Selection for rate and efficiency of lean gain in Hereford cattle. 2. Evaluation of correlated responses

1990 ◽  
Vol 51 (1) ◽  
pp. 35-46 ◽  
Author(s):  
R. A. Mrode ◽  
C. Smith ◽  
R. Thompson
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Conversion Ratio ◽  
Food Conversion ◽  
Correlated Responses ◽  
Selected Lines ◽  
Female Progeny ◽  
Food Conversion Ratio ◽  
Hereford Cattle ◽  
Selection For

ABSTRACTCorrelated responses in two lines of Hereford cattle selected for lean growth rate (LGR) from birth to 400 days of age and lean food conversion ratio (LFCR) from 200 to 400 days of age for a period of 8 years were evaluated. Correlated changes were estimated by two methods: deviation of selected lines from a control line and restricted maximum likelihood. Generally, estimates from the two methods were similar but tended to be more precise for the latter. Statistically significant correlated responses occurred in growth rate in the LGR line and in lean proportion and food conversion ratio in both selected lines. Selection for LGR was accompanied by increases in body weight at various ages in both male and female progeny. In the LFCR line there were little or no changes in body weight for male calves but some increases at certain ages for female progeny. There were no adverse correlated responses detected in reproductive traits such as calving difficulty and calving and pre-weaning mortality.

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.

Selection for components of efficient lean growth in Landrace pigs

1994 ◽  
Vol 1994 ◽  
pp. 10-10
Author(s):  
M.K. Curran ◽  
N.D. Cameron
Keyword(s):  
Growth Rate ◽  
Selection Criteria ◽  
Conversion Ratio ◽  
Control Line ◽  
Food Conversion ◽  
Lean Growth ◽  
Food Conversion Ratio ◽  
Daily Food ◽  
Selection For ◽  
One Year

To study responses to divergent selection for lean growth rate (LGA), lean food conversion ratio (LFC) and daily food intake (DFI), an experiment was started in 1984 at Edinburgh and Wye. 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 Landrace pigs after four generations of selection.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 32, 29 and 270 units and results are presented in s.d. units.Boars and gilts were purchased from eight British nucleus herds and boars from national artificial insemination centres in 1982. Homozygous or heterozygous halothane positive pigs were not included in the experiment. The base population consisted of 20 sires and 89 dams. Within each of the three selection groups, there were high and low selection lines with a control line, each consisting of 10 boars and 20 gilts, with a generation interval of one year. There were two control lines, one for LGA and one for LFC and DFI, as selection groups were arrowed continuously. The total number of pigs tested per line and average inbreeding coefficient at generation 4, within selection group are given below.

Management strategies to maximize pigmeat output: effect of group size and split-marketing

2005 ◽  
Vol 81 (1) ◽  
pp. 171-177 ◽  
Author(s):  
M. K. O'Connell ◽  
P. B. Lynch ◽  
J. V. O'Doherty
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Group Size ◽  
Unit Area ◽  
Live Weight ◽  
Conversion Ratio ◽  
Carcass Weight ◽  
Food Conversion ◽  
Food Conversion Ratio ◽  
2D And 3D

AbstractTwo experiments were completed with grower-finisher pigs to determine if pigmeat output, as measured by carcass gain per m2 per year, could be increased, by 1: increasing group size or 2: split-marketing pen groups. In experiment 1, 390 pigs (mean initial live weight 36·7 (s.d. 1·99) kg) were assigned to one of three treatments each with 10 replicates: 11, 13 or 15 pigs per single-sex group in pens measuring 11·04 m2. Space allowance was 1·00, 0·85 and 0·74 m2 per pig, respectively. Pelleted food was provided ad libitum. There were no differences (P > 0·05) between group sizes in growth rate, food intake, food conversion ratio, carcass growth and carcass food conversion ratio, backfat and muscle depth or carcass lean content. Pigmeat output per unit area increased with each increase in group size (234, 279 and 314 kg/m2 per year for 11, 13 and 15 pigs: P < 0·001). In experiment 2, 26 groups of 13 pigs (mean initial live weight 38·3 (s.d. 2·15) kg) were assigned to one of three treatments: 1D - group sold on 1 day (no. = 9), 2D - group sold over 2 days (14 days apart, no. = 10), or 3D - group sold over 3 days (each 7 days apart, no. = 7). Pigs were given a standard liquid diet three times daily. No differences (P > 0·05) were observed between treatments for overall growth rate, food intake, food conversion ratio, carcass weight, carcass lean content, backfat and muscle depth, carcass growth and carcass food conversion ratio or killing-out proportion of pigs. Split-marketing increased cycle length (67·7, 75·9 and 76·8 days for 1D, 2D and 3D, respectively; P < 0·001). Live and carcass daily growth rates per pig place decreased with increase in number of sale days (live: 772, 680, 670 g/day and carcass: 658, 575, 571 g/day; P < 0·001). Carcass gain per unit area decreased in split-marketed groups (358, 318, 312 kg/m2 per year for 1D, 2D and 3D, respectively: P < 0·05). Carcass weight variation (s.d.) within pen decreased with each increase in number of sale days (s. d. 5·28, 3·81 and 1·74, respectively; P < 0·001). In conclusion, pigmeat output, as measured by carcass gains per m2 per year, was improved with increase in group size and by marketing all pigs in a group on a single day.

