Correlated response to selection for litter size environmental variability in rabbits' resilience.

Resilience is the ability of an animal to return soon to its initial productivity after facing diverse environmental challenges. This trait is directly related to animal welfare and it plays a key role in fluctuations of livestock productivity. A divergent selection experiment for environmental variance of litter size has been performed successfully in rabbits over ten generations.

Characteristics of ripened Tronchón cheese from raw goat milk containing legally admissible amounts of antibiotics.

The aim of this study was to evaluate the transfer of the most widely used antibiotics in dairy goats from milk to cheese as well as their effect on the cheese-making process and cheese characteristics during ripening. Antibiotic-free milk was spiked individually with 7 veterinary drugs (amoxicillin, benzylpenicillin, cloxacillin, erythromycin, ciprofloxacin, enrofloxacin, and oxytetracycline) at an equivalent concentration of the European Union maximum residue limit. Spiked goat milk was used to make mature Tronchón cheeses, which were analyzed at 0, 30, and 60 d of maturation to determine pH, chemical composition, proteolytic and lipolytic activities, and color and textural properties.

Five genomic regions have a major impact on fat composition in Iberian pigs.

The adipogenic nature of the Iberian pig defines many quality attributes of its fresh meat and dry-cured products. The distinct varieties of Iberian pig exhibit great variability in the genetic parameters for fat deposition and composition in muscle. The aim of this work is to identify common and distinct genomic regions related to fatty acid composition in Retinto, Torbiscal, and Entrepelado Iberian varieties and their reciprocal crosses through a diallelic experiment.

Spatio-temporal and risk factor analysis of alleles related to Scrapie resistance in sheep in Great Britain before, during and after a national breeding program.

Certain genotypes of sheep have been identified to increase their susceptibility (the VRQ allele) or resistance (the ARR allele) to classical scrapie. This study's aim was to assess the spatio-temporal pattern of the ARR and VRQ alleles in Great Britain (GB) and to explore the risk factors associated to their presence. Data was collected from the GB scrapie active surveillance program, the sheep and goat inventory survey (GB census survey) and the agricultural survey for the period 2002-2015.

Breeding for robustness: investigating the genotype-by-environment interaction and micro-environmental sensitivity of Genetically Improved Farmed Tilapia (Oreochromis niloticus).

Robustness has become a highly desirable breeding goal in the globalized agricultural market. Both genotype-by-environment interaction (G × E) and micro-environmental sensitivity are important robustness components of aquaculture production, in which breeding stock is often disseminated to different environments. The objectives of this study were (i) to quantify the degree of G × E by assessing the growth performance of Genetically Improved Farmed Tilapia (GIFT) across three countries (Malaysia, India and China) and (ii) to quantify the genetic heterogeneity of environmental variance for body weight at harvest (BW) in GIFT as a measure of micro-environmental sensitivity.

Correlated responses to selection for intramuscular fat in several muscles in rabbits.

The aim of this study was to evaluate the effect of six generations of selection for intramuscular fat (IMF) in muscle Longissimus thoracis et lumborum (LTL) at 9 wk. in IMF and fatty acid (FA) composition of muscles with diverse metabolic profile in rabbits. Direct response to selection was 0.

Effect of selection for intramuscular fat on the fatty acid composition of rabbit meat.

Intramuscular fat (IMF) content and composition are relevant for the meat industry due to their effect on human health and meat organoleptic properties. A divergent selection experiment for IMF of Longissimus dorsi (LD) muscle was performed in rabbits during eight generations. The aim of this study is to estimate the correlated responses to selection for IMF on the fatty acid composition of LD.

Correlated response in litter size components in rabbits selected for litter size variability.

A divergent selection experiment for the environmental variability of litter size (Ve) over seven generations was carried out in rabbits at the University Miguel Hernández of Elche. The Ve was estimated as the phenotypic variance within the female, after correcting for year-season and parity-lactation status. The aim of this study was to analyse the correlated responses to selection in litter size components.

Selection for environmental variance of litter size in rabbits.

Background: In recent years, there has been an increasing interest in the genetic determination of environmental variance. In the case of litter size, environmental variance can be related to the capacity of animals to adapt to new environmental conditions, which can improve animal welfare.

Results: We developed a ten-generation divergent selection experiment on environmental variance.

Embryologic changes in rabbit lines selected for litter size variability.

A divergent selection experiment on litter size variability was carried out. Correlated response in early embryo survival, embryonic development, size of embryos, and size of embryonic coats after four generations of selection was estimated. A total of 429 embryos from 51 high-line females and 648 embryos from 80 low-line females were used in the experiment.

Host responses associated with chronic staphylococcal mastitis in rabbits.

Staphylococcal infection causes substantial economic losses in commercial rabbit production systems, and is associated with a wide variety of lesions, including chronic suppurative mastitis, which mainly affects breeding females. Most chronic staphylococcal infections in rabbits are caused by the ST121 lineage of Staphylococcus aureus, although other less common lineages, such as ST96 can also be involved. The aims of the present study were to characterise the host immune response in natural cases of mastitis in rabbits caused by S.

Use of dry citrus pulp or soybean hulls as a replacement for corn grain in energy and nitrogen partitioning, methane emissions, and milk performance in lactating Murciano-Granadina goats.

