ALTERNATIVE SELECTION CRITERIA FOR THE GENETIC IMPROVEMENT OF FEED EFFICIENCY IN BROILER CHICKENS

1988 ◽  
Vol 68 (3) ◽  
pp. 611-618
Author(s):  
L. N. IRWIN ◽  
G. W. FRIARS ◽  
R. J. JULIAN

A hierarchical mating of 25 sires and 192 dams produced 862 progeny that yielded complete records to market age in two hatches of broiler chickens. These progeny were housed in two levels of cages. Half of the birds were subjected to a compensatory feed treatment which was used as an indicator of appetite. Increased feed consumption, following fasting, resulted in increased deposition of abdominal fat. Various approaches were investigated with respect to maximizing the genetic improvement of feed efficiency. Estimates of the heritabilities of feed:gain, gain:feed, total feed intake, compensatory feed intake and compensatory gain were all low (0.24 or less), with generally high standard errors. The estimated heritabilities of gain and gain corrected for feed intake at 0.46 suggests that selection for the latter trait has potential for improving gain at a statistically fixed feed intake. The standard errors on estimates of genetic correlations were too wide to allow predicted selection changes in correlated traits, and thus these correlations were not presented. Key words: Broiler chickens, feed efficiency, compensatory feed intake, abdominal fat deposition

1999 ◽  
Vol 1999 ◽  
pp. 47-47
Author(s):  
R.M. Herd ◽  
S.C. Bishop

Net feed efficiency refers to variation in feed consumption between animals net of requirements for maintenance and production, and may be measured as residual feed intake (RFI). Because RFI is independent of liveweight (LW) and growth rate, selection for improved net feed efficiency is likely to reduce feed intake with little change in growth. The purpose of this study was to establish whether there exists genetic variation in RFI in young British Hereford bulls, and to determine the phenotypic and genetic correlations of RFI with key production traits.The data consisted of performance measurements on 540 bull progeny of 154 British Hereford sires, collected over ten 200-day postweaning performance tests conducted between 1979 and 1988. The traits analysed were food intake (FI), 200 to 400-day daily gain (ADG), 400-day weight (W400), predicted carcass lean content (LEAN), lean growth rate (LGR), food conversion ratio (FI/ADG) and lean FCR (LFCR; FI/(ADG x LEAN), described by Bishop (1992).


1996 ◽  
Vol 76 (1) ◽  
pp. 81-87 ◽  
Author(s):  
L. Q. Fan ◽  
J. W. Wilton ◽  
P. E. Colucci

Genetic parameters of feed intake and efficiency and production traits for lactating beef cows were estimated from data collected from 1980 to 1988 at the Elora Beef Research Centre, Guelph, Ontario. Estimates were obtained using restricted maximum likelihood (REML) with an individual animal model with year–season–treatment, sex of calf, parity, breeding system, covariate daily change of backfat depth and direct genetic and permanent environmental effects. The data included 1174 observations, 511 cows, 369 dam–maternal grand dam pairs and 245 sires of cows. Feed efficiency for milk was calculated as milk yield relative to energy consumed for milk and maintenance and residual feed consumption as estimated energy intake minus energy requirements as estimated by the National Research Council. Heritabilities for Herefords alone and total data, respectively, were estimated to be 0.02 and 0.11 for cow's daily ME intake (MEI), 0.26 and 0.26 for daily milk yield (DMY), 0.45 and 0.33 for milk fat percentage (MFP), 0.29 and 0.40 for metabolic body weight (MBW), 0.21 and 0.10 for calf weaning weight as a proportion of cow weight at weaning (PPW), 0.18 and 0.11 for feed efficiency for milk (FE), and 0.23 and 0.03 for residual feed consumption (RFC). Genetic correlations of output (DMY) and input (MEI) were 0.31 for Hereford and 0.75 for the total data. Genetic correlations of RFC with both output (DMY) and input (MEI) were low. Genetically, PPW was positively associated with FE and DMY and negatively associated with MBW. Key words: Genetic parameters, feed efficiency, lactation, beef cow


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P > 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P < 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.


2002 ◽  
Vol 2002 ◽  
pp. 84-84
Author(s):  
A. Hassanabadi ◽  
A. golian

Purpose of researches in feed restriction area is improvement of feed efficiency, decrease of carcass fat content and abdominal fat pad size (Plavnik and Hurvitz,1991).Birds after early life feed restriction have less maintenance requirements due to decrease of heat increment and decrease of basal metabolic rate and specific dynamic action of food (Forsum et al.,1981).In many investigations, compensatory growth have not observed (Summers et al.,1990).It seems administration of Thyroid hormone after feed restriction can induce compensatory growth. The objective of the present study was to investigate the effect of early feed restriction and L-Thyroxin administration after early feed restriction on compensatory growth in broiler chickens.


