Responses of whole body protein synthesis and degradation to plantain herb in sheep exposed to heat

Heat stress and feeding effects on the mucosa-associated and digesta microbiome and their relationship to plasma and digesta fluid metabolites in the jejunum of dairy cows

The intestinal microbiota plays a pivotal role in digestive processes and maintains gut health and intestinal homeostasis. These functions may be compromised by increased environmental heat, which in turn reduces feed intake and gut integrity and activates the intestinal immune system. It remains unknown whether high ambient temperatures, which cause heat stress (HS) in dairy cows, disturb the eubiosis of the microbial community, and if so, to which extent the reduction in feed intake and the impairment of circulating and intestinal metabolites account for the alterations of the jejunal microbiota. To address these questions, jejunal digesta, mucosa, and plasma samples were collected from cows exposed to heat stress (HS; 28°C, temperature-humidity index [THI] = 76, n = 10), control conditions (CON; 16°C, THI = 60, n = 10), or pair-fed (PF; 16°C, THI = 60, n = 10) for 7 d. Digesta fluids were examined for pH, acetate, nonesterified fatty acids (NEFA), glucose, and lactate, and plasma samples were analyzed for glucose, lactate, BHB, triglycerides, NEFA, creatinine, and urea. The microbiota of the digesta and mucosa samples were analyzed by 16S rRNA sequencing. The α-diversity was higher in mucosa than digesta but was not affected by high ambient temperatures. However, the mucosa-associated microbiota appeared more responsive to ambient heat than the digesta microbiome. The adaptive responses under HS conditions comprised an increased mucosal abundance of Bifidobacteriaceae, Succinivibrionaceae UCG-001, Clostridia and Lactobacillus. In the digesta, HS has exerted effects on microbial abundance of Colidextribacter, and Lachnospiraceae UCG-008. Several correlations between plasma or intestinal metabolites and microbiota were elucidated, including Methanobacteriaceae correlating positively with plasma BHB and digesta glucose concentrations. Moreover, the reduction in feed intake during HS had non-negligible effects on microbial diversity and the abundance of certain taxa, underpinning the importance of nutrient supply on maintaining intestinal homeostasis.

Response of plantain (Plantago lanceolata L.) supplementation on nutritional, endo-parasitic, and endocrine status in lambs

The aim of the present study was to assess the effects of plantain herb (Plantago lanceolata L.) supplementation on growth, plasma metabolites, liver enzymatic activity, hormonal status, gastrointestinal parasites, and carcass characteristics of lambs. A total of 24 lambs, aged 6 months weighing 8.0 ± 0.5 kg were randomly allocated to one of two dietary treatments: (1) CL diet-roadside grass and concentrate mixture; (2) PL diet-CL diet + 5% fresh plantain supplementation on a DM basis. The PL diet group exhibited 23% higher (P = 0.01) average daily gain and 15% improved (P = 0.03) feed conversion efficiency. Circulating cholesterol concentrations were suppressed by 9% (P = 0.03), and liver enzyme activity was improved by 5-25% (P < 0.05) in the lamb fed PL diet, compared with CL diet only. The inclusion of plantain in the diet was highly effective at suppressing the parasites, Paramphistomum spp. (P = 0.003) and coccidial parasites (P = 0.04), but not stomach worms. Moreover, plantain supplementation increased growth hormone and insulin concentrations in plasma level, whereas decreased carcass fat by 32.7%. Therefore, supplementation of the lambs' diet with plantain showed some beneficial effects on productivity and parasitic infection, while it led to a leaner carcass.

