scholarly journals Study of failures in a rabbit line selected for growth rate

2016 ◽  
Vol 24 (1) ◽  
pp. 47 ◽  
Author(s):  
C. Naturil-Alfonso ◽  
R. Lavara ◽  
P. Millán ◽  
P.G. Rebollar ◽  
J.S. Vicente ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Luteinizing Hormone ◽  
Ovulation Induction ◽  
Thickness Measurement ◽  
Live Body Weight ◽  
Lh Release ◽  
Fat Thickness ◽  
Selection For ◽  
Perirenal Fat

<p>Selection for growth rate is negatively related with reproductive fitness. The aim of this work was to analyse the causes of fertility failure in rabbit does selected for growth rate and characterised for reproductive deficiencies (line R). In the experiment, 82 does were divided into 2 groups: naturally mated (NM) and artificially inseminated (AI), to relate luteinizing hormone (LH) concentration with ovulation induction and pregnancy rate by laparoscopic determination. Additionally, in 38 of these females ovulation rate and metabolites determination (leptin, NEFA, BOHB and glucose) were analysed and perirenal fat thickness measurement and live body weight (LBW) determined. The results showed that all ovulated does (both NM and AI) presented higher concentrations of LH than non-ovulated females. In addition, non-ovulated females showed high levels of leptin and BOHB, as well as LBW. Females from line R have an inherit reduced fertility due to ovulation failure as a consequence of a reduction in LH release, which could be explained by a heavier body weight and higher leptin concentrations.</p>

scholarly journals Effect of restricted feeding under rearing on reproduction, body condition and blood metabolites of rabbit does selected for growth rate

2017 ◽  
Vol 25 (4) ◽  
pp. 303 ◽  
Author(s):  
C. Naturil-Alfonso ◽  
F. Marco-Jiménez ◽  
J.J. Pascual ◽  
J.S. Vicente
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Litter Size ◽  
Body Condition ◽  
Reproductive Cycle ◽  
Reproductive Performance ◽  
Young Rabbit ◽  
Fat Thickness ◽  
Ad Libitum ◽  
Perirenal Fat

Young rabbit females selected for growth rate can have nutritional needs which may not be met by the common practice of feed restriction during rearing in commercial rabbit production. The aim of this study was to analyse the effect of two different feeding programmes: restricted and ad libitum feeding, applied in young rabbit females for one month at the end of rearing, on reproductive performance, body condition and circulating metabolic hormones and metabolites in a rabbit line selected by growth rate in 3 consecutive reproductive cycles. Thus, twenty-four 16-week-old does were randomly assigned to a group in which the daily recommended nutrient intakes were satisfied (fed restricted: 130 g/day, n=13) or a group fed to satiety (ad libitum: 235.5 g/day, n=11) during one month. Then, all does were inseminated in 3 consecutive cycles using a 42-day reproductive cycle. Measurements of does’ body weight, perirenal fat thickness and plasma leptin, non-esterified-fatty-acids (NEFA), beta-hydroxybutyrate (BOHB) and fructosamine were performed at artificial insemination (AI), parturition and weaning time in 3 consecutive cycles. Reproductive performance of does was evaluated based on fertility, litter size at parturition, prolificacy and productivity. Differences in body weight were found only in the 1<sup>st</sup> cycle, ad libitum fed females being heavier than restricted ones. Nevertheless, body weight variances disappeared in later cycles. No differences were found in perirenal fat thickness. Finally, in ad libitum fed females slight differences were found in plasma levels of NEFAs (452 vs. 258 μekv/L and 527 vs. 306 μekv/L for 1<sup>st</sup> and 2<sup>nd</sup> cycles) and BOHB (0.26 vs. 0.03 mM for 2<sup>nd</sup> cycle), but disappeared in the 3<sup>rd</sup> reproductive cycle. Fertility, prolificacy and productivity was not significantly affected by the feeding programme. Nevertheless, total litter size showed to be higher in ad libitum fed females at second parturition (8.7 vs. 5.9 kits). Therefore, the evaluated feeding programmes until first AI in females selected by growth rate had no effect on their reproductive outcomes, as the global reproductive performance was not affected.

scholarly journals Selection for higher body weight in Nelore cattle is effective in achieving an increase of longissimus muscle area without reducing subcutaneous fat thickness

2012 ◽  
Vol 41 (6) ◽  
pp. 1426-1432 ◽  
Author(s):  
Tiago Roque Pinheiro ◽  
Maria Eugênia Zerlotti Mercadante ◽  
Lucia Galvão de Albuquerque ◽  
Sarah Figueiredo Martins Bonilha ◽  
Fábio Morato Monteiro
Keyword(s):  
Body Weight ◽  
Subcutaneous Fat ◽  
Longissimus Muscle ◽  
Muscle Area ◽  
Subcutaneous Fat Thickness ◽  
Fat Thickness ◽  
Selection For ◽  
Nelore Cattle

Sex effects on fat hardness meter readings of market weight pigs

1995 ◽  
Vol 75 (4) ◽  
pp. 509-515 ◽  
Author(s):  
A. P. Sather ◽  
S. D. M. Jones ◽  
W. M. Robertson ◽  
Sophie Zawadski
Keyword(s):  
Growth Rate ◽  
Growth Rate Constant ◽  
Quadratic Term ◽  
Cross Sectional ◽  
Linear Interaction ◽  
Fat Quality ◽  
Lean Growth ◽  
Fat Thickness ◽  
Selection For ◽  
Sectional Surface

A portable fat hardness meter (FHM) was used to measure the firmness of the inner fat layer on a cross sectional surface over the second thoracic vertebra of pork carcasses. This was a 4-yr study with data collected on 141 barrows, 214 gilts and 270 boars. A statistical model, after adjusting for year and breed of sire (i.e., Lacombe, Landrace, Yorkshire), included sex, linear and quadratic covariates for carcass growth rate (i.e., carcass weight per day of age), a linear covariate for leanness (i.e., carcass fat thickness or dissectible lean) within sex, and a linear by linear covariate of growth rate by leanness, and was used to describe a response surface with fat hardness. No pigs in this study had extremely soft fat (i.e., FHM < 420). However, 4, 2 and 0% of the boars, gilts and barrows had very soft fat (i.e., FHM 420–619). While 10% of the barrows had extremely hard (i.e., FHM > 970) or very hard fat (i.e., FHM 930–970), only 1% of the gilts had very hard fat, and no boars were included in these classes. Relative to the FHM readings of gilts (i.e., 805 ± 6.2), boars (i.e., 780 ± 5.6) had softer fat (P = 0.0002) while barrows (i.e., 835 ± 7.4) had harder fat (P = 0.0001). The majority of boars had slightly soft fat (i.e., FHM 750–829) while gilts and barrows had slightly hard (i.e., FHM 830–889) fat. Regression coefficients for growth rate on fat hardness were homogeneous among the sexes. As growth rate increased fat hardness increased, but was attenuated by a negative quadratic term. Increased leanness was linearly antagonistically related with fat hardness. There were differential effects across sexes (P = 0.0261). As leanness increased, fat became softer among boars and gilts compared with barrows. A linear by linear interaction of growth rate with leanness attenuated this effect. Holding growth rate constant, a 25% reduction of carcass fatness would be expected to reduce fat hardness by 40, 35 and 20 points in boars, gilts, and barrows, respectively. While selection for increased lean growth may result in some degradation in fat quality, the trend towards marketing heavy pigs as they become leaner should be sufficient to offset this effect. Key words: Swine, carcass, grading, growth rate, fat, lean

scholarly journals The performance testing of boars II. Phenotypic and genetic correlations

1971 ◽  
Vol 43 (2) ◽  
pp. 103-110
Author(s):  
Elsi Ettala
Keyword(s):  
Growth Rate ◽  
Total Variation ◽  
Feed Efficiency ◽  
Genetic Correlations ◽  
Performance Testing ◽  
Stepwise Multiple Regression ◽  
Daily Growth ◽  
Fat Thickness ◽  
Selection For ◽  
Different Characteristics

In this study the interrelationships between the various characteristics for the boar material described in the first part were analysed. For this purpose the phenotypic, genetic and intra-sire correlation matrix as well as stepwise multiple regression analyses were calculated by computer for the material of 138 boars. The results showed that there was a very strong correlation between fat thickness and testing score (rG = —0.95***, rP = —0.88***). Of the total variation in the testing score 85.2 % was accounted for by the variation in fat thickness. Although the testing score is made up of the points for fat thickness and growth, the latter accounted for only 9.2 % of the variation in the score. Daily growth was positively associated with the testing score and negatively with the amount of feed units required per growth kilogram, but significantly so only for the intra-sire correlations; the genetic correlations being even, contrary to expectation. The association between growth rate and fat thickness was positive (rG = 0.47***). Of the total variation in feed efficiency the testing score accounted for 35.6 %. A high testing score was associated with a favourable feed efficiency (rg = —0.63***). By correlation studies attempts were also made to find out whether it would be possible to shorten the testing period without decreasing the accuracy. The correlations show that the growth rate can be predicted with an appreciable degree of accuracy already from the weight at the 8th testing week. The correlations between the above weight and growth rates were; rG = 0.84***, rP = 0.82***. From the associations between different characteristics one can decide on the suitability of testing and the consequences of selection for particular traits.