Selection for components of efficient lean growth rate in pigs 1. Selection pressure applied and direct responses in a Large White herd

1994 ◽  
Vol 59 (2) ◽  
pp. 251-262 ◽  
Author(s):  
N. D. Cameron
Keyword(s):  
Growth Rate ◽  
Divergent Selection ◽  
Correlated Response ◽  
Food Conversion ◽  
Correlated Responses ◽  
Direct Response ◽  
Large White ◽  
Selection For ◽  
The Difference ◽  
And Control

AbstractResponses to four generations of divergent selection for lean groivth rate with ad-libitum feeding (LGA), for lean food conversion (LFC) and for daily food intake (DFI) in Large White pigs were studied. The LGA (LFC) selection criterion was designed to obtain equal correlated responses in growth rate (food conversion ratio) and carcass lean content, measured in phenotypic s.d. The selection criteria had phenotypic s.d. of 27, 29 and 253 units, respectively, and results are presented in s.d. units. There was a total of 3537 pigs, with an average of 40 boars and 40 gilts performance tested in each of the high, low and control lines per generation and the lines consisted of 10 sires and 20 dams. The generation interval was equal to 13·5 months. Animals were performance tested in individual pens with mean starting and finishing weights of 30 kg and 85 kg respectively.Cumulative selection differentials in the three selection groups were 5·8, 3·6 and 3·3 phenotypic s.d. for LGA, LFC and DFI respectively. Direct responses to divergent selection were 1·7, 1·3 and 1·2 (s.e. 0·17) for LGA, LFC and DFI. The correlated response in LFC (1·6 (s.e. 0·18)) with selection on LGA was greater than the direct response in LFC. Conversely, the direct response in LGA was greater than the correlated response (1·1 (s.e. 0·18)) with selection on LFC. The response in LFC (–1·1 (s.e. 0·17)) with selection on DFI was similar in size but opposite in sign to the direct response in LFC. Responses were asymmetric about the control, as the high LGA and LFC responses were proportionately smaller (0·74 and 0·58) than low line responses. In contrast, the difference between the high DFI and control was four times greater than the difference between low line and control.Heritabilities of LGA, LFC and DFI were 0·38, 0·35 and 0·29 (s.e. 0·03), when estimated by residual maximum likelihood, with common environmental effects of 0·09 (s.e. 0·02). Genetic correlations for LGA with LFC and DFI were positive, 0·76 (s.e. 0·03) and 0·23 (s.e. 0·07), but the genetic correlation between DFI and LFC was negative, –0·45 (s.e. 0·06). The experiment demonstrated that substantial responses to selection can be achieved in LGA, LFC and DFI. Selection on LGA resulted in larger direct and correlated responses than selection on LFC.

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.

scholarly journals Determination of Suitable Water Salinity and Live Food in The Rearing of Eel (Anguilla bicolor) Fry

2008 ◽  
Vol 7 (1) ◽  
pp. 71
Author(s):  
. Sutrisno
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Conversion Ratio ◽  
Live Food ◽  
Water Salinity ◽  
Food Conversion ◽  
Food Conversion Ratio

