Effect of Cistanche deserticola on Rumen Microbiota and Rumen Function in Grazing Sheep.

For a long time, veterinary drugs and chemical additives have been widely used in livestock and poultry breeding to improve production performance. However, problems such as drug residues in food are causing serious concerns. The use of functional plants and their extracts to improve production performance is becoming increasingly popular. This study aimed to evaluate the effect of Cistanche deserticola in sheep feed on rumen flora and to analyze the causes to provide a theoretical basis for the future use of Cistanche deserticola as a functional substance to improve sheep production performance. A completely randomized experimental design was adopted using 24 six-month-old sheep males divided into four groups (six animals in each group) which were fed a basic diet composed of alfalfa and tall fescue grass. The C. deserticola feed was provided to sheep at different levels (0, 2, 4, and 6%) as experimental treatments. On the last day (Day 75), ruminal fluid was collected through a rumen tube for evaluating changes in rumen flora. The test results showed that Prevotella_1, Lactobacillus, and Rikenellaceae_RC9_gut_group were the dominant species at the genus level in all samples. Lactobacillus, Rikenellaceae_RC9_gut_group, Ruminococcaceae_NK4A214_group, Butyrivibrio_2, and Christensenellaceae_R-7_group differed significantly in relative abundance among the treatment groups. The polysaccharides in C. deserticola was the major factor influencing the alteration in rumen flora abundance, and had the functions of improving rumen fermentation environment and regulating rumen flora structure, etc. Hence, C. deserticola can be used to regulate rumen fermentation in grazing sheep to improve production efficiency.

Effects of oat hay and leguminous forage mixture feeding on enteric methane emission, energy utilization, and feed conversion efficiency in male crossbred Simmental beef cattle.

Dietary manipulation has the potential to mitigate methane (CH4 ) emission and to maintain or enhance livestock productivity. We conducted two experiments to investigate the effects of replacing oat hay by leguminous forages (alfalfa hay [AH], 0, 8, 16, and 24%, experiment 1; common vetch hay [CVH], 0, 10, 20, and 30%, experiment 2) on energy metabolism of crossbred Simmental cattle. In experiment 1, total volatile fatty acid (VFA) concentrations increased quadratically with increasing AH proportions (p = .006) with a forage-to-concentrate ratio of approximately 50:50, whereas the CH4 energy to gross energy intake ratio (CH4 -E:GEI) was significantly lower with 16% AH compared with 24% AH diet (p < .05). In experiment 2, there were no differences in the total VFA concentrations among the four diet groups with a forage-to-concentrate ratio of around 60:40 (p > .05); however, CH4 -E:GEI was significantly lower in the 30% CVH diet compared with the 10% CVH diet (p < .05). There was no significant difference in feed conversion efficiency among the four diet groups in each experiment. The results suggest that substituting 16 and 30% oat hay by AH and CVH provide optimal diets with forage-to-concentrate ratios of 50:50 and 60:40, respectively, which may reduce CH4 emission without compromising the feed conversion efficiency of crossbred Simmental cattle.

Substitution of leguminous forage for oat hay improves nitrogen utilization efficiency of crossbred Simmental calves.

Low nitrogen (N) utilization efficiency (NUE, the ratio of retained N to N intake [NI]) of ruminants is always a potential dietary protein wastage as well as a global environmental problem, and dietary N manipulation is the most effective way to improve NUE. We conducted 2 experiments to investigate the effects of replacing oat hay by leguminous forages (alfalfa hay [AH] in experiment [Exp] 1 and common vetch hay [CVH] in Exp 2) with 4 levels (0%, 8%, 16% or 24% AH and 0%, 10%, 20% or 30% CVH on dry matter [DM] basis) at the same crude protein (135 g/kg DM) and metabolizable energy (10.1 MJ/kg DM) on feed intake, N metabolism, NUE and blood composition of crossbred Simmental calves. Sixteen calves of each Exp were assigned to the four diets in a randomized block design. Faecal N (FN) output and the ratio of FN to NI increased with increasing AH/CVH proportions, whereas urinary N (UN) output, the ratio of UN to NI, and the ruminal ammonia N concentration gradually decreased in both experiments. Nutrient digestibility (DM, organic matter [OM] and neutral detergent fibre [NDF]) of calves showed a parabolic trend with gradually increasing AH/CVH proportions. The highest values of nutrient digestibility (DM, OM and NDF) of calves were observed in 16% AH in Exp 1 and 20% CVH in Exp 2. Our findings suggest that 16% and 20% substitution (as a percentage of the total DM allowance) of AH and CVH, respectively, for oat hay are optimal diets to improve NUE and reduce the potential impact of N excretion from livestock farming on the environment through shifting routes of N from urine to faeces without negative effects on live weight gain and nutrient digestibility of crossbred Simmental calves in dryland environments.

Effects of the Diet Inclusion of Common Vetch Hay Versus Alfalfa Hay on the Body Weight Gain, Nitrogen Utilization Efficiency, Energy Balance, and Enteric Methane Emissions of Crossbred Simmental Cattle.

A low nitrogen utilization efficiency (NUE, the ratio of retained N to N intake) and high methane (CH4) emissions of ruminants can lead to potentially high diet protein wastage and directly contribute to global warming. Diet manipulation is the most effective way to improve NUE or reduce CH4 emissions. This study investigated how replacing oat hay with alfalfa hay (AH) or common vetch hay (CVH) with different proportions (20% (20) and 40% (40) of the total dry matter (DM) allowance) affects the body weight gain (BWG), NUE, and CH4 emissions of crossbred Simmental cattle. The forage dry matter intake (DMI) and the total DMI of cattle fed on a CVH40 diet were significantly higher than the values for those fed on AH20 or AH40 diets (p < 0.05). There were no differences in the BWG for the four treatments observed, however, nutrient digestibility significantly decreased in the AH40 diet as compared with the AH20 diet (p < 0.05). The NUE was significantly lower in AH40 than in CVH20. The CH4 emissions were significantly lower for the CVH40 diet than with the AH20 diet (p < 0.05). Our findings suggest that a 20% AH and 40% CVH substitution for oat hay are the optimal proportions to maintain the BWG, NUE, nutrient digestibility, and reduce the CH4 emissions of crossbred Simmental cattle. Overall, CVH has a greater potential to reduce CH4 emissions than AH.