Effect of Dietary Rumen-Protected L-Tryptophan Supplementation on Growth Performance, Blood Hematological and Biochemical Profiles, and Gene Expression in Korean Native Steers under Cold Environment

Supplemental effects of rumen-protected L-tryptophan at various levels on starch digestion, melatonin and gastrointestinal hormones in Holstein steers

The effects of different level of rumen-protected L-tryptophan (RPL-T) supplementation on starch digestion, melatonin (MEL) and gastrointestinal (GI) hormones secretion in Holstein steers were evaluated. Four Holstein steers (201 ± 24 kg) were employed in a 4×4 Latin square design. The dietary treatments were the control (basal diet) and RPL-T groups of basal diet + 191.1 mg/kg body weight (BW), basal diet + 95.6 mg/kg BW, and basal diet + 19.1 mg/kg BW groups. Blood samples were collected to measure blood hormones on day 0, 1, 3, and 5 of the experiment to study serum MEL and GI tract and duodenal starch degradability. The design was 4 × 4 Latin square and the data were analyzed using the ANOVA procedure by SPSS. The D-glucose content in the RPL-T treatment groups was significantly reduced (p < 0.05) compared to the control group. The serum cholecystokinin (CCK) levels were increased in the RPL-T treatment group compared to the control group. However, there was no significant difference between all RPL-T treatment groups. The results of serum MEL were also similar to CCK results. The serum secretin levels were not significantly different (p > 0.05) between all groups. The apparent starch disappearance rates in GI track were lower (p < 0.05) in treatment groups compared with the control, and there was no significant difference between all RPL-T treatment groups. Digestion was increased (p < 0.05) in all treatment groups compared to the control. Overall, there were significant differences in starch digestibility, CCK, and MEL compared to the control group, but there were no significant differences in concentration of RPL-T. Therefore, considering the economic purpose, 19.1mg/kg BW is recommended as an appropriate level of addition to increase the productivity of beef cattle.

Differential expressions of FASN, SCD, and FABP4 genes in the ribeye muscle of omega-3 oil-supplemented Tattykeel Australian White lambs

BACKGROUND

The concept of the functional nutritional value of health-beneficial omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) is becoming a phenomenon among red meat consumers globally. This study examined the expressions of three lipogenic genes (fatty acid binding protein 4, FABP4, fatty acid synthase, FASN; and stearoyl-CoA desaturase, SCD) in the ribeye (Longissimus thoracis et lumborum) muscle of Tattykeel Australian White (TAW) lambs fed fortified omega-3 diets and correlations with fatty acids. To answer the research question, "are there differences in the expression of lipogenic genes between control, MSM whole grain and omega-3 supplemented lambs?", we tested the hypothesis that fortification of lamb diets with omega-3 will lead to a down-regulation of lipogenic genes. Seventy-five six-month old TAW lambs were randomly allocated to the (1) omega-3 oil-fortified grain pellets, (2) unfortified grain pellets (control) or (3) unfortified MSM whole grain pellets diet supplements to generate three treatments of 25 lambs each. The feeding trial lasted 47 days.

RESULTS

From the Kruskal-Wallis test, the results showed a striking disparity in lipogenic gene expression between the three dietary treatments in which the FABP4 gene was significantly up-regulated by 3-folds in the muscles of lambs fed MSM Milling (MSM) whole grain diet compared to the omega-3 and control diets. A negative correlation was observed between FASN gene expression and intramuscular fat (IMF), eicosapentaenoic acid (EPA), total polyunsaturated fatty acids (PUFA), omega-6 polyunsaturated fatty acids (n-6 PUFA) and monounsaturated fatty acids (MUFA). The FABP4 gene expression was positively correlated (P < 0.05) with EPA and docosahexaenoic acid (DHA).

CONCLUSION

Taken together, this study's results suggest that FABP4 and FASN genes perform an important role in the biosynthesis of fatty acids in the ribeye muscle of TAW lambs, and supplementary diet composition is an important factor influencing their expressions.

