In 1946, Dr. H.H. "Stony" Stonaker along with a $25,000 grant from the American Hereford Association to study comprest cattle, began the inbreeding study. In addition to the cattle already at Fort Lewis, he purchased bull and cows from herds around the region.
HISTORY OF INBRED LINES DEVELOPED AT SJBRC
The SJBRC inbreeding project was designed to examine the effects of intensive inbreeding and subsequent linecrossing on various economically important traits in Hereford cattle. It was initiated in 1946 under the direction of Dr. H.H. Stonaker. He served as project leader until Dr. James Brinks assumed those duties in 1968. Dr. Brinks served as the project leader until he retired in 1996. Dr. David Schafer now served as project leader.
Since the project's inception, 23 inbred Hereford lines (three of which are currently in existence), a non-inbred line sired by linecross bulls, and a control line utilizing outside sires have been formed. Seven of the original lines were formed using foundation females from the existing Fort Lewis herd. During the course of the project, many of the lines were discontinued due to below average performance and/or the presence of genetic defects.
The following is a brief history of the Hereford lines developed at the SJBRC since 1946 (Brinks, 1975).
ANIMAS (1). The six Polled Hereford foundation females of the Animas line, purchased from a Nebraska breeder, were the product of mating President Mischief (3030144) to his daughters. The two foundation sires, FLR President Mischief (6392011) and FLR President Mischief 80 (6834047) resulted from similar matings. The initial mating scheme involved the mating of full- and half-sibs. Four calf crops, produced at the station in 1953-55 and 1958, weaned 24 calves with an average inbreeding of 38%. The Animas line was discontinued in 1958 as it became evident that the performance of this line was below that of other lines already in the herd.
Bonanza (2). The eight purchased Polled Hereford foundation females (three of which were the product of sire X daughter matings) were all sired by Numode 2 (4323704). Numode 2, an outcross bull out of Quester's Queen 2 (3545308), was a grandson of Plata Domino 36 (3093731). Additionally, CARF Sears Loboy O10 (6691376), the first sire used in this line, was out of one of the foundation cows (Lomaid D Sal (5265805)) and Numode 2. The Bonanza line, created by mating inbred half-sibs, produced its first calf crop in 1953. A total of 61 calves, with an average inbreeding of 38% were produced over the 12 year period this line was in existence. Five different sires were used before the line was discontinued in 1964 due to the occurrence of dwarfism.
Brae Arden (3). This line was begun with the purchase of six foundation females and a bull from a Wyoming breeder. All females and the bull, Brae Arden 8 (4210909), were sired by Brae Carlos 14 (3377516). This line had been closed to outside breeding since 1926 in the Wyoming herd and was founded by Bonnie Arden (1454389). All foundation cattle at the station traced back to Bonnie Arden through Brae Carlos 14, Brae Arden 3 (2353469), Carlos Arden 23 (2353469), and/or Carlos Arden 5 (1960015). The foundation animals had inbreeding coefficients ranging from 14 to 28% with Brae Arden 8 being 28% inbred. The first calf crop (1948) was produced by mating Brae Arden 8 to his half sibs. Twenty-four sires were used from 1948 through 1982. A total of 303 inbred calves, with an average inbreeding of 45%, were produced over the 35 year period.
Colorado (4). The 16 foundation Hereford females of the Colorado line were of Fort Lewis (Prince Domino) breeding, with the majority of them sired by CSC Dominator 6 (3713447) or Forest Domino (1760831). Foundation sire CSC Dominator 6, who produced progeny from 1946 through 1950, was sired by Jr. Dominator 14 (2870303) and was out of Princess Domino C 324 (2254836) while Forest Domino was a son of Prince Domino (499611). During the 31 years (1946 through 1976) this line was in existence, 12 sires were used to produce 167 inbred calves with an average inbreeding of 40%.
