Stx2e released into the supernatant was significantly attenuated in the zinc-supplemented media compared to that in the control, with the 50% cytotoxic dose values of 163.2 ± 12.7, 211.6 ± 33.1 and 659.9 ± 84.2 after 24 hr of growth in the presence of ZnO, ZnCO₃, or no supplemental zinc, respectively. The hemolytic zones around colonies grown on sheep blood agar supplemented with zinc were significantly smaller than those of colonies grown on control agar. Similarly, hemoglobin absorbance after exposure to the supernatants of STEC cultures incubated in sheep blood broth supplemented with zinc was significantly lower than that resulting from exposure to the control supernatant. These in vitro findings indicated that zinc formulations directly impair the factors associated with the virulence of STEC, suggesting a mechanism by which zinc supplementation prevents swine edema disease.

Comparison of porous and nano zinc oxide for replacing high-dose dietary regular zinc oxide in weaning piglets

The aim of this study was to compare the effect of dietary supplementation with low dose of porous and nano zinc oxide (ZnO) on weaning piglets, and to evaluate the possibility of using them as an alternative to high dose of regular ZnO. Piglets were randomly allocated into four treatment groups fed with four diets: (1) basal diet (NC), (2) NC+ 3000 mg/kg ZnO (PC), (3) NC + 500 mg/kg porous ZnO (HiZ) and (4) NC + 500 mg/kg nano ZnO (ZNP). The result showed that piglets in HiZ group had less diarrhea than ZNP group (P < 0.05). Besides, there was no significant difference between PC, HiZ and ZNP groups in terms of serum malondialdeyhde (MDA) concentration and glutathione peroxidase (GSH-Px) activity (P > 0.05). Analysis of trace metal elements revealed that piglets fed with high dose of regular ZnO had the highest Zn level in kidney (P < 0.05), which may induce kidney stone formation. Additionally, a decrease in ileal crypt depth was observed in PC, HiZ and ZNP group, suggesting an effective protection against intestinal injury. Results of mRNA analysis in intestine showed that ZNP supplementation had better effects on up-regulated trefoil factor 3 (TFF3) and nuclear factor erythroid 2-related factor 2 (Nrf2) levels in duodenum and jejunum than HiZ did (P < 0.05), implying that nano ZnO may possess higher anti-inflammatory capacity than porous ZnO. In conclusion, dietary supplementation with low dose of porous and nano ZnO had similar (even better) effect on improving growth performance and intestinal morphology, reducing diarrhea and intestinal inflammatory as high dose of regular ZnO in weaning piglets. Compared with nano ZnO, porous ZnO had better performance on reducing diarrhea but less effect on up-regulation of intestinal TFF3 and Nrf2.

Strategies and challenges to increase the precision in feeding zinc to monogastric livestock

Practical diets for monogastric livestock must be supplemented with zinc (Zn) due to their high contents of antagonistic substances like phytates. Current feeding recommendations include quite generous safety margins because of uncertainties regarding the gross Zn requirements under varying rearing conditions. Furthermore, the use of pharmacological Zn doses to stabilise animal performance and wellbeing is widespread. Taken together, modern diets for pigs and poultry contain considerably more Zn than necessary to meet animal requirements, which is associated with concerns related to the environment as well as animal and consumer safety. Therefore, European authorities most recently reduced the allowed upper limits for Zn in complete feed. To maintain animal productivity and wellbeing while reducing the Zn load in complete feed, all measures that stabilize feed Zn bioavailability must be applied. Most importantly, reliable information on the gross Zn requirement under practical conditions must be provided, considering the bioavailability of native or supplemented feed Zn, antagonisms with dietary factors as well as the physiological status of the animal.

