Grazing Restrictions Research Articles

PERFORMANCE OF DAIRY COWS DURING DIFFERENT SEASONS WITH DAILY HERBAGE ALLOWANCE: A REVIEW

Pasture-based feeds are favored nowadays due to their cost-effectiveness and effect on animal welfare. Daily herbage allowance (DHA) affects the performance of dairy cows across different seasons. The key determinant of the performance of livestock is the dry matter intake (DMI) of herbage in pasture-based systems. A decline in average summer rainfall may result in considerably higher concentrate supplementation requirements to compensate for the loss in pasture growth and availability during autumn. Supplementation during autumn and winter boost total DMI and sustain milk output under grazing restrictions. Generally, milk production increases at high DHA but has no significant influence on milk fat content. In Spring, greater milk production lessens cows’ maintenance energy needs, and lower pasture content is linked to lower methane generation in the rumen. Methane generation declines in summer with increased digestibility at high intake levels. It is recommended to conduct an experiment exhibiting all seasons to eliminate factors that may affect the results across various studies. This review will understand variation in daily herbage intake of cows at pasture that allows the management of total intake to optimize milk production and identification of cows that are more efficient at converting feed into milk.

Pasture-Scale Evaluation of Postemergence Applications of Aminopyralid for Controlling Medusahead (Taeniatherum caput-medusae)

The exotic annual grass medusahead (Taeniatherum caput-medusae [L.] Nevski) has invaded millions of hectares in the western United States. The herbicide aminopyralid is an emerging tool for controlling medusahead. Aminopyralid reduces viability of grass seeds when applied just before seed production. In annual grasslands, desirable forage grasses generally begin seed production before medusahead, and applying aminopyralid when medusahead is still mostly vegetative but forage grasses have begun producing seed allows medusahead to be targeted somewhat selectively. In recent experiments, this approach reduced medusahead viability and cover to near zero and increased forage grasses. These experiments occurred in small plots, and results may differ in pastures if grazing or environmental heterogeneity causes plant stages to vary. Moreover, the results may prove highly sensitive to application timing. To address these information gaps, we factorially combined grazing and aminopyralid treatments in pastures and varied application timings in small plots. In pastures, aminopyralid reduced medusahead cover from about 45% to 20% one yr and from 60% to 20% another year. These reductions are smaller than in past research, but this doesn't seem attributed to the larger treatment area because reductions were similar in pastures and small plots treated the same time. Despite smaller reductions in medusahead cover, forage grasses increased as much or more than previously, perhaps because aminopyralid previously more sharply reduced forage grass seed viability. Seed viability did not vary with grazing, indicating grazing can occur during treatment, because aminopyralid does not have grazing restrictions. Careful application timing is critical: Just 12 d separated the least (jointing and boot stages) and most (boot to early heading) effective timings for controlling medusahead. A low rate of aminopyralid (22% of maximum labeled rate) is needed to reduce medusahead seed production, and the low cost of the low rate should encourage repeated applications when necessary.

Role of monitoring in environmental regulation: An empirical analysis of grazing restrictions in pastoral China

To alleviate grassland degradation, top-down command-and-control environmental regulation measures such as grazing bans and balance grazing have been implemented to control herders’ animal-stocking rates in the pastoral areas of northern China. However, previous literature has generally acknowledged that grazing restrictions have been ineffective in controlling overgrazing, as herders continue to graze illegally. This study provides the first empirical analysis that examines the mechanism through which a successful grazing restriction might occur and investigates the roles that each instrument component (restriction types, compensation, and monitoring) of the policy mix play in determining its effectiveness. The analysis is based on an unbalanced panel dataset of 348 herd households with 1025 observations surveyed from two major pastoral provinces in China during the years 2015-2017. A fixed-effects panel model is estimated to identify empirically the effects of grazing restrictions on herders’ grazing intensity and overgrazing. Results show that the grazing ban alone had an insignificant impact on overgrazing and that the effectiveness of the grazing ban critically depends upon monitoring. Surprisingly, we find that higher compensation levels in the grazing ban zones lead to increased grazing intensities. Further analysis shows that adequate monitoring is a necessary condition for a successful grazing restriction; data reflecting the monitoring on just 20.9% herders met desired criteria. We suggest that the current command-and-control measures should be replaced with an incentive-based approach that provides subsidies based on outcomes of actual stock-rate reduction. It is also crucial to enforce grazing restrictions by implementing adequate monitoring of herders’ grazing behaviour.