Don (5). The five foundation cows purchased to begin the Don line were all sired by Rouge Domino 401 (4329587), and were great granddaughters of Real Prince Domino 26 (2467578) on both the sire and dam sides of the pedigrees. The foundation sire, Rouge Domino 401, was out of Beau Domino 20 (2995410) and Belle Donald (3632339), and was a grandson of Real Prince Domino 26. Initially, for the first 2 years, Rouge Domino 401 was mated back to his slightly inbred daughters. The first two sons of Rouge Domino 401 used in this line, CARF Sears Don 180 (6386902) and CARF Sears Don 204 (6678577), were products of sire-daughter matings as well. Over the 28 years (1950 through 1978) this line was in existence, 185 calves were produced with an average inbreeding of 43%.
Fort Lewis (6). The 24 foundation females of the Fort Lewis line were obtained from the existing Fort Lewis cow herd and were primarily daughters of Forest Domino (1760831). The foundation sire, Ft. Lewis Dominator 1 (3924759), was sired by Jr. Dominator 14 (2870303) and was out of Violet Lewis (2377749). Violet Lewis was sired by Forest Domino and was the dam of College Royal Domino 3, the foundation sire of the Royal line. The first son of Ft. Lewis Dominator 1 to be used in this line was Ft. Lewis Dominator 31, who was out Ft. Lewis Dominator 1's dam Violet Lewis. Ft. Lewis Dominator 31 was mated to inbred half-sibs to continue this line. The Fort Lewis line was terminated in 1953 to provide room for the expansion of more superior lines. Over the 7 year period the line was in existence, a total of 92 inbred calves were produced with an average inbreeding of 26%.
La Plata (7). The 10 foundation females in the La Plata line were of Fort Lewis (Prince Domino) breeding. Seven of these females were progeny of Baca R. Domino 41 (3698359), the foundation sire of the La Plata line. Baca R. Domino 41 was sired by OJR Royal 10 (2892596) and was out of Baca Domino B 53 (2525290). The second most highly used sired in the La Plata line, La Plata Domino 2 (4871016), was a son of Baca R. Domino 41 and A Mabel DL (3924769). The first calves in this line, sired by Baca R. Domino 41, were dropped in 1946. Later calf crops were produced by mating La Plata Domino 2 to his half sibs until the line was eliminated in 1955 due to below average performance. During the 8 years the La Plata line was at the station, a total of 56 inbred calves were produced with an average inbreeding of 21%.
Mesa (8). The 11 comprest foundation females used to form the Mesa line were of Fort Lewis (Prince Domino) breeding and were the progeny of six different sires. Hiwan Prince C 58 (4244577), the foundation sire, was a comprest bull sired by Wyoming Domino 34 (3115660) and was out of Colo Princess H2 (2964375). Hiwan Prince C 58 was mated to the foundation cows and later to his daughters to initiate the Mesa line. He produced progeny from 1947 through 1953 and his son, Mesa 290 (6843976), a result of a sire-daughter mating, sired calves in 1954. The Mesa line was discontinued in 1954 due to below average productivity as well as the high incidence of dwarf calves resulting from comprest X comprest matings. A total of 33 inbred progeny with an average inbreeding of 17% were produced during the 8 years this line was at the station.
Monarch (9). This line was initiated by the purchase of six daughters of Plus Blanchard 28 (3996790) from a Colorado breeder. Plus Blanchard 28, sired by Plus Domino 106 (2978593) and out of Carlos Dora (2847528), was mated to his daughters to produce progeny at the station from 1952 through 1954. The first son of Plus Blanchard 28 to be used on the station, Sears Monarch 2140 (7539286), was out of the foundation cow Miss Plus 45 (6096026). Until the line was discontinued in 1977 to make room for the more superior lines, a total of 218 inbred progeny with an average inbreeding of 28% were produced.
