Effects of dietary glycerol supplementation on meat quality, palatability, and lipid metabolism gene expression in the longissimus thoracis of Hanwoo steers

This study tested the hypothesis that dietary glycerol supplementation (GS) would affect growth of Hanwoo steers, beef marbling and palatability, and gene expression for lipid uptake and transport and lipogenesis in the longissimus thoracis (LT). Diets with or without 45.2 g daily glycerol supplementation/kg dry matter concentrate were tested in fourteen Hanwoo steers during a 16-week feeding trial. GS did not affect (P ≥ 0.40) the average daily gain or the gain-to-feed ratio. GS increased the LT marbling score (P = 0.01). GS enhanced (P ≤ 0.01) the sensory traits, including the flavor and overall acceptance of the LT. GS tended (0.05 < P ≤ 0.10) to upregulate mRNA levels of fatty acid translocase, lipoprotein lipase, and fatty acid binding protein 4 genes in the LT. These tendencies of upregulated expression of fatty acid uptake and cytosolic transport genes may, in part, contribute to the increased marbling by GS. The increased marbling degree caused by GS may improve palatability including the flavor and overall acceptance of the LT.

Effects of genomic estimated breeding value and dietary energy to protein ratio on growth performance, carcass trait, and lipogenic gene expression in Hanwoo steer

"Genome-based precision feeding" is a concept that involves the application of customised diets to different genetic groups of cattle. We investigated the effects of the genomic estimated breeding value (gEBV) and dietary energy to protein ratio (DEP) on growth performance, carcass traits, and lipogenic gene expression in Hanwoo (Korean cattle) steers. Forty-four Hanwoo steers (BW = 636 kg, age = 26.9 months) were genotyped using the Illumina Bovine 50 K BeadChip. The gEBV was calculated using genomic best linear unbiased prediction. Animals were separated into high gEBV of marbling score or low-gMS groups based on the upper and lower 50% groupings of the reference population, respectively. Animals were assigned to one of four groups in a 2 × 2 factorial arrangement: high gMS/high DEP (0.084 MJ/g), high gMS/low DEP (0.079 MJ/g), low gMS/high DEP, and low gMS/low DEP. Steers were fed concentrate with a high or low DEP for 31 weeks. The BW tended to be higher (0.05 < P < 0.1) in the high-gMS groups compared to the low-gMS groups at 0, 4, 8, 12, and 20 weeks. The average daily gain (ADG) tended to be lower (P = 0.08) in the high-gMS group than in the low-gMS group. Final BW and measured carcass weight (CW) were positively correlated with the gEBV of carcass weight (gCW). The DEP did not affect ADG. Neither the gMS nor the DEP affected the MS and beef quality grade. The intramuscular fat (IMF) content in the longissimus thoracis (LT) tended to be higher (P = 0.08) in the high-gMS groups than in the low-gMS groups. The mRNA levels of lipogenic acetyl-CoA carboxylase and fatty acid binding protein 4 genes in the LT were higher (P < 0.05) in the high-gMS group than in the low-gMS group. Overall, the IMF content tended to be affected by the gMS, and the genetic potential (i.e., gMS) was associated with the functional activity of lipogenic gene expression. The gCW was associated with the measured BW and CW. The results demonstrated that the gMS and the gCW may be used as early prediction indexes for meat quality and growth potential of beef cattle.

Effects of stress after road transportation and oral administration of chromium and meloxicam on plasma cortisol concentrations and behavior in dairy calves

Objective

This study was performed to determine the effects of stress after road transportation and oral administration of chromium and meloxicam on growth performance, plasma cortisol, serum metabolites, and behavior in dairy calves.

Methods

A total of 50 Holstein heifers (average body weight [BW]: 172±4.19 kg; average age: 5.53±0.12 months) were randomly assigned to five groups including NL (not transported + D-lactose; 1 mg/kg BW), TL (transported + D-lactose; 1 mg/kg BW), TC (transported + chromium; 0.5 mg/kg dry matter [DM] feed), TM (transported + meloxicam; 1 mg/kg BW), and TMC (transported + combination of meloxicam and chromium; 1 mg/kg BW and 0.5 mg/kg DM, respectively). Doses of D-lactose monohydrate, meloxicam, and chromium were prepared for oral administration by suspension in 15 mL of water in a 20-mL dosing syringe. Blood was collected before transportation, immediately after 120 km of transportation (IAT), and at 6, 24, and 48 h after transportation.

Results

Neither transportation nor administration of meloxicam and/or chromium affected (p = 0.99) average daily gain and feed intake. Plasma cortisol concentrations in the NL group (average 0.13 and 0.18 nmol/L, respectively) were lower (p<0.001) compared to the TL group (average 0.39 and 0.61 nmol/L, respectively) at IAT and 48 h after transportation. At 48 h after transportation, cortisol concentrations were lower (p<0.05) in the TC group (average 0.22 nmol/L) than in the TL group (average 0.61 nmol/L), and TC calves had similar cortisol concentrations to NL calves. Lying duration (min/d) was shorter (p<0.05) in the TL group than in the NL group at 2 d after transportation. Lying duration was longer (p<0.05) for the TC and TMC groups than for the TL group at 2 d after transportation.