Impact of Cold Stress on Physiological, Endocrinological, Immunological, Metabolic, and Behavioral Changes of Beef Cattle at Different Stages of Growth

The purpose of this study was to investigate the effect of cold stress (CS) on the physiological, blood, and behavioral parameters of beef cattle according to their growth stage. Twelve calves in the growing stages (220.4 ± 12.33 kg, male and non-castrated) and twelve steers in the early fattening stages (314.2 ± 18.44 kg) were used in this experiment. The animals were randomly distributed into three homogenized groups (four animals each) for 14 days, namely threshold, mild–moderate cold stress (MCS), and extreme cold stress (ECS), according to the outside ambient temperature. The feed and water intakes were recorded daily. The physiological parameters, blood parameters, and behavioral patterns were measured weekly. All data were analyzed using repeated-measures analysis. The calves exposed to the ECS decreased (p < 0.064, tendency) their dry matter intake compared to the threshold and MCS groups. The HR and RT increased (p < 0.001) in the ECS compared to the threshold in calves and steers. Moreover, increased (p < 0.05) blood cortisol, non-esterified fatty acids (NEFA), and time spent standing were observed after exposure to ECS in calves and steers. However, the calves exposed to the ECS had decreased (p = 0.018) blood glucose levels compared to the threshold. In conclusion, ECS affects the dry matter intake, HR, RT, blood cortisol, NEFA, and behavioral patterns in beef calves and steers. This phenomenon indicated that beef cattle exposed to CS modulated their behavior and blood parameters as well as their physiological response to maintain homeostasis regardless of the growth stage.

Bovine Immunology: Implications for Dairy Cattle

The growing world population (7.8 billion) exerts an increased pressure on the cattle industry amongst others. Intensification and expansion of milk and beef production inevitably leads to increased risk of infectious disease spread and exacerbation. This indicates that improved understanding of cattle immune function is needed to provide optimal tools to combat the existing and future pathogens and improve food security. While dairy and beef cattle production is easily the world's most important agricultural industry, there are few current comprehensive reviews of bovine immunobiology. High-yielding dairy cattle and their calves are more vulnerable to various diseases leading to shorter life expectancy and reduced environmental fitness. In this manuscript, we seek to fill this paucity of knowledge and provide an up-to-date overview of immune function in cattle emphasizing the unresolved challenges and most urgent needs in rearing dairy calves. We will also discuss how the combination of available preventative and treatment strategies and herd management practices can maintain optimal health in dairy cows during the transition (periparturient) period and in neonatal calves.

Effects of Dietary Supplementation of Acetate and L-Tryptophan Conjugated Bypass Amino Acid on Productivity of Pre- and Post-Partum Dairy Cows and Their Offspring

Simple Summary

This study examined the effect of acetate and L-tryptophan-conjugated bypass amino acid (ACT), supplemented (15 g/day) to Holstein cows during late pregnancy, on their productivity and the performance of offspring. We identified that the supplementation of ACT incorporated into diet was beneficial for improving the feed intake, blood hematology, and metabolites of the prepartum, and also had a positive effect on reducing saturated fatty acids in the colostrum of the cows postpartum and on the body weight of the newborn calves. The results of this study suggest that ACT supplementation improves the productivity of dairy cows.

Abstract

In this study, we investigated the effect of dietary supplementation with acetate and L-tryptophan-conjugated bypass amino acid (ACT) during late pregnancy on the production performance of cows pre- and postpartum and their offspring. Eight multiparous Holstein cows (calving date ±15 d, 2nd parity; n = 4) were supplied with diets without ACT supplementation (Control) or with 15 g/day ACT supplementation (ACT). The results showed that ACT improved the feed intake (FI) in dry cows. No differences in blood hematological parameters were found between the two groups of prepartum cows. The serum glutamic-oxaloacetic transaminase activity increased and the triglyceride concentration decreased in the ACT-treated group compared to the control group. In the postpartum cows, milk compositions were not affected by ACT supplementation. Saturated fatty acid (SFA) content in the colostrum was significantly lower in the ACT-treated group than in the control group. Serum glucose (GLC) level was significantly higher in the ACT-treated group than in the control group. Monocyte and GLC levels were lower in calves of groups where their dams had received ACT. Overall, we found higher FI in the dry cows, lower colostrum SFA levels, and heavier calf birth weight (5.5 kg) when the dams were supplemented with ACT, suggesting a positive nutrient compensation by ACT supplementation to dry cows.