scholarly journals Production and body composition traits of broilers in relation to breast weight evaluated by path analysis

2011 ◽  
Vol 68 (3) ◽  
pp. 320-325 ◽  
Author(s):  
Leandro Homrich Lorentz ◽  
Leila de Genova Gaya ◽  
Raquel Lunedo ◽  
José Bento Sterman Ferraz ◽  
Fernanda Marcondes de Rezende ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Path Analysis ◽  
Partial Correlation ◽  
Correlation Coefficients ◽  
Breast Muscle ◽  
Live Body Weight ◽  
The Matrix ◽  
Selection For ◽  
Breast Weight

Breast weight has great economic importance in poultry industry, and may be associated with other variables. This work aimed to estimate phenotypic correlations between performance (live body weight at 7 and 28 days, and at slaughter, and depth of the breast muscle measured by ultrasonography), carcass (eviscerated body weight and leg weight) and body composition (heart, liver and abdominal fat weight) traits in a broiler line, and quantify the direct and indirect influence of these traits on breast weight. Path analysis was used by expanding the matrix of partial correlation in coefficients which give the direct influence of one trait on another, regardless the effect of the other traits. The simultaneous maintenance of live body weight at slaughter and eviscerated body weight in the matrix of correlations might be harmful for statistical analysis involving systems of normal equations, like path analysis, due to the observed multicollinearity. The live body weight at slaughter and the depth of the breast muscle as measured by ultrasonography directly affected breast weight and were identified as the most responsible factors for the magnitude of the correlation coefficients obtained between the studied traits and breast weight. Individual pre-selection for these traits could favor an increased breast weight in the future reproducer candidates of this line if the broilers' environmental conditions and housing are maintained, since the live body weight at slaughter and the depth of breast muscle measured by ultrasonography were directly related to breast weight.

scholarly journals Effect of Saccharomyces cerevisiae dried yeast on the meat performance traits and selected indicators of humoral immunity in lambs

2013 ◽  
Vol 82 (2) ◽  
pp. 147-151 ◽  
Author(s):  
Stanisław Milewski ◽  
Roman Wójcik ◽  
Bożena Zaleska ◽  
Joanna Małaczewska ◽  
Zenon Tański ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Body Weight ◽  
Humoral Immunity ◽  
Longissimus Dorsi ◽  
Serum Concentrations ◽  
Performance Traits ◽  
Fat Thickness ◽  
Ceruloplasmin Activity ◽  
Experimental Group

The aim of this study was to determine the effect of Saccharomyces cerevisiae on indicators of meat performance traits in sheep as well as on selected non-specific indicators of humoral and cellular defense. The experiment was performed on 32 suckling Kamieniec lambs divided into two equal groups (control and experimental). Over a period of 60 days, experimental group of lambs were fed a diet supplemented with Saccharomyces cerevisiae dried yeast (the yeast supplement did not change the value of the feed ration). The following meat performance indicators were determined: body weight, daily gains, growth rate, the dimensions of musculus longissimus dorsi sections, skin and subcutaneous fat thickness and fat thickness over the loin “eye” area. Selected indicators of non-specific humoral immunity (lysozyme activity, ceruloplasmin activity, total protein and gamma globulin content) were determined in the blood serum of lambs. Compared to control, yeast administered to the experimental group of lambs significantly increased the values of the analyzed meat performance traits i.e. body weight, growth rate, musculus longissimus dorsi dimensions (P ≤ 0.05) and daily gains (P ≤ 0.01), pointing to improved muscle development. Lambs fed the yeast showed a significant (P ≤ 0.01) increase in lysozyme and ceruloplasmin activity and increased serum concentrations of gamma globulins. Significant differences between the experimental and control groups were not observed only with respect to the serum concentrations of total protein. Suuplementing the lambs’ feed with yeast had a positive effect on meat performance traits and indicators of humoral immunity.

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.

Sign in / Sign up

Export Citation Format

Share Document