Conclusion

Transportation increased cortisol concentrations and affected lying behavior, while chromium administration reduced cortisol concentrations and changed lying behavior. Thus, chromium administration before transportation may be a viable strategy to alleviate stress elicited by road transportation.

PSV-40 Effects of regrouping and administrations of meloxicam and chromium on plasma cortisol concentrations and behaviors in dairy calves

This study investigated effects of regrouping and oral meloxicam and chromium administration on growth performance, blood cortisol concentrations, and behaviors in dairy calves. Fifty Holstein calves (average age 196 ± 24.7 days, average body weight 198kg ± 32.7 kg) were equally divided into five groups: no regrouping with lactose monohydrate administration (NL), regrouping with lactose monohydrate administration (GL), regrouping with Cr administration (GC), regrouping with meloxicam administration (GM), and regrouping with both meloxicam and Cr administration (GMC). Blood was collected before regrouping and at 3h, 9h, 24h, 1w, and 2w after regrouping. Behaviors have been monitored from d1 to d7. Regrouping did not affect average daily gain (ADG), and the administrations of both meloxicam and chromium increased (P &lt; 0.02) ADG compared to NL group during 2 weeks. Regrouping increased (P &lt; 0.05) plasma cortisol concentrations in GL group, and both meloxicam and chromium and its combination treatments decreased cortisol concentrations compared to GL group at 24h, but not at other times. Regrouping increased (P &lt; 0.05) fight, duration of eating time, head bunt, drinking time, and standing time behaviors in GL group at d1, d2, d2, d3, and d4 respectively. Regrouping also increased (P &lt; 0.05) displacement at eating place in GL group from d3 to d6, but this effect was not significant (P &lt; 0.05) at d7. In conclusion, regrouping caused elevation of plasma cortisol concentrations and abnormal behaviors. Meloxicam, chromium, and/or its combined administrations improved growth performance and reduced circulating cortisol concentrations in regrouped dairy calves, suggesting a feasible strategy to alleviate regrouping stress.

Testosterone deficiency caused by castration increases adiposity in male rats in a tissue-specific and diet-dependent manner

Background

Testosterone deficiency in men is clinically associated with the development of metabolic syndrome, which manifests as obesity, hepatic steatosis, and type-2 diabetes. We investigated the effects of castration-induced testosterone deficiency on body adiposity and the expression of genes related to lipid metabolism and glucose uptake and androgen signaling in male rats fed a normal diet (ND) or a high-fat diet (HFD).

Methods

Changes in lipid and glucose metabolism and androgen signaling were investigated at physiological and molecular levels in the muscle, liver, and adipose tissues of non-castrated and castrated rats under ND or HFD feeding.

Results

Castration-induced testosterone deficiency predisposed animals on ND to early development of fatty liver by activating fatty acid (FA) synthesis, whereas HFD activated hepatic FA uptake CD36 expression, leading to the development of hepatic steatosis. In rats fed ND, castration induced muscle fat accumulation by activating CD36 expression. In the subcutaneous fat of ND-fed rats, castration increased adiposity and the expression of FA synthesis-related genes, but it decreased glucose transporter gene expression. In the abdominal fat of rats fed ND, castration increased adiposity by upregulating FA synthesis-related genes, and HFD promoted adiposity by inducing FA uptake, glucose transporter, and FA synthesis-related gene expression. In rats fed ND, castration decreased body growth and muscle weight and downregulated the expression of genes androgen signaling in the longissimus dorsi muscle.

Conclusions

Testosterone deficiency increases adiposity in a tissue-specific and diet-dependent manner. Testosterone deficiency decreases body and muscle weights and downregulates androgen signaling.