<p>This study was conducted to determine suitable water salinity and live food in the rearing of eel,  <em>Anguilla bicolor </em>fry.  Eel fry in weight of 0.15±0.008 g/tail were reared at controlled tank at density of 2 fish liter<sup>-1</sup> for 42 days.  Experiment was devided into two steps.  In the first step of experiment, eel fry were reared at different water salinity, i.e., 0; 5; 10 and 15 ppt.  Fish were fed on <em>Tubifex</em> at satiation.  The best result from the first experiment was then used in the second step of study to examine proper live food for eel fry.  Fish were fed on live food (<em>Tubifex</em>, <em>Artemia</em>, or <em>Spirulina</em>) at 10% body weight.  Survival rate, specific growth rate and food conversion ratio were observed.  The result of experiment showed that survival rate of eel fry reared in water salinity of 5 ppt (100%), 10 (96%) and 15 ppt (97%) was higher (p<0.05) compared to that of 0 ppt (58%).  Specific growth rate was also higher (p<0.05) in fish reared in water salinity of 5 (2.33%), 10 (1.65%) and 15 ppt (1.57%) compared to that of 0 ppt (0.022%).  Survival rate and specific growth rate of fish at treatment of 5, 10 and 15 ppt were insignificantly different (p>0.05).  The best food conversion ratio was also being obtained at treatment of 5 ppt (3.36), followed repectively by 10 ppt (5.11), 15 ppt (5.70) and 0 ppt (21.11).  No different survival rate of eel fry by feeding on different live food was obtained.  Higher specific growth rate was achieved at feeding of <em>Artemia</em> (2.82% per day), followed respectively by <em>Tubifex </em>(1.85% per day) and <em>Spirulina </em>(0.15% per day).  Food coversion ratio in each treatment was 4.42, 2.77 and 134.33, respectively.</p> <p>Keywords:  eel, salinity, live food</p> <p> </p> <h5>ABSTRAK</h5> <p>Penelitian dilakukan dengan tujuan untuk mengetahui salinitas air dan jenis pakan alami yang tepat dalam pemeliharaan benih ikan sidat <em>(Anguilla bicolor)</em>. Benih sidat dengan berat rata-rata 0,15±0,008 g/ekor dipelihara selama 42 hari pada wadah terkontrol dengan kepadatan 2 ekor/liter. Penelitian dibagi kedalam dua tahap. Pada tahap pertama benih sidat diperlihara pada media dengan salinitas 0; 5, 10 dan 15 ppt.  Pakan alami berupa cacing sutera diberikan secara satiasi.  Salinitas terbaik hasil penelitian tahap pertama digunakan pada penelitian tahap kedua untuk mengetahui jenis pakan alami (cacing sutera <em>Tubifex</em>, <em>Artemia</em>, atau <em>Spirulina</em>) yang cocok untuk benih sidat.  Pakan diberikan sebanyak 10% bobot tubuh.   Paramater yang diamati meliputi sintasan, laju pertumbuhan spesifik dan efisiensi pakan.  Hasil penelitian menunjukkan  bahwa sintasan benih ikan sidat yang dipelihara pada salinitas 5 (100%), 10 (96%) dan 15 ppt (97%) lebih tinggi (p<0,05) daripada yang dipelihara pada salinitas 0 ppt (58%).  Laju pertumbuhan spesifik juga lebih tinggi (p<0,05) pada benih yang dipelihara pada salinitas 5 (2,33%), 10 (1,65%) dan 15 ppt (1,57%) dibandingkan dengan salinitas 0 ppt (0,022%).  Sintasan dan laju pertumbuhan spesifik antara perlakuan 5, 10 dan 15 ppt tidak berbeda nyata (p>0,05). Konversi pakan terbaik juga diperoleh pada perlakuan 5 ppt (3,36), diikuti berturut-turut 10 ppt (5,11), 15 ppt (5,70) dan 0 ppt (21,11).  Pemberian pakan alami yang berbeda tidak berpengaruh terhadap sintasan benih sidat, tetapi berpengaruh terhadap pertumbuhan.  Pemberian <em>Artemia</em> memberikan laju pertumbuhan spesifik tertinggi, yaitu 2,82%/hari, <em>Tubifex </em>(1,85%/hari) dan <em>Spirulina </em>(0,15%/hari).  Konversi pakan tiap perlakuan berturut-turut adalah  4,42; 2,77 dan 134,33.</p> Kata kunci:  ikan sidat, salinitas, pakan alami

scholarly journals EFFECT OF STOCKING DENSITY ON GROWTH PERFORMANCE OF DOMESTICATED BARB (Barbonymus balleroides)

2017 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Otong Zenal Arifin ◽  
Jojo Subagja ◽  
Vitas Atmadi Prakoso ◽  
Endang Haris Suhud
Keyword(s):  
Body Weight ◽  
Survival Rate ◽  
Stocking Density ◽  
Conversion Ratio ◽  
Food Conversion ◽  
Daily Growth ◽  
Food Conversion Ratio ◽  
Best Value ◽  
Growth Performances ◽  
Dimension 2

Barb (Barbonymus balleroides) considerably has economic potential as aquaculture commodity. However, there was still lack of development on aquaculture for this species. This study was conducted to observe the effect of different stocking density on growth of barb. The fish (body weight: 14.89 ± 0.13 g) were stocked in nine floating nets (dimension: 2 m x 2 m x 1 m) inside the concrete ponds with three stocking density treatments (10, 15, and 20 fish/m3). Each treatment consisted of three replications. Fish were fed on commercial pellet (30% of crude protein) as much as 3% of the biomass per day with twice a day of feeding frequency. Data of growth performances (body weight, specific growth rate, average daily growth, biomass, food conversion ratio, and survival rate) were collected every 30 days during 90 days of rearing period. Water quality variables (temperature, pH, and dissolved oxygen) were observed during experiment. The results showed that the optimal stocking density for the growth of barb was 10 fish/m3. Best value of food conversion ratio was found 10 fish/m3 compared with 15 and 20 fish/m3 (P<0.05). Meanwhile, there were no significant differences on survival rate between treatments. These results also showed the potential of rearing barb on culture ponds with appropriate stocking density.

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