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You searched for subject:(Replacement heifer). Showing records 1 – 3 of 3 total matches.

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1. Ruble, Grady D. Comparison of Retaining Replacement Heifers in a Straight-bred Angus System Versus Purchasing Crossbred Replacement Heifers to Be Bred to a Terminal Sire.

Degree: MS, Animal Science, 2018, South Dakota State University

Two evaluations were conducted to evaluate the biological and economic production efficiency of retaining replacement females in a straight-bred Angus herd (HR) as opposed to purchasing crossbred replacements for a terminal sire production system (PR) where maximum maternal and individual heterosis is achieved. The first study was a comparison of the HR system versus PR system. It was modeled after a 100 hd, straightbred Angus cowherd that raises their own replacement females. The (NASEM, 2016) model was used to determine the required metabolizable energy (ME)/animal for each stage of production. Stages were broken into segments including weaning – d 28, d 29 – breeding, breeding – mid-gestation. It was determined, that on the same ME resources, an operator can run 117 cows and produce 7,833 more kilograms in the PR system compared to the 100 cows in the HR system. Economically, the PR system produced $10,949 more dollars of net income than the HR system. In the second study, 25 Angus and 29 SimAngus heifers were placed in the South Dakota State University Cow Calf Education and Research Facility Insentec feeding system, where they were evaluated for dry matter intake, average daily gain, gain:feed, metabolizable energy intake, predicted dry matter intake, and residual feed intake based on NRC prediction equations. At the start of the trial there was no difference in initial BW. The first period (d 1 - 98) featured no difference in BW, DMI, G:F, ME intake, predicted DMI or RFINRC. However, Angus heifers exhibited a greater ADG (P ≤ 0.02) than SimAngus heifers. During period 2 (d 99 - 167), heifer BW, G:F, and RFINRC were not different between breeds; however, Angus heifers had a greater ADG (P ≤ 0.02), DMI (P < 0.01), ME intake (P Advisors/Committee Members: Cody L. Wright.

Subjects/Keywords: crossbreeding; purchased; raised; replacement heifer; Animal Sciences; Beef Science

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APA (6th Edition):

Ruble, G. D. (2018). Comparison of Retaining Replacement Heifers in a Straight-bred Angus System Versus Purchasing Crossbred Replacement Heifers to Be Bred to a Terminal Sire. (Masters Thesis). South Dakota State University. Retrieved from https://openprairie.sdstate.edu/etd/2950

Chicago Manual of Style (16th Edition):

Ruble, Grady D. “Comparison of Retaining Replacement Heifers in a Straight-bred Angus System Versus Purchasing Crossbred Replacement Heifers to Be Bred to a Terminal Sire.” 2018. Masters Thesis, South Dakota State University. Accessed December 05, 2020. https://openprairie.sdstate.edu/etd/2950.

MLA Handbook (7th Edition):

Ruble, Grady D. “Comparison of Retaining Replacement Heifers in a Straight-bred Angus System Versus Purchasing Crossbred Replacement Heifers to Be Bred to a Terminal Sire.” 2018. Web. 05 Dec 2020.

Vancouver:

Ruble GD. Comparison of Retaining Replacement Heifers in a Straight-bred Angus System Versus Purchasing Crossbred Replacement Heifers to Be Bred to a Terminal Sire. [Internet] [Masters thesis]. South Dakota State University; 2018. [cited 2020 Dec 05]. Available from: https://openprairie.sdstate.edu/etd/2950.

Council of Science Editors:

Ruble GD. Comparison of Retaining Replacement Heifers in a Straight-bred Angus System Versus Purchasing Crossbred Replacement Heifers to Be Bred to a Terminal Sire. [Masters Thesis]. South Dakota State University; 2018. Available from: https://openprairie.sdstate.edu/etd/2950


University of Georgia

2. Studstill, Matthew Wilson. Improving management techniques in southeastern beef cattle production.

Degree: 2015, University of Georgia

Two experiments were conducted to improve common management techniques on beef cattle operations. Experiment 1 analyzed beef heifers for pre-breeding measurements that relate to reduced time to conception and positive pregnancy outcome. Odds of pregnancy increased by 15% for every 2.5 cm increase in hip height, and by 20% for every one month increase in heifer age at the start of the breeding period. Hip height was not associated with conception during the first 35 days (P = 0.204) but after 35 days the hazard rate for conception increased by 15% for every 2.5 cm increase in hip height (P = 0.005). Experiment 2 studied the effect on ruminal kinetics in vitro when feeding forages varying in nutritive value in association with common supplementation strategies. The objective of this experiment was to measure the change in DM, NDF and ADF digestibility of two forage species (‘Kentucky 31’ tall fescue and ‘Tifton 85’ bermudagrass) over seven time points (0, 3, 6, 12, 18, 24, and 48 h). These forages were subjected to harvesting intervals typical of production systems that graze cattle or produce hay in Georgia. Samples of harvest data was subjected to NIR spectroscopy to determine quality. Forages were stratified by RFQ, in order to create three quality categories: high (HIG), median (MED), and poor (LOW). The various qualities were paired with common supplementation strategies: no supplementation control (CON), liquid molasses urea (LIQ), and corn gluten feed (CGF). Regression analysis showed an increase (P < 0.01) in IVDMD, total gas production, neutral detergent fiber digestible (NDFD) and acid detergent fiber digestible (ADFD) with increased incubation time. Diets that consisted of the HIG treatment had the greatest (P < 0.001) IVDMD, NDFD and ADFD compared to the AVG treatment which was intermediate between LOW and HIG treatments. However, effect of supplementation differed between varieties of forage. Poor quality tall fescue supplemented with CGF had greater (P < 0.05) DMD compared to CON and LIQ treatments.

