• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1353-1362
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• 2005

The stressful physiological and environmental conditions around weaning often promote the proliferation of pathogens in the digestive tract of piglets resulting in diarrhoea and reduced daily weight gain. Typical dietary practices to maintain growth performance and health have led to an increased use of antimicrobial growth promoters. Due to the advanced ban of antibiotics in pig production, new concepts have been developed to secure animal health and growth performance, feed efficiency, and product quality as well. Several naturally occurring compounds seem to beneficially affect the composition and activity of the microflora in the gastrointestinal tract (GIT) of pigs. These are, among others, organic acids, probiotics, prebiotics, and enzymes. Organic acids are already widely used, especially in pigs, due to their positive effects on GIT health and growth performance. Probiotics have been shown to be effective against diarrhoea though effects may be dependent on diet composition and environmental conditions. Prebiotics may influence composition and activity of the intestinal microflora. Additionally, pre- and probiotics may exert positive influences on immune response, whereas enzymes may enhance feed digestibility by breaking down anti-nutritional factors. In the following, the focus will be directed to the role of organic acids, probiotics, prebiotics, and feeding enzymes as potential modulators of GIT health.

• Animal Bioscience
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• v.34 no.8
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• pp.1392-1402
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• 2021

Objective: The growth rate of pigs is related to differentiation and proliferation of muscle cells, which are regulated by growth factors and expression of growth-related genes. Thus, the objective of this study was to establish optimal culture conditions for Jeju black pig (JBP) muscle cells and determine the relationship of various factors involved in muscle growth with the proliferation of JBP muscle cells. Methods: Muscles were taken from the femur skeletal muscle of JBP embryos. After isolation of the muscle cells, cells were cultured in a 6-well plate under four different culture conditions to optimize culture conditions for JBP muscle cells. To analyze proliferation rate of JBP muscle cells, these muscle cells were seeded into 6-well plates at a density of 1.5×10⁵ cells per well and cultured for 3 days. Western blot and quantitative real-time polymerase chain reaction were applied to verify the myogenic differentiation 1 (MyoD) expression and growth-related gene expression in JBP muscle cells, respectively. Results: We established a muscle cell line from JBP embryos and optimized its culture conditions. These muscle cells were positive for MyoD, but not for paired box 7. The proliferation rate of these muscle cells was significantly higher in a culture medium containing bFGF and epidermal growth factor + basic fibroblast growth factor (EGF+bFGF) than that without a growth factor or containing EGF alone. Treatment with EGF and bFGF significantly induced the expression of MyoD protein, an important transcription factor in muscle cells. Moreover, we checked the changes of expression of growth-related genes in JBP muscle cells by presence or absence of growth factors. Expression level of collagen type XXI alpha 1 gene was changed only when EGF and bFGF were added together to culture media for JBP muscle cells. Conclusion: Concurrent use of EGF and bFGF increased the expression of MyoD protein, thus regulating the proliferation of JBP muscle cells and the expression of growth-related genes.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.2
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• pp.159-162
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• 1995

Broilers were fed diets supplemented with various levels of a probiotic (mixture of the following direct-fed microorganisms: Lactobacillus, Bacillus, and Streptococcus). Growth performance, abdominal fat, excreta, and litter ammonia level were determined. The results showed that birds fed the probiotic-supplemented diets had better weight gain (p < 0.01) and feed conversion (gain:feed;p < 0.12) when compared to the birds fed the unsupplemented diet. No differences in feed intake and abdominal fat were observed among birds fed the different experimental diets. Excreta (p < 0.05) and litter (p < 0.01) ammonia levels were reduced by dietary probiotic supplementation. A dosage of 0.25 g of the probiotic/kg of diet is needed to maiximize growth performance during both the starter and finisher periods. A higher dosage (approximate 0.5 g/kg) is needed to minimize litter ammonia production.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1298-1304
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• 2006

The aim of this study was to provide basic haematological information to allow improved nutritional management for velvet production in spotted deer (Cervus nippon) by investigating biochemical changes in blood values during the antler growth period. Blood samples, obtained from the jugular vein of twenty-five deer, were taken every 10 days from casting (day 0) to harvesting (day 50) of velvet antler. Negligible changes were found in the concentrations of total protein, albumin, and creatinine during the antler growth period, but there were significant changes in the concentrations of urea (p<0.05) and uric acid (p<0.01). The concentration of triglyceride was significantly higher (p<0.05) during the antler growth period compared to casting time, while serum high-density lipoprotein concentrations were low and remained unchanged during the antler growth period. Serum glucose concentration increased (p<0.05) significantly and was slightly changeable during antler growth. The serum concentrations of Ca and P did not fluctuate during antler growth, while those of Na, K and Cl showed slight differences between the time of casting and the rest of the antler growth period. No significant changes in concentrations of AST, ALT, amylase, CK, GGT and LDH were detected during the antler growth period. However, the concentration of ALK-P increased during antler growth reaching its peak on day 50 after casting. We found a significant difference in the concentration of ALK-P between the time of casting and the rest of the antler growth period (p<0.01). Consequently, antler growth was associated with mild changes in measured serum biochemical values with the exception of ALK-P activity in spotted deer.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.3
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• pp.410-415
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• 2002

