Beef Research Program: Roman L. Hruska U.S. Meat Animal Research Center Copyright (c) 2013 University of Nebraska - Lincoln All rights reserved. http://digitalcommons.unl.edu/hruskareports Recent documents in Beef Research Program: Roman L. Hruska U.S. Meat Animal Research Center en-us Wed, 03 Apr 2013 01:44:44 PDT 3600 Responses to <i>Varroa destructor</i> and <i>Nosema ceranae</i> by several commercial strains of Australian and North American honeybees (Hymenoptera: Apidae) http://digitalcommons.unl.edu/hruskareports/200 http://digitalcommons.unl.edu/hruskareports/200 Mon, 01 Apr 2013 10:22:48 PDT The potential impact of varroa (Varroa destructor, Anderson & Trueman) on Australian beekeeping and agriculture depends in part on the levels of resistance to this parasite expressed by Australian commercial honeybees (Apis mellifera). The responses of seven lines of Australian honeybees to V. destructor were compared with the responses of a stock of Italian honeybees from the United States known for its susceptibility to V. destructor and two stocks known for their resistance to V. destructor, Russian honeybees (RHB) and a stock expressing the varroa sensitive hygiene trait (VSH). The experiment began in May with uniform colonies having uniform infestation of V. destructor. V. destructor infestations measured as the percentage of adult bees infested in the Australian lines and the Italian stock rose from less than 10% in August to over 25% in October. From August to November, 44% of both the Australian and Italian colonies died while strongly exhibiting symptoms of parasitic mite syndrome. In contrast, RHB and VSH colonies displayed comparative resistance to V. destructor. Their infestation rates rose from about 5% in August to 10% (RHB) and 14% (VSH) in October. Likely, some of this increase resulted from invasion pressure by mites from the dying Australian and Italian colonies. During the August to November period, 4.4% of the RHB and 14.3% of the VSH colonies died. In comparisons of the seven Australian lines, only non-significant and trivial differences were found for infestation and mortality rates. All Australian lines were highly susceptible to V. destructor. Additionally, evaluations of rates of Nosema ceranae infections were made throughout the course of the experiment. Although high levels of infection were found across all stocks and lines, no stock or line exhibited an adverse effect from N. ceranae infection.

]]> Thomas E. Rinderer et al. Consistent divergence times and allele sharing measured from cross-species application of SNP chips developed for three domestic species http://digitalcommons.unl.edu/hruskareports/199 http://digitalcommons.unl.edu/hruskareports/199 Mon, 01 Apr 2013 10:11:45 PDT Recent advances in technology facilitated development of large sets of genetic markers for many taxa, though most often model or domestic organisms. Cross-species application of genomic technologies may allow for rapid marker discovery in wild relatives of taxa with well-developed resources. We investigated returns from cross-species application of three commercially available SNP chips (the OvineSNP50, BovineSNP50 and EquineSNP50 BeadChips) as a function of divergence time between the domestic source species and wild target species. Across all three chips, we observed a consistent linear decrease in call rate (~1.5% per million years), while retention of polymorphisms showed an exponential decay. These results will allow researchers to predict the expected amplification rate and polymorphism of cross-species application for their taxa of interest, as well as provide a resource for estimating divergence times.

]]> J. M. Miller et al. Reduced Lentivirus Susceptibility in Sheep with <i>TMEM154</i> Mutations http://digitalcommons.unl.edu/hruskareports/198 http://digitalcommons.unl.edu/hruskareports/198 Mon, 01 Apr 2013 10:05:15 PDT Visna/Maedi, or ovine progressive pneumonia (OPP) as it is known in the United States, is an incurable slow-acting disease of sheep caused by persistent lentivirus infection. This disease affects multiple tissues, including those of the respiratory and central nervous systems. Our aim was to identify ovine genetic risk factors for lentivirus infection. Sixty-nine matched pairs of infected cases and uninfected controls were identified among 736 naturally exposed sheep older than five years of age. These pairs were used in a genome-wide association study with 50,614 markers. A single SNP was identified in the ovine transmembrane protein (TMEM154) that exceeded genome-wide significance (unadjusted p-value 3x10-9). Sanger sequencing of the ovine TMEM154 coding region identified six missense and two frame shift deletion mutations in the predicted signal peptide and extracellular domain. Two TMEM154 haplotypes encoding glutamate (E) at position 35 were associated with infection while a third haplotype with lysine (K) at position 35 was not. Haplotypes encoding full-length E35 isoforms were analyzed together as genetic risk factors in a multi-breed, matched case-control design, with 61 pairs of 4- year-old ewes. The odds of infection for ewes with one copy of a full-length TMEM154 E35 allele were 28 times greater than the odds for those without (p-value < 0.0001, 95% CI 5–1,100). In a combined analysis of nine cohorts with 2,705 sheep from Nebraska, Idaho, and Iowa, the relative risk of infection was 2.85 times greater for sheep with a full-length TMEM154 E35 allele (p-value < 0.0001, 95% CI 2.36–3.43). Although rare, some sheep were homozygous for TMEM154 deletion mutations and remained uninfected despite a lifetime of significant exposure. Together, these findings indicate that TMEM154 may play a central role in ovine lentivirus infection and removing sheep with the most susceptible genotypes may help eradicate OPP and protect flocks from reinfection.

