Yoo Yong Kim

Journal of Animal Science and Technology (JAST) is a peer-reviewed, open access journal publishing original research, review articles and notes in all fields of animal science. Topics covered by the journal include: genetics and breeding, physiology, nutrition of monogastric animals, nutrition of ruminants, animal products (milk, meat, eggs and their by-products) and their processing, grasslands and roughages, livestock environment, animal biotechnology, animal behavior and welfare.

Objective: The purpose of this experiment was to evaluate the effects of dietary replacement of fish meal (FM) by black soldier fly (BSF) larvae on growth performance, blood profiles, immune response, and diarrhea incidence in weaning pigs.Methods: A total of 160 weaning ([Yorkshire×Landrace]×Duroc) pigs (7.47±0.02 kg body weight [BW]) were assigned to four treatments according to sex and initial BW, with five replicates of eight pigs per pen in a randomized complete block design. Experimental diets with BSF larvae replaced FM at 0%, 25%, 50%, and 100% for phase I (0 to 2 weeks). During the phase II (3 to 4 weeks) treatments were as follows: 1) Control: corn‒soybean-based diet containing FM 4%, 2) BSF25: corn‒soybean-based diet containing FM 3% and BSF larvae 1%, 3) BSF50: corn‒soybean-based diet containing FM 2% and BSF larvae 2%, 4) BSF100: corn‒soybean-based diet containing BSF larvae 4%.Results: There were no significant differences among the treatment groups in BW and average daily gain during the experimental period. However, an increased tendency of average daily feed intake was observed (linear, p = 0.09), and gain to feed ratio tended to decrease as the replacement rate of FM with BSF larvae increased (linear, p = 0.06). During phase I, creatinine concentration decreased linearly as BSF larvae level increased (linear, p = 0.02). During phase II, the glucose concentration linearly changed as an increase in BSF larvae level (linear, p = 0.02). Meanwhile, pigs fed with increasing BSF larvae levels showed increased albumin and total protein concentration trends (linear, p = 0.05, p = 0.05).Conclusion: In weaning pig diets, defatted BSF larvae can substitute up to 50% of FM without negatively affecting immunological response, blood metabolites, or performance. These encouraging results imply that BSF larvae may be a viable and efficient substitute for FM in pig diets.

Objective: This study investigates the feasibility of substituting fishmeal with black soldier fly larvae (BSF) in weaning pig diets, with the objective of overcome the limitations of conventional animal protein sources and explore BSF larvae as a sustainable alternative protein.Methods: A total of 192 weaning ([Yorkshire×Landrace])×Duroc) pigs (8.12±0.01 kg body weight [BW]) were assigned to four treatments based on sex and initial BW, with six replicates of eight pigs per pen in a randomized complete block design. Experimental diets with different levels of BSF larvae were as follows: 1) Control: corn‒soybean-based diet, 2) BSF25: corn‒soybean-based diet containing black solder fly larvae as a replacement for 25% of plasma protein, 3) BSF50: corn‒soybean-based diet containing black solder fly larvae as a replacement for 50% of plasma protein, 4) BSF100: corn‒soybean-based diet containing black solder fly larvae as a replacement for 100% of plasma protein.Results: From 0–2 weeks, the average daily gain and gain:feed ratio were decreased as the BSF larvae level increased (p<0.05), and the BSF25 group had higher BW compared to other groups (p<0.05). In blood profiles, increasing levels of BSF larvae in the diet linearly decreased albumin levels at 28 d after weaning (p<0.05). For immune response, there was a linear decrease in IgG concentration by increasing levels of BSF larvae (p<0.05), and the BSF25 group had the highest value among all treatments only in phase I (p<0.05).Conclusion: The results of this study demonstrate that BSF larvae meal can be a viable alternative protein source in diets of weaned pigs. The optimal ratio of BSF larvae replacing plasma protein is up to 25%, which leads to improved growth performance and immune response.

Journal of Animal Science and Technology (JAST) is a peer-reviewed, open access journal publishing original research, review articles and notes in all fields of animal science. Topics covered by the journal include: genetics and breeding, physiology, nutrition of monogastric animals, nutrition of ruminants, animal products (milk, meat, eggs and their by-products) and their processing, grasslands and roughages, livestock environment, animal biotechnology, animal behavior and welfare.

Journal of Animal Science and Technology (JAST) is a peer-reviewed, open access journal publishing original research, review articles and notes in all fields of animal science. Topics covered by the journal include: genetics and breeding, physiology, nutrition of monogastric animals, nutrition of ruminants, animal products (milk, meat, eggs and their by-products) and their processing, grasslands and roughages, livestock environment, animal biotechnology, animal behavior and welfare.

