The association of food conversion ratio, age at slaughter and carcass quality in pigs fed ad libitum

1969 ◽  
Vol 11 (3) ◽  
pp. 317-324 ◽  
Author(s):  
J. B. Owen ◽  
J. R. Morton
Keyword(s):  
Genetic Correlations ◽  
Conversion Ratio ◽  
Residual Effects ◽  
Progeny Testing ◽  
Restricted Feeding ◽  
Food Conversion ◽  
Large White ◽  
Related Factors ◽  
Food Conversion Ratio ◽  
Ad Libitum

SUMMARYData from a boar progeny testing scheme based on ad libitum feeding were analysed to test the hypothesis that the resultant correlations of food conversion ratio with related factors would differ from those found under conditions of restricted feeding.The results support the hypothesis, showing that the primarily genetic correlations derived from boar effects for growth and conversion ratio, are lower than those reported elsewhere for restricted feeding. It was also shown that these primarily genetic correlations could vary between breeds, the leanness associated with rapid growth in Wessex not being found in Large White, and that the correlations due to residual effects containing a greater environmental component varied widely from test to test.It is concluded that the parameters used in the design of a genetic improvement scheme should be derived specifically for each breed and feeding system. However, if the marked variability in phenotypic correlations noted here is generally applicable, this could present a difficult problem in the design of pig improvement programmes with multiple objectives.

Genotype with feeding regime interaction in pigs divergently selected for components of efficient lean growth rate

1995 ◽  
Vol 61 (1) ◽  
pp. 123-132 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran
Keyword(s):  
Growth Rate ◽  
Conversion Ratio ◽  
Restricted Feeding ◽  
Food Conversion ◽  
Feeding Regime ◽  
Lean Growth ◽  
Food Conversion Ratio ◽  
Daily Food ◽  
Feeding Regimes ◽  
Ad Libitum

AbstractThe genotype with feeding regime interaction was examined by testing pigs from four selection groups on both ad libitum and restricted feeding regimes. Within each selection group, there were high, low and control lines, which had been selected for lean food conversion ratio (LFC), daily food intake (DFI) or lean growth rate on ad libitum (LGA) or on restricted (LGS) feeding, in Large White-Edinburgh (LW) and Landrace-Wye (LR) populations. There were 1187 LW pigs and 768 LR pigs in the study, with 344 LW and 133 LR pigs tested on the alternative feeding regime.In the LW population, pigs in the high LGS line grew significantly faster than the high LGA and LFC lines with ad libitum feeding (919 v. 847 and 786 (s.e.d. 31) g/day), but had similar food conversion ratios and backfat depths. The high LGS and high DFI lines were similar for growth rate, daily food intake and food conversion ratio, but backfat depth was significantly lower in the high LGS line than in the high DFI line (12·0 v. 25·9 (s.e.d. 0·7) mm). On restricting feeding, the rankings of the selection lines for growth rate, food conversion ratio and mid-back fat depth were broadly similar to those with ad libitum feeding, except for the high LFC line. In the LR population, the high LGS, LGA and LFC lines did not differ significantly in growth rate, daily food intake, food conversion ratio and backfat depth within either the ad libitum or restricted feeding regimes. Growth rate of the high LGS line was similar to the high DFI line on ad libitum feeding (828 v. 836 (s.e.d. 40) g/day), but significantly higher on restricted feeding (704 v. 636 (s.e.d. 23) g/day). On both feeding regimes, food conversion ratio and backfat depth were significantly lower in the high LGS line compared with the high DFI line.In the LW population, the genetic correlation between feeding regimes for growth rate was significantly less than one (0·4 (s.e. 0·20)), but was not significantly different from unity (0·8 (s.e. 0·14)) for backfat depths. Based on the performance test results, selection for lean growth with testing on a restricted feeding regime may be preferable to testing animals on an ad libitum feeding regime.