]]> Michael P. Heaton et al. Dual – Species Biofilm Formation by Shiga – toxin Producing <i>Escherichia coli</i> O157:H7 and O26:H11 serotypes http://digitalcommons.unl.edu/hruskareports/197 http://digitalcommons.unl.edu/hruskareports/197 Mon, 01 Apr 2013 09:40:11 PDT E. coli O26:H11 strains could outgrow O157:H7 companion strains in planktonic and biofilm phases, and also effectively compete with pre-colonized O157:H7 cells to establish themselves in mixed biofilms. E. coli O157:H7 strains were unable to displace preformed O26:H11 biofilms. Therefore, E. coli O26:H11 remains a potential risk in food safety.

]]> Rong Wang et al. Germplasm Evaluation Program Progress Report No. 23 http://digitalcommons.unl.edu/hruskareports/196 http://digitalcommons.unl.edu/hruskareports/196 Mon, 01 Apr 2013 09:28:52 PDT It is important to match genetic potential of cow herds with the climatic environment and feed resources available for beef production in diverse regions of the U.S. and with consumer preferences for beef products that excel in consistency, leanness, palatability and tenderness. Since 1969, the Germplasm Evaluation Program at the U.S. Meat Animal Research Center has been conducted to characterize breeds representing diverse biological types for a wide spectrum of biological traits of economic importance in beef production. Previous results have shown that Bos indicus X Bos taurus (e.g., Brahman and Sahiwal, sired F1 cross cows out of Hereford and Angus dams) were exceptionally productive and efficient cows, especially in subtropical climates (e.g., Florida versus Nebraska). However, as the proportion Bos indicus increased the advantages of Bos indicus crosses were tempered by older age at puberty and reduced meat tenderness. This report focuses on characterization of alternative sources of tropically adapted germplasm compared to Angus and Hereford sired crosses.

]]> T. L. Wheeler et al. Germplasm Evaluation Program Progress Report No. 22 http://digitalcommons.unl.edu/hruskareports/195 http://digitalcommons.unl.edu/hruskareports/195 Mon, 01 Apr 2013 09:19:02 PDT Breeds with differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and breed complementarity through crossbreeding and development of Composite populations to match genetic potential with different markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of economic importance to beef production. This report presents preliminary results from Cycle VII of the Germplasm Evaluation Program (GPE) at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) which focused on characterization of the seven Bos taurus breeds that register the largest number of animals in their respective herd books. Each breed, except Red Angus, had been characterized in earlier Cycles of the Germplasm Evaluation Program as shown in Table 1. The objective of Cycle VII was to evaluate relative changes in these breeds since they were evaluated with samples of sires born 25-30 years earlier and to provide a current evaluation of these prominent Bos taurus breeds.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program- Progress Report No. 21 http://digitalcommons.unl.edu/hruskareports/194 http://digitalcommons.unl.edu/hruskareports/194 Mon, 01 Apr 2013 09:13:20 PDT Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and breed complementarity through crossbreeding and development of composite populations to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of economic importance to beef production. This report presents preliminary results from Cycle VII of the Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) which focused on characterization of the seven Bos taurus breeds that register the largest number of animals in their respective herd books. Each of the seven breeds, except Red Angus, had been characterized in earlier cycles of the Germplasm Evaluation Program as shown in Table 1. The objective of Cycle VII was to evaluate relative changes that have occurred in these breeds since they were evaluated with samples of sires born 25-30 years earlier and to provide a current evaluation of these prominent Bos taurus breeds.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program- Progress Report No. 20 http://digitalcommons.unl.edu/hruskareports/193 http://digitalcommons.unl.edu/hruskareports/193 Mon, 01 Apr 2013 08:48:22 PDT Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and development of composite populations to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. This report presents preliminary results from Cycle VI of the Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) which focuses primarily on characterization of Continental European breeds with a history of dual purpose (milk and meat production) use and the Wagyu breed from Japan reputed to have unusual propensity to deposit marbling in Japanese beef production systems.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program Progress Report No. 19 http://digitalcommons.unl.edu/hruskareports/192 http://digitalcommons.unl.edu/hruskareports/192 Mon, 01 Apr 2013 08:31:26 PDT Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and composite populations to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of importance to beef production. Previous results have shown that Bos indicus X Bos taurus (e.g., Brahman, Sahiwal and Nellore sired F1 cows out of Hereford and Angus dams) crosses were exceptionally productive and efficient cows, especially in a subtropical environment (e.g., Florida versus Nebraska). However, as the proportion Bos indicus increased, the advantages of Bos indicus crosses were tempered by older age at puberty and reduced meat tenderness. This report presents preliminary results from Cycle V of Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) focusing primarily on characterization of some heavy muscled continental European breeds and some tropically adapted breeds compared to Hereford and Angus sired crosses for characteristics of importance in beef production.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program- Progress Report No. 18 http://digitalcommons.unl.edu/hruskareports/191 http://digitalcommons.unl.edu/hruskareports/191 Mon, 01 Apr 2013 08:20:47 PDT Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and composite populations to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of importance to beef production. Previous results have shown that Bos indicus X Bos taurus (e.g., Brahman, Sahiwal and Nellore sired F1cows out of Hereford and Angus dams) crosses were exceptionally productive and efficient cows, especially in a subtropical environment (e.g., Florida versus Nebraska). However, as the proportion Bos indicus increased, the advantages of Bos indicus crosses were tempered by older age at puberty and reduced meat tenderness. This report presents preliminary results from Cycle V of Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) focusing primarily on characterization of some heavy muscled continental European breeds and some tropically adapted breeds compared to Hereford and Angus sired crosses for characteristics of importance in beef production.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program- Progress Report No. 17 http://digitalcommons.unl.edu/hruskareports/190 http://digitalcommons.unl.edu/hruskareports/190 Mon, 01 Apr 2013 08:03:48 PDT Breed differences in performance characteristics are an important genetic resource for- improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and composite populations to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of importance to beef production. Previous results have shown that Bos indicus X Bos taurus (e.g., Brahman, Sahiwal and Nellore sired F1 cows out of Hereford and Angus dams) crosses were exceptionally productive and efficient cows, especially in a subtropical environment (e.g., Florida versus Nebraska). However, as the proportion Bos indicus increased, the advantages of Bos indicus crosses were tempered by older age at puberty and reduced meat tenderness. This report presents preliminary results from Cycle V of Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) focusing primarily on characterization of some heavy muscled continental European breeds and some tropically adapted breeds compared to Hereford and Angus sired crosses for characteristics of importance in beef production.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program- Progress ReportNo. 16 http://digitalcommons.unl.edu/hruskareports/189 http://digitalcommons.unl.edu/hruskareports/189 Mon, 01 Apr 2013 07:40:16 PDT Breed differences in performance characteristics are an important genetic resource for improving efficiency of bee} production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and composite populations to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of importance to beef production. Previous results have shown that Bos indicus X Bos taurus (e.g.. Brahman, Sahiwal and Nellore sired F1cows out of Hereford and Angus dams) crosses were exceptionally productive and efficient cows, especially in a subtropical environment (e.g., Florida versus Nebraska). However, as the proportion Bos indicus increased, the advantages of Bos indicus crosses were tempered by older age at puberty and reduced meat tenderness. This report presents preliminary results from Cycle V of Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) focusing primarily on characterization of some heavy muscled continental European breeds and some tropically adapted breeds compared to Hereford and Angus sired crosses for characteristics of importance in beef production.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program- Progress Report No. 15 http://digitalcommons.unl.edu/hruskareports/188 http://digitalcommons.unl.edu/hruskareports/188 Mon, 01 Apr 2013 07:28:36 PDT Preliminary Results From Cycle V of The Cattle Germplasm Evaluation Program At The Roman L. Hruska U.S. Meat Animal Research Center

Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and new composite breeds to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of importance to beef production. Previous results have shown that Bos indicus X Bos taurus (e.g., Brahman, Sahiwal and Nellore sired F1 cows out of Hereford and Angus dams) crosses were exceptionally productive and efficient cows, especially in a subtropical environment(e.g., Florida versus Nebraska). However, as the proportion Bos indicus increased, the advantages of Bos indicus crosses were tempered by older age at puberty and reduced meat tenderness. This report presents preliminary results from Cycle V of Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal. Research Center (MARC) focusing primarily on characterization of some heavy muscled continental European breeds and some tropically adapted breeds compared to Hereford and Angus sired crosses for characteristics of importance in beef production.

]]> Larry V. Cundiff et al. Germplasm Evaluation Program- Progress Report No. 14 http://digitalcommons.unl.edu/hruskareports/187 http://digitalcommons.unl.edu/hruskareports/187 Mon, 01 Apr 2013 07:18:50 PDT Angus bulls (born 1982-1984) were used in Cycle IV and the remaining 16 bulls (born since 1988) were used for the first time in Cycle V.

Tuli. The Tuli, a Sanga type of cattle (non-humped), was developed relatively recently in a research program initiated in the 1940's using foundation cattle considered to be the most productive type selected from indigenous Tswana cattle in Zimbabwe. Australian scientists at CSIRO, Tropical Agricultural Research Station, Rockhampton, Queensland, and a consortium of private breeders in Australia imported frozen Tuli embryos from Zimbabwe into Australia in 1990. Semen from nine Tuli bulls was imported from Australia for use in the experiment.

Boran. Borans are a pure Zebu breed (Bos indicus, humped) that evolved in southern Ethiopia and are believed to have been developed for milk and meat production under stressful tropical conditions. They were imported into Australia from East Africa (Zambia). Semen from eight Boran bulls was imported from Australia for the experiment.

Brahman. Semen from a current broad sample of 21 Brahman (Grey and Red) bulls (born from 1984-1989, mean birth year 1987) was used to produce FI progeny. Semen was used from 26 bulls (born from 1964 to 1975, mean birth year 1969) sampled earlier in the program to facilitate pooling of data over cycles and estimate genetic trends.

