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Performance and Diets of Sheep Grazing Within a Northern Idaho Conifer Plantation Item Info
![The performance and diets of sheep (Ovis aries) grazing within a 4-year-old conifer plantation in northern Idaho were examined. The study site was divided into five 0.75-ha pastures and grazed at 5 herbage allowance HA levels during the summers of 1991 and 1992. HA levels ranged from 1.71 to 3.78 kg DM sheep-1 day-1 in 1991 and from 2.25 to 3.91 kg DM sheep-1 day-1 in 1992. Sheep grazed the pastures for 78 and 64 days in 1991 and 1992, respectively. Sheep weights and current year’s standing crop of shrubs and herbs were monitored immediately before the animals entered the pastures, at monthly intervals, and at termination of each year’s grazing season. When sheep were weighed, fecal grab samples were collected and subsequently analyzed for 2,6-diaminopimelic acid (FDAPA) and botanical composition using microhistological procedures. Regression analysis was used to determine whether average daily gain (ADG) and FDAPA were related to HA. Dietary overlap among the HA levels was evaluated using Kulczynski’s similarity index. Relative forage preferences indices (RPI) were calculated. Seasonlong ADG was positively related to HA in 1991 and from-14 to 45g in 1992. Results indicated that in 1991, when vegetative growing conditions were favorable, HA of ≥ 2.06 kg DM sheep-1 day-1 was required to achieve ADG of 110g. In 1992, when growing conditions were unfavorable, ADG only reached 45 g when HA was 3.91 kg DM sheep-1 day-1. Seasonlong FDAPA levels were not related to HA in either year (p=0.21 in 1991; p=0.84 in 1992). FDAPA ranged from 0.66 to 0.81 mg g fecal DM-1 in 1991 and from 0.62 to 0.73 mg g fecal DM-1 in 1992.There was a weak positive relationship between FDAPA and HA (p=0.12) from 16 August to 31 August 1991. ADG was related to FDAPA from 16 July to 15 August 1991 (p=0.06) and from 16 August to 31 August 1991 (p=0.01). Seasonlong dietary overlap ranged from 49 to 80% in 1991 and from 41 to79% in 1992 indicating that diets of the sheep were quite similar across grazing treatments considering the species diversity of the plant community within the conifer plantation. Major species in the sheep diets included redstem ceanothus (Ceanothus sanguineus Pursh), Scouler willow (Salix scouleriana Barratt), and ninebark (Physocarpus malvaceus [L.] Kuhn). RPI across treatments showed that the sheep selected for graminoids and shrubs seemed to avoid forbs. Results indicate that environmental conditions (e.g., temperature and precipitation) during spring and summer have marked effect on sheep performance. Sheep producers and forest managers must work together for prescribed sheep grazing to work smoothly within a conifer plantation. Most sheep producers will be reluctant to graze conifer plantations at high intensities that result in decreased sheep performance. Therefore, forest managers desiring the benefits from higher grazing intensities should consider expected sheep performance when establishing grazing fees.](https://objects.lib.uidaho.edu/uief/small/uief_0103_sm.jpg)
- Title:
- Performance and Diets of Sheep Grazing Within a Northern Idaho Conifer Plantation
- Creator:
- McCoy, Scott D.
- Date Created:
- 1995-06
- Description:
- The performance and diets of sheep (Ovis aries) grazing within a 4-year-old conifer plantation in northern Idaho were examined. The study site was divided into five 0.75-ha pastures and grazed at 5 herbage allowance HA levels during the summers of 1991 and 1992. HA levels ranged from 1.71 to 3.78 kg DM sheep-1 day-1 in 1991 and from 2.25 to 3.91 kg DM sheep-1 day-1 in 1992. Sheep grazed the pastures for 78 and 64 days in 1991 and 1992, respectively. Sheep weights and current year’s standing crop of shrubs and herbs were monitored immediately before the animals entered the pastures, at monthly intervals, and at termination of each year’s grazing season. When sheep were weighed, fecal grab samples were collected and subsequently analyzed for 2,6-diaminopimelic acid (FDAPA) and botanical composition using microhistological procedures. Regression analysis was used to determine whether average daily gain (ADG) and FDAPA were related to HA. Dietary overlap among the HA levels was evaluated using Kulczynski’s similarity index. Relative forage preferences indices (RPI) were calculated. Seasonlong ADG was positively related to HA in 1991 and from-14 to 45g in 1992. Results indicated that in 1991, when vegetative growing conditions were favorable, HA of ≥ 2.06 kg DM sheep-1 day-1 was required to achieve ADG of 110g. In 1992, when growing conditions were unfavorable, ADG only reached 45 g when HA was 3.91 kg DM sheep-1 day-1. Seasonlong FDAPA levels were not related to HA in either year (p=0.21 in 1991; p=0.84 in 1992). FDAPA ranged from 0.66 to 0.81 mg g fecal DM-1 in 1991 and from 0.62 to 0.73 mg g fecal DM-1 in 1992.There was a weak positive relationship between FDAPA and HA (p=0.12) from 16 August to 31 August 1991. ADG was related to FDAPA from 16 July to 15 August 1991 (p=0.06) and from 16 August to 31 August 1991 (p=0.01). Seasonlong dietary overlap ranged from 49 to 80% in 1991 and from 41 to79% in 1992 indicating that diets of the sheep were quite similar across grazing treatments considering the species diversity of the plant community within the conifer plantation. Major species in the sheep diets included redstem ceanothus (Ceanothus sanguineus Pursh), Scouler willow (Salix scouleriana Barratt), and ninebark (Physocarpus malvaceus [L.] Kuhn). RPI across treatments showed that the sheep selected for graminoids and shrubs seemed to avoid forbs. Results indicate that environmental conditions (e.g., temperature and precipitation) during spring and summer have marked effect on sheep performance. Sheep producers and forest managers must work together for prescribed sheep grazing to work smoothly within a conifer plantation. Most sheep producers will be reluctant to graze conifer plantations at high intensities that result in decreased sheep performance. Therefore, forest managers desiring the benefits from higher grazing intensities should consider expected sheep performance when establishing grazing fees.
- Document Type:
- Thesis
- Library Call Number:
- SF375.4.I2M23 1995
- Subjects:
- Flat Creek sheep diet grazing sheep performance grazing areas grazing treatments range resources
- Location:
- UIEF
- Latitude:
- 46.869607
- Longitude:
- -116.733856
- Department:
- Department of Rangeland Science
- Type:
- text
- Format:
- application/pdf
Source
- Preferred Citation:
- "Performance and Diets of Sheep Grazing Within a Northern Idaho Conifer Plantation", UIEF Research Exchange, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/uief/items/uief_0103.html
Rights
- Rights:
- In copyright, educational use permitted.
- Standardized Rights:
- http://rightsstatements.org/vocab/InC-EDU/1.0/