Milk Production, N Partitioning, and Methane Emissions in Dairy Cows Grazing Mixed or Spatially Separated Simple and Diverse Pastures

Abstract

Increasing pasture diversity and spatially separated sowing arrangements can potentially increase the dry matter intake of high-quality forages leading to improved animal production. This study investigated the effects of simple (two-species) and diverse (six-species) pastures planted either in mixed or spatially separated adjacent pasture strips on performance, N partitioning, and methane emission of dairy cows. Thirty-six mid-lactation Jersey cows grazed either (1) simple mixed, (2) simple spatially separated, (3) diverse mixed, or (4) diverse spatially separated pastures planted in a complete randomized block design with three replicates. Compared to simple pasture, diverse pasture had lower CP content but higher condensed tannins and total phenolic compounds with an overall positive effect on yield of milk solids, nitrogen utilization, including a reduction of N output from urine, and methane yields per dry matter eaten. The spatial separation increased legume and CP content in simple pasture but decreased NDF in both diverse and simple pastures. In conclusion, increasing diversity using pasture species with higher nutritive value and secondary compounds can help improving the production while decreasing the environmental effect of dairy farming, while spatial separation had a minor effect on feed intake and yield, possibly due to overall high-quality pastures in early spring.

Nitrogen Balance of Dairy Cows Divergent for Milk Urea Nitrogen Breeding Values Consuming Either Plantain or Perennial Ryegrass

“…Dietary and management strategies focusing on diverse swards and grazing management have been extensively explored as ways to reduce N losses [ 4 , 16 , 17 , 18 , 19 ], with the use of narrow-leaf plantain ( Plantago lanceolata L. (PL)) showing promising results for reducing total N excretions and UN concentrations in dairy cows [ 20 , 21 ]. PL is known to contain secondary bioactive compounds, such as acubin, catalpol, and acteoside [ 22 , 23 ], that have been reported to have antimicrobial and diuretic effects [ 22 , 24 ], which may influence the N partitioning of the animals.…”

Integrating Plantain (Plantago lanceolata L.) and Italian Ryegrass (Lolium multiflorum Lam.) into New Zealand Grazing Dairy System: The Effect on Farm Productivity, Profitability, and Nitrogen Losses

“…Since the implementation of nitrate leaching regulations [ 9 ], New Zealand dairy farmers have been under pressure to reduce their environmental footprint while maintaining farm profitability. Several mitigation strategies have been explored to reduce overall N leaching, both at the animal level in terms of urine volume and N concentration [ 6 , 10 , 11 , 12 ] and at the soil level in terms of preventing run-off and N capture [ 8 , 13 , 14 ]. These mitigation strategies have focused on different pathways and include: (1) reducing animal N intake or altering N partitioning (i.e., more N towards milk and faeces and less to urine) by dietary manipulation (e.g., feeding high-sugar grass to increase energy to N ratio in the diet) [ 6 , 11 , 15 ]; (2) breeding cattle which produce urine with a lower N concentration [ 16 , 17 ]; and (3) increasing N uptake from soil by establishing swards comprising plant species varying in functional traits, such as growth activity during the season (e.g., Italian ryegrass Lolium multiflorum Lam.…”

Urine and fecal excretion patterns of dairy cows divergent for milk urea nitrogen breeding values consuming either a plantain or ryegrass diet

“…Numerous approaches have been taken at a system and now at an animal level to address these externalities. The use of diverse pastures and strategic feeding have shown promising results for reducing UN excretion (Beukes et al, 2014;Carmona-Flores et al, 2020;Garrett et al, 2021). Plantain [Plantago lanceolata L. (PL)] diets have been identified as a useful tool for mitigating N losses (Box et al, 2017;Beck et al, 2020;Bryant et al, 2020) compared with a conventional ryegrass-[Lolium perenne L. (RG)] based diet, which is widely fed in New Zealand pastoral systems.…”