1999 ◽  
Vol 79 (4) ◽  
pp. 425-431 ◽  
Author(s):  
B. W. Kennedy ◽  
J. C. M. Dekkers ◽  
R. K. Moore ◽  
L. Jairath

Production and feed intake data on 36 115 first lactation Holstein cows obtained from Quebec Dairy Herd Analysis Service were combined with conformation data from the Holstein Association of Canada to estimate genetic correlations among production, energy intake, and conformation traits. Traits considered were 305-d milk yield, 305-d grain energy and total energy intake, feed efficiency (fat corrected milk yield/total energy intake), body weight at calving, capacity, size, stature, rump width and final score. Genetic and phenotypic parameters were estimated using Restricted Maximum Likelihood based on two-trait animal mixed model analyses. The model contained fixed effects of herd-year, season of calving, age of calving, sire group and a random animal genetic effect. Estimates of heritability were within the published range for all traits. Of the conformation traits examined, capacity, size and stature had the highest correlations with body weight, with phenotypic correlations between 0.36 and 0.43, and genetic correlations between 0.61 and 0.79. Feed efficiency was negatively correlated to all body size measures, both phenotypically (−0.01 to −0.29) and genetically (−0.31 to −0.53), but most significantly with body weight, capacity, size, and stature. Fat-corrected milk yield showed negligible phenotypic and low to moderately negative genetic (−0.07 to −0.29) correlations with body weight and related type traits. Total energy intake was positively related to all measures of body size, most notably body weight, while grain energy intake had moderately negative genetic correlations (−0.20 to −0.40) with the same body size traits. Because of their detrimental relationships with feed efficiency, negative selection emphasis should be placed on body weight and the related type traits capacity, size and stature. Capacity, size and stature are of moderate utility when selecting indirectly for body weight, total energy intake and feed efficiency. Key words: Dairy cattle, genetics, production, conformation, feed efficiency


2016 ◽  
Vol 18 (1) ◽  
pp. 30 ◽  
Author(s):  
Laurentius Rumokoy ◽  
Endang Pudjihastuti ◽  
Ivonne Maria Untu ◽  
Wisje Lusia Toar

This study was conducted to evaluate the effects of papain crude extract addition in mash and pellet feed forms on production performance of broiler chickens in order to obtain the best level of extract papain in mash or pellet form. This natural protease enzyme was extracted from unripe papaya. A complete random design was applied in this study and it was arranged with factorial 4 * 2 and three replications. The treatments were 4 levels of papain (0, 0.03, 0.05, and 0.07 %) and two physical forms of feed (mash and pellet). Broilers production parameters measured were: feed intake, body weight, feed conversion ratio (FCR) and carcass percentage. The results of analysis of variance showed that the interaction was highly significant (P <0.01) for feed intake, body weight, carcass percentage respectively while feed conversion showed significant interaction (P <0.05). The significant differences in the feed consumption described the role of papain enzyme through treatment of CEP and the physical form of feed. The results indicate that the all treatment of papain crude extract level  both in mash and pellet feed form were able to improve feed intake, body weight, FCR and carcass percentage of broiler chickens, whereas the best performance was obtained in the treatment of 0.05% papain crude extract in mash form of diets.


2018 ◽  
Vol 6 (2) ◽  
pp. 174-180
Author(s):  
D. Rawat ◽  
R. Shah ◽  
D.B. Nepali ◽  
J.L. Yadav