Supplementation of pigs diet with zinc and copper as alternative to conventional antimicrobials

Modern commercial pig farming systems inflict increased stress in animals, which often leads to various negative changes in the gastro-intestinal tract, especially in the case of piglets. Ban of antibiotics, used as growth promoters, has caused a need for alternatives to conventional antimicrobials in swine diets. Use of pre-/or probiotics, organic acids and plant extracts is often recommended, but it seems that zinc oxide and cooper salts, which were traditionally included in high doses to piglets diet, possess the highest efficacy. In commercial conditions feeding piglets with high doses of Zn and/or Cu stimulates piglets daily gain and decreases feed conversion factor. However, as heavy metals Zn and Cu tend to accumulate in soil and cause serious environmental pollution of soil and tap-water. Furthermore, high zinc concentrations (2500÷3000 mg/kg feed) in feed may have an impact on development of antimicrobial resistance, and may regulate the expression of genes that modify piglets' immune response. Therefore, the use of high doses of ZnO and/or Cu salts, as growth promoter, has always been a subject of discussion, and caused different legal status of such treatment in various EU countries. This short review describes current European Food Safety Authority (EFSA) point of view on the use of ZnO in medicated feed. The higher bioavailability of recently introduced new sources or forms of these metals allows for substantial reduction of dietary inclusion rate, which should have a positive outcome for pigs health and the environment.

The Potential Impact of Animal Science Research on Global Maternal and Child Nutrition and Health: A Landscape Review

High among the challenges facing mankind as the world population rapidly expands toward 9 billion people by 2050 is the technological development and implementation of sustainable agriculture and food systems to supply abundant and wholesome nutrition. In many low-income societies, women and children are the most vulnerable to food insecurity, and it is unequivocal that quality nutrition during the first 1000 d of life postconception can be transformative in establishing a robust, lifelong developmental trajectory. With the desire to catalyze disruptive advancements in global maternal and child health, this landscape review was commissioned by the Bill & Melinda Gates Foundation to examine the nutritional and managerial practices used within the food-animal agricultural system that may have relevance to the challenges faced by global human health. The landscape was categorized into a framework spanning 1) preconception, 2) gestation and pregnancy, 3) lactation and suckling, and 4) postweaning and toddler phases. Twelve key findings are outlined, wherein research within the discipline of animal sciences stands to inform the global health community and in some cases identifies gaps in knowledge in which further research is merited. Notable among the findings were 1) the quantitative importance of essential fatty acid and amino acid nutrition in reproductive health, 2) the suggested application of the ideal protein concept for improving the amino acid nutrition of mothers and children, 3) the prospect of using dietary phytase to improve the bioavailability of trace minerals in plant and vegetable-based diets, and 4) nutritional interventions to mitigate environmental enteropathy. The desired outcome of this review was to identify potential interventions that may be worthy of consideration. Better appreciation of the close linkage between human health, medicine, and agriculture will identify opportunities that will enable faster and more efficient innovations in global maternal and child health.

Nanosize of zinc oxide and the effects on zinc digestibility, growth performances, immune response and serum parameters of weanling piglets

The aim of this study was to investigate the effect of dietary supplementation of nanosize zinc on zinc digestibility, growth performances, immune response and serum parameters of weanling piglets. Ninety-six LYD weanling piglets were assigned to control, zinc oxide (ZnO), organic-Zn (Zn-methionine) and nanosize ZnO (nano-Zn) groups with four replicates. The zinc was at the 120 mg/kg level in the treatment group's diet, while the control group's was 80 mg/kg Zn. The experiment results indicated that the nano-Zn and organic-Zn groups had significantly higher Zn digestibility compared to the ZnO and control groups. For the immune response traits, the IgG level and goat red blood cells (GRBC) antibody titer were nano-Zn and organic-Zn>ZnO>control; in the phytohemagglutinin (PHA) challenge test result, nano-Zn>organic-Zn>ZnO>control; in regard to the γ-globulin level, nano-Zn and organic-Zn>ZnO and control, with significant difference between groups. In the serum parameters aspect, serum Zn concentration in nano-Zn and organic-Zn groups were higher than in the ZnO and control groups, serum growth hormone concentration was increased in the nano-Zn group than in the other groups. In conclusion, nanosize zinc oxide for dietary supplementation can increase zinc digestibility, serum growth hormone levels and carbonic anhydrase activity and enhance the immune response of weanling piglets.

