University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Papers and Publications in Animal Science Animal Science Department January 1981 COMPARISON OF THREE-BREED AND BACKCROSS SWINE FOR LITTER PRODUCTIVITY AND POSTWEANING PERFORMANCE E. R. Wilson Oklahoma State University, Stillwater R. K. Johnson University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/animalscifacpub Part of the Animal Sciences Commons Wilson, E. R. and Johnson, R. K., "COMPARISON OF THREE-BREED AND BACKCROSS SWINE FOR LITTER PRODUCTIVITY AND POSTWEANING PERFORMANCE " (1981). Faculty Papers and Publications in Animal Science. 19. https://digitalcommons.unl.edu/animalscifacpub/19 This Article is brought to you for free and open access by the Animal Science Department at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Papers and Publications in Animal Science by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. COMPARISON OF THREE-BREED AND BACKCROSS SWINE FOR LITTER PRODUCTIVITY AND POSTWEANING PERFORMANCE 1 E. R. Wilson 2 and R. K. Johnson 3 Oklahoma State University, Stillwater 74074 Summary ci-osses of swine (Smith and McLaren, 1967; Fahmy and Bernard, 1971; Fahmy et al., Duroc, Hampshire and Yorkshire boars were 1971; Nelson and Robison, 1976; Schneider, mated with crossbred gilts of Duroc-Hampshire, 1976; Sellier, 1976; Young et al., 1976a,b; Duroc-Yorkshire and Hampshire-Yorkshire breed- Johnson et al., 1978.) have clearly shown the ing to produce 133 three-breed and 259 back- existence of individual and maternal heterosis cross litters that were farrowed during four for important swine production traits. Since seasons beginning in the fall of 1975. Three- maternal heterosis has been shown to increase breed cross litters were .31 -+ .27, .57 + .24 and significantly the number of pigs and litter .50 + .24 pigs larger than backcross litters at weight at 42 days (Johnson et al., 1978), a birth, 21 and 42 days, respectively, and .6 -+ crossbred dam should be used in commercial .34, 2.3 -+ 1.2 and 5.4 + 2.4 kg heavier at these swine production. However, several considera- ages. The differences in average pig weight and tions must be made in the selection of breeds survival percentage were small. Three-breed and breed combinations for mating systems. As cross litters gained faster (.024 +- .007 kg/day) an example, three-breed terminal crosses and were younger (-4.7 -+ 1.5 days) at 100 maintain 100% individual and maternal heter- kilograms. Three-breed cross pigs were about osis but are more complex to manage than 3% more efficient than backcross pigs. The two-breed systems, which have less than maxi- differences in average backfat probe and mum heterosis. Another example is a rotation average daily feed intake were small and not cross, which allows a producer to raise replace- significant. Breed of sire contrasts for litter ment females but maintains less than maximum traits were small and not significant. How- heterosis. ever, significant differences between sire breeds There is a lack of experimental results for existed for postweaning performance. Also, few evaluating different mating schemes. Experi- differences between crossbred dam groups were mental results that verify the relationship significant for litter size or litter weight, but between heterosis and degree of heterozygosity significant differences in postweaning perform-_ are also lacking. ance existed between progeny of crossbred dam The purpose of this experiment was to groups. In general, pigs with Duroc breeding evaluate three-breed cross and backcross pigs had the fastest growth rate and those with from dams of Duroc-Hampshire,Duroc-Yorkshire Hampshire breeding were the leanest. and Hampshire-Yorkshire breeding for litter and (Key Words: Swine, Crossbreeding Systems, growth traits. Specific objectives were to Litter Productivity, Post-weaning Performance.) compare the estimate of one-half individual pig heterosis from this study with earlier estimates Introduction of heterosis, and to compare the performance Reports on specific two- and three-breed of the three types of crossbred dams and sire breeds for litter traits and postweaning perfor- mance. Journal Article 3616 of the Agr. Exp.Sta., Okla- homa State Univ., Stillwater. Research conducted by the Dept. of Anim. Sci. (Project 1620) in cooperation Materials and Methods with the USDA, ARS, Southern Region. Backcross and three-breed cross litters of 2 KLEEN LEEN, INC., 2720 First Ave., NE, Cedar Duroc, Hampshire and Yorkshire breeding were Rapids, IA 52402. 