Belgian Blue. Muscle hyperplasia (double muscling) has been favored for at least 40 years by Belgian Blue breeders in Belgium. Semen from 26 bulls is being used in the experiment.

Piedmontese. Piedmontese originates in the Piedmont region of northern Italy. Muscle hyperplasia has also been emphasized as a criterion of selection in this breed. Seventeen Piedmontese sires included in Cycle IV of the program were repeated to produce one calf crop (1992) in Cycle V.

Calves were produced in the spring of 1992- 1994. Each year a sample of about 80 male calves were left intact to evaluate growth and pubertal development of bulls. The remaining male calves were castrated within 24 hours of birth. Calves we~ creep fed whole oats from mid-July until weaning in early October.

]]> Roman L. Hruska U.S. Meat Animal Research Center Germ Plasm Evaluation Program- Progress Report No. 13 http://digitalcommons.unl.edu/hruskareports/186 http://digitalcommons.unl.edu/hruskareports/186 Mon, 01 Apr 2013 07:11:18 PDT Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and new composite breeds to match genetic potential with diverse markets, feed resources and climates. Beef producers are under increasing pressure to reduce fat while maintaining or improving tenderness and palatability of products. No single breed excels in all traits of importance to beef production. Previous results have shown that Bos indicus X Bos taurus (e.g., Brahman, Sahiwal and Nellore sired FI cows out of Hereford and Angus dams) crosses were exceptionally productive and efficient cows, especially in a subtropical environment (e.g., Florida versus Nebraska). However, the advantages of Bos indicus crosses were tempered by older age at puberty and reduced meat tenderness as the proportion Bos indicus increased. This report presents preliminary results from Cycle V of Germplasm Evaluation Program at the Roman L. Hruska U.S. Meat Animal Research Center (MARC) focusing primarily on characterization of some heavy muscled continental European breeds and some tropically adapted breeds compared to Hereford and Angus sired crosses for characteristics of importance in beef production.

]]> Larry V. Cundiff et al. Germ Plasm Evaluation Program- Progress Report No. 12 http://digitalcommons.unl.edu/hruskareports/185 http://digitalcommons.unl.edu/hruskareports/185 Mon, 01 Apr 2013 07:01:58 PDT Breed differences in performance characteristics are an important genetic resource for improving efficiency of beef production. Diverse breeds are required to exploit heterosis and complementarity through crossbreeding and to match genetic potential with diverse markets, feed resources and climates. This report presents preliminary results from an ongoing study at the Roman L. Hruska U.S. Meat Animal Research Center to characterize breeds of cattle representing different biological types for traits that influence quantity and value of production.

Experimental Procedure:

The Germ Plasm Evaluation (GPE) program has been conducted in four cycles. Table 1 shows the mating plan for cycles I, II, III, and IV. Each cycle was initiated by mating Hereford and Angus cows by artificial insemination (AI) to sires of diverse breeds. Semen from the same Hereford and Angus bulls has been used throughout to produce control Hereford-Angus (original HAx, sires born 1968-70) reciprocal crosses in each cycle. In cycle IV, new samples of Hereford and Angus (current HAx, sires born 1982-84) bulls were added to evaluate genetic trends within these breeds. In cycle IV, semen from 14 original control Angus, 11 original control Hereford, 30 current Angus, 32 current Hereford (14 horned and 18 polled), 29 Longhorn, 24 Piedmontese, 31 Charolais, 29 Salers, 31 Galloway, 22 Nel1ore, and 26 Shorthorn bulls is being used by AI to produce about 200 calves per sire breed in five calf crops (1986-1990). Following an AI period of about 45 days, one or two bulls each of Angus, Hereford, Charolais, Gelbvieh, and Pinzgauer bulls are used each year by natural service in single-sire breeding pastures for about 21 days. These breeds are being used in clean-up matings to increase ties to previous cycles and facilitate eventual pooling of results over all four cycles.

]]> Larry V. Cundiff et al. Germ Plasm EvaluationProgram- Progress Report No. 11 http://digitalcommons.unl.edu/hruskareports/184 http://digitalcommons.unl.edu/hruskareports/184 Mon, 01 Apr 2013 06:49:09 PDT A vast array of both resources and cattle breeds are available for beef production in the United States. Although feeding concentrates has provided for a relatively high degree of uniformity in the growing-finishing segment of beef production, resources used for cow-calf production have remained and will continue to remain very diverse. In the United States, stocking rates range from one cow per 2 acres or less to only one cow per 300 or 400 acres because of differences in climate, land, and feed resources.

The germ plasm base for beef cattle production in North America was broadened considerably during the 1970.s, primarily, as a result of the introduction of new breeds of European origin made possible by the development of appropriate quarantine facilities and procedures by Agriculture Canada. The newly introduced breeds, in addition to those already available, provide a wide range of performance characteristics in beef cattle.