Subjects/Keywords: Replacement Heifer Development; Pregnancy outcome; Kentucky 31 Tall Fescue; Tifton 85 Bermudagrass; forage nutritive value; dry matter yield; supplementation strategies; liquid-molasses supplement; corn gluten feed

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APA (6th Edition):

Studstill, M. W. (2015). Improving management techniques in southeastern beef cattle production. (Thesis). University of Georgia. Retrieved from http://hdl.handle.net/10724/31518

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Studstill, Matthew Wilson. “Improving management techniques in southeastern beef cattle production.” 2015. Thesis, University of Georgia. Accessed December 05, 2020. http://hdl.handle.net/10724/31518.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Studstill, Matthew Wilson. “Improving management techniques in southeastern beef cattle production.” 2015. Web. 05 Dec 2020.

Vancouver:

Studstill MW. Improving management techniques in southeastern beef cattle production. [Internet] [Thesis]. University of Georgia; 2015. [cited 2020 Dec 05]. Available from: http://hdl.handle.net/10724/31518.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Studstill MW. Improving management techniques in southeastern beef cattle production. [Thesis]. University of Georgia; 2015. Available from: http://hdl.handle.net/10724/31518

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

3. Monday, Jessica Dawn. Evaluation of peripubertal replacement breeding animals in beef herds.

Degree: MSin Veterinary Biomedical Science, Department of Clinical Sciences, 2017, Kansas State University

The selection of young replacement animals can have a significant impact on beef herd reproductive performance. Replacement heifers can be utilized to improve reproductive performance by replacing mature animals that failed to meet the production with young, cycling heifers that can have the potential of improving the reproductive momentum of a herd. The use of yearling bulls in natural breeding herds has the advantage of shortening the generational interval of the herd and has the potential of reducing the cost per cow exposed as additions to the bull battery. This thesis involves two studies that investigated methods used for the selection of peripubertal replacement animals in beef herds. The first study evaluated the ability of the novel Ready-Intermediate-Problem (RIP) replacement heifer evaluation matrix to classify heifers into groups that allow producers to select for replacements that meet production goals. Beef heifers (n=341) were classified according to the RIP matrix guidelines and then exposed to AI breeding, bull breeding, or a combination of both as per the management plans for each participating herd. Following breeding season the heifers were evaluated to determine pregnancy status, pregnancy status to single AI exposure, days bred, and the number of 21 day cycles needed during breeding season to become pregnant. After breeding season, 298 (87%) of the heifers were pregnant, 204 (68%) of which became pregnant in the first 21 days of the breeding season. Probability of overall pregnancy and pregnancy after single AI exposure was not significantly associated with RIP classification. There was a significant interaction in RIP classification by 21 day cycle. The second study was a retrospective study using BSE result data to determine the proportion of yearling beef bulls that are classified as satisfactory potential breeders when reevaluated after failing their initial breeding soundness evaluation (BSE) and to identify any predictive factors at initial BSE for satisfactory performance at revaluation. The study included 2,805 beef bulls between 11 and 14 months of age at first BSE evaluated at KABSU from 2006 to 2014. Generalized linear mixed models were created to assess potential associations among breed, age, and interaction between breed and age and passing the initial evaluation and identify predictive factors for risk of passing BSE after initial failure. The majority (93%) of the study bulls passed one of up to three BSEs. There was a significant interaction between age and breed of bull at initial BSE. Identification of suitable peripubertal replacement animals that will improve herd reproductive performance remains a challenge for producers. There are several factors that can affect replacement animals’ ability to perform according to expectations at the beginning of the breeding season. Classification of heifers into categories that can predict performance during breeding season with reasonable confidence can assist producers in identifying heifers that complement the reproductive… Advisors/Committee Members: Robert L. Larson.

Subjects/Keywords: Breeding soundness evaluation; Theriogenology; Replacement heifer; Reproductive performance; Reproductive tract scoring

…replacements. Well managed replacement heifer programs are essential to good reproductive efficiency… …in beef herds. The goal of a replacement heifer program is to bring new, productive animals… …population of heifers that should not be used in heifer replacement programs as well as the heifers… …that should be superior additions in a heifer replacement program.3-14 However, lack of… …failing the initial evaluation. 4 Chapter 2 - Review of Literature Replacement heifer… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Monday, J. D. (2017). Evaluation of peripubertal replacement breeding animals in beef herds. (Masters Thesis). Kansas State University. Retrieved from http://hdl.handle.net/2097/35530

Chicago Manual of Style (16th Edition):

Monday, Jessica Dawn. “Evaluation of peripubertal replacement breeding animals in beef herds.” 2017. Masters Thesis, Kansas State University. Accessed December 05, 2020. http://hdl.handle.net/2097/35530.

MLA Handbook (7th Edition):

Monday, Jessica Dawn. “Evaluation of peripubertal replacement breeding animals in beef herds.” 2017. Web. 05 Dec 2020.

Vancouver:

Monday JD. Evaluation of peripubertal replacement breeding animals in beef herds. [Internet] [Masters thesis]. Kansas State University; 2017. [cited 2020 Dec 05]. Available from: http://hdl.handle.net/2097/35530.

Council of Science Editors:

Monday JD. Evaluation of peripubertal replacement breeding animals in beef herds. [Masters Thesis]. Kansas State University; 2017. Available from: http://hdl.handle.net/2097/35530

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