Maximum herd efficiency in meat production IV. Crossbred reproduction and constant slaughter mass (original) (raw)
Related papers
Breeding for reproduction traits in context of multiplication herds efficiency in swine
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013
Presented study is a follow-up to the studies focused on eff ect of diff erent selection pressure applied on two subpopulations of purebred Czech Large White sows on performance in multiplication herds. Higher selection pressure particularly on litter size and number of function nipples, while lower pressure on growth performance was applied in one population. About 1214 farrows of 393 F1 Czech Large White sows were included into statistical evaluation. The mixed linear models using the procedure REML in SAS for Windows 9.1.2. was used. The hypothesis that progeny of sows from hyper-prolifi c subpopulation breed in multiplier herds have diff erent performance was not confi rmed which is in contrast to previous studies. This non-homogeneity can be related to non-additive genetic eff ects which are caused by crossbreeding while selection methods are based on additive models.
Selection on purebred and crossbred Performance for litter size in pigs*
Archives Animal Breeding, 2000
The present study deals with estimation of genetic parameter for purebred and crossbred Performance of live born piglets, in order to choose the optimal selection method. Data sets of two pure breeds, line L03 and L04, with 5,422 sows, a two line crossbred, L303, with 3,553 sows and a three line crossbred, L350, with 3,609 sows of a North-German breeding Company were recorded. Estimated genetic correlation between purebred and crossbred Performance were rg = 0.59 and 0.40 for reciprocal crosses L03xL04 and L04xL03, respectively. Further investigations showed that the genetic correlation is influenced by genotype-environment interactions between a nucleus farm and a farm on production level. Full-sib effects showed a proportion of FS = 0.06 on the phenotypic variance of litter size. They were confounded with additive genetic variance and permanent environment variance, when full-sib effects were neglected. The percentage of equal selected purebred sires of line L03 were 80% when 30% ...
Preventive Veterinary Medicine, 2011
In several countries slaughter pigs are paid for individually, according to slaughter weight and lean meat percent (LMP). Production of uniform batches of pigs within the optimal weight and LMP limits will obtain the best price. Therefore, all pigs should have a similar growth rate (average daily gain, ADG) and reach an appropriate slaughter weight within the same time period. LMP may serve as a proxy for ADG since pigs with low LMP have significantly higher ADG than pigs with high LMP and vice versa. Both breeding strategy and feeding system may influence the range of variation among pigs. The aim of this study was to test the two following hypotheses: (1) Herds purchasing breeding gilts have a higher mean value and a lower variation (standard deviation) in LMP than herds producing their own breeding gilts and (2) Herds using restricted feeding of finishers have a higher mean value and a lower variation (standard deviation) in LMP than herds with ad libitum feeding of finishers.
Revista Brasileira de Zootecnia, 2019
The objective of this study was to evaluate the impact of farrowing and mortality rates on inbreeding levels and genetic gain through data simulation. Data came from two real populations A and B, composed of Pietrain and Landrace breed pigs, respectively. To generate the simulated populations, a Fortran-language simulator was developed using the (co)variances of the breeding values and productive and reproductive information obtained from populations A and B, as well as restrictions on mating and animals selected per generation. Two data files were created. The first contained the pedigree of the previous 10 years, with 21,906 and 251,343 animals in populations A and B, respectively. The second included the breeding values for age, backfat thickness, and feed conversion, all of which were adjusted for 110 kg live weight, for both populations; longissimus dorsi muscle depth adjusted for 110 kg live weight, for population A only; and number of live piglets at the fifth day of life per farrowing, for population B only. Three scenarios were simulated by varying the farrowing and mortality rates during the lactation period. Ten generations were simulated, with 30 replicates for each generation and scenario. Inbreeding levels in closed production units increase with productive and reproductive losses, and these reduce the variances of breeding values, selection intensity, and genetic gains by reducing the number of animals available for selection. Actions that maximize farrowing rates are more important than those that minimize mortality rates during the lactation period, since a reduction in simulated farrowing resulted in greater losses of genetic gains.