Effect of a Rumen-Protected Microencapsulated Supplement from Linseed Oil on the Growth Performance, Meat Quality, and Fatty Acid Composition in Korean Native Steers

Simple Summary

In vitro and in vivo studies on the supplementation of rumen-protected microencapsulated fatty acid from linseed oil (MO) on rumen digestibility, physiological profile, growth performance, meat quality, and meat fatty acid profile in Korean native steers were conducted. The in vitro study showed that 3% MO is an optimal dose, as there were decreases in the neutral detergent fiber and acid detergent fiber digestibility at 48 h. Supplementation with 3% MO not only promotes growth performance but also enhances the omega-3 fatty acid concentration of meat in Korean native steers.

Abstract

We evaluated the effects of a rumen-protected microencapsulated supplement from linseed oil (MO) on ruminal fluid, growth performance, meat quality, and fatty acid composition in Korean native steers. In an in vitro experiment, ruminal fluid was taken from two fistulated Holstein dairy cows. Different levels of MO (0%, 1%, 2%, 3%, and 4%) were added to the diet. In an in vivo experiment, eight steers (average body weight = 597.1 ± 50.26 kg; average age = 23.8 ± 0.12 months) were assigned to two dietary groups, no MO (control) and MO (3% MO supplementation on a DM basis), for 186 days. The in vitro study revealed that 3% MO is an optimal dose, as there were decreases in the neutral detergent fiber and acid detergent fiber digestibility at 48 h (p < 0.05). The in vivo study showed increases in the feed efficiency and average daily gain in the 3% MO group compared to the control group on days 1 to 90 (p < 0.05). Regarding meat quality, the shear force produced by the longissimus thoracis muscle in steers from the 3% MO group was lower than that produced by the control group (p < 0.05). Interestingly, in terms of the fatty acid profile, higher concentrations of C22:6n3 were demonstrated in the subcutaneous fat and higher concentrations of C18:3n3, C20:3n3, and C20:5n3 were found in the intramuscular fat from steers fed with 3% MO (p < 0.05). Our results indicate that supplementation with 3% MO supplements improves the growth performance and meat quality modulated by the omega-3 fatty acid content of meat in Korean native steers.

Dietary supplementation of acetate-conjugated tryptophan alters feed intake, milk yield and composition, blood profile, physiological variables, and heat shock protein gene expression in heat-stressed dairy cows

The purpose of this study was to investigate the effects of dietary supplementation of rumen-protected tryptophan (RPT) at four levels on milk yield, milk composition, blood profile, physiological variables, and heat shock protein gene expression in dairy cows under conditions of moderate-severe heat stress (MSHS, THI = 80~89). Sixteen early-lactating dairy cows (body weight = 719 ± 66.4 kg, days in milk = 74.3 ± 7.1, milk yield = 33.55 ± 3.74 kg, means ± SEM) were randomly assigned in a factorial arrangement to one of the four treatments: control group (n = 4, no RPT supplementation), 15 g/d RPT (n = 4), 30 g/d RPT (n = 4), or 60 g/d RPT group per cow (n = 4) supplemented to the TMR. A higher dry matter intake (DMI) and milk yield were found in the 30 g RPT group compared with the other groups, and the 3.5% fat-corrected milk yield, energy-corrected milk yield, milk fat, protein, β-casein, mono-unsaturated fatty acid, and poly-unsaturated fatty acid contents, and serum glucose content were observed in the 30 g RPT group (p < 0.05). The milk lactose concentration was significantly higher in the 30 g RPT group compared with the control and 60 g RPT groups (p < 0.05). The plasma cortisol level was lower, while the serotonin and melatonin concentrations were higher in the 30 g group compared with the other groups (p < 0.05). Heat shock protein (HSP) 70 expression was downregulated in the control and 15 g RPT groups, whereas the expression of HSP90 and HSPB1 remained unchanged among the groups. In particular, the 30 g RPT group was considered to have an improved DMI, milk yield, and lactose concentration, as well as anti-heat stress effects due to the simulation of serotonin and melatonin during MSHS.