In 1969, the Roman L. Hruska U.S. Meat Animal Research Center implemented a program to characterize a broad range of biological types of cattle as represented by breeds that differ widely in characteristics such as growth rate, carcass composition, mature size and milk production level. The primary objective was to characterize breeds representing diverse biological types for the full spectrum of traits relating to beef production. The breeds used in this program have been classified into six different biological types based on the criteria of (1) growth rate and mature size, (2) lean to fat ratio, (3) age at puberty and (4) milk production (table 1).

]]> Larry V. Cundiff et al. Germ Plasm Evaluation Program- Progress Report No. 10 http://digitalcommons.unl.edu/hruskareports/183 http://digitalcommons.unl.edu/hruskareports/183 Wed, 27 Mar 2013 09:55:56 PDT This report updates reproduction and maternal performance data for cows in Cycle II, Phase 2 and Cycle III, Phase 2 of the Germ Plasm Evaluation Program.

The cattle Germ Plasm Evaluation Program has been conducted in three cycles. Cycle I involved breeding Hereford, Angus, Jersey, South Devon, Limousin, Simmental, and Charolais bulls by artificial insemination (AI) to Hereford and Angus cows to produce three calf crops (Cycle I, Phase 2) in the spring of 1970, 1971 and 1972.

Cycle II, initiated wit~ the 1972 breeding season, involved the Hereford and Angus cows used in the first cycle. These cows were bred by AI to Hereford, Angus, Red Poll, Brown Swiss, Gelbvieh, Maine Anjou, and Chianina sires to produce two calf crops (Cycle II, Phase 2) in the spring of 1973 and 1974. In addition, in Cycle II, Phase 2, Red Poll and Brown Swiss cows were added to the program and mated to Hereford, Angus, Red Poll, and Brown Swiss sires in a four-breed diallel crossbreeding experiment.

Cycle III was initiated during the 1974 breeding season. In Cycle III, the Hereford and Angus cows used to initiate Cycles I and II were mated by AI to Hereford, Angus, Pinzgauer, Tarentaise, Brahman, and Sahiwal sires to produce two calf crops (Cycle III, Phase 2) in the spring of l975 and 1976.

Fifteen of the Hereford and 16 of the Angus sires used in Cycle I were also used in Cycle II and Cycle III to insure a stable control population of Hereford and Angus reciprocal crosses that are used as a basis for comparison between different cycles and phases of the program. Within each cycle of sire breeds, foundation cows (Hereford and Angus, in Cycles I, II, and III, plus Red Poll and Brown Swiss in Cycle II) are referred to as Phase 1. Their calves are called Phase 2, and the calves from Phase 2 cows are designated Phase 3. Specific mating plans for each cycle and phase of the program are provided in the appendix of Progress Report No. 9.

]]> Larry V. Cundiff et al. Germ Plasm Evaluation Program- Progress Report No. 9 http://digitalcommons.unl.edu/hruskareports/182 http://digitalcommons.unl.edu/hruskareports/182 Wed, 27 Mar 2013 09:50:23 PDT This report provides reproduction and maternal performance data for cows in each cycle and phase of the Germ Plasm Evaluation Program.

The cattle Germ Plasm Evaluation Program has been conducted in three cycles. Cycle I involved breeding Hereford, Angus, Jersey, South Devon, Limousin, Simmental, and Charolais bulls by artificial insemination (AI) to Hereford and Angus cows to produce three calf crops (Cycle I, Phase 2) in the spring of 1970, 1971 and 1972.

Cycle II. initiated with the 1972 breeding season involved the Hereford and Angus cows used in the first cycle. These cows were bred by AI to Hereford, Angus, Red Poll, Brown Swiss, Gelhvieh, Maine Aniou, and Chianina sires to produce two calf crops (Cycle II. Phase 2) in the spring of 1973 and 1974. In addition, in Cycle II, Phase 2, Red Poll and Brown Swiss cows were added to the program and mated to Hereford, Angus, Red Poll, and Brown Swiss sires in a four-breed diallel crossbreeding experiment.

Cycle III was initiated during the 1974 breeding season. In Cycle III, the Hereford and Angus cows used to initiate Cycles I and II were mated by AI to Hereford, Angus, Pinzgauer, Tarentaise, Rrahman, and Sahiwal sires to produce two calf crops (Cycle III. Phase 2) in the sprinq of 1975 and 1976.

]]> Larry V. Cundiff et al. Germ Plasm Evaluation Program- Progress Report No. 8 http://digitalcommons.unl.edu/hruskareports/181 http://digitalcommons.unl.edu/hruskareports/181 Wed, 27 Mar 2013 09:38:06 PDT The cattle Germ Plasm Evaluation Program has been conducted in three cycles. Cycle I involved breeding Hereford, Angus, Jersey, South Devon, Limousin, Simmental and Charolais bulls by artificial insemination (AI) to Hereford and Angus cows to produce three calf crops (Cycle I, Phase 2) in the spring of 1970, 1971 and 1972.

Cycle II, initiated with the 1972 breeding season, involved the Hereford and Angus cows used in the first cycle. These cows were bred by AI to Hereford, Angus, Red Poll, Brown Swiss, Gelbvieh, Maine Anjou 4nd Chianina sires to produce two calf crops (Cycle II, Phase 2) in the spring of 1973 and 1974. In addition, in Cycle II, Phase 2, Red Poll and Brown Swiss cows were added to the 'program and mated to Hereford, Angus, Red Poll and Brown Swiss sires to provide for a four-breed diallel crossbreeding experiment.