Swine Feed Efficiency: Genetic Impact
2012
Feed costs have traditionally been the highest contributor to cost of production in swine, representing 2/3 of the cost to produce a market hog. Feed efficiency is a trait that is significantly influenced by genetics, with a heritability in the moderate range (30%-40% of the differences between animals in feed efficiency are due to genetics). The genetic system that a swine producer utilizes can have a significant impact on herd feed efficiency and the operation’s feed costs. The genetic system is comprised of the genetic composition of the sire and dam lines, plus, the crossbreeding system. The critical aspects for the sire and dam lines include a combination of the genetic supplier used by the producer, the specific lines utilized for the terminal sire lines and maternal dam lines, and the genetic improvement program of the genetic supplier. It is important to remember that the genetic composition of each market hog is derived equally from the sire and from the dame of the pigs.
1983
A deterministic computer model was constructed to simulate biological and economic inputs and outputs for life cycle pork production. Parameters and relationships used were developed and verified by comparison with experimental results in the literature. Driving variables are mean genetic potentials for lean growth rate, fat growth rate, preweaning viability, age at puberty, conception rate, number born alive, and maximum milk production, and management decisions (interval from first estrus to mating, maximum number of parities, rebreeding intervals, weaning age and marketing policy). Genetic potentials can differ between generations and subpopulations. Production inputs include metabolizable energy, crude protein, feed costs and fixed and variable nonfeed costs. Costs represent Midwestern environmentally regulated, slatted-floor farrowing and nursery units and modified-open-front finishing buildings. Production outputs include pigs and culled sows. The model calculates several measures of biological and economic efficiency, e.g., Meal or dollar input/kg of live weight or of carcass lean outputs. (
animal, 2013
Offspring born from normal litter size (10 to 15 piglets) but classified as having lower than average birth weight (average of the sow herd used: 1.46 ± 0.2 kg; mean ± s.d.) carry at birth negative phenotypic traits normally associated with intrauterine growth restriction, such as brain-sparing and impaired myofiber hyperplasia. The objective of the study was to assess long-term effects of intrauterine crowding by comparing postnatal performance, carcass characteristics and pork quality of offspring born from litters with higher (>1.7 kg) or lower (<1.3 kg) than average litter birth weight. From a population of multiparous Swiss Large White sows (parity 2 to 6), 16 litters with high (H = 1.75 kg) or low (L = 1.26 kg) average litter birth weight were selected. At farrowing, two female pigs and two castrated pigs were chosen from each litter: from the H-litters those with the intermediate (HI= 1.79 kg) and lowest (HL= 1.40 kg) birth weight, and from L-litters those with the high...
The Outcomes of Selection in a Closed Herd on a Farm in Operation
Asian-Australasian journal of animal sciences, 2015
A herd of Berkshire pigs was established in 2003 and subjected to selection without introduction of any genetic resources until 2007. The complete pedigree, including 410 boars and 916 sows, as well as the records from 5,845 pigs and 822 litters were used to investigate the results obtained from the selections. The index of selection for breeding values included days to 90 kg (D90kg), backfat thickness (BF) and number of piglets born alive (NBA). The average inbreeding coefficients of pigs were found to be 0.023, 0.008, 0.013, 0.025, 0.026, and 0.005 from 2003 to 2007, respectively. The genetic gains per year were 12.1 g, -0.04 mm, -3.13 days, and 0.181 head for average daily gain (ADG), BF, D90kg, and NBA, respectively. Breeding values of ADG, BF and D90kg were not significantly correlated with inbreeding coefficients of individuals, except for NBA (-0.21). The response per additional 1% of inbreeding was 0.0278 head reduction in NBA. The annual increase of inbreeding was 0.23% and...
Livestock Science, 2011
Different selection pressure on the litter size and growth performance traits has been applied on two subpopulations of Czech Large White sows (hyperprolific or normal). About 1933 farrows of 614 Czech Large White sows were included. The hypothesis that progeny of sows from hyperprolific subpopulation breed in multiplier herds have higher litter size traits was tested. Effects on the growth performance traits are reported so. Though the applied selection pressure on the number of functional nipples was low, these traits have remarkably increased in the HP subpopulation. Likewise, both studied growth performance traits reacted positively on the selection pressure and the differences between populations were highly significant. Surprisingly, no significant differences in litter size traits were found either in the first or in the first to fifth parity. The results outlined that the selection criteria applied in the breeding herds can efficiently increase the traits with middle or high heritability coefficients in multiplier herds. However, the selection seems rather non effective as far as the litter size traits are concerned, as the heritability coefficients of these are low and hence are influenced by crossbreeding. Using of auxiliary selection traits should be therefore considered for improvement of economic efficiency of multiplier herds.