Progress 10/01/12 to 10/31/13
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Residual feed intake (RFI) can identify sheep that grow more efficiently during a grower test; however, to our knowledge it is not known if RFI classification predicts growth efficiency on forage based diets in subsequent feeding trials. Our objectives were to determine intake and growth rates of ewes divergently classified for high and low RFI fed either chopped or pelleted alfalfa hay (2 x 2 factorial). To establish efficiency classification, forty six ewe lambs had unlimited access to a pelleted grower diet for 63 d. Residual feed intake (RFI) values were calculated as the difference between actual and predicted DMI based on metabolic BW and ADG. Thereafter, half of the ewe lambs that had the most positive (Inefficient; n = 16) and most negative (Efficient; n = 16) RFI values were placed into one of two pens that had ad libitum access to either pelleted or chopped alfalfa hay. Ewe lamb BW, LM area (LMA), and 12th rib back fat (FD) were measured at the beginning and end of the 56 d feeding period. No interactions between RFI classification and method of hay processing were detected (P ≥ 0.17) for all measurements. Pelleted hay increased (P < 0.01) ewe lamb BW, DMI, ADG, G:F, LMA, and FD compared to chopped hay. Inefficient ewes had greater DMI and RFI values (P < 0.01) than efficient ewes; however, no difference (P ≥ 0.46) were detected between RFI groups for ADG, G:F, or LMA. Inefficient ewes tended (P = 0.06) to have greater final FD than efficient ewes. Within hay treatments, numerical differences for DMI and RFI values between efficiency groups were twice as large for ewes on the pelleted hay compared to chopped hay diet. This data suggests that ewe efficiency as determined by RFI is repeatable on subsequent forage based trial; however, difference in intake and efficiency are more apparent if forage is pelleted.
Publications
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Reduction of feed required for normal lamb and wool production could improve the profitability of sheep producers. Our objectives were to determine animal performance, feed efficiency, and feeding behavior traits of yearling ewes during active growth (Exp. 1) and at maintenance (Exp. 2). Furthermore, we compared the repeatability of these traits between the two experiments. Within each experiment, residual feed intake (RFI) was strongly correlated (0.77 and 0.89) with DMI and no relationships were detected between RFI and ADG or metabolic BW. Ewes in the low-RFI group had a 19 and 29% reduction in DMI compared to ewes in the high-RFI group for Exp. 1 and 2, respectively. Weak positive correlations (0.33 and 0.27; Exp. 1 and 2, respectively) were detected between meal duration and RFI. No differences were detected for wool fiber diameter change (Exp. 1) or hay digestibility (Exp. 2) among RFI groups (P > 0.70). No significant correlations were detected for feed efficiency and animal performance traits between Exp. 1 and 2. Weak to moderate correlations were detected for feeding behavior traits between Exp. 1 and 2. These results suggest that considerable feed efficiency differences exist in ewe lambs during active growth and yearling ewes at maintenance. However, based upon the lack of relationship between Exp. 1 and 2 for feed efficiency, the authors suggest that RFI established on a post weaning growth test may not results in more efficient ewes on the range. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Considerable animal variation existed among ewes for growth, feed efficiency, and feeding behavior traits. RFI determination effectively selected animals that consumed less feed without affecting ewe BW or ADG. Feeding behavior data showed that low-RFI ewes (high efficiency) spent less time at the feed bunk than high-RFI ewes. No relationship was detected for ewe feed efficiency traits between experiments conducted during active growth and at maintenance. Assuming Exp. 2 represents a typical range animal diet, the lack of correlation between Exp. 1 and 2 indicate that determination of RFI on grower feed test may not select for animals that are more efficient in a range ewe operation.
Publications
- No publications reported this period
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Reduction of feed required for normal lamb and wool production could improve the profitability of sheep producers. Our objectives were to determine growth and feed efficiency traits of Targhee sheep receiving a growing diet as ewe-lambs (Exp. 1) and a maintenance diet as yearlings (Exp. 2). Furthermore, we compared the repeatability of these traits between the two experiments. Within each experiment, residual feed intake (RFI) was strongly correlated (0.77 and 0.89) with DMI and no relationships were detected between RFI and ADG or metabolic BW. The low-RFI group had a 19 and 29% reduction in DMI compared to the high-RFI group for Exp. 1 and 2, respectively. No differences were detected for wool fiber diameter change (Exp. 1) or hay digestibility (Exp. 2) among RFI groups (P≥0.70). No significant correlations were detected for growth or feed efficiency traits between Exp. 1 and 2. These results suggest that considerable feed efficiency differences exist in ewe lambs during active growth and yearlings at maintenance. However, based upon the lack of relationship between Exp. 1 and 2 for feed efficiency, the authors suggest that RFI established on a post-weaning growth test may not result in more efficient ewes on the range. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Residual feed intake (RFI) is the difference between 288 actual feed intake and predicted intake for maintenance and production. Residual feed intake was used to separate ewe-lambs and yearlings into high, medium, and low efficiency groups. In both experiments, RFI selection of efficiency groups effectively identified animals that consumed less feed without affecting ewe BW or ADG. However, 294 relationships were detected for feed efficiency traits between 295 experiments conducted as ewe-lambs during active growth and as yearlings at maintenance. Assuming Exp. 2 represents a typical range ewe diet, the lack of correlation between Exp. 1 and 2 indicate that determination of RFI on grower feed test may not select for animals that are more efficient in a range ewe operation.
Publications
- Redden, R.R, L. M. M. Surber, B. L. Roeder, B. M. Nichols, J. A. Paterson, and R. W. Kott. 2011. Residual feed efficiency established in a post-weaning growth test may not result in more efficient ewes on the range. Small Ruminant Research. (Online publication complete: 20-JAN-2011 DOI information: 10.1016/j.smallrumres.2010.12.007).