Adrenal glucocorticoids, secreted by the stimulus of adrenocorticotropic hormone (ACTH), are catabolic hormones in the pig. The present study was conducted to find whether active immunization against ACTH would suppress cortisol secretion accompanied by an increased growth rate in growing-finishing barrows. ACTH was conjugated to keyhole limpet hemocyanin or human histone using glutaraldehyde or 3-maleimidobenzoic acid N-hydroxysuccinimide, under a 2 (ACTH vs no hapten)${\times}$2 (carrier)${\times}$2 (crosslinker) factorial arrangement of treatments. Cross-bred barrows weighing approximately 25 kg were injected with an ACTHcarrier or carrier only conjugate every 4th wk and slaughtered at approximately 110 kg body weight. Antibodies against ACTH were detected in serum, as determined by $[^{125}I]$ACTH-binding activity, in most animals immunized against the ACTH conjugate, but not in carrier only-injected animals, except for the animals which had received the hapten conjugated to histone via glutaraldehyde. The $[^{125}I]$ACTH-binding activity of serum increased after the second booster injection, but overall ACTH antibody titer was very low. Main effect was not detected not only for the carrier and crosslinker but for the hapten in serum cortisol concentration, ADG, loin muscle area, backfat thickness and longissimus muscle composition including fat and protein. In addition, bound $[^{125}I]$ACTH percentage had no relation to cortisol concentration or to any of the above growth-related variables. Results suggest that ACTH or its conjugates used in the present study were not immunogenically potent enough to affect the glucocorticoid secretion and thus the growth of the immunized pigs.

• Animal Bioscience
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• v.34 no.6
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• pp.967-974
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• 2021

Objective: The objective of this study was to estimate the genetic correlation (rpc) of growth performance between purebred (Duroc and Korean native) and synthetic (WooriHeukDon) pigs using a single-step method. Methods: Phenotypes of 15,902 pigs with genotyped data from 1,792 pigs from a nucleus farm were used for this study. We estimated the rpc of several performance traits between WooriHeukDon and purebred pigs: day of target weight (DAY), backfat thickness (BF), feed conversion rate (FCR), and residual feed intake (RFI). The variances and covariances of the studied traits were estimated by an animal multi-trait model that applied the Bayesian inference. Results: rpc within traits was lower than 0.1 for DAY and BF, but high for FCR and RFI; in particular, rpc for RFI between Duroc and WooriHeukDon pigs was nearly 1. Comparison between different traits revealed that RFI in Duroc pigs was associated with different traits in WooriHeukDon pigs. However, the most of rpc between different traits were estimated with low or with high standard deviation. Conclusion: The results indicated that there were substantial differences in rpc of traits in the synthetic WooriHeukDon pigs, which could be caused by these pigs having a more complex origin than other crossbred pigs. RFI was strongly correlated between Duroc and WooriHeukDon pigs, and these breeds might have similar single nucleotide polymorphism effects that control RFI. RFI is more essential for metabolism than other growth traits and these metabolic characteristics in purebred pigs, such as nutrient utilization, could significantly affect those in synthetic pigs. The findings of this study can be used to elucidate the genetic architecture of crossbred pigs and help develop new breeds with target traits.

• Journal of Animal Science and Technology
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• v.61 no.4
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• pp.234-238
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• 2019

This experiment was conducted to evaluate the effects of dietary protease on growth performance, blood constituents, and carcass characteristics of growing-finishing pigs. A total of 48 growing pigs (initial body weight, $34.8{\pm}0.62kg$) were randomly assigned to 2 dietary treatments (6 pigs/pen; 4 replicates/treatment). The treatments were a diet based on corn and soybean meal (CON) and CON supplemented with 0.01 % of protease (PRO). Pigs were fed respective dietary treatments with a 2-phase feeding program for 12 weeks. Pigs fed PRO had higher average daily gain (ADG; phase I, 866.38 vs. 821.75 g/d; overall, 910.96 vs. 866.30 g/d; p < 0.05) and gain to feed ratio (G:F; phase I, 0.345 vs. 0.363 g/g; p < 0.05) than those fed CON. However, there were no differences on blood constituents and carcass characteristics between CON and PRO of growing-finishing pigs. In conclusion, dietary protease supplementation in the typical diet for growing-finishing pigs improved growth rate.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.8
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• pp.1150-1156
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• 2014