Long-term persistence of wildlife populations in a pastoral area.

Facilitating coexistence between people and wildlife is a major conservation challenge in East Africa. Some conservation models aim to balance the needs of people and wildlife, but the effectiveness of these models is rarely assessed. Using a case‐study approach, we assessed the ecological performance of a pastoral area in northern Tanzania (Manyara Ranch) and established a long‐term wildlife population monitoring program (carried out intermittently from 2003 to 2008 and regularly from 2011 to 2019) embedded in a distance sampling framework. By comparing density estimates of the road transect‐based long‐term monitoring to estimates derived from systematically distributed transects, we found that the bias associated with nonrandom placement of transects was nonsignificant. Overall, cattle and sheep and goat reached the greatest densities and several wildlife species occurred at densities similar (zebra, wildebeest, waterbuck, Kirk's dik‐dik) or possibly even greater (giraffe, eland, lesser kudu, Grant's gazelle, Thomson's gazelle) than in adjacent national parks in the same ecosystem. Generalized linear mixed models suggested that most wildlife species (8 out of 14) reached greatest densities during the dry season, that wildlife population densities either remained constant or increased over the 17‐year period, and that herbivorous livestock species remained constant, while domestic dog population decreased over time. Cross‐species correlations did not provide evidence for interference competition between grazing or mixed livestock species and wildlife species but indicate possible negative relationships between domestic dog and warthog populations. Overall, wildlife and livestock populations in Manyara Ranch appear to coexist over the 17‐year span. Most likely, this is facilitated by existing connectivity to adjacent protected areas, effective anti‐poaching efforts, spatio‐temporal grazing restrictions, favorable environmental conditions of the ranch, and spatial heterogeneity of surface water and habitats. This long‐term case study illustrates the potential of rangelands to simultaneously support wildlife conservation and human livelihood goals if livestock grazing is restricted in space, time, and numbers.

Open access post-harvest grazing and farmers’ preferences for forage production incentives in Ethiopia

Open access post-harvest in situ grazing is widespread in areas where a mixed crop-livestock system is common. Where this is not discouraged, because livestock is important, conservation agriculture, which depends on keeping the soil surface covered with crop residues is unlikely to be implemented. One way to reduce open access grazing is through restricting communal grazing access to allow rights of exclusion, while simultaneously improving the production of livestock feeds. This paper analyzes farmers’ perceptions about post-harvest free grazing on agricultural lands and identifies incentives that motivate forage production, to help inform forage development and policy. We collected data from randomly selected farm households in the Nile Basin of Ethiopia and used a choice experiment method. We found that a majority of farmers would prefer post-harvest grazing restrictions to the existing reciprocal post-harvest grazing. Farmers also had strong preferences for forage production policy incentives, but the results reveal considerable preference heterogeneity. The study provides policy makers with needed information in formulating policy incentives for smallholder forage production systems.

A model for estimating the total absorbed dose to the thyroid in Swedish inhabitants following the Chernobyl Nuclear Power Plant accident: implications for existing international estimates and future model applications

The time-integrated absorbed dose to the thyroid gland in the years after a fallout event can indicate the potential excess number of thyroid cancers among young individuals after a radionuclide release. Typical mean values of the absorbed dose to the thyroid have been calculated previously using reported data on radioiodine obtained from air sampling and dairy milk surveys in Sweden after the Chernobyl fallout, not including the contribution from 134Cs and 137Cs. We have developed a model for Swedish conditions taking these additional dose contributions into account. Our estimate of the average time-integrated absorbed dose to the thyroid, Dth,tot, during the first 5 years after fallout ranged from 0.5−4.1 mGy for infants and from 0.3−3.3 mGy for adults. The contribution to Dth,tot from 131I through inhalation and milk consumption varied considerably among different regions of Sweden, ranging from 9%−79% in infants, and from 4%−58% in adults. The external irradiation and exposure from the ingestion of 134,137Cs in foodstuffs accounted for the remaining contributions to Dth,tot (i.e. up to 96% for adults). These large variations can be explained by the highly diverse conditions in the regions studied, such as different degrees of fractionation between wet and dry deposition, different grazing restrictions on dairy cattle, and differences in 134,137Cs transfers through food resulting from differences in the local fallout. It is our conclusion that the main contribution to Dth,tot from nuclear power plant fallout in areas subjected to predominantly wet deposition will be from external exposure from ground deposition, followed by internal exposure from contaminated food containing the long-lived fission product 137Cs and the neutron-activated fission product 134Cs. The contribution from 134,137Cs to the thyroid absorbed dose should thus be taken into account in future epidemiological studies.