Prospector (10). The six foundation females of the Prospector line were of Fort Lewis (Prince Domino) breeding. The foundation sire, Bonvue Prince 17 (4585280), sired by Comprest Prince 3 (3511786) and out of Bonvue Princess 11 (3431623), was mated to the foundation cows, and then to his daughters to initiate the line. Two widely used bulls in the Prospector line, Prospector 300 (6844009) and Prospector 2010 (7411412), were both sired by Bonvue Prince 17 and were out of Blanca Lewis 4 (5204787), a daughter of Bonvue Prince 17. To date, a total of 338 inbred calves have been produced in the Prospector line with an average inbreeding of 39%.
Royal (11). The 36 foundation females of the Royal line were of Fort Lewis breeding, and trace back to Prince Domino (499611) through College Royal Domino 2 (2903710), College Royal Domino (2382420), Forest Domino (1760831), and/or Domino 27 (1330493). The foundation sire, College Royal Domino 3 (3610929), sired by College Royal Domino 2 and out of Violet Lewis (2377749), was mated to the related foundation females, which included a number of his daughters, to initiate the Royal line. College Royal Domino 3 produced progeny from 1946 through 1950, after which time his inbred sons were used as sires in this line. To date, a total of 23 different sires have been used producing 231 inbred calves with an average inbreeding of 45%.
San Juan (12). The 10 foundation females of the San Juan line were of Fort Lewis breeding. Eight of these females were daughters of WHR Flash 74 (3404715), the foundation sire of the line. WHR Flash 74 was sired by WHR Onward Flash 1 (2667660) and was out of Miss Reg 31 (2716029). The son of WHR Flash 74, Fort Lewis Flash 10 (4881042), was mated to his inbred half-sibs to continue the inbreeding in this line. During the 38 years this line remained on the station (1946 through 1983), a total of 287 inbred calves with an average inbreeding of 40% were produced, and a total of 15 sires were used.
Tarrington (14). The six foundation females of the Tarrington line, born in 1952, were all daughters of Tarrington Onward (6254198). Tarrington Onward, sired by Tarrington March On (6253423) and out of Queen Mab (6253341), was an imported bull from England. These six foundation cows, mated back to their sire, remained on the Wyoming ranch from which they were purchased until the cows calved and had been rebred to Tarrington Onward. After rebreeding, the foundation females as well as their calf crop were transported to the station during the summer of 1956. The first son of Tarrington Onward to be used at the station, Tarrington 6000 (9468886), was out of the foundation cow, Bar 13 Elizabeth 7 (7152466). To date, a total of 330 inbred calves with an average inbreeding of 36% have been produced.
Real Prince (15). The eight foundation cows of the Real Prince line were of Colorado State College breeding, the majority of which were granddaughters of Real Prince 36 (2873524). The foundation sire, CSC D Prince (52375895), resulted from mating Real Prince 36 to his daughter CSC Jr Real Princess (4316868). CSC D Prince was mated to his inbred half-sisters to initiate the line. A total of four sires were used in this line from 1950 through 1967, after which time the Real Prince line was discontinued due to poor productivity. During the 18 years the Real Prince line remained at the station, a total of 71 inbred calves, with an average inbreeding of 38%, were produced.
Rover (16). Three inbred bulls, UC Rover Premier 11 (8306200), UC Rover Duke 15 (9290373), and UC Rover Duke 13 (9290371), of the Rover line developed at the University of California, Davis, produced linecross progeny in 1957, 1958 and 1960. Matings were made to linecross cows of Brae Arden, Don, La Plata and San Juan breeding. No inbred matings were made on the station; thus, an inbred Rover line was never initiated.
Model Domino (17). The majority of the foundation females of the Model Domino line were primarily daughters or granddaughters of Model Domino Misch (3729729). The foundation sire, CARF Sears 5302 (9091117) (19% inbred), was a double bred grandson of Model Domino Misch through CARF Sears 024 (6332184) and Miss Model Misch 49 (5685254). CARF Sears 5302 was mated to his linebred half-sisters to initiate the Model Domino line. Only two calf crop (1958 and 1959) were weaned. Only five inbred calves, with an average inbreeding of 23%, were produced in the Model Domino line prior to being discontinued because of poor productivity.