Cycle III was initiated during the 1974 breeding season. In Cycle III, the Hereford and Angus cows used to initiate Cycles I and II were mated by AI to Hereford, Angus, Pinzgauer, Tarentaise, Brahman, and Sahiwal sires to produce two calf crops (Cycle III, Phase 2) in the spring of 1975 and 1976.

Fifteen of the Hereford and 16 of the Angus sires used in Cycle I were also used in Cycle II and Cycle III to insure a stable control population of Hereford and Angus reciprocal crosses that are used as a basis for comparison between different cycles and phases of the program. Within each cycle of sire breeds, foundation cows (Hereford and Angus, in Cycles I, II and III, plus Red Poll and Brown Swiss in Cycle II) are referred to as Phase 1. Their calves are called Phase 2, and the calves from Phase 2 cows are designated Phase 3. Specific mating plans for each cycle and phase of the program are provided in the appendix.

]]> Roman L. Hruska U.S. Meat Animal Research Center Germ Plasm Evaluation Program- Progress Report No. 7 http://digitalcommons.unl.edu/hruskareports/180 http://digitalcommons.unl.edu/hruskareports/180 Wed, 27 Mar 2013 09:29:59 PDT The cattle Germ Plasm Evaluation Program has been conducted in three cycles. Cycle I involved breeding Hereford, Angus, Jersey, South Devon, Limousin, Simmental and Charolais bulls by artificial insemination (AI) to Hereford and Angus cows to produce three calf crops (Cycle I, Phase 2) in the spring of 1970, 1971 and 1972.

Cycle II, initiated with the 1972 breeding season, involved the Hereford and Angus cows used in the first cycle. These cows were bred by AI to Hereford, Angus, Red Poll, Brown Swiss, Gelbvieh, Maine Anjou and Chianina sires to produce two calf crops (Cycle II, Phase 2) in the spring of 1973 and 1974. In addition, in Cycle II, Phase 2, Red Poll and Brown Swiss cows were added to the program and mated to Hereford, Angus, Red Poll and Brown Swiss sires to provide for a four-breed diallel crossbreeding experiment.

Cycle III was initiated during the 1974 breeding season. In Cycle III, the Hereford and Angus cows used to initiate Cycles I and II were mated by AI to Hereford, Angus, Pinzgauer, Tarentaise, Brahman, and Sahiwal sires to produce two calf crops (Cycle III, Phase 2) in the spring of 1975 and 1976.

Fifteen of the Hereford and 16 of the Angus sires used in Cycle I were also used in Cycle II and Cycle III to insure a stable control population of Hereford and Angus reciprocal crosses that are used as a basis for comparison between different cycles and phases of the program. Within each cycle of sire breeds, foundation cows (Hereford and Angus, in Cycles I, II and III, plus Red Poll and Brown Swiss in Cycle II) are referred to as Phase 1. Their calves are called Phase 2, and the calves from Phase 2 cows are designated Phase 3. Specific mating plans for each cycle and phase of the program are provided in the appendix.

]]> Roman L.Hruska U.S. Meat Animal Research Center Germ Plasm Evaluation Program- Progress Report No. 6 http://digitalcommons.unl.edu/hruskareports/179 http://digitalcommons.unl.edu/hruskareports/179 Wed, 27 Mar 2013 09:19:56 PDT The cattle Germ Plasm Evaluation Program has been conducted in three cycles. Cycle I involved breeding Hereford, Angus, Jersey, South Devon, Limousin, Simmental and Charolais bulls by artificial insemination (AI) to Hereford and Angus cows to produce three calf crops (Cycle I, Phase 2) in the spring of 1970, 1971 and 1972.

Cycle II, initiated with the 1972 breeding season, involved the Hereford and Angus cows used in the first cycle. These cows were bred by AI to Hereford, Angus, Red Poll, Brown Swiss, Gelbvieh, Maine Anjou and Chianina sires to produce two calf crops (Cycle II, Phase 2) in the spring of 1973 and 1974. In addition, in Cycle IL, Phase 2, Red Poll and Brown Swiss cows were added to the program and mated to Hereford, Angus, Red Poll and Brown Swiss sires to form a four-breed diallel crossbreeding experiment.

Cycle III was initiated during the 1974 breeding season. In Cycle III, the Hereford and Angus cows used to initiate Cycles I and II were mated by AI to Hereford, Angus, Brahman, Sahiwal, Pinzgauer and Tarentaise sires to produce two calf crops (Cycle III, Phase 2) in the spring of 1975 and 1976.

Fifteen of the Hereford and 16 of the Angus sires used in Cycle I were also used in Cycle II and Cycle III to insure a more stable control population of Hereford and Angus reciprocal crosses that are used as a basis for comparison between different cycles and phases of the program. Within each cycle of sire breeds, foundation cows (Hereford and Angus, in Cycles I, II and III, plus Red Poll and Brown Swiss in Cycle II) are referred to as Phase 1. Their calves are called Phase 2 and the calves from Phase 2 cows are designated Phase 3. Specific mating plans for each cycle and phase of the program are given in the appendix.