312 Effects of castration stress on behaviors and leukocyte cytokine gene expression in Korean cattle bull calves

This study investigated behavioral, physiological, and inflammatory responses, as well as leukocyte cytokine gene expression, of Korean cattle calves following surgical castration. Nineteen Korean cattle bull calves (average body weight, 254.5 kg; average age, 8.2 months) were assigned to one of two treatment groups: control (n = 9) and surgical castration (n = 10). Castration was performed surgically using Newberry knives and a Henderson castrating tool. Blood was collected immediately before castration and at 0.5 h, 6 h, 1 d, 3 d, 7 d, and 14 d after castration, and analyzed cortisol and substance P concentrations and leukocyte cytokine gene expression by quantitative real-time PCR. Behaviors were observed for 3 h, from 0.5 to 3.5 h after castration. Feed intake was recorded daily, and body weight was measured 1 d prior to the experiment and 14 d after castration. Castration decreased average daily gain (P = 0.005) and gain-to-feed ratio (P = 0.003). Castration reduced the time spent eating (P &lt; 0.001) and the frequency of eating (P = 0.003) and increased (P &lt; 0.001) the frequency of lying during the 3 h after castration. Castration temporarily increased circulating plasma cortisol (P &lt; 0.001) and salivary cortisol concentrations (P = 0.03) at 0.5 h after castration. Castration temporarily increased (P &lt; 0.05) plasma substance P concentration at 1 d after castration. Castration increased plasma haptoglobin concentration at 1 d and 3 d after castration. With regard to leukocytes, castration increased (P &lt; 0.05) mRNA levels of inflammatory cytokine interleukin-1-beta and interleukin-1 receptor antagonist (IL1RA) genes at 6 h after castration, and increased (P &lt; 0.05) IL1RA, interleukin-1-alpha, and interleukin-6 mRNA levels at 1 d after castration. In conclusion, castration of Korean cattle bull calves temporarily induced stress, retarded growth, and affected behaviors and inflammatory cytokine gene expression.

PSXI-27 Association of an increased marbling score by dietary glycerol supplementation with lipid metabolism gene expression in Korean cattle steers

This study investigated effects of dietary glycerol supplementation on liver, muscle, and adipose gene expression related with gluconeogenesis and lipid metabolism and association of gene expression levels with marbling score in Korean cattle steers. Fourteen Korean cattle steers (average age 28.4 months; average body weight 733 kg) were equally assigned to two groups (0 and 5% glycerol supplementation). Glycerol was provided with glycerol (63%)-adsorbed ground wheat bran (37%, DM) by top dressing during roughage feeding. A concentrate (1.2% of body weight) and 1.0 kg of ryegrass were individually fed twice daily. After four months of study, steers were slaughtered, and marbling score was evaluated. Longissimus thoracis (LT) and subcutaneous adipose tissue at the 13th thoracic vertebra area and liver were collected and analyzed for mRNA levels by quantitative real-time PCR. Statistical significance was analyzed by analysis of variance. Correlations were analyzed using Pearson’s correlation analysis. Glycerol supplementation increased (P = 0.01) marbling score. In the LT, glycerol supplementation tended to increase (0.05 &lt; P ≤ 0.10) lipid uptake CD36 and lipoprotein lipase (LPL) mRNA levels. In subcutaneous adipose tissues, glycerol supplementation increased (P ≤ 0.05) LPL, adipogenic sterol regulatory element binding protein 1 (SREBP1), and lipogenic acetyl CoA carboxylase (ACC) mRNA levels and tended to increase (0.05 &lt; P &lt; 0.10) CD36, adipogenic peroxisome proliferator-activated gamma (PPARG), and lipogenic fatty acid synthase (FASN) expression. It did not affect (P &gt; 0.05) mRNA levels of hepatic gluconeogenesis genes. Marbling score showed significant positive correlations (0.57 &lt; r &lt; 0.68; P &lt; 0.05) with mRNA levels of several genes including LPL, PPARG, SREBP1, and ACC in adipose tissues, but not with any genes examined in the LT. Our study demonstrates that lipid uptake, adipogenesis and lipogenesis may mainly contribute to the increased marbling score by glycerol supplementation.

Genetic, management, and nutritional factors affecting intramuscular fat deposition in beef cattle - A review

Intramuscular fat (IMF) content in skeletal muscle including the longissimus dorsi muscle (LM), also known as marbling fat, is one of the most important factors determining beef quality in several countries including Korea, Japan, Australia, and the United States. Genetics and breed, management, and nutrition affect IMF deposition. Japanese Black cattle breed has the highest IMF content in the world, and Korean cattle (also called Hanwoo) the second highest. Here, we review results of research on genetic factors (breed and sex differences and heritability) that affect IMF deposition. Cattle management factors are also important for IMF deposition. Castration of bulls increases IMF deposition in most cattle breeds. The effects of several management factors, including weaning age, castration, slaughter weight and age, and environmental conditions on IMF deposition are also reviewed. Nutritional factors, including fat metabolism, digestion and absorption of feed, glucose/starch availability, and vitamin A, D, and C levels are important for IMF deposition. Manipulating IMF deposition through developmental programming via metabolic imprinting is a recently proposed nutritional method to change potential IMF deposition during the fetal and neonatal periods in rodents and domestic animals. Application of fetal nutritional programming to increase IMF deposition of progeny in later life is reviewed. The coordination of several factors affects IMF deposition. Thus, a combination of several strategies may be needed to manipulate IMF deposition, depending on the consumer’s beef preference. In particular, stage-specific feeding programs with concentrate-based diets developed by Japan and Korea are described in this article.

A nationwide survey on thyroid care delivery in Japan, with special emphasis on resources allocation

Results of a nationwide survey show an uneven distribution of 'thyroidologists' and special facilities for the diagnosis and treatment of thyroid disease in Japan. A case is made for more systematic resource allocation in regional planning.