An experiment was conducted, with objective to determine the feed consumption, final live weight, weight gain, feed efficiency and economy in broiler chicken fed with locally available low protein based diets (20 percent CP in starter and 18 percent CP in finisher) supplemented with methionine, lysine and homeopathic medicine alfalfa. For this hundred fifty day-old birds of commercial broiler (Vencobb) were randomly assigned to five dietary treatments(10 chicks/treatment) and replicated three times in CRD with treatments composition of low protein based diets (LPB)  (T0), LPB+ 100g/100 met + 300g/100  lysine (T1), LPB + 200g/100 met +300g/100lysine (T2), LPB + Alfalfa 5ml/100 chicks 2 day in week with drinking water (T3) and LPB + Alfalfa 5ml/100 chicks 3 day in week with drinking water (T4). Synthetic methionine and lysine was used for supplementation of deficient amino acid. Same condition was applied in finisher diets of broiler chicken. The result showed that chicks fed with LPB in both starter and finisher diet had significantly (P<0.05) lower feed intake, final live weight , total weight gain, feed efficiency and income over feed and chicks cost (IOFCC) with compromising chicks fed with LPB with addition of methionine and lysine each and also homeopathic medicine alfalfa in starter and finisher period. Highest feed intake, final live weight, weight gain, feed efficiency was obtained with treatment (T1) followed by treatment (T2). However, positive growth response and better health status of chicks was also observed from supplementation of homeopathic medicine alfalfa with LPB and non-significant difference on Income Over Feed and Chicks Cost was obtained with treatment (T1). So, it was concluded that with supplemental methionine, lysine and alfalfa, the CP level of broiler chicks could be reduced up to 20 percent in starter and 18 percent in finisher diets without adverse effect on feed intake, final live weight, weight gain, feed efficiency and Income overfeed and chicks cost, provided under locally based feed ingredients.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 174-180 


2001 ◽  
Vol 52 (4) ◽  
pp. 471 ◽  
Author(s):  
P. F. Arthur ◽  
G. Renand ◽  
D. Krauss

Data on young Charolais bulls were used to evaluate the effect of age of dam, and provide genetic parameter estimates for growth and feed efficiency traits in weaners compared with yearlings. Records on 510 performance test bulls born from 1985 to 1989 and 792 progeny test bulls born from 1988 to 1997 were used, plus available pedigree information (total n = 5493). After weaning (approximately 225 days of age), progeny test bulls were housed in barns and tested until 15 months for all bulls and 19 months of age for half of the bulls. From the records, the test period was artificially partitioned into a weaner and a yearling test. Both tests were for 140 days, with the weaner test commencing at approximately 274 days of age (6–8 weeks after weaning), and the yearling test commencing at approximately 430 days of age. For each test (weaner or yearling), average daily gain, daily feed intake, feed conversion ratio (feed intake per unit weight gain), and residual feed intake (feed intake net of the expected requirements for growth and maintenance) were calculated. Liveweights at 12 and 18 months of age were also studied. Age of dam effect was significant (P < 0.05) for weight at 12 and 18 months of age, and for all weaner traits except residual feed intake. All the traits studied were moderately heritable (0.20–0.46) except for feed conversion ratio in yearlings (0.10). Genetic correlations for the same traits measured in weaners and later in yearlings were less than unity (0.42–0.95), with the 3 highest correlations obtained for weight (0.950.03), feed intake (0.900.07), and residual feed intake (0.750.12). Therefore, for genetic improvement purposes, traits measured in weaners should be considered different from those measured in yearlings, except for weight and feed intake. However, the medium to very high genetic correlations between weaner and yearling tests for most of the traits studied indicate that selection based on weaners will have a positive correlated response in yearlings and vice versa.


2008 ◽  
Vol 51 (4) ◽  
pp. 366-371 ◽  
Author(s):  
R. Wassmuth ◽  
E. Gernand ◽  
H. Lenz ◽  
C. Mendel

Abstract. Title: Feed intake and eating behaviour of growing lambs, 1st communication: heritabilities and genetic correlations In the test stations “Grub” (Bavaria) and “Schöndorf” (Thuringia) data were collected on lambs of the breeds Merinolandschaf and Merino Longwool. Feed intake during the whole test period (FAP), feed efficiency (FAW), daily feed intake (TFM), the number of daily visits (TBH) and eating time (TBD) of lambs were measured. In total, data from 1,608 lambs with 37,161 daily records in “Grub” and 1,424 lambs with 35,356 daily records in “Schöndorf” were included. The aim of the present study was to estimate heritabilities and genetic correlations for different traits of feed intake and eating behaviour. In “Schöndorf” the heritability of FAP and FAW was 0.29 and 0.32, respectively. In the test station “Grub” the heritability of the same traits was 0.58 and 0.57, respectively. The heritability of TBH, TBD and TFM were 0.33, 0.25 and 0.05, respectively, in “Schöndorf” and 0.49, 0.36 and 0.10, respectively, in “Grub”. The genetic correlations between the eating behaviour traits TBH and TBD on one hand and feed intake (FAP, FAW, TFM) on the other hand were low. It could be concluded that feed intake as well as eating behaviour showed considerable variances and heritabilities. Further, eating behaviour was not a good indicator of feed intake.


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