Characterization of Short-Term Heat Stress in Holstein Dairy Cows Using Altered Indicators of Metabolomics, Blood Parameters, Milk MicroRNA-216 and Characteristics

Simple Summary

In this study, we characterize the influence of short-term (4 days) heat stress on Holstein cows during early lactation. The use of indicators, such as production performance, physiological variables, blood parameters, micro-RNA expression, and metabolomes, in heat-stressed cows during early lactation—which is a high-stress phase—may provide insights into how to deal with the level of damage to dairy cows, through appropriate nutritional and management strategies. We identify that short-term heat stress has a negative effect, to some extent, on feed and water intake, rectal temperature, heart rate, blood hematology and metabolites, milk characteristics, miRNA expression in milk, and metabolomics in blood.

Abstract

This study aims to characterize the influence of short-term heat stress (HS; 4 day) in early lactating Holstein dairy cows, in terms of triggering blood metabolomics and parameters, milk yield and composition, and milk microRNA expression. Eight cows (milk yield = 30 ± 1.5 kg/day, parity = 1.09 ± 0.05) were homogeneously housed in environmentally controlled chambers, assigned into two groups with respect to the temperature humidity index (THI) at two distinct levels: approximately ~71 (low-temperature, low-humidity; LTLH) and ~86 (high-temperature, high-humidity; HTHH). Average feed intake (FI) dropped about 10 kg in the HTHH group, compared with the LTLH group (p = 0.001), whereas water intake was only numerically higher (p = 0.183) in the HTHH group than in the LTLH group. Physiological parameters, including rectal temperature (p = 0.001) and heart rate (p = 0.038), were significantly higher in the HTHH group than in the LTLH group. Plasma cortisol and haptoglobin were higher (p < 0.05) in the HTHH group, compared to the LTLH group. Milk yield, milk fat yield, 3.5% fat-corrected milk (FCM), and energy-corrected milk (ECM) were lower (p < 0.05) in the HTHH group than in the LTLH group. Higher relative expression of milk miRNA-216 was observed in the HTHH group (p < 0.05). Valine, isoleucine, methionine, phenylalanine, tyrosine, tryptophan, lactic acid, 3-phenylpropionic acid, 1,5-anhydro-D-sorbitol, myo-inositol, and urea were decreased (p < 0.05). These results suggest that early lactating cows are more vulnerable to short-term (4 day) high THI levels—that is, HTHH conditions—compared with LTLH, considering the enormous negative effects observed in measured blood metabolomics and parameters, milk yield and compositions, and milk miRNA-216 expression.

Rumen and Serum Metabolomes in Response to Endophyte-Infected Tall Fescue Seed and Isoflavone Supplementation in Beef Steers

Fescue toxicosis impacts beef cattle production via reductions in weight gain and muscle development. Isoflavone supplementation has displayed potential for mitigating these effects. The objective of the current study was to evaluate isoflavone supplementation with fescue seed consumption on rumen and serum metabolomes. Angus steers (n = 36) were allocated randomly in a 2 × 2 factorial arrangement of treatments including endophyte-infected (E+) or endophyte-free (E−) tall fescue seed, with (P+) or without (P−) isoflavones. Steers were provided a basal diet with fescue seed for 21 days, while isoflavones were orally administered daily. Following the trial, blood and rumen fluid were collected for metabolite analysis. Metabolites were extracted and then analyzed by UPLC-MS. The MAVEN program was implemented to identify metabolites for MetaboAnalyst 4.0 and SAS 9.4 statistical analysis. Seven differentially abundant metabolites were identified in serum by isoflavone treatment, and eleven metabolites in the rumen due to seed type (p < 0.05). Pathways affected by treatments were related to amino acid and nucleic acid metabolism in both rumen fluid and serum (p < 0.05). Therefore, metabolism was altered by fescue seed in the rumen; however, isoflavones altered metabolism systemically to potentially mitigate detrimental effects of seed and improve animal performance.

