Combination of legume-based herbage and total mixed ration (TMR) maintains intake and nutrient utilization of TMR and improves nitrogen utilization of herbage in heifers

Abstract

Diets combining herbage and total mixed rations (TMR) are increasingly used in temperate regions for feeding ruminants, but little information is available regarding the effects on nutrient intake and digestion of this feeding management in beef cattle. The aim of this study was to determine the effects of combining TMR (10% CP and 13% ADF), and legume-based herbage (14% CP and 27% ADF) on intake, nutrient digestion, ruminal fermentation, microbial N flow and glucose and nitrogen metabolism in heifers. The experiment was a 3×3 Latin square design replicated three times; each period lasted 18 days (10 adaptation days and 8 measurement days). Nine cross-bred (Aberdeen Angus×Hereford) heifers (214±18 kg) fitted with permanent rumen catheters and housed in individual metabolic cages were assigned to one of three treatments: 24 h access to TMR ( T ), 24 h access to herbage ( H ) or combined diets with 18 h access to TMR and 6 h access to herbage ( T+H ). Data were evaluated using a mixed model. Animals fed T+H (TMR 71% and herbage 29%) diets tended to have a higher dry matter intake as a proportion of their BW than animals fed T. The T+H diet did not change ruminal fermentation (pH, N-NH3 and volatile fatty acids) or the N metabolism relative to the T diet, but increased the glucagon concentration and altered glucose metabolism. Conversely, animals fed T+H had increased purine derivatives excretion, increased N use efficiency for microbial protein synthesis and decreased plasma urea and urinary N excretion relative to animals fed H diet. The use of combined diets led to consumption of nutrients similar to a TMR diet, without reducing nutrient use and could improve N utilization compared with the herbage-only diet.

Effects of a Change from an Indoor-Based Total Mixed Ration to a Rotational Pasture System Combined with a Moderate Concentrate Feed Supply on the Health and Performance of Dairy Cows

“…In contrast, Bargo et al [ 42 ], observed a positive association between serum urea levels and pasture protein content. Despite higher CP concentrations of pasture, Santana et al [ 43 ] and Kohn [ 44 ] reviewed that milk or blood urea N are indicators for diet adequacy and nitrogen utilization efficiency in lactating dairy cattle. This underlines the energy deficit of the PG and rumen microflora of PG cows, resulting in ammonia excessively passing into the bloodstream and being converted to urea in the liver, or leading to an increased endogenous amino acids catabolism.…”

Lamb Fattening Under Intensive Pasture-Based Systems: A Review

“…Pasture supplementation with TMR (mixture of forage and concentrates) appears as a strategy that can improve the uptake of N-ammonia and improve microbial protein synthesis on a forage-based diet in cattle [116]; but in sheep, this approach has been little explored. Our group evaluated different levels of fresh forage supplementation to a total mixed ration (TMR) (0, 0.50, 0.75, and only fresh forage) in lambs.…”

“…Most of the work done with temperate pastures as the only food, and with the aggregate of concentrates or ration completely mixed, have been carried out in dairy cattle [116,[119][120][121]. If these effects could be demonstrated in sheep, this strategy could be used to produce high yields of high-quality lamb meat with the inclusion of high levels of fresh forage.…”

Design and parameter optimization of spiral-dragon type straw chopping test rig

“…where, P is the average power, kW; P 1 is the initial power, kW; P 2 is the working power, kW; P 3 is the final power, kW. Y = 77.34 + 2.45A + 2.07B + 3.92C + 2.30D + 4.53E + 1.64AB -1.92AC -2.36AD -2.38AE -3.13BC -0.83BD -1.98BE + 0.49CD -1.23CE -2.60DE -2.78A 2 -2.37B 2 -5.16C 2 -1.28D 2 -3.04E 2 (7) P = 7.57 + 1.60A + 0.24B + 0.50C + 0.78D + 0.14E + 0.27AB -0.17AC -0.066AD -0.13AE -0.35BC + 0.17BD + 0.13BE + 0.33CD -0.022CE + 0.053DE + 0.19A 2 -0.089B 2 -0.019C 2 -0.089D 2 + 0.087E 2 (8)…”

“…Large-scale breeding is an important meat sheep breeding method because of its advantages of high rate of domestic animals for sale, remarkable economic benefits and easy to manage [1][2][3] . Total mixed rations (TMR) denotes the balanced diet that can be obtained based on the nutritional requirements of ruminants at different stages of growth and development to ensure a balanced feed intake for ruminants, improve the utilisation rate of crude feed, facilitate production of sheep breeding, environmental control and satisfy the requirements of modern meat sheep standardisation and intensification.…”