3 Dept. of Anita. ScL, Univ. of Nebraska, Lincoln, farrowed and raised at the Southwest Livestock 68503. and Forage Research Station, E1 Reno, Okla- 18 JOURNAL OF ANIMAL SCIENCE, VoL 52, No. 1, 1981 COMPARISON OF THREE-BREED AND BACKCROSS SWINE 19 homa. Farrowings occurred during four seasons, 21- and 42-day litter traits because one died from the fall of 1975 to the spring 1977. and four lost their litters between birth and 21 Purebred boars and crossbred females were days. produced at the OSU swine farm at Stillwater The experimental design and the number of from the purebred Duroc, Hampshire and boars, sows and pigs per breed or breed cross Yorkshire herds that had been established in are presented in table 1. Data were collected on 1969 (Johnson et al., 1973). All females the reproductive success rate of the gilts, litter farrowing were gilts. size, litter weight and individual pig weight at An 8-week breeding season was used each birth and 21 and 42 days. Differences in season, with the fall breeding beginning Dec- conception rates among crossbred female breed ember 1 and the spring breeding beginning June groups were compared by chi-square tests 1. Farrowings took place in a central farrowing (Snedecor and Cochran, 1967). Growth rate, house with crates and slotted wood floors. At days to 100 kg, average backfat probe and pen approximately 1 week of age, the litters were feed efficiency were evaluated postweaning. All moved to a nursery with individual pens and fully formed pigs (alive or dead) were included solid concrete floors. All boars were castrated in litter size at birth. at 21 days of age and creep feed was offered at Statistical analyses of litter productivity and this time. Litters were weaned at 42 days and postweaning performance were done on litter about 2 weeks later were moved to the finishing means. Average daily gain, days to 100 kg and facility. Pigs were group fed in concrete pens, average probe backfat measurements for gilts with 10 to 18 animals per pen. They were were adjusted to a barrow basis by the addition allotted to pens by breed group, with barrows to gilt records of the mean difference between and gilts mixed in pens, and started on test at barrow and gilt data. Postweaning performance approximately 9 weeks of age. Diets were 16% was analyzed in this manner because these protein to about 50 kg and 14% protein from estimates gave unbiased estimates of population 50 to 100 kg, with either wheat or sorghum as parameters and produced an input matrix that the grain base. Pigs were weighed off-test could be inverted by existing computer fac- weekly as they approached 100 kg, at which ilities. This technique was also used by Young time they were probed for backfat. et al. (1976b) and Johnson et al. (1978). Gilts were monitored during the breeding The statistical model was: period and classified into one of three cate- gories: (1) not detected in estrus. (2) detected in estrus and mated but did not become preg- Yijklm = U + S i + Bj + (SB)ij + Rk(ii ) + D 1 § nant or (3) pregnant. The records for five gilts that forrowed were deleted from analyses of (SD)il + (BD)il + (SBD)ij i + em(ijkl ), TABLE 1. EXPERIMENTAL DESIGN AND DISTRIBUTION OF SIRES, LITTERS AND PIGS No. of No. of No. of No. of Breed of No. of Breed of litters at litters 21 and pigs in pens for feed sire' sires gilt a birth 42 days feedlot efficiency Duroc 24 D H 46 44 324 15 DY 44 44 275 14 HY 43 42 310 17 Hampshire 23 DH 43 43 260 13 DY 42 42 307 13 HY 43 42 247 11 Yorkshire 25 DH 48 47 321 17 DY 41 41 278 15 HY 42 42 267 11 Total 72 392 387 2,589 126 aD = Duroc, H = Hampshire, Y -- Yorkshire. Breed of gilt includes reciprocal crosses (e.g., DH includes both D • H and H X D females) in approximately equal numbers. 20 WILSON AND JOHNSON where Yijklmtis..ih the litter mean for the i th Results and Discussion year-season, breed of sire, k th sire within Reproductive Efficiencies. The distribution season and breed of sire and Ith breed of of reproductive successes and failures is shown dam. R k()ij and e m(ijkl) were assumed to be in table 2. There were no significant differences normally d~stributed independent random vari- between the reciprocal cross female groups; 2 2 ables with zero mean and variance o r and Oe, thus, they were combined. Differences between respectively. All remaining factors were as- the breed groups in conception rate were very sumed to be fixed. Initial analysis showed that small, whether it was based on the number effects of sire within season-year and breed of retained for breeding or the number that sire were not significant for average number of mated. The percentage of females that did not pigs or litter weight at birth, 21 or 42 days. mate was 2.7%; Johnson et al. (1978) reported These traits were reanalyzed with sires excluded nonmating rates of 8% among crossbreds and from the model. Fixed model analyses were 10% among purebred females.