Effect of herbal supplementation on growth, immunity, rumen histology, serum antioxidants and meat quality of sheep

There is a wide range of feed additives deliberately designed to be used in sheep diets that can improve production performance. Whereas herbal supplementation is gaining popularity not only for improving sheep productivity and mutton quality but also for safe application without any harmful residual effects. The present study was designed to investigate the effect of plantain (Plantago lanceolata L.) and/or garlic leaf (Allium sativum) dietary supplementation on growth performance, immunity, rumen histology, serum antioxidants and meat quality of sheep. The experiment consisted of a completely randomized design with 32 one-year-old sheep (initial mean live weight 9 ± 0.2 kg) allocated to four groups (8 sheep per group). Rice straw and concentrates-based total mixed ration pellets (2390 kcal/kg DM, CP = 15.1%) were offered as a control diet (CL diet). Herbal treatment diets included (i) CL diet + 10 g DM of plantain herb (PL diet), (ii) CL diet + 10 g DM of garlic leaf (GL diet) and (iii) CL diet + 5 g DM of PL and 5 g DM of GL (PG diet). Compared with the CL diet group, the live weight gain and feed conversion ratio were 18% to 26% and 13% to 20% higher in herbal-supplemented groups, respectively. Moreover, the herbal-supplemented groups, especially the PL diet group had higher serum immunoglobulin concentration, antioxidant capacity and rumen papillae size compared to the control. Besides, the lowest caul fat and pelvic fat levels were observed in the PL diet group followed by PG, GL and CL diet groups. In addition, lower mutton ether extract and saturated fatty acid along with higher polyunsaturated fatty acid levels were found in all herbal-supplemented groups. In conclusion, dietary supplementation with PL and/or GL might be used as an alternative in sheep to promote growth, health status and lean mutton production.

Cistanche deserticola Addition Improves Growth, Digestibility, and Metabolism of Sheep Fed on Fresh Forage from Alfalfa/Tall Fescue Pasture

Simple Summary

Cistanche deserticola is a functional plant which mainly grows in desert and is parasitic on roots of the host species Haloxylon ammodendron. It has advantages in improving bodily intestinal peristalsis, immunity, anti-aging, anti-oxidation, and liver health and was supplied for sheep in this experiment to study the effects of C. deserticola addition on nutrients digestion, nitrogen balance, energy utilization, and methane production. The results revealed that C. deserticola has good utilization value in animal nutrition. The data are useful for further research on this natural plant additive to improve the health and productivity of the sheep fed on fresh forage from alfalfa/tall fescue pastures.

Abstract

This study is targeted at evaluating whether C. deserticola addition promotes digestion, nitrogen and energy use, and methane production of sheep fed on fresh forage from alfalfa/tall fescue pastures. The sheep feeding trial was conducted with four addition levels with C. deserticola powder, and a basal diet of fresh alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea). Addition levels of 4% and 6% improved average body weight gain (BWG) by 215.71 and 142.86 g/d, and feed conversion ratio (FCR) by 0.20 and 0.14, respectively. Digestibility of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), and ether extract (EE) was 62.25%, 65.18%, 58.75%, and 47.25% under the addition level of 2%, which is greater than that in the control group. C. deserticola addition improved energy utilization efficiency, while addition levels of 2% and 4% increased nitrogen intake and deposited nitrogen. Overall, C. deserticola has the potential to improve growth performance, digestion of sheep, so it has suitability to be used as a feed additive.

Effect of Chinese herbal medicine on kinetics of plasma phenylalanine, tyrosine and whole body protein synthesis in sheep

The aim of this study was to evaluate the effect of feeding decoction of a traditional nourishing Chinese herbal medicine formula on rates of plasma phenylalanine and tyrosine turnover and whole body protein synthesis in sheep. Ruminal fermentation characteristics and blood metabolites were also determined. Six sheep were subjected to either mixed hay (MH‐diet, as control) or MH‐diet supplemented with 2% of Chinese herbal medicine (mixture of Astragalus root, Angelica root, and Atractylodes rhizome; CHM‐diet) in a crossover design for each of 3‐week period. The isotope dilution of [²H₅]phenylalanine and [²H₂]tyrosine was performed as a primed‐continuous infusion to measure plasma phenylalanine and tyrosine kinetics. Concentrations of total volatile fatty acid, acetate, and propionate in the rumen tended to be higher (p < 0.10), and the pH value was lower (p = 0.04) for the CHM‐diet than the MH‐diet. Turnover rates of plasma phenylalanine and tyrosine tended to be higher (p < 0.10) for the CHM‐diet than the MH‐diet. Furthermore, whole body protein synthesis was greater (p = 0.04) for the CHM‐diet compared with the MH‐diet. The Chinese herbal medicine improved rumen fermentation and enhanced protein metabolism in sheep. Hence, it is suggested that the decoction of Chinese herbal medicine formula could be considered as a potential feed additive for ruminant production.