The aim of this study was to assess the effect of substitution of dietary corn grain by dry citrus pulp or soybean hulls on energy and nitrogen partitioning, substrate oxidation, methane emission, and milk performance in dairy goats during midlactation. Twelve multiparous Murciano-Granadina goats of similar body weight (41.7 ± 2.

A robust rabbit line increases leucocyte counts at weaning and reduces mortality by digestive disorder during fattening.

The present work evaluates how a rabbit line selected for robustness and two other lines selected for productive criteria, could have affected the physiological maturity and blood leukocytes counts of young rabbits at weaning, as well as their possible effect on the subsequent performance and health status during the growing period. The study was conducted on a total of 2904 young rabbits weaned at 30 days, belonging to three different genetic types (line H, founded for litter size at birth and selected for litter size at weaning during 17 generations; line LP, characterised by robustness founded for reproductive longevity criteria and selected for litter size at weaning for 7 generations; and line R, founded and selected during 25 generations for average daily gain from the 4th to the 9th week of life). Two different diets were used during lactation.

Towards an improved estimation of the biological components of residual feed intake in growing cattle.

Residual feed intake (RFI) is the difference between observed and predicted feed intake. It is calculated as the residuals from a multiple regression model of DMI on the various energy expenditures (e.g.

Different resource allocation strategies result from selection for litter size at weaning in rabbit does.

This study examined the effect of long-term selection of a maternal rabbit line, solely for a reproductive criterion, on the ability of female rabbits to deal with constrained environmental conditions. Female rabbits from generations 16 and 36 (n=72 and 79, respectively) of a line founded and selected to increase litter size at weaning were compared simultaneously. Female rabbits were subjected to normal (NC), nutritional (NF) or heat (HC) challenging conditions from 1st to 3rd parturition.

Environmental sensitivity differs between rabbit lines selected for reproductive intensity and longevity.

To better understand the mechanisms that allow some animals to sustain their productive effort in harsh environmental conditions, rabbit does from two selection lines (LP and V) were housed in normal (NC), nutritional (NF) or heat (HC) challenging environmental conditions from first to third partum. The LP line (n=85) was founded on reproductive longevity criteria by selecting does from commercial farms that had a minimum of 25 partum with more than 7.5 kits born alive per parity.

Divergent selection for intramuscular fat content in rabbits. I. Direct response to selection.

The aim of this study was to evaluate the selection response on intramuscular fat (IMF) content of LM after 3 generations of divergent selection. Heritability and genetic means for IMF content were also analyzed. Selection was based on the phenotypic value of IMF content measured in 2 full sibs of the first parity.

Divergent selection for intramuscular fat content in rabbits. II. Correlated responses on carcass and meat quality traits.

Correlated responses on carcass and meat quality characteristics after 3 generations of divergent selection for intramuscular fat (IMF) content were assessed by comparing the high and low lines. Selection was based on the phenotypic value of IMF content of LM, measured in 2 full sibs of the first parity. Traits measured were: BW, HCW, commercial carcass weight (CCW), reference carcass weight (RCW), scapular (SF) and perirenal fat (PF) content, meat-to-bone ratio (M:B) of the hind leg, pH of LM, color (lightness, L*; redness, a*; and yellowness, b*) of the carcass and of a LM section, protein content, and fatty acid (FA) composition of LM.

Energy partitioning and substrate oxidation by Murciano-Granadina goats during mid lactation fed soy hulls and corn gluten feed blend as a replacement for corn grain.

The aim of this experiment was to study the effect of substituting corn grain by soy hulls and corn gluten feed blend on energy partitioning, substrate oxidation, and milk performance in dairy goats during mid lactation. Ten multiparous Murciano-Granadina goats in mid lactation were fed 2 isoenergetic and isoproteic diets [19.08MJ/kg of dry matter (DM) and 18.

Application of NIRS for predicting fatty acids in intramuscular fat of rabbit.

The aim of this study was to evaluate the use of near infrared reflectance spectroscopy (NIRS) for predicting fatty acid content in intramuscular fat to be applied in rabbit selection programs. One hundred and forty three freeze-dried Longissimus muscles (LM) were scanned by NIRS (1100-2498nm). Modified Partial Least Squares models were obtained.

Influence of genetic line on lipid metabolism traits of rabbit muscle.

The effects of genetic line on intramuscular fat content, perirenal fat content, and activity of some enzymes involved in lipid metabolism were studied. One hundred twenty animals from 3 synthetic lines, A and V selected for litter size at weaning and R selected for growth rate between weaning and slaughter, were used in this experiment. One-half of the rabbits were slaughtered at 9 or 13 wk of age, and perirenal fat content (PF) and 2 muscles, LM and semimembranosus proprius (SP), were studied.

Aneuploidy in rabbit males: semen traits and fertility.

Chromosomal analyses were performed from peripheral blood samples from 20 adult rabbit males from Line R. This line has been selected for growth rate after weaning through 25 generations. Seminal characteristics and reproductive outcomes from these males were also examined.

Changes in collagen, texture and sensory properties of meat when selecting rabbits for growth rate.

The consequences of selection for growth rate and the associated decrease of maturity at slaughter in rabbits on collagen content, collagen solubility, meat texture (Warner-Bratzler shear device) and the sensory properties of the m. Longissimus were studied. Sixty rabbits from the 7th generation of a line selected for growth rate (group C) were compared to 60 rabbits from the 23rd generation of the same line (group S).