Dietary Zinc Effects on Growth Performance and Immune Response of Endotoxemic Growing Pigs

Roberts, E.S.,van Heugten, E.,Lloyd, K.,Almond, G.W.,Spears, J.W. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.10

A $2{\times}3$ factorial arrangement of treatments was used in a completely randomized design to determine the effects of dietary Zn on performance and immune response of acutely endotoxemic growing pigs (n=96, mean BW=24.9 kg). Factors included 1) intramuscular injection of $10{\mu}g/kg$ BW of Escherichia coli lipopolysaccharide (LPS) or control and 2) supplemental Zn at 10, 50, or 150 ppm. Diets were fed beginning after weaning (initial body weight=7.6 kg) in the nursery and continued for 16 d into the grower phase. The basal corn-soybean meal grower diet contained 1% lysine and 34.3 ppm Zn. Pigs were acclimated for 12 d in the growerfinishing facility before LPS treatment on d 13. Gain, feed intake, and feed efficiency were unaffected by dietary Zn. Feed intake decreased (p<0.10) and gain/feed was greater (p<0.10) from d 13 to d 16 for pigs injected with LPS. Serum Zn and alkaline phosphatase activity increased (p<0.05) with increasing Zn levels. The febrile response to LPS peaked at 6 h post exposure and pigs were afebrile within 12 h. Rectal temperature was greater (p<0.05) in pigs receiving 50 and 150 ppm Zn than in pigs supplemented with 10 ppm Zn. In vivo cellular immune response, measured on d 13 by skin thickness response to phytohemagglutinin (PHA), was greater after 6 h (p<0.05) in pigs fed 10 ppm Zn and exposed to LPS compared to all other treatments, but was not affected at 12, 24 or 48 h. Zinc did not affect mitogen induced lymphocyte proliferation. Zinc supplemented at 50 or 150 ppm resulted in an enhanced febrile response in pigs subjected to iatrogenic endotoxemia, but did not affect pig performance or immune response measurements.

Effects of Dietary Zinc on Performance and Immune Response of Growing Pigs Inoculated with Porcine Reproductive and Respiratory Syndrome Virus and Mycoplasma hyopneumoniae

Roberts, E.S.,Heugten, E. van,Spears, J.W.,Routh, P.A.,Lloyd, K.L.,Almond, G.W. Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.10

The objective of this study was to determine the effects of dietary Zn level on performance, serum Zn concentrations, alkaline phosphatase activity (ALP), and immune response of pigs inoculated with Porcine Reproductive and Respiratory Syndrome virus (PRRSv) and Mycoplasma hyopneumoniae. A $2{\times}4$ factorial arrangement of treatments was used in a randomized design. Factors included; 1) PRRSv and M. hyopneumoniae inoculation (n=36 pigs) or sham inoculation (n=36 pigs) with media when pigs entered the grower facility (d 0) at 9 weeks of age and 2) 10, 50, 150 ppm supplemental Zn sulfate (${ZnSO}_4$) from weaning until the completion of the study, or 2,000 ppm supplemental ${ZnSO}_4$for two weeks in the nursery and then supplementation with 150 ppm ${ZnSO}_4$for the remainder of the trial. The basal diet contained 34 ppm Zn. Pigs were weighed on d 0, 10, 17, 24 and 31 and blood samples were collected on d 0, 7, 14, 21 and 28. Pigs inoculated with PRRSv were serologically positive at d 28 and control pigs remained negative to PRRSv. In contrast, the M hyopneumoniae inoculation was inconsistent with 33.3% and 52.8% of pigs serologically positive at d 28 in the control and infected groups, respectively. A febrile response was observed for approximately one week after inoculation with PRRSv. Feed intake (p<0.01) and gain (p<0.1) were less in PRRSv infected pigs than control pigs for the 31 d study. However, performance did not differ among pigs in the four levels of ${ZnSO}_4$. Assessments of immune responses failed to provide unequivocal influence of either PRRSv inoculation or ${ZnSO}_4$level. These data suggest that PRRSv and M. hyopneumoniae act to produce some performance deficits and the influence of Zn supplementation of nursery age pigs does not have clear effect in grower pigs affected with disease.