English

A study to examine the attitudes and awareness of the local communities towards conservation values of the park, its flora and fauna with particular emphasis on mountain nyala was carried out in the Bale Mountains National Park in 2007. The study specifically investigated how attitudes vary with different groups of people involved in either recent or long term settlements; people with different livelihood strategies and among people that live at different distances away from the park. Questionnaire and interviews were directed to randomly selected households and key-informants in 7 villages located near the park. Out of the 136 people interviewed, 26% of the respondents felt that they benefited, while 55% experienced conflict by living near the park. The most important benefits were leasing of horses to tourists (62%), serving as tourist guide (44%), and use of the park’s vehicles during the time of emergency (38%). A significant portion (83%) of the respondents agreed that there was lack of equity in benefit distribution. The main conflicts were fear of forceful relocation (84%), livestock grazing restrictions (74%) and restriction of firewood collection (54%). Perceived benefits and conflicts varied across livelihood strategy but not proximity to the park and duration of settlement. The majority of respondents (66%) believed that their presence in the area does not contribute to habitat degradation, an attitude more commonly held among recent settlers than long-term settlers. The overall attitude of the local people towards the park and the presence of mountain nyala were positive. 80% of the respondents would support the park’s conservation activities suggesting that there is a room to enhance cooperation of the local people and improve the prospects for conservation of the mountain nyala and its habitat.   Key words: Attitude, benefit, conservation, conflict, encroachment, local people, mountain nyala.

Better Access to New Technologies and Credit Service, Farmers^|^prime; Land Use Decision, and Policy for Poverty Alleviation and Rangeland Conservation

This paper focuses upon the incompatibility between poverty alleviation and environmental conservation and the solution to the incompatibility in an agro-pastoral area of China. The effects on income and grazing pressureof restricting herd size, prohibiting rangeland reclamation, introduction of sedentary beef production, and credit provision were examined using linear programming in a cropping system and a pastoral system in Inner Mongolia, China. Eight scenarios on land use regulations were compared: unrestricted grazing with or without prohibition of rangeland reclamation, four grazing restrictions (1 or 2 sheep equivalent/ha; 5 or 10 sheep equivalent/person), and two grazing prohibitions (half-year or all year). Complete prohibition of rangeland reclamation and grazing reduced income, but with different effects in the two systems. Rangeland reclamation prohibition reduced income more in the cropping system (-26%) than in the pastoral system (-9%), while grazing prohibition reduced income more in the pastoral system (-55%) than in the cropping system (-14%). Grazing restrictions had little effect on income (0 to -9%) in the cropping system, but more severe restrictions (1 sheep equivalent/ha or 5 sheep equivalent/person) had major negative impact on income (-31% and -30% respectively) in the pastoral system. Introduction of sedentary beef production increased income under all three grazing restriction scenarios in both systems, by 30-42% in the cropping system and 3-18% in the pastoral system, relative to unrestricted grazing without land reclamation. Compared with no credit service, providing credit for poor households of the cropping system to introduce sedentary beef production increased their income by 51%, and increased income for poor households in the pastoral system under the grazing restriction of 1 sheep equivalent/ha by 416%.

Influencia del pastoreo restringido en el efecto macho en cabras en baja condición corporal durante la estación de anestro