Objective: The objective of this study was to investigate the effects of increasing dietary crude protein (CP) concentration on growth performance, rumen characteristics, blood metabolites, and methane (CH4) emissions in finishing Hanwoo steers.Methods: Twenty-four 26-month-old Hanwoo steers (717±50.1 kg) were utilized in a 12-week study based on a completely randomized block design. The animals were randomly assigned to one of four dietary treatments by feeding concentrate mixes with different CP levels (15.0%, 16.2%, 17.5%, and 18.5% on a dry matter [DM] basis). Forage was fed ad libitum, while the concentrate mix was provided in a fixed amount.Results: Forage and total dry matter intake (DMI) linearly increased (p≤0.029) with increasing CP levels while concentrate intake was not affected by treatments. Initial and final body weight and average daily gain were not different among treatments. Feed efficiency showed a trend of linear decrease (p = 0.092) with increasing CP levels. Rumen parameters, including ruminal pH, total volatile fatty acid, molar proportions of acetate, propionate, isobutyrate, butyrate, isobutyrate, valerate, and acetate to propionate ratio, were not affected by treatments. Treatments also did not affect blood concentrations of total protein, urea, glucose, non-esterified fatty acid, albumin, creatinine, triglyceride, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, calcium, and phosphorus. Concentrations of CH4 from respiration or eructation were not affected by dietary CP. CH4 ppm per DMI and neutral detergent fiber (NDF) intake was not also different among treatment in respiration or eructation. However, CH4 ppm per forage NDF intake linearly decreased (p≤0.005) with increasing CP from both respiration and eructation.Conclusion: These findings provide no clear evidence that increasing the CP content of the concentrate mix from 15.0% to 18.5% DM improves growth performance and body metabolism in finishing Hanwoo steers. Nevertheless, they suggest that a higher CP level may negatively affect feed efficiency.

Objective: The present study aimed to evaluate the effects of bacteriophage cocktail supplementation in diet of gestation sows on both the sows and their progeny.Methods: A total of 57 F1 multiparous sows (Yorkshire×Landrace) were allotted to one of three treatment groups in a completely randomized design. The sows were fed cornsoybean meal-based diet supplemented with 0%, 0.05%, or 0.10% of a bacteriophage cocktail during the gestation, followed by a common diet during lactation. Body weight and backfat thickness were measured during the trial along with blood collection for immunoglobulin analysis. Fecal samples were collected on 4, 6, 8, and 10 weeks of gestation period to examine fecal microflora. Litter performance and milk composition were investigated at 24 hrs postpartum and on d 21 of lactation.Results: Increasing bacteriophage cocktail supplementation levels in gestation diets resulted in linear increas (p<0.05) in feed intake of lactating sows and in the weight of live litters, while showing quadratic increas (p<0.05) in litter weight gain from d 0 to 21 of lactation. Dietary treatment had no impact on the serum concentrations of IgG and IgM in the sows. Increasing dietary bacteriophage cocktail levels in gestation diets resulted in a linear increas (p<0.05) in the fat content of colostrum. The elevation of dietary bacteriophage cocktail in microflora of sows resluted in a significant increase (p<0.05) in Lactobacillus count for d 63 and 105 of the gestation period, while concurrently decreasing Escherichia coli (E. coli; p<0.05) and Salmonella (p<0.10) counts during the late gestation period.Conclusion: The supplementation of a 0.05% bacteriophage cocktail in the diet of gestating sows could improve total litter weight, alive litter weight at birth, and litter weight gain during the lactation. This effect is attributed to positive changes in fecal microflora with an increase of Lactobacillus and a decrease of E. coli and Salmonella.

Objective: This study aimed to investigate the effects of star anise (SA) supplementation during late gestation and lactation on the performance of multiparous sows and their progeny until 21 days post-weaning.Methods: A total of forty pregnant sows were individually kept in stalls and allocated into two treatment groups using a completely randomized design based on body weight, backfat thickness, and parity. The treatments consisted of either 0% or 0.1% SA supplementation during late gestation and lactation. Following the lactation period, 160 weaned piglets were used to investigate the imprinting effects of SA. The dietary treatment was continued in a manner that the piglets received the same diet as their littermates. Data collected included serum antioxidant status in sows, milk composition, and stress indicators in piglets, measured at various stages.Results: Sows fed with SA during late gestation exhibited significantly higher serum total antioxidant status (p<0.03). Additionally, SA supplementation increased lactose content in the milk (p<0.01). Piglets from sows fed the SA diet during late gestation showed lower serum cortisol and epinephrine concentrations at weaning (p<0.01, p<0.04, respectively). SA supplementation during lactation further reduced serum cortisol levels in weaning piglets at one day after weaning (p<0.05).Conclusion: The current experiment indicated that supplementing dietary SA in gestation and lactation diet showed higher serum antioxidant properties in sows and improved the quality of sow milk, consequently enhancing litter performance.

Journal of Animal Science and Technology (JAST) is a peer-reviewed, open access journal publishing original research, review articles and notes in all fields of animal science. Topics covered by the journal include: genetics and breeding, physiology, nutrition of monogastric animals, nutrition of ruminants, animal products (milk, meat, eggs and their by-products) and their processing, grasslands and roughages, livestock environment, animal biotechnology, animal behavior and welfare.