Effects of a lipid-encapsulated zinc oxide supplement on growth performance and intestinal morphology and digestive enzyme activities in weanling pigs

This study compared the effects of varying lipid content and dietary concentration of a lipid-encapsulated (LE) ZnO product to those of native ZnO and thereby to find insights into optimal lipid coating and dosage of the Zn supplement. A total of 192 21-d-old weanling pigs were allotted to 48 pens, after which each six pens received a ZnO-free basal diet supplemented with 125 ppm ZnO (100 ppm Zn; BASAL), 2,500 ppm Zn as native ZnO (HIGH), or 100 or 200 ppm Zn as LE ZnO (LE-100 or LE-250) containing 8%, 10%, or 12% lipid [LE-8%, LE-10%, or LE-12%, respectively; 2 × 3 factorial arrangement within the LE-ZnO diets (LE-ALL)] for 14 d. Forty pigs were killed at the end for histological and biochemical examinations. None of ADG, ADFI, gain:feed, and fecal consistency score differed between the LE-ALL and either of the BASAL and HIGH groups. Hepatic and serum Zn concentrations were greater (p <0.05) in the HIGH vs. LE-ALL group, but did not differ between LE-ALL and BASAL, between LE-100 and -250, or among LE-8%, -10%, and -12% groups. Villus height (VH), crypt depth (CD), and the VH:CD ratio in the duodenum, jejunum, and ileum did not differ between the LE-ALL and either of the BASAL and HIGH groups, except for a greater CD in the duodenum in the LE-ALL vs. HIGH group. Additionally, VH and CD in the duodenum and VH:CD in the jejunum were greater in the LE-250 vs. LE-100 group. Specific activities of sucrase, maltase, and leucine aminopeptidase in these intestinal regions and those of amylase and trypsin in the pancreas were not influenced by the lipid content or dietary concentration of LE ZnO and also did not differ between the LE-ALL and either of the BASAL and HIGH groups, except for a greater pancreatic amylase activity in the former vs. HIGH group. In conclusion, the present results indicate that the LE ZnO, regardless of its lipid percentage or supplementation level examined in this study, has no significant effect on growth performance, fecal consistency, or digestive enzyme activities of weanling pigs under the experimental conditions.

Effects of dietary supplementation of modified zinc oxide on growth performance, nutrient digestibility, blood profiles, fecal microbial shedding and fecal score in weanling pigs

One hundred and forty piglets ((Landrace × Yorkshire) × Duroc, 21 day of age) with an initial weight of 6.50 ± 0.71 kg, were randomly allotted into four treatments to determine the effects of a modified form of zinc oxide (ZnO) on growth performance, nutrient digestibility, blood profiles, fecal microbial shedding and fecal score in weanling pigs. Dietary treatments were: (i) NC, negative control, basal diet containing zinc (Zn) from the premix; (ii) PC, positive control, basal diet containing Zn-free premix + 3000 ppm ZnO; (iii) H1, basal diet containing Zn-free premix + 3000 ppm ZnO (phase 1, days 1 to 14)/200 ppm modified ZnO (phase 2, days 15 to 42); (iv) H2, basal diet containing Zn-free premix + 300 ppm modified ZnO (phase 1)/200 ppm modified ZnO (phase 2). During days 1 to 14, average daily gains (ADG) were higher (P = 0.04) in PC, H1 and H2 groups than that in NC group. Overall, H1 treatment increased the ADG compared with NC (P = 0.05). On day 14, the alkaline phosphatase and plasma Zn concentration were increased (P = 0.01 and 0.04, respectively) in PC, H1 and H2 treatments compared with NC treatment. On days 14 and 42, the fecal Lactobacillus counts in NC group were lowest (P = 0.01, P = 0.04 respectively) among treatments. All supplemented groups showed lower (P = 0.03) fecal score than NC treatment on days 21 and 28. In conclusion, dietary supplementation with modified ZnO increased growth rates and reduced fecal scores in weanling pig. Modified ZnO could be used as a substitute to ZnO as a growth promoter and reduce Zn excretion to the environment because of the lower dosage. [Correction added on 3 February 2015, after first online publication: the initial weight of '6.50 ± 1.11 kg' has been replaced with '6.50 ± 0.71 kg' in the abstract.].