This study was carried out to assess if grazing restrictions at the breeding period affects male effect during the anoestrus season of goats in low body condition (LBC). Thirty two female goats in LBC (1.63±0.30, 1=thin and 4=obese) subjected to restricted grazing, (one hour a day) were used, fifteen of them were brought back to a 6 h/d grazing (MG) schedule 15 d before the beginning of breeding, and the rest (n=17) remained to restricted grazing (RG) until the end of the breeding period. Another group of 14 goats in medium body condition (2.64±0.40) subjected to a 6 h/d grazing schedule were used as control (CG). The breeding season started on March 29. Body weight during the whole experiment was significantly higher (P 0.05) were found between these last two treatments. The proportion of goats with ovulatory activity before the breeding season started was higher in CG (28.6 %) that in MG (0 %) or RG (11.8 %). Among the anovular goats, the response to male effect was higher in CG (100 %) and in MG (93.3 %) than in RG (60 %), showing their first oestrus at 8.9±3.2, 11.4±3.3, and 10.7±4.4 d in CG, MG and RG, respectively (P>0.05). These results indicate that restricted grazing reduced the male effect of goats maintained at low body condition, while restoration of the grazing restriction 15 d before the beginning of the breeding period restored the response to male effect.

Alfalfa weevil (Coleoptera:Curculionidae) management in alfalfa by spring grazing with cattle.

The effect of continuous, intensive grazing by cattle in the 1st alfalfa growth cycle on larval densities of the alfalfa weevil, Hyera postica (Gyllenhal), was evaluated in "Alfagraze' and "Apollo' alfalfa, which are tolerant and not tolerant to grazing, respectively. In small-cage exclusion trials, grazing reduced larval numbers in 1991 by 65% in Alfagraze and by 32% in Apollo. Larval numbers in 1992 were low (< or = 0.6 larvae per stem) and were not reduced significantly by grazing. Grazing and use of early insecticide treatments of permethrin or carbofuran at low rates with < or = 7-d grazing restrictions to suppress larval numbers before grazing also were examined in large-plot exclusion trails in 1993 and 1994. Grazing reduced larval densities by 60% in 1993 and 45% in 1994 during a 3-wk period beginning 3 wk after grazing was initiated. However, alfalfa weevil larvae caused moderate leaf injury in 1993 and severe injury in 1994 before grazing reduced larval numbers. Use of permethrin at 0.11 kg (AI)/ha or carbofuran or chlorpyrifos at 0.28 kg (AI)/ha effectively reduced larval numbers and prevented leaf injury before grazing began. Therefore, a combination of an early application of an insecticide treatment with a short grazing restriction followed by continuous grazing will control alfalfa weevil larvae while allowing cattle to graze and directly use forage of grazing-tolerant alfalfa.

Recovery of intertidal benthic diatoms after biocide treatment and associated sediment dynamics

It appears that, under suitable conditions, diatom assemblages can respond very quickly to a toxic event. The data suggest an inoculum of cells from the water column can multiply rapidly. Sediment-inhabiting macrofauna are more seriously affected, reducing grazing restrictions on the developing diatom assemblages. The structure and behaviour of the sediment was intimately related to biological factors including bioturbation and biogenic stabilization in a complex and interdependent manner. Further work is now required on the interaction of grazing organisms and microbial communities in the dynamics of intertidal cohesive sediments.

Population structure and recommendations for conservation of the narrowly endemic alpine butterfly, Boloria acrocnema (Lepidoptera: Nymphalidae)

Boloria acrocnema is a glacial relict species, known from two colonies in alpine southwestern Colorado, USA. Mark-recapture techniques were used to analyse its population structure at its type locality, Mt Uncompahgre. Adult activity there is confined largely to about 1 ha in which the larval foodplant, Salix nivalis, is abundant. Mark-recapture data indicate that daily population sizes are low, most adults remain in residence at the colony only a few days, and there are age-specific sexual differences in movement, with older females perhaps leaving the colony site. Survival of B. acrocnema is probably governed by a pattern of local extinctions, counter-balanced by colonizations of new habitat. The autoecology of B. acrocnema is discussed in the light of present conservation needs of this butterfly. Management actions being taken by several agencies are also presented; these include enforcing grazing restrictions, monitoring collecting pressure, and formal listing of this species under federal and state endangered species programmes.

The occurrence and significance to animal health of salmonellas in sewage and sewage sludges.

A total of 882 samples of settled sewage, sewage sludges and final effluents from eight sewage treatment plants were examined for the presence of salmonellas. Of these samples 68% were positive, isolations being made most frequently from settled sewage (85%), raw sludge (87%) and anaerobically digested sludge (96%). Fewer isolations were made from final effluent (24%) and processed sludges (58%). Samples usually contained less than 200 salmonellas/100 ml and arguments are presented that such concentrations should not lead to disease in animals if suitable grazing restrictions are followed.