Effect of feeding whole-crop corn silage as dietary roughage on physiological and digestive response of sheep under heat exposure

The present study was conducted to investigate the effect of feeding whole-crop corn silage (WCS) compared with mixed hay (MH) or grass silage (GS) on physiological and digestive responses of sheep at thermoneutral temperature (20°C) or exposed to heat (30°C). Six sheep were fed ad libitum with one of three diets in a replicated 3 × 3 Latin square design for 24 days. After 14 days’ adaptation, they were exposed to thermoneutral (20°C) and then heat exposure (30°C) for 5 days each. Rumen sample was collected on Day 4, whereas physiological response and nitrogen (N) balance were carried-out for three successive days in each exposure period. Respiration rate and rectal temperature of WCS-fed sheep were lower (P < 0.05) than of MH and GS fed sheep and both were higher (P < 0.01) during heat exposure. The intakes of dry matter (DM) and N and the digestibilities of N and neutral detergent fibre were lower (P < 0.05) for the WCS diet than for MH and GS diets and they did not differ between two temperature exposures. However, WCS-fed sheep had higher (P < 0.05) digestibilities of DM and organic matter, as well as metabolisable energy intake (M/D) than the sheep fed MH or GS diet, and there was no temperature effect on them. As DM and N intakes were lower for the WCS diet, the variables of rumen fermentation were also lower (P < 0.05) than the other two diets except propionate and butyrate concentrations, and they did not differ between temperature exposures except NH3 concentration. In conclusion, physiological responses were improved in the WCS diet and this approach thus shows promise for feeding heat-exposed animals. However, as results were inconsistent in terms of nutrient intake and digestibility, further work is needed and we suggest investigating the effect of feeding WCS with supplemented N.

Effects of Chinese herbal medicine on plasma glucose, protein and energy metabolism in sheep

BACKGROUND

The use of antibiotics in animal diets is facing negative feedback due to the hidden danger of drug residues to human health. Traditional Chinese herbal medicine has been used to replace antibiotics in the past two decades and played an increasingly important role in livestock production. The present study was carried out to assess the feeding effects of a traditional nourishing Chinese herbal medicine mixture on kinetics of plasma glucose, protein and energy metabolism in sheep. Ruminal fermentation characteristics were also determined.

METHODS

Four sheep were fed on either mixed hay (MH-diet) or MH-diet supplemented with 2% of Chinese herbal medicine (mixture of Astragalus root, Angelica root and Atractylodes rhizome; CHM-diet) over two 35-day periods using a crossover design. The turnover rate of plasma glucose was measured with an isotope dilution method using [U-13C]glucose. The rates of plasma leucine turnover and leucine oxidation, whole body protein synthesis (WBPS) and metabolic heat production were measured using the [1-13C]leucine dilution and open circuit calorimetry.

RESULTS

Body weight gain of sheep was higher (P = 0.03) for CHM-diet than for MH-diet. Rumen pH was lower (P = 0.02), concentration of rumen total volatile fatty acid tended to be higher (P = 0.05) and acetate was higher (P = 0.04) for CHM-diet than for MH-diet. Turnover rates of plasma glucose and leucine did not differ between diets. Oxidation rate of leucine tended to be higher (P = 0.06) for CHM-diet than for MH-diet, but the WBPS did not differ between diets. Metabolic heat production tended to be greater (P = 0.05) for CHM-diet than for MH-diet.

CONCLUSIONS

The sheep fed on CHM-diet had a higher body weight gain and showed positive impacts on rumen fermentation and energy metabolism without resulting in any adverse response. Therefore, these results suggested that the Chinese herbal medicine mixture should be considered as a potential feed additive for sheep.