]]> Roman L.Hruska U.S. Meat Animal Research Center Germ Plasm EvaluationProgram- Progress Report No. 5 http://digitalcommons.unl.edu/hruskareports/178 http://digitalcommons.unl.edu/hruskareports/178 Wed, 27 Mar 2013 09:12:42 PDT The cattle Germ Plasm Evaluation Program has been conducted in three cycles. Cycle I involved breeding Hereford, Angus, Jersey, South Devon, Limousin, Simmental and Charolais bulls by artificial insemination (AI) to Hereford and Angus cows to produce three calf crops (Cycle I, Phase 2) in the spring of 1970, 1971 and 1972.

Cycle II, initiated with the 1972 breeding season, involved the Hereford and Angus cows used in the first cycle. These cows were bred by AI to Hereford, Angus, Red Poll, Brown Swiss, Gelbvieh, Maine Anjou and Chianina sires to produce two calf crops (Cycle II, Phase 2) in the spring of 1973 and 1974. In addition, in Cycle II, Phase 2, Red Poll and Brown Swiss cows were added to the program and mated to Hereford, Angus, Red Poll and Brown Swiss sires.

Cycle III was initiated during the 1974 breeding season. In Cycle III, the Hereford and Angus cows used to initiate Cycles I and II were mated by AI to Hereford, Angus, Brahman, Sahiwal, Pinzgauer and Tarentaise sires to produce two calf crops (Cycle III, Phase 2) in the spring of 1975 and 1976.

Fifteen of the Hereford and 16 of the Angus sires used in Cycle I were also used in Cycle II and Cycle III to insure a more stable control population of Hereford and Angus reciprocal crosses that are used as a basis for comparison between different cycles and phases of the program. Within each cycle of sire breeds, foundation cows (Hereford and Angus, in Cycles I, II and III, plus Red Poll and Brown Swiss in Cycle II) are referred to as Phase 1. Their calves are called Phase 2 and the calves from Phase 2 cows are designated Phase 3. Specific mating plans for each cycle and phase of the program are given in the appendix.

]]> U.S. Meat Animal Research Center Germ Plasm EvaluationProgram- Progress Report No. 4 http://digitalcommons.unl.edu/hruskareports/177 http://digitalcommons.unl.edu/hruskareports/177 Wed, 27 Mar 2013 09:02:41 PDT The cattle Germ Plasm Evaluation Program has been conducted in three cycles. Cycle I involved breeding Hereford, Angus, Jersey, South Devon, Limousin, Simmental and Charolais bulls by artificial insemination (AI) to Hereford and Angus cows to produce three calf crops (Cycle I, Phase2) in the spring of 1970, 1971 and 1972.

Cycle II, initiated with the 1972 breeding season, involved the Hereford and Angus cows used in the first cycle. These cows were bred by AI to Hereford, Angus, Red Poll, Brown Swiss, Ge1bvieh, Maine Anjou and Chianina sires to produce two calf crops (Cycle II, Phase2) in the spring of 1973 and 1974. In addition, in Cycle II, Phase2, Red Poll and Brown Swiss cows were added to the program and mated to Hereford, Angus, Red Poll and Brown Swiss sires.

Cycle III was initiated during the 1974 breeding season. In Cycle III, the Hereford and Angus cows used to initiate Cycles I and II were mated by AI to Hereford, Angus, Brahman, Sahiwa1, Pinzgauer and Tarentaise sires to produce two calf crops (Cycle III, Phase 2) in the spring of 1975 and 1976.

Fifteen of the Hereford and 16 of the Angus sires used in Cycle I were also used in Cycle II and Cycle III to insure a more stable control population of Hereford and Angus reciprocal crosses that are used as a basis for comparison between different cycles and phases of the program. Within each cycle of sire breeds, foundation cows (Hereford and Angus, in Cycles I, II and III, plus Red Poll and Brown Swiss in Cycle II) are referred to as Phase 1. Their calves are called Phase 2 and the calves from Phase 2 cows are designated Phase 3. Specific mating plans for each cycle and phase of the program are given in the appendix.

]]> U.S. Meat Animal Research Center Evaluating Germ Plasm for Beef Production, Cycle 1- Progress Report No. 3 http://digitalcommons.unl.edu/hruskareports/176 http://digitalcommons.unl.edu/hruskareports/176 Wed, 27 Mar 2013 08:48:16 PDT Because of the large number of combinations of production resources and variations in beef market requirements, one type of cattle will not be most efficient in all production systems. The wide spectrum of cattle types available in the world offers the opportunity of quickly matching genetic resources with production and market requirements. Characterization of available genetic resources for economically important traits is necessary if we are to use this opportunity wisely. Initially, change in production characteristics can be made more rapidly by using existing variation among breeds than by selecting within breeds. However, selection within breeds remains the primary method for continuing change in average genetic merit.