The influence of feeding level from 20 to 45 kg live weight on the performance and body composition of female and entire male pigs

1983 ◽  
Vol 36 (2) ◽  
pp. 193-199 ◽  
Author(s):  
R. G. Campbell ◽  
M. R. Taverner ◽  
D. M. Curic
Keyword(s):  
Body Composition ◽  
Energy Intake ◽  
Crude Protein ◽  
Live Weight ◽  
Conversion Ratio ◽  
Restricted Feeding ◽  
Food Conversion ◽  
Digestible Energy ◽  
Protein Deposition ◽  
Ad Libitum

ABSTRACTForty-two pigs representing equal numbers of entire males and females were used to study the effects on the performance and body composition of four restricted levels of feeding (14·5, 20·3, 24·9 and 29·4 MJ digestible energy per day), and of offering the same diet (14·5 MJ digestible energy per kg and 210 g crude protein per kg) ad libitum between 20 and 45 kg live weight.Over the four restricted feeding treatments there were no significant differences between the sexes for the performance and body composition of four restricted levels of feeding (14·5, 20·3, 24·9 and 29·4 MJ digestible energy per day), and of offering the same diet (14·5 MJ digestible energy per kg and 210 g crude protein per kg) ad libitum between 20 and 45 kg live weight.Although ad libitum energy intake was the same for both sexes (34·2 MJ digestible energy per day), raising digestible energy intake from that provided by the highest restricted feeding treatment (29·4 MJ/day) to ad libitum resulted in marked differences between the sexes for performance and body composition.For males, raising digestible energy intake from 29·3 to 34·2 MJ/day improved the rate of live-weight gain and protein deposition by 0·15 and 0·10 respectively but had no further effect on food conversion ratio or body fat. The same increase in digestible energy intake for females improved growth rate by only 0·065, had no further effect on the rate of protein deposition but increased markedly food conversion ratio and body fat.

The effect of slaughter weight and sexual status on performance characteristics of male Holstein-Friesian cattle offered a cereal-based diet

2006 ◽  
Vol 82 (3) ◽  
pp. 397-404 ◽  
Author(s):  
R. M. Kirkland ◽  
T. W. J. Keady ◽  
D. C. Patterson ◽  
D. J. Kilpatrick ◽  
R. W. J. Steen
Keyword(s):  
Live Weight ◽  
Conversion Ratio ◽  
Food Conversion ◽  
Mean Values ◽  
Slaughter Weight ◽  
Fat Depots ◽  
Food Conversion Ratio ◽  
Holstein Friesian ◽  
Ad Libitum ◽  
Friesian Cattle

AbstractA total of 180 Holstein-Friesian male calves, mean age and live weight (LW) at start of the study 112 (s.d. 26·0) days and 134 (s.d. 37·6) kg, respectively, were used to evaluate the effect of slaughter weight on food efficiency and animal performance. Animals were offered concentrates ad libitum and a restricted quantity of straw and slaughtered at one of six LWs as bulls: 300, 350, 400, 450, 500 or 550 kg. A further group of cattle were slaughtered as steers at 450 kg LW. Mean age at slaughter was 247 and 434 days for bulls slaughtered at 300 and 550 kg LW respectively. Neither rate of LW or carcass gain was influenced by weight at slaughter ( P>0·05), with mean values of 1·31 and 0·70 kg/day, respectively. Food conversion ratio, killing-out proportion, carcass conformation, fat classification and weight of internal fat depots increased ( P<0·001) as slaughter weight of the bulls increased. In the comparison of steers and bulls slaughtered at 450 kg, steers had lower ( P<0·001) rates of LW and carcass gains and had a higher ( P<0·001) food conversion ratio than comparable bulls. Steers had lower ( P<0·001) estimated carcass lean, and higher ( P<0·01) estimated carcass fat concentrations than bulls slaughtered at the same LW.

A note on the behaviour and performance of growing pigs provided with straw in a novel housing system

1993 ◽  
Vol 56 (2) ◽  
pp. 269-272 ◽  
Author(s):  
D. S. Arey ◽  
J. M. Bruce
Keyword(s):  
Growth Rate ◽  
Conversion Ratio ◽  
Growing Pigs ◽  
Housing System ◽  
Food Conversion ◽  
Large White ◽  
Daily Number ◽  
Ad Libitum ◽  
Number Of Visits ◽  
And Performance