Electra (19). The Electra line was initiated and maintained off the station of a Colorado breeder from 1952 until 1968 through the lease of ten cows and Valiant Mesa (P7566741), the foundation sire of the line. Valiant Mesa was sired by Valiant Trumode (435986) and was out of Ellen Royal (436317). Valiant Mesa and his sons were mated to these ten cows and their offspring to maintain the Electra line. In 1969, three daughters and three granddaughters of Valiant Mesa were returned to the station along with the bull, Atomic V Mesa 6704 (1463801). Atomic V Mesa 6704 produced progeny in the Electra line from 1970 through 1972. During the 14 years the line existed at the station (1968 through 1982), a total of 120 inbred calves with an average inbreeding of 28% were produced.
Ouray (23). In 1966, the high gaining linecross bull of the 1965-66 performance test, Prospector SJ 5472 (13671349), was mated to a randomly selected group of linecross cows. Prospector SJ 5472 was sired by the inbred sire, Prospector 9022 (10875749) and was out of a San Juan linecross dam, Juanita BA 0067 (11307009). The resulting progeny exhibited unusually high performance and a new inbred line, Ouray, was formed using Prospector SJ 5472 as the foundation sire. In 1968, Prospector SJ 5472 was mated to five of his daughters, as well as to a group of linecross cows of predominantly Colorado, Don, Monarch, Prospector, and Tarrington breeding. In 1969 his son Prospector T 7572 (14661067), out of the 1967 progeny group, was mated to his half-sisters and linecross cows of similar breeding. Thus, the Ouray line was initiated through sire-daughter, half-sib and outcross matings. To date, a total of 180 inbred calves with an average inbreeding of 21% have been produced.
Hermosa (24). The foundation females of the Hermosa line were of Brae Arden, Royal and San Juan breeding. Brae Arden R 8434 (15156137), one of the two foundation sires of this line, was sired by the inbred sire, Brae Arden 5642 (13671428) and was out of the linecross dam Royalita SJ 2107 (12321265). Brae Arden R 8434 produced progeny in 1971 and 1972. The other foundation sire, Brae Arden SJ 0788 (15594332) was sired by Brae Arden 5410 (13671320) and was out of the linecross dam, Juanita R 4431 (13303374). Brae Arden SJ 0788 produced progeny in 1972 and 1973 and his son, Hermosa 2414 (16109246) produced progeny in 1974. During the 12 years (1971 through 1982) the Hermosa line was in existence, a total of 8 different sires were used, producing 112 inbred calves with an average inbreeding of 19%.
Regal (29). The foundation dams of the Regal line were Brae Arden x San Juan linecross females. The foundation sire, Tarrington SJ 7104 (17346536), sired by Tarrington 2634 (16109323), produced a total of 13 inbred calves from 1979-1982. Only three other sires, all of which were progeny of Tarrington SJ 7104, have been used in the line. Together with Tarrington SJ 7104, Regal 9066 (17714999), Regal 0222 (17947579) and Regal 2056 (18370566) produced 27 calves with an average inbreeding of 26% over the 8-yr period (1979-1986).
Colorado-Don (30). The Colorado-Don line was formed from animals selected from both the Colorado and Don lines. Colorado-Don 8062 (17540457), the foundation sire of the Colorado-Don line, produced a total of 10 inbred calves in 1980. During the 5 year period (1980-1984) that the Colorado-Don line remained at the station, a total of 48 inbred calves with an average inbreeding of 28% were produced.
Effects of Inbreeding
The effects of inbreeding on reproduction and growth traits, along with the effects of hybrid vigor upon crossing have been well documented. Increased inbreeding has been shown to have detrimental effects on reproductive traits and measures of early growth.
Heterosis estimates averaged 10% for weaning weight and ranged from 5 to 10% for postweaning growth traits.
Response to selection studies indicated that the development of inbred lines, with subsequent line crossing, resulted in significant genetic progress over time. Line cross calves averaged 4.62 lbs./year improvement over a 25 year period.