This trail was conducted to study the effect of L-proline on the growth performance, and blood parameter in the weaned lipopolysaccharide (LPS)-challenged pigs. Thirty six pigs ($9.13{\pm}0.85$ kg) were assigned randomly to dietary treatments in a $2{\times}3$ factorial arrangement in a 20-d growth assay. Factors were intraperitoneal injection with saline or LPS, and three dietary L-proline supplement levels (0%, 0.5%, or 1.0%). On d 10, blood samples were collected at 3 h after LPS (100 ${\mu}g$ LPS/kg body weight [BW]) or saline injection. On d 20 of the trial, all pigs were orally administrated D-xylose (0.1 g/kg BW) at 2 h, and blood samples were collected at 3 h after LPS or saline injection. As a result, dietary supplementation with 0.5% proline had a tendency to increase average daily gain (ADG) in piglets during d 10 to 20 (p = 0.088). Without LPS challenge, dietary supplementation with 1.0% proline had no effect on growth hormone (GH) concentrations on d 10 (p>0.05), but decreased it after LPS challenge (p<0.05). There was LPS challenge${\times}$proline interaction for GH concentrations on d 10 (p<0.05). Dietary supplementation with 1.0% proline decreased glucagon concentration on d 10 after LPS challenge (p<0.05). In addition, dietary supplementation with proline increased superoxide dismutase (SOD) activity significantly on d 10 and 20 (p<0.05), and 1.0% proline increased heat shock proteins-70 concentration on d 10 (p<0.05). Moreover, proline supplementation increased diamine oxidase (DAO) concentrations after LPS challenge (p<0.05). There was LPS challenge${\times}$proline interaction for DAO (p<0.05). Furthermore, dietary supplementation with 1.0% proline increased the D-xylose level when no LPS challenge (p<0.05). These results indicate that proline supplementation could improve growth performance, increase SOD activities, and has a positive effect on the gastrointestinal tract digestibility in early weaned pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.45-51
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• 2007

A growth trial (Expt. 1) and an in vitro fermentation experiment (Expt. 2) were conducted to determine the response of growth performance, cecal fermentation characteristics and in vitro gas production to incremental levels of substitution of digestible fiber for lignified fiber in the diet of weaned rabbits. Three diets, formulated by substituting soyhulls (SH; used as digestible fiber source) for soybean straw (used as lignified fiber source) at substitution levels of 0, 25 and 50%, were used in a factorial design. In the growth trial (Expt. 1), increasing levels of SH substitution resulted in a quadratic increase in daily body weight gain rate (p<0.04) and feed conversion efficiency (p<0.02), but in a numerical decrease in dietary DM intake (p=0.15). When SH were included in the diet at 25% substitution level, rabbits had the highest rate of liveweight gain and feed conversion efficiency. As SH substitution level increased, pH values and ammonia-N of cecal contents linearly (p<0.001) decreased, but total VFA concentration linearly (p<0.03) increased. With incremental levels of SH substitution, the percentage of acetate and butyrate linearly (p<0.05) reduced, but the percentage of propionate and minor acids linearly (p<0.03) increased. Increasing the SH substitution levels tended to increase incidence of diarrhea. In the in vitro fermentation experiment (Expt. 2), regardless of origin of substrates fermented, increasing SH substitution level resulted in increased maximal gas production (p<0.001) and shortened gas production lag time, but had no effect on gas production rate (p>0.2). These observations suggest that incrementally feeding SH to rabbits could stimulate their cecal microbial activity, allowing cecal fermentation to shift towards favoring fiber digestion. In conclusion, digestible fiber from soyhulls may partially substitute for more lignified fiber, soybean straw, without having an adverse effect on cecal fermentative and microbial activity and growth performance. For growing rabbits, about 73% of total dietary NDF should be supplied by effective NDF, the remainder could come from digestible NDF, such as soyhulls.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1558-1565
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• 2020

Objective: The objective of this study was to characterize the number of loci affecting growth traits and the distribution of single nucleotide polymorphism (SNP) effects on growth traits, and to understand the genetic architecture for growth traits in Hanwoo (Korean cattle) using genome-wide association study (GWAS), genomic partitioning, and hierarchical Bayesian mixture models. Methods: GWAS: A single-marker regression-based mixed model was used to test the association between SNPs and causal variants. A genotype relationship matrix was fitted as a random effect in this linear mixed model to correct the genetic structure of a sire family. Genomic restricted maximum likelihood and BayesR: A priori information included setting the fixed additive genetic variance to a pre-specified value; the first mixture component was set to zero, the second to 0.0001×σ²_g, the third 0.001×σ²_g, and the fourth to 0.01×σ²_g. BayesR fixed a priori information was not more than 1% of the genetic variance for each of the SNPs affecting the mixed distribution. Results: The GWAS revealed common genomic regions of 2 Mb on bovine chromosome 14 (BTA14) and 3 had a moderate effect that may contain causal variants for body weight at 6, 12, 18, and 24 months. This genomic region explained approximately 10% of the variance against total additive genetic variance and body weight heritability at 12, 18, and 24 months. BayesR identified the exact genomic region containing causal SNPs on BTA14, 3, and 22. However, the genetic variance explained by each chromosome or SNP was estimated to be very small compared to the total additive genetic variance. Causal SNPs for growth trait on BTA14 explained only 0.04% to 0.5% of the genetic variance Conclusion: Segregating mutations have a moderate effect on BTA14, 3, and 19; many other loci with small effects on growth traits at different ages were also identified.