AbstractStraw-Flow is a novel housing system for growing pigs which simplifies the handling of bedding and manure by allowing pigs to take unchopped straw from dispensers. Three groups of 50, 50 and 60 Large-White × Landrace pigs were housed in Straw-Flow pens from 5 to 90 kg. They were supplied daily with 50 to 100 g unchopped straw per pig and given food ad libitum. From 30 to 90 kg, mean growth rate was 863 g/day and food conversion ratio was 2·56 kg food per kg growth. The pigs' behaviour was divided approximately into: 0·820 lying, 0·100 active, 0·075 feeding and 0·005 drinking (on a proportional basis). There were no differences (P > 0·05) between groups or different weights for any of the behaviour categories. The pigs were less active before noon than after noon (P < 0·05). The daily number of visits to the drinker between weights 5 and 25 kg fell from 23·7 to 11·0 (P < 0·05). A single drinker, of new design, appeared to be adequate for a group of 50 to 60 pigs.

The performance of Hereford × Friesian offspring of bulls selected for lean growth rate and lean food conversion efficiency

1992 ◽  
Vol 54 (1) ◽  
pp. 23-30 ◽  
Author(s):  
S. C. Bishop ◽  
J. S. Broadbent ◽  
R. M. Kay ◽  
I. Rigby ◽  
A. V. Fisher
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Genetic Correlations ◽  
Conversion Ratio ◽  
Carcass Composition ◽  
Control Line ◽  
Food Conversion ◽  
Breeding Values ◽  
Lean Growth ◽  
Food Conversion Ratio

AbstractThe performance of Hereford × Friesian calves sired by Hereford bulls selected for either lean growth rate (LGR) or lean food conversion ratio (LFCR), or by unselected Hereford bulls, was evaluated on 327 calves on three farms over 2 years. Animals started test at 130 days of age on average and remained on test for approximately 300 days, whereupon all animals were slaughtered and carcass dissections were undertaken. Individual food intake was measured on tioo of the farms (189 animals), but only intake per pen of animals was measured on the third farm and individual food intake had to be estimated. LGR, LFCR and other traits describing performance were calculated from the growth, food intake and carcass composition data.If no breed or environment interactions exist it is expected that proportionately 0-5 of the genetic differences between selected and control line bulls would be transmitted to their offspring. For the LGR and LFCR line bulls these values were 0·38 and 0·44, respectively, however the LGR value had a much smaller confidence interval. Genetic correlations derived from regressing breeding values predicted from offspring performance on breeding values predicted from the bulk's own performance in the selection experiment were 0·62 (s.e. 0·28) and 0·96 (s.e. 0·28) for LGR and LFCR, respectively. Heritabilities were: live-weight gain on test, 0·27; daily gain, 0·48; food intake, 0·06; food conversion ratio, 0·46; predicted carcass lean content, 0·10; killing-out proportion, 0·10; LGR, 0·36 and LFCR, 0·48.

Evaluation of overseas pig breeds using imported semen 1. Growth and carcass performance

1984 ◽  
Vol 103 (3) ◽  
pp. 561-570 ◽  
Author(s):  
R. A. Sutherland ◽  
A. J. Webb ◽  
J. W. B. King
Keyword(s):  
Live Weight ◽  
Conversion Ratio ◽  
Food Conversion ◽  
Large White ◽  
Ad Libitum ◽  
Carcass Performance ◽  
Economic Worth ◽  
The Cost ◽  
Sufficient Precision ◽  
Imported Semen

SummaryAlthough a given foreign breed may offer worthwhile genetic improvement, the cost of importing purebred stock makes its evaluation difficult. An experiment was performed in which the breeds compared were represented instead by semen from boars standing at national artificial insemination stations in their native countries. Contemporary groups of Large White × Norwegian Landrace females were inseminated, some with British Large White (LW) semen, and some with semen from Canadian Yorkshire (CY), Danish Landrace (DL), Norwegian Landrace (NL), or United States (American) Duroc (AD) or Yorkshire (AY). One pair (male castrate and gilt) from each litter was performance tested from 27 to 82 kg live weight fed ad libitum (AL), another pairwas tested over the same weight range but fed to a time-based scale (TS). The number of LW, CY, DL, AD, AY and NL sires used was 51, 12, 21, 7, 6 and 23 respectively; a total of 401 litterswas evaluated. The differences between the progeny of LW sires and those of CY, DL, AD, AY and NL were, respectively: in daily live-weight gain (g), AL, –30, 40, –80, –50, –40 (maximum s.E. 16) with no significant differences for TS; in food conversion ratio, AL,0·02, – 0·13, 0·03, –0·05, 0·00 and TS, 000, – 0·14, 0·05, –0·03, –0·06 (maximum S.E. 0·049 for both feeding regimens); in percentage of lean by weight in the rumpback joint, AL, –2·1, –1·9, –1·8, 2·3, –0·7 and TS, – 0·1, –0·9, –1·9, 3·0, – 1·4 (maximum s.E. 1·28 for both); in overall economic worth (pence per pig sired), AL, – 150, 50, – 170, 110, – 40 and TS, – 10, 100, – 200, 190, 30 (maximum s.E. 83 for both). The U.S. Yorkshire and Danish Landrace seem unlikely to be of use commercially in the U.K., while the most promising breeds, U.S. Duroc and Canadian Yorkshire, have not yet been evaluated with sufficient precision to reduce the risk involved in their use to an acceptable level.

