Genetic effects on maternal performance and litter pre-weaning and post-weaning traits in rabbits

1984 ◽  
Vol 38 (2) ◽  
pp. 293-300 ◽  
Author(s):  
S. Lukefahr ◽  
W. D. Hohenboken ◽  
P. R. Cheeke ◽  
N. M. Patton
Keyword(s):  
Body Weight ◽  
New Zealand ◽  
Food Intake ◽  
Litter Size ◽  
Total Mortality ◽  
Litter Traits ◽  
Mortality Incidence ◽  
Teat Number ◽  
Maternal Performance ◽  
Daily Gain

AbstrtactFlemish Giant (FG) and New Zealand White (NZW) purebreds and terminal crossbreds (TX) (Flemish Giant sires × Florida White-New Zealand White dams) were evaluated during a 10-month period for maternal and litter pre-weaning and post-weaning performance. For the doe traits studied, teat number was greatest and litter interval was shortest, while body weight at breeding age (154 days), litter weight at 21 days and day 1 to 21 food intake were lowest for crossbred does. These traits were similar for pure doe groups, with the exception of body weight, for which FG does were heavier. For the preweaning litter traits examined (no. = 101 litters), litter size born was smallest in the TX group (the purebred groups being similar) and was largest at weaning (28 days) for NZW. Proportion of kits born alive was lowest in FG litters, while the NZW and TX groups were comparable. Litter and average birth and weaning weights, litter daily gain, and doe and litter food intake (1 to 28 days) were all highest in FG litters and lowest in TX litters. Repeatability estimates (t) were low (t < 0·05) for litter size and birth weight traits, and were moderate to high (0·18 < t < 0·58) for the remaining maternally influenced characters. For the post-weaning litter traits studied (no. = 86 litters), NZW litters were larger in number and heavier at market age (56 days), and consumed more food from 28 to 56 days than FG and TX litters. Purebred FG litters, however, had heavier average market weights per rabbit, while purebred NZW and TX litters were similar. Mortality due to respiratory disease was higher in FG litters than in NZW and TX litters. Total mortality incidence was lowest in the TX group.

Is mammary output capacity limiting to lactational performance in mice?

1996 ◽  
Vol 199 (2) ◽  
pp. 337-349 ◽  
Author(s):  
K A Hammond ◽  
K C Lloyd ◽  
J Diamond
Keyword(s):  
Food Intake ◽  
Litter Size ◽  
Mammary Glands ◽  
High Food ◽  
Uptake Capacity ◽  
Start Up ◽  
Lactational Performance ◽  
Teat Number ◽  
Size Controlled ◽  
Stimulation Of

Using lactation in mice as a model, we sought to determine whether ceilings on sustained energy expenditure reside in the capacities of energy-acquiring and input organs (such as the intestine) or of energy-expending and output organs (such as the mammary glands). To distinguish between these possibilities experimentally, we surgically varied the teat number of lactating mother mice while simultaneously varying their litter size. The energy burden on each teat (i.e. the pup/teat ratio) could thus be varied independently of the energy burden (i.e. litter size) on the mother herself or on her intestine. At each teat number, pup mass proved to be maximal at intermediate litter sizes. At a given pup/teat ratio, mothers with five teats weaned pups no larger than the pups of normal (10-teat) mothers, even though the total energy burden on the former mothers was only half as large. Mothers with only two teats could not wean any pups. Litter size controlled maternal food intake, which in turn controlled intestinal mass and nutrient uptake capacity. Disproportionately high food intake for the smallest litters appears to reflect capital start-up costs of lactation. Pup mass is evidently limited by inadequate suckling stimulation of mammary glands.

BODY WEIGHT AND FOOD CONSUMPTION OF LACTATING RATS NURSING VARIOUS SIZES OF LITTERS

1967 ◽  
Vol 38 (3) ◽  
pp. 263-268 ◽  
Author(s):  
K. ÔTA ◽  
A. YOKOYAMA
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Food Consumption ◽  
Ovarian Function ◽  
Experimental Period ◽  
Close Correlation ◽  
Female Rats ◽  
Linear Relationships ◽  
Rate Of Increase ◽  
Daily Gain

SUMMARY Changes in body weight and food consumption during lactation in rats nursing various sizes of litters were studied. The rate of increase in body weight of the mother rats during the experimental period (day 3–14 of lactation) was very similar in mothers with different numbers (2, 4, 8 and 12) of suckling pups/litter. It is suggested that the weight increase of adult female rats during lactation is related more closely to the alteration of ovarian function caused by the suckling stimulus than to the enhanced food intake during this period. Both the food intake of mother rats and the daily gain in weight of litters increased as the number of suckling pups/litter increased and as lactation advanced. Linear relationships were observed between the logarithm of the litter size and both the food intake of the mother rats and the weight gain of the litters. The presence of a close correlation between the food intake of mother rats and the quantity of milk produced by them is suggested.

Differences in food resource allocation in a long-term selection experiment for litter size in mice 2. Developmental trends in body weight against food intake

2000 ◽  
Vol 71 (1) ◽  
pp. 39-47 ◽  
Author(s):  
W. M. Rauw ◽  
P. Luiting ◽  
M. W. A. Verstegen ◽  
O. Vangen ◽  
P. W. Knap
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Litter Size ◽  
Genetic Factors ◽  
Food Resource ◽  
Growth Efficiency ◽  
Control Line ◽  
Growing Period ◽  
Pregnancy And Lactation ◽  
Maintenance Requirements

AbstractIn the accompanying paper, specific genetic factors for body weight and food intake were identified in non-reproductive male and female mice of a line selected for high litter size at birth (average of 22 born per litter) and a non-selected control line (average of 10 born per litter). The existence of these factors are indicated by variation in efficiency parameters such as growth efficiency and maintenance requirements. Residual food intake (RFI) and Parks’ estimates of growth efficiency (AB) and maintenance requirements (MEm) were used to quantify these factors. In the growing period, females had a higher RFI (are less efficient) than males. At maturity, selected mice had higher RFI than control mice and selected females had higher RFI than selected males. AB was higher in selected-line mice than in control-line mice, and higher in males than in females. MEm was higher in selected-line mice than in control-line mice, and higher in females than in males. The results indicate the existence of specific genetic factors for both growth efficiency and maintenance requirements. Selected females may increase RFI in the adult state to anticipate the metabolically stressful periods of pregnancy and lactation, to support a genetically highly increased litter size.

scholarly journals Phenotypic relationships between gestation length and preweaning litter traits in rabbits.

2021 ◽  
Vol 31 (2) ◽  
pp. 154-160
Author(s):  
O. N. Durunna ◽  
U. E. Ogundu
Keyword(s):  
Litter Size ◽  
Average Daily Gain ◽  
Gestation Length ◽  
Litter Weight ◽  
Litter Traits ◽  
Degree Of Association ◽  
High Degree ◽  
The Relationship ◽  
Daily Gain ◽  
Size At Birth

A total of 135 kittens from 22 kindlings were used to determine the relationship between gestation length (GL) and some preweaning litter traits alongside the weight of their 12 dams. Average daily gain at 21 days (ADG21), average litter weight at birth (ALWB), kindling to weaning viability (KWV), litter size at birth{L.SB), litter size at 21 days (LS21), litter weight at 21 days(LW21), litter weight at birth (LWAB), and still birth number (SBN) when subjected to multiