Litter Survival Differences between Divergently Selected Lines for Environmental Sensitivity in Rabbits

Agea, Iván; García, M. L.; Blasco, A.; Argente, M. J.

doi:10.3390/ani9090603

Cited by 9 publications

(15 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Primiparous does have litters with the highest number and percentage of kits below 45 g, increasing the chance of kits mortality (Szendr} o and Barna 1984;Poigner et al 2000a,b). In fact, the probability of individual survival is related to birth weight, as the kits with lower birth weight have a lower probability of survival (Agea et al 2019). This was observed also in the current study, although the effect of parity was not statistically significant on MR.…”

Section: Discussionsupporting

confidence: 76%

“…Litters of does in the 6th parturition were the most homogeneous, while the 3rd, 4th and 7th included few light kits and many heavy kits. It is well known that there is a positive correlation between survival and uniformity of weight at birth, without affecting individual and LW (Agea et al 2019). In fact, Bolet et al (2007) found a negative correlation between LS and mn-BAW and an increase in mn-BAW variance in larger litters.…”

Section: Discussionmentioning

confidence: 91%

See 1 more Smart Citation

Effect of does parity order on litter homogeneity parameters

Pollesel

Tassinari

Frabetti³

et al. 2020

Italian Journal of Animal Science

View full text Add to dashboard Cite

In rabbits' reproductive performance, litter size, birth weight, growth, and mortality rate are among the most important indicators to define the productive potential and they are associated with parity order. Birth weight and little size are valuable parameters as related to mortality and weaning weight. Thus, it is important to study individual newborn and intra-litter homogeneity parameters. This trial aimed to consider the litter homogeneity weight at birth, both within each litter and in the whole population, in order to suggest new proper within-litter homogenisation parameters. In this study, the 1st and 6th parity order had, respectively, the lowest and highest values in litter size (8.96 vs 12.39, n), born-alive (8.36 vs 12.22, n), litter weight (456.4 g vs 719.8, g), born-alive weight, and quartiles' homogeneity. These parameters decreased in greater parity orders. No significant effects on stillborn numbers and mortality rates were evidenced. All these litter homogeneity evaluation parameters appeared interesting in describing differences between parity orders. The results confirmed that does parity order influences litter size and born-alive weight, but also the intra-and inter-litter homogenisation. Litter homogenisation is crucial to ensure a proportionate share of milk, more equal growth, and better productive performances. Based on these results, we suggest for the commercial genetic centres to equalise the litters according to the birth weight, by dividing the population into quartiles and rearing kits with light birth weight in smaller litters and those with heavier birth weight in larger litters. HIGHLIGHTS Does parity order influences litter size and born-alive weight Kit's quartiles distribution is a useful tool for equalisation practice

show abstract

Section: Discussionsupporting

confidence: 76%

Section: Discussionmentioning

confidence: 91%

Effect of does parity order on litter homogeneity parameters

Pollesel

Tassinari

Frabetti³

et al. 2020

Italian Journal of Animal Science

View full text Add to dashboard Cite

show abstract

“…In addition, it correlated low birth weights with lower survival, although many other environmental factors exacerbate this effect. Agea et al [ 18 ] reported higher weights for the LW variable, and Fadare and Fatoba [ 19 ] presented lower weights than those found in this work.…”

Section: Resultscontrasting

confidence: 59%

Genetic parameters of growth traits and carcass weight of New Zealand white rabbits in a tropical dry forest area

2021

View full text Add to dashboard Cite

Objective: The objective of this study was to estimate the heritability ( h 2 ), repeatability ( r ), and correlations ( r ŷ i y i ) in some traits of zootechnical interest in a population of New Zealand white rabbits of a tropical dry forest area. Materials and Methods: Three mating groups were formed, each one of 1 male and 70 females. The traits evaluated were litter size at birth (LB), born alive (BA), born dead (BD), litter weight born alive (LW), litter weight at weaning (LWW), weaning weight (WW), slaughter weight (SW), and carcass weight (CW). Weaning took place at 42 days, and the fattening phase lasted 60 ± 3 days. A descriptive statistical study was carried out on the study variables. Paternal heritability was estimated ( ) and maternal ( ), repeatability, rabbit index IC, and Pearson’s correlations ( r ŷ i y i ) between traits. The descriptive statistics showed high variation for the BD traits. Results: The values of the productivity found were similar to those presented in studies around the world. h 2 presented magnitudes between low and medium. ranged between 0.09 and 0.42 and between 0.11 and 0.45 for . In general, the values of were higher than the values of . The r values for the traits LB, BA, LW, LWW, and SW presented low magnitude, while it was medium for WW and CW. From the values of r , IC was calculated for each of the rabbits, allowing their categorization, which will be used in future selection plans. r ŷ i y i among the variables ranged from −0.01 to 0.860. They were generally positive and mostly not significant ( p > 0.05); they took a magnitude from low to moderate, except for the correlation between LB and BA. Conclusion: The production of rabbits under tropical conditions is similar to other reports. The genetic parameters evaluated were medium-to-low, indicating a robust non-additive gene and/or environmental effect.

show abstract

“…Therefore, there is an important increase in the mobilization of dam’s body reserves, which leads them to lose body condition (review by Castellini et al [ 25 ]). In this sense, we also observed a decrease in body condition between 10 days after delivery and weaning in both lines, although the decrease is slightly higher in the low line due to a large number of kits at weaning [ 18 ].…”

Section: Discussionmentioning

confidence: 92%

“…Uniformity in litter size and body weight has been related to immune response and resistance to diseases (see review [ 17 ]). Additionally, we have found that selection for reducing residual variance of litter size increases litter size without affecting the individual weight neither at birth nor at weaning [ 18 ].…”

Section: Discussionmentioning

confidence: 99%

Correlated Response to Selection for Litter Size Residual Variability in Rabbits’ Body Condition

Agea

Garcia

Blasco

et al. 2020

Animals

Self Cite

View full text Add to dashboard Cite

A divergent selection experiment for residual variance of litter size at birth was carried out in rabbits during twelve generations. Residual variance of litter size was estimated as the within-doe variance of litter size after pre-correction for year and season as well as parity and lactation status effects. The aim of this work was to study the correlated response to selection for litter size residual variability in body condition from mating to weaning. Body condition is related directly to an animal’s fat deposits. Perirenal fat is the main fat deposit in rabbits. Individual body weight (IBW) and perirenal fat thickness (PFT) were used to measure body condition at second mating, delivery, 10 days after delivery, and weaning. Litter size of the first three parities was analyzed. Both lines decreased body condition between mating to delivery; however, the decrease in body condition at delivery was lower in the low line, despite this line having higher litter size at birth (+0.54 kits, p = 0.93). The increment of body condition between delivery and early lactation was slightly higher in the low line. On the other hand, body condition affected success of females’ receptivity and fertility at the third mating, e.g., receptive females showed a higher IBW and PFT than unreceptive ones (+129 g and +0.28 mm, respectively), and fertile females had a higher IBW and PFT than unfertile ones (+82 g and +0.28 mm, respectively). In conclusion, the does selected for reducing litter size variability showed a better deal with situations of high-energy demand, such as delivery and lactation, than those selected for increasing litter size variability, which would agree with the better health and welfare condition in the low line.

show abstract

Litter Survival Differences between Divergently Selected Lines for Environmental Sensitivity in Rabbits

Cited by 9 publications

References 25 publications

Effect of does parity order on litter homogeneity parameters

Effect of does parity order on litter homogeneity parameters

Genetic parameters of growth traits and carcass weight of New Zealand white rabbits in a tropical dry forest area

Correlated Response to Selection for Litter Size Residual Variability in Rabbits’ Body Condition

Contact Info

Product

Resources

About