"Dietary supplementation of L-tryptophan" increases muscle development, adipose tissue catabolism and fatty acid transportation in the muscles of Hanwoo steers

This study investigated the effects of dietary rumen-protected L-tryptophan (TRP) supplementation (43.4 mg of L-tryptophan kg⁻¹ body weigt [BW]) for 65 days in Hanwoo steers on muscle development related to gene expressions and adipose tissue catabolism and fatty acid transportation in longissimus dorsi muscles. Eight Hanwoo steers (initial BW = 424.6 kg [SD 42.3]; 477 days old [SD 4.8]) were randomly allocated to two groups (n = 4) of control and treatment and were supplied with total mixed ration (TMR). The treatment group was fed with 15 g of rumen-protected TRP (0.1% of TMR as-fed basis equal to 43.4 mg of TRP kg⁻¹ BW) once a day at 0800 h as top-dressed to TMR. Blood samples were collected 3 times, at 0, 5, and 10 weeks of the experiment, for assessment of hematological and biochemical parameters. For gene study, the longissimus dorsi muscle samples (12 to 13 ribs, approximately 2 g) were collected from each individual by biopsy at end of the study (10 weeks). Growth performance parameters including final BW, average daily gain, and gain to feed ratio, were not different (p > 0.05) between the two groups. Hematological parameters including granulocyte, lymphocyte, monocyte, platelet, red blood cell, hematocrit, and white blood cell showed no difference (p > 0.05) between the two groups except for hemoglobin (p = 0.025), which was higher in the treatment than in the control group. Serum biochemical parameters including total protein, albumin, globulin, blood urea nitrogen, creatinine phosphokinase, glucose, nonesterified fatty acids, and triglyceride also showed no differences between the two groups (p > 0.05). Gene expression related to muscle development (Myogenic factor 6 [MYF6], myogenine [MyoG]), adipose tissue catabolism (lipoprotein lipase [LPL]), and fatty acid transformation indicator (fatty acid binding protein 4 [FABP4]) were increased in the treatment group compared to the control group (p < 0.05). Collectively, supplementation of TRP (65 days in this study) promotes muscle development and increases the ability of the animals to catabolize and transport fat in muscles due to an increase in expressions of MYF6, MyoG, FABP4, and LPL gene.

In Vitro and In Vivo Studies of Rumen-Protected Microencapsulated Supplement Comprising Linseed Oil, Vitamin E, Rosemary Extract, and Hydrogenated Palm Oil on Rumen Fermentation, Physiological Profile, Milk Yield, and Milk Composition in Dairy Cows

The aim of the present study was to evaluate the effects of adding dietary rumen-protected microencapsulated supplements into the ruminal fluid on the milk fat compositions of dairy cows. These supplements comprised linseed oil, vitamin E, rosemary extract, and hydrogenated palm oil (MO; Microtinic® Omega, Vetagro S.p.A, Reggio Emilia, Italy). For in vitro ruminal fermentation, Holstein-Friesian dairy cows each equipped with a rumen cannula were used to collect ruminal fluid. Different amounts (0%, 1%, 2%, 3%, 4%, and 5%) of MO were added to the diets to collect ruminal fluids. For the in vivo study, 36 Holstein-Friesian dairy cows grouped by milk yield (32.1 ± 6.05 kg/d/head), days in milk (124 ± 84 d), and parity (2 ± 1.35) were randomly and evenly assigned to 0.7% linseed oil (LO; as dry matter (DM) basis) and 2% MO (as DM basis) groups. These two groups were fed only a basal diet (total mixed ration (TMR), silage, and concentrate for 4 weeks) (period 1). They were then fed with the basal diet supplemented with oil (0.7 LO and 2% MO of DM) for 4 weeks (period 2). In the in vitro experiment, the total gas production was found to be numerically decreased in the group supplemented with 3% MO at 48 h post in vitro fermentation. A reduction of total gas production (at 48 h) and increase in ammonia concentration (24 h) were also observed in the group supplemented with 4% to 5% MO (p < 0.05). There were no differences in the in vitro fermentation results, including pH, volatile fatty acids, or CH4 among groups supplemented with 0%, 1%, and 2% MO. The results of the in vitro study suggest that 2% MO is an optimal dosage of MO supplementation in cows' diets. In the in vivo experiment, the MO supplement more significantly (p < 0.01) increased the yield of total w3 fatty acids than LO (9.24 vs. 17.77 mg/100 g milk). As a result, the ratio of total omega-6 to omega-3 fatty acids was decreased (p < 0.001) in the MO group compared to that in the LO group (6.99 vs. 3.48). However, the milk yield and other milk compositions, except for milk urea nitrogen, were similar between the two groups (p > 0.05). Collectively, these results suggest that the dietary supplementation of 2% MO is beneficial for increasing omega-3 fatty acids without any negative effects on the milk yield of dairy cows.