An experiment was carried out to examine the effect of supplementation on the performance of springcalving dairy cows grazing swards of differing perennial ryegrass and white clover content. Seventeen heifers and sixty-four Friesian cows in their third to ninth week of lactation were turned oui onto one of three pastures with different proportions of perennial ryegrass and white clover. Nine animals on each pasture received either 0. 2 or 4 kg d"'' of a concentrate with a crude protein concentration of 180 g kg"' dry matter (DM). Prior to grazing, swards contained proportionately 0-01 (L), 0' 15 (M) and 0-20 (H) of total DM as clover. During the experiment, grazing pressures were adjusted by movement of buffer fences to maintain compressed sward heights at 6 cm. Samples taken 26 and 68 d after the start of grazing showed little change in the proportion of clover in sward L (< 001 and 002 respectively), but convergence in ihe proportion of clover in swards M and L (008-0-16 and 0-I0-0-I5 respectively). Mean daily yields of milk. fat. protein and lactose increased significantly with increased clover content and, even without supplementation, daily yields were 254, 0-98. 0-73 and 1-09 kg respectively on sward H. Ofthe milk components, only protein was significantly increased by increasing sward clover content. The response In milk yield to supplementation was greater on sward L than on swards M and H.

No abstract

In 2009, a group of practitioners took action to restore 175 miles of riparian habitat impaired by invasive plants along the Dolores River in southwestern Colorado and eastern Utah. Recognizing the magnitude of ecological, jurisdictional, and management challenges associated with this large‐scale initiative, this group of managers built trust and relationships with key partners to foster collaboration across boundaries and cultivate consensus of a variety of perspectives and forms of knowledge. What emerged was a network of individuals, organizations, and agencies dedicated to restoring the Dolores River riparian corridor while sharing information and learning from one another. This public–private collaboration, called the Dolores River Restoration Partnership (DRRP), has been successful in creating a process by which financial, technical, and human resources are shared across boundaries to restore a riparian corridor. Specifically, the DRRP developed effective planning documents, a responsive governance structure, monitoring protocols, and a shared mindset for extracting lessons learned that have been instrumental in making progress toward its shared restoration goals and addressing a wide variety of restoration challenges. The tools developed by the partnership and lessons learned from their utility are outlined in this case study as a means to inform other collaborative restoration efforts.

Two systems of grazing management involving preferential treatment of high-yielding dairy cows were compared with a grazing system in which both high-and low-yielders received uniform treatment. Cows were rotationally grazed across I-day paddocks without concentrate supplementation from 23 April to 8 October 1985, with a mean stocking rate over the season of 5-4 cows ha'. Preferential treatment of high-yielding cows was achieved either by using a leader/follower approach (LF) with highyielding cows in the leader group, or by preferential forage feeding (PFF) where high-yielding cows were allowed access to grass silage for 1 -5 h daily and grazed alongside low-yielders. Control (C) cows grazed together as a single group. The high grazing stocking rates used on all three treatments resulted in good grass utilization with residual sward heights, assessed by a rising-plate sward stick, of 45, 50 and 48 mm for the LF, PFF and C treatments respectively. Animal performance data for the LF, PFF and C treatments respectively were: milk yield (kg d"') 15-1, 15-6 and 14-7 {s.e. 0-78); milk fat yield (g d " ') 598, 606 and 567 (s.e. 34); milk protein yield (g d " ') 500, 519 and 480 (s.e. 31); and liveweight gain (kg d "') 0-12, 0-23 and 0-25 {s.e. 0-05). These results indicate that leader/follower grazing had little overall effect on animal performance when high grazing tCorrespondence and preseni address: Dr C, S, Mayne, Agriculiural Research Insitiuie of Nonhern Ireland, HJllsborough. Co. Down, BT26 6DR, UK, severity was imposed, with the improvement in animal performance cf high-yielding cows in the leader group being offset by the reduced performance of the follower group. Buffer-feeding of high-yielding, rotationally-grazed cows with high-quality grass silage had little effect on animal performance and resulted in a decrease in the efficiency of grassland utilization. Silage appeared to substitute for herbage, with a reduction in herbage DM intake of 0-55 kg per kg silage DM consumed.

SUMMARYA study is reported of the effect of initial potential for milk production of individual cows on the change in milk output consequent upon a change in amount of feed allowed per day. In this study equal initial rations and equal changes in ration were imposed on all cows. The main conclusion was that the greater the initial yield of milk, of milk fat, of solids-not-fat (SNF) or the SNF content of the milk of a cow the greater was the effect of a change in feed allowance on that attribute. It is argued that the effects are large enough to warrant consideration in practical feeding systems.