In 1969 a germ plasm evaluation program was started at the U.S. Meat Animal Research Center. The primary objective was to characterize biological and environmental relationships among production traits relating to growth, feed use efficiency, carcass composition and quality, reproduction, maternal traits, and carcass and meat traits. Breeds or breed crosses form an identifiable source of biological or genetic variation in production traits.

The first cycle of breed crosses (Cycle I) resulted from artificial insemination (AI) of Hereford and Angus cows by Hereford, Angus, Jersey, South Devon, Limousin, Charolais, and Simmental bulls. The Hereford and Angus cows were purchased as calves from commercial producers. A large number of sires were used in the program: 32 Hereford, 35 Angus, 33 Jersey, 27 South Devon, 20 Limousin, 26 Charolais, and 27 Simmental bulls. Hereford and Angus sires were sampled from those selected on individual performance by AI organizations for their progeny testing programs. Jersey bulls were selected at random from two commercial AI organizations, and the South Devon bulls were sampled from an importation made in 1969 by a commercial organization. Charolais, Limousin, and Simmental bulls were sampled from those available from commercial organizations. In addition, Limousin and Simmental semen was obtained from the Canada Department of Agriculture. No progeny test results were available on any of the bulls at the time they were sampled for this program.

]]> U.S. Meat Animal Research Center Germ Plasm Evaluation Program Report No. 2 http://digitalcommons.unl.edu/hruskareports/175 http://digitalcommons.unl.edu/hruskareports/175 Wed, 27 Mar 2013 08:33:52 PDT The cattle Germ Plasm Evaluation Program at the U.S. Meat Animal Research Center is designed to characterize different biological types, as represented by different breeds, for the full spectrum of economic traits relating to growth, feed efficiency, reproduction, maternal ability and carcass and meat traits. The basic objective of this program is to develop an understanding relating to optimizing such biological factors as cow size, milk level, etc., in different feed environments and production situations.

The program was started with the 1969 breeding season. The first cycle (Cycle I, Phase 2)* involved breeding Hereford and Angus cows (Phase 1) by artificial insemination (AI) to Hereford, Angus, Jersey, South Devon, Limousin, Simmental and Charolais bulls (table 1, appendix). The three calf crops (1970, 1971 and 1972) by these sire breeds were born in March, April and early May. Reports on birth and weaning traits of all calves and on postweaning growth, feed efficiency and carcass and meat traits of the steers (ARS-NC-13, March, 1974) are available by request. All female progeny were retained for evaluation of reproduction and maternal traits.

The second cycle (Cycle II) started with the 1972 breeding season and includes two calf crops (1973 and 1974). Brown Swiss and Red Poll female populations were added to the Hereford and Angus cow herds used in Cycle I. The Hereford and Angus females were bred by AI to Hereford, Angus, Brown Swiss, Red Poll, Maine Anjou, Gelbvieh and Chianina bulls; the Red Poll and Brown Swiss females were bred by AI to Hereford, Angus, Red Poll and Brown Swiss bulls (table 2, appendix). Performance data being collected is similar to that obtained for the first cycle.

This report provides summarized data from the Cycle I, Phase 2 cows for puberty and conception as yearlings plus calving, rebreeding and weaning information as 2-year-olds (cows born in 1970-71-72), 3-year-olds (cows born in 1970-71) and 4-year-olds (cows born in 1970). Birth and preweaning data are presented for the calves (Cycle I, Phase 3) out of Cycle I, Phase 2, 2-year-old cows and sired by Hereford, Angus, Brahman, Devon and Holstein bulls (table 3, appendix). Data are included on calving difficulty and preweaning growth for the 1973-74, Cycle II, Phase 2 calf crops. Information is included on the 1973, Cycle II, Phase 2 calf crop for postweaning growth, puberty and conception as yearlings of the heifers and postweaning growth, feed efficiency and carcass and meat traits of the steers.

]]> U.S. Meat Animal Research Center Germ Plasm Evaluation Program Report No. 1 http://digitalcommons.unl.edu/hruskareports/174 http://digitalcommons.unl.edu/hruskareports/174 Wed, 27 Mar 2013 08:20:40 PDT The cattle germ plasm evaluation program at the U.S. Meat Animal Research Center is designed to characterize breeds representing different biological types in the full spectrum of economic traits relating to growth, feed efficiency, reproduction, maternal ability and carcass and meat traits. The basic objective of this program is to develop an understanding relating to optimizing such biological factors as cow size, milk level, etc., in different feed environments and production situations.

The program was started with the 1969 breeding season. The first cycle involved breeding by artificial insemination (AI), Hereford, Angus, Jersey, South Devon, Limousin, Summental and Charolais bulls to Hereford and Angus Cows. The three calf-crops for Cycle 1, Phase 1 of the program were born in March, April and early May of 1970, 1097, and 1972 and were weaned in October or November at approximately 200 days of age. All male calves were fed out as steers and slaughtered to evaluate growth, feed efficiency and carcass and meat traits. All female progeny were retained for evaluation of reproduction and maternal traits (Cycle 1, Phase 2). Mating plans are given in the appendix tables on the part of the program for which results are presented in this report.

]]> U.S. Meat Animal Research Center