- Surber, L.M.M., M. E. Rude, B. L. Roeder, T. K Mosley, A. V. Grove, J. W. Walker, and R.W. Kott, 2011. Percent spotted knapweed (Centaurea stoebe) in the diets of grazing sheep. Invasive Plant Science and Management.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Reduction of feed required for normal lamb and wool production could improve the profitability of sheep producers. Our objectives were to determine growth and feed efficiency traits of Targhee sheep receiving a growing diet as ewe-lambs (Exp. 1) and a maintenance diet as yearlings (Exp. 2). Furthermore, we compared the repeatability of these traits between the two experiments. Within each experiment, residual feed intake (RFI) was strongly correlated (0.77 and 0.89) with DMI and no relationships were detected between RFI and ADG or metabolic BW. The low-RFI group had a 19 and 29% reduction in DMI compared to the high-RFI group for Exp. 1 and 2, respectively. No differences were detected for wool fiber diameter change (Exp. 1) or hay digestibility (Exp. 2) among RFI groups (P≥0.70). No significant correlations were detected for growth or feed efficiency traits between Exp. 1 and 2. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
These results suggest that considerable feed efficiency differences exist in ewe lambs during active growth and yearlings at maintenance. However, based upon the lack of relationship between Exp. 1 and 2 for feed efficiency, the authors suggest that RFI established on a post-weaning growth test may not result in more efficient ewes on the range.
Publications
- Redden, R.R, L. M. M. Surber, B. L. Roeder, B. M. Nichols, J. A. Paterson, and R. W. Kott. 2011. Residual feed efficiency established in a post-weaning growth test may not result in more efficient ewes on the range. Small Ruminant Research. (Online publication complete: 20-JAN-2011 DOI information: 10.1016/j.smallrumres.2010.12.007).
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Reduction of feed required for normal lamb and wool production could improve the profitability of sheep producers. Our objectives were to determine animal performance, feed efficiency, and feeding behavior traits of yearling ewes during active growth (Exp. 1) and at maintenance (Exp. 2). Furthermore, we compared the repeatability of these traits between the two experiments. In both experiments, residual feed intake (RFI) was strongly correlated (0.77 and 0.89) with DMI and no relationships were detected between RFI and ADG or metabolic BW. Ewes in the low RFI group had a 19 and 29% reduction in DMI compared to ewes in the high RFI group for Exp. 1 and 2, respectively. Weak positive correlations (0.33 and 0.27; Exp. 1 and 2, respectively) were detected between meal duration and RFI. No differences were detected for wool fiber diameter change or hay digestibility in Exp. 1 and 2, respectively. No significant correlations were detected for feed efficiency and animal performance traits between Exp. 1 and 2. Weak to moderate correlations were detected for feeding behavior traits between Exp. 1 and 2. These results suggest that considerable feed efficiency differences exist in ewe lambs during active growth and yearling ewes at maintenance. However, the lack of relationship between Exp. 1 and 2 for feed efficiency suggests that RFI established on a postweaning growth test may not results in more efficient ewes on the range. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Presented results at numerous producer meetings
Publications
- Redden, R.R., R. W. Kott, L.M.M. Surber, J. A. Boles, A. W. Layton, J. M. Martin, and P. G. Hatfield. 2009. Post-weaning management of lambs alters subsequent feedlot performance and tissue deposition. Sheep and Goat J. [On-line] 24: http://www.sheepusa.org/Sheep_and_Goat_Research_Journal .
- Borg, R. C., D. R. Notter, and R. W. Kott. 2009. Genetic analysis of ewe stayability and its association with lamb growth and adult production. J Anim. Sci. 87:3515-3524.
- Borg, R. C., D. R. Notter, and R. W. Kott 2009. Phenotypic and genetic associations between lamb growth traits and adult ewe body weights in western range sheep. J Anim Sci. 87:3506-3514.
- Kott, R.W., James Moore, Mike Schuldt and Marko Manoukian. 2009. Assisting Wool Producers In Accessing An Emerging Global Market. Journal of Extension [On-line], 47(1).
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Primary objectives of this project was to explore the potential use of individual EID devises combined with and group lot identification to provide tractability within the sheep industry and to provide producer education. The EID part of the study involved 1200 ewes from 2 producer premises. In this study overall retention and read rates in ewes at one year post application was approximately 99%. Lambs (1604 lambs) from 6 Producer Premises and being transported to 4 Feeder Premises and 1 Slaughter Facility (premises encompassed 5 states) were used in a survey investigation was on the possibility of utilizing group lot designation for feedlot lambs. Their preliminary findings suggest that the group lot system will work in the feedlot industry and warrants further investigation. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The "Sheep Identification Working Group" which was developed by the American Sheep Industry Association has discussed findings from these preliminary investigative projects on several occasions and developed a series of recommendations. These recommendations were presented to the sheep industry at ASI National Convention, Phoenix, Arizona in Tucson in January 2006. First electronic EID ear tags are probably going to be a component of a sheep NAIS system. However they are currently relatively expensive compared to the value of the animal and their use needs to be combined with some sort of group lot system. The interface between EID device and record system needs to be improved. Also there appears that potentially different types of EID ear tags vary and these differences are probably location and operation dependent. These differences need to be identified. For an EID ear tag system to be feasible they must have high retention, low reactivity, ease of application and a long functional life. Because of the high cost relative to the value of the animal it is imperative that other possibilities for animal tracking such as group-lot tracking be explored to compliment the EID component of a sheep NAIS system.
Publications
- No publications reported this period
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