Occurrence and Decontamination of Mycotoxins in Swine Feed

Chaytor, Alexandra C.,Hansen, Jeff A.,Van Heugten, Eric,See, M. Todd,Kim, Sung-Woo Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.5

Contamination of agricultural crops by mycotoxins results in significant economic losses for grain producers and, when consumed, it can cause reduced growth and health in a wide range of animal species. Hundreds of mycotoxin producing molds exist, however each has a different frequency and pattern of occurrence, as well as differences in the severity of the diseases (mycotoxicoses) they cause. Among the mycotoxins considered to be major contaminates are aflatoxin, deoxynivalenol, fumonisin, ochratoxin, and zearalenone. Although a multitude of species can be harmed by consumption of these mycotoxins, swine appear to be the most commonly affected commodity species. The swine industry can thus experience great losses due to the presence of mycotoxin contamination in feeds. Subsequently, recognition and prevention of mycotoxicoses is extremely important and dependent on adequate grain sampling and analysis methods pre-harvest, as well as effective strategies post-harvest to reduce consumption by animals. The aim of this review is to provide an overview of the major mycotoxin contaminants in grains, to describe methods of analysis and prevention to reduce mycotoxicoses in swine and other animals, and finally to discuss how mycotoxins directly affect swine production.

Effect of Copper Source (Cupric Citrate vs Cupric Sulfate) and Level on Growth Performance and Copper Metabolism in Pigs

Armstrong, T.A.,Spears, J.W.,van Heugten, E.,Engle, T.E.,Wright, C.L. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.8

Two experiments were conducted to evaluate the efficacy of cupric citrate (Cu-citrate) relative to cupric sulfate $(CuSO_4)$ as a Cu source for weanling and grow-finish pigs. In addition, the use of liver and bile Cu concentrations as indices of the bioavailability of Cu sources was investigated. Experiment one consisted of a nursery phase (35 d; initial BW=6.4 kg, final BW=21.4 kg) followed by a grow-finish phase (103 d; initial BW=21.5 kg, final BW=111.7 kg). Experiment two only consisted of a nursery phase (35 d; initial BW=6.3 kg, final BW=18.6 kg). Dietary treatments were identical for both experiments and consisted of: control (10 ppm $CuSO_4$); control+66 or 225 ppm $CuSO_4$; control+33, 66, or 100 ppm Cu-citrate. An antibiotic was included in diets for Exp. 1 but not Exp. 2. In both experiments, growth performance variables were similar for pigs receiving Cu-citrate and $CuSO_4$; however, growth performance was not improved by high concentrations of $CuSO_4$. Liver and bile Cu were increased (p<0.05) by 225 ppm $CuSO_4$; however, lower dietary concentrations of Cu from either $CuSO_4$ or Cu-citrate did not affect the Cu concentration of liver or bile relative to that observed in the control pigs. Irrespective of Cu source, there was no linear (p>0.10) increase in plasma Cu with increasing Cu concentrations in the diet for both experiments. However, the plasma Cu concentrations were highest (p<0.10) in pigs receiving diets supplemented with 225 ppm $CuSO_4$. Sixteen randomly chosen pigs per treatment in Exp. 1 were continued through the grow-finish phase. Body weight gain and feed intake were improved (p<0.10) by 66 ppm $CuSO_4$, but other dietary Cu treatments did not alter pig performance compared to the control diet. Plasma Cu concentrations were increased (p<0.10) by 225 ppm $CuSO_4$ in the growing phase and by 225 ppm $CuSO_4$ and 100 ppm Cu-citrate in the finishing phase. These data reveal no consistent effect of $CuSO_4$ on performance; therefore, it is difficult to assess the efficacy of these two Cu sources. In addition, these studies demonstrate that liver and bile Cu are not good indicators of Cu bioavailability in pigs fed adequate to pharmacological concentrations of Cu.