Copper from copper hydroxychloride in diets for growing pigs increases feed efficiency, improves energy utilization and changes intestinal microbial activity

copper;digestibility;gene expression;growth performance;microbial protein;pigs

Espinosa, Charmaine Diwa

关键词: copper;    digestibility;    gene expression;    growth performance;    microbial protein;    pigs;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/104817/ESPINOSA-DISSERTATION-2019.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Ten experiments were conducted to investigate effects of Cu from Cu hydroxychloride on growth performance, digestibility of nutrients, intestinal microbial protein, immune response, intestinal permeability, and lipid metabolism of pigs. The first 3 experiments were conducted to determine effects of Cu hydroxychloride on digestible energy (DE) and metabolizable energy (ME), apparent total tract digestibility (ATTD) of energy and acid hydrolyzed ether extract (AEE), diarrhea frequency, blood characteristics, and growth performance of nursery pigs (initial body weight: 6.80 ± 1.69 kg) fed a diet based on corn and soybean meal (SBM). Results indicated that supplementation of 150 mg Cu/kg from Cu hydroxychloride improved (P < 0.05) growth performance of pigs and reduced (P < 0.05) diarrhea frequency. However, no differences among treatments were observed for concentrations of tumor necrosis factor α (TNF-α), immunoglobulin A, blood urea N (BUN), total protein, or albumin, and the observed improvement in growth performance did not appear to be a result of increased digestibility of energy or AEE. In Exp. 4, the effects of Cu hydroxychloride on growth performance, diarrhea frequency, and blood characteristics of weanling pigs (initial body weight: 6.14 ± 0.90 kg) without or with exposure to heat stress were determined. Pigs were fed a control diet, the control diet plus 5% choice white grease (CWG), the control diet plus 100 mg/kg Cu from Cu hydroxychloride, or the control diet plus 5% CWG and 100 mg/kg Cu from Cu hydroxychloride. Results indicated that supplementation of Cu hydroxychloride to diets fed to weanling pigs without or with addition of CWG reduced (P < 0.05) diarrhea frequency and improved (P < 0.05) growth performance both if pigs were kept under normal temperature and if they were exposed to heat stress. There was also an increase (P < 0.05) in concentration of peptide YY and a reduction (P < 0.05) in TNF-α concentration on d 14 for pigs fed Cu hydroxychloride diets compared with pigs fed diets without Cu hydroxychloride. It was, therefore, concluded that Cu hydroxychloride likely improves the immune system which may be the reason for the reduced diarrhea frequency of pigs fed Cu hydroxychloride. Experiments 5 and 6 were conducted to test the hypothesis that Cu from Cu hydroxychloride improves gain:feed (G:F) when fed to pigs (initial body weight: 15.40 ± 2.39 kg) by increasing ATTD of AEE. Results indicated that G:F linearly increased (P < 0.05) as CWG concentration increased in diets. Supplementation of Cu hydroxychloride to diets improved (P < 0.05) G:F of pigs, which resulted in a CWG equivalence of 2.8 to 3.8% for 150 mg Cu/kg from Cu hydroxychloride. Supplementation of Cu to diets improved (P < 0.05) ATTD of AEE by 20% due to reduced (P < 0.10) endogenous loss of fat (from 11.23 to 7.14 g/kg dry matter intake), but did not affect energy digestibility or true total tract digestibility of fat. This indicates that the increased G:F of pigs that was observed in Exp. 5 as a result of Cu supplementation to diets was not due to improved ATTD of gross energy or AEE, but may be a result of Cu influencing post-absorptive lipid metabolism. Experiment 7 was conducted to test the hypothesis that Cu hydroxychloride improves nutrient digestibility and alters the concentration of microbial protein in the small intestine or large intestine by pigs (initial body weight: 33.3 ± 3.40 kg) fed a corn-soybean meal diet or a diet based on corn, soybean meal, and distillers dried grains with solubles (DDGS). The apparent ileal digestibility (AID) and ATTD of crude protein were not affected by dietary Cu concentrations, but, the AID and ATTD of AEE were greater (P < 0.05) in diets supplemented with Cu hydroxychloride compared with diets without Cu hydroxychloride. There was also a reduction (P < 0.05) in the concentration of microbial protein and in the total concentration of volatile fatty acids in feces when diets were supplemented with Cu hydroxychloride indicating that Cu hydroxychloride reduced microbial activity in the intestinal tract, which likely was the reason for the increased AID and ATTD of AEE. Experiment 8 was designed to test the hypothesis that Cu hydroxychloride improves growth performance by upregulating the mRNA transcription of genes involved in lipid metabolism of pigs (initial body weight: 15.05 ± 0.98 kg) fed a diet based on corn, SBM, and distillers dried grains with solubles (DDGS). Pigs were fed a corn-SBM-DDGS control diet that included Cu to meet the requirement. A second diet was formulated by adding 150 mg Cu/kg from Cu hydroxychloride to the control diet. Results indicated that overall average daily gain (ADG) and G:F were greater (P < 0.05) for pigs fed the diet containing Cu hydroxychloride compared with pigs fed the control diet. Pigs fed the diet supplemented with Cu hydroxychloride also had increased (P < 0.05) abundance of cluster of differentiation 36 in liver and increased (P < 0.05) abundance of fatty acid binding protein 4 and lipoprotein lipase in subcutaneous adipose tissue. Inclusion of Cu hydroxychloride also tended to increase (P < 0.10) abundance of fatty acid binding protein 1, peroxisome proliferator-activated receptor alpha, and carnitine palmitoyl transferase 1 B in liver, skeletal muscle, and subcutaneous adipose tissue, respectively. These results indicated that Cu from Cu hydroxychloride positively influences lipid metabolism, which may explain the increased G:F of pigs fed diets containing Cu hydroxychloride. Experiments 9 and 10 were designed to test the hypothesis that Cu hydroxychloride improves growth performance and blood characteristics, and reduces intestinal permeability of nursery pigs (2 wk post-weaning) fed diets without or with inclusion of cereal co-products. Overall ADG and G:F were greater (P < 0.05) for pigs fed diets with Cu hydroxychloride compared with pigs fed diets without Cu hydroxychloride; however, dietary Cu concentrations did not affect the lactulose:mannitol ratio in urine from pigs fed experimental diets. Supplementation of Cu hydroxychloride to diets also positively influenced (P < 0.05) BUN, albumin, and cytokine concentrations of nursery pigs indicating that Cu from Cu hydroxychloride increases amino acid utilization for protein synthesis and improves the immune system of pigs. In conclusion, supplementation of Cu from Cu hydroxychloride to diets for pigs positively influences the immune system, changes intestinal microbial activity, and upregulates abundance of some genes involved in post-absorptive metabolism of lipids. Combined, these changes resulted in improved energy metabolism, improved G:F, and sometimes also improved ADG. These changes also resulted in improved intestinal health of pigs.