Selection for components of efficient lean growth in Large White pigs

1994 ◽  
Vol 1994 ◽  
pp. 9-9
Author(s):  
N.D. Cameron
Keyword(s):  
Growth Rate ◽  
Selection Criteria ◽  
Conversion Ratio ◽  
Food Conversion ◽  
Correlated Responses ◽  
Large White ◽  
Lean Growth ◽  
Food Conversion Ratio ◽  
Daily Food ◽  
Selection For

An experiment was started in 1984 at Edinburgh and Wye to study responses to divergent selection for lean growth rate (LGA), lean food conversion ratio (LFC) and daily food intake (DFI). This paper measured the selection pressure applied, the responses in the selection criteria and estimated the genetic and phenotypic relationships between the selection criteria with ad-libitum feeding of Large White pigs after four generations of selection.Selection objectives and criteria. The LGA (LFC) selection objective was to obtain equal correlated responses in growth rate (food conversion ratio) and carcass lean content, measured in phenotypic s.d. The LGA, LFC and DFI selection criteria had phenotypic s.d. of 27, 29 and 250 units and results are presented in s.d. units.

Effect of gender, terminal sire line and age at slaughter on performance, carcass characteristics and meat quality of heavy pigs

2003 ◽  
Vol 77 (1) ◽  
pp. 33-45 ◽  
Author(s):  
M. A. Latorre ◽  
P. Medel ◽  
A. Fuentetaja ◽  
R. Lázaro ◽  
G. G. Mateos
Keyword(s):  
Meat Quality ◽  
Average Daily Gain ◽  
Intramuscular Fat ◽  
Conversion Ratio ◽  
Longissimus Muscle ◽  
Food Conversion ◽  
Large White ◽  
A Value ◽  
Food Conversion Ratio ◽  
Female Line

AbstractTwo hundred and forty pigs of 56 ± 3 days of age were used to investigate the effects of sex (barrows; gilts), boar sire (DD, Danish Duroc; ND × LW, Dutch Duroc × Large White ; P × LW, Pietrain × Large White) and slaughter age (160; 175 days) on performance and carcass and meat quality. Treatments were arranged factorially (2 × 3 × 2) and there were four replicates (five pigs per replicate) per treatment. The female line was Landrace × Large White in all cases. Barrows had greater daily food intake (P <0·001) and average daily gain (P <0·01) and had poorer food conversion ratio (P <0·001) than gilts. Carcasses from castrates were fatter and had a lower yield of trimmed lean cuts than carcasses from females (P <0·001). Longissimus muscle from barrows had more intramuscular fat and higher a* value than muscle from gilts (P <0·05). Pigs from DD sire line grew faster (P <0·05) and had a better food conversion ratio (P <0·001) than pigs from the other two lines. Dressing proportion and backfat thickness were greatest for P × LW sired pigs (P <0·01) and proportion of trimmed lean cuts was greater for DD and P × LW than for ND × LW sired pigs (P <0·01). Longissimus muscle from DD sired pigs had less protein (P <0·01) and more intramuscular fat (P <0·001) than muscle from the remaining lines. Longissimus muscle from P × LW line had more intense colour than muscle from DD and ND × LW lines (P <0·01). Pigs slaughtered at 175 days had poorer food conversion ratio (P <0·01) and less trimmed primal cut proportion (P <0·001) than pigs slaughtered at 160 days. Also, increasing the age at slaughter increased intramuscular fat content (P <0·01), a* value (P <0·001) and colour intensity of the muscle (P <0·01). Danish Duroc boars are a good alternative to ND × LW or P × LW boars for production of heavy pigs whether the crossbreds are sacrificed at 160 or 175 days. Also, an increase in age at slaughter impairs growth efficiency and yield of lean cuts but improves some aspects of meat quality, which might be of interest in the production of heavy pigs destined for the dry-cured product industry.

Selection for improved food conversion ratio on ad libitum group feeding in pigs

1983 ◽  
Vol 37 (3) ◽  
pp. 375-385 ◽  
Author(s):  
A. J. Webb ◽  
J. W. B. King
Keyword(s):  
Weight Gain ◽  
Live Weight ◽  
Conversion Ratio ◽  
Food Conversion ◽  
Daily Food Intake ◽  
Food Conversion Ratio ◽  
Daily Food ◽  
Group Feeding ◽  
Ad Libitum ◽  
Selection For

ABSTRACTAn experiment was conducted to show the effectiveness of selection for improved food conversion ratio on ad libitum group feeding. Selection (32 ♀♀ and 8 ♂♂) and unselected control (32 ♀♀ and 16 ♂♂ lines were maintained for seven generations at the rate of one per year. Progeny were fed ad libitum from 27 to 82 kg live weight: boars singly or in pairs, and gilts in litter groups. Selection was on pen average food conversion ratio (food/live-weight gain), recalculated as each pig reached 82 kg.In spite of selection differentials averaging 0·61 s.d. per generation, there was no response (selection minus control) in food conversion at Generation 6 (−0·03, s.e. 0·08). However, there were correlated increases in daily live-weight gain (56, s.e. 18 g), daily food intake (145, s.e. 59 g) and ultrasonic backfat (2·4, s.e. 0·4 mm). In Generation 7, 146 full-sib pairs (male castrate and gilt) were tested on ad libitum or scale (0·77 g/g ad libitum daily food intake) feeding. Line by feeding regime interactions were absent for all traits except killing-out proportion and belly thickness.The increased fatness of the selection line on ad libitum feeding was retained on the scale (2·2 v. 2·4, s.e. 10 mm), suggesting a primary difference in partition of nutrients rather than intake. The selection procedure adopted was not successful in improving food conversion, but no clear conclusions could be drawn from the experiment. Uncertainty remains as to the value of group food consumption measurements in selection programmes.

Estimation of sire with feeding regime interaction in pigs

1988 ◽  
Vol 46 (1) ◽  
pp. 87-95 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran ◽  
R. Thompson
Keyword(s):  
Average Daily Gain ◽  
Genetic Correlations ◽  
Restricted Feeding ◽  
Large White ◽  
Feeding Regime ◽  
Weighted Analysis ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
Residual Variances ◽  
Daily Gain

ABSTRACTThe interaction of sire with feeding regime (ad libitum and restricted) was assessed in the first stage of a selection experiment. There were 79 sires (59 Large White (Edinburgh) and 20 British Landrace (Wye)) with 1549 progeny (745 at Edinburgh and 804 at Wye) in the study. Progeny within each litter were allocated at random to each feeding regime. Pigs started test at 30 (± 3) kg and finished test at 85 (± 5) kg for ad libitum fed pigs or after 84 days on test for restricted fed pigs. All pigs were individually penned. At the end of test, food intake, weight off test and ultrasonic backfat depths were recorded. Variance components were estimated using restricted maximum likelihood and a weighted analysis took account of the different residual variances between feeding regimes, within each breed.There were differences in some genetic parameters due to feeding regime within breeds. No evidence of a sire with feeding regime interaction for average daily gain or food conversion ratio was detected in Large White pigs (genetic correlations between ad libitum and restricted feeding were 1·21 (s.e. 0·17) and 0·89 (s.e. 0·19) respectively). Similar conclusions could not be made for the sample of British Landrace pigs due to the large standard errors of the genetic correlation estimates. For ultrasonic backfat depths, the negative estimates of sire variances under restricted feeding prevent calculation of the genetic correlations and conclusions to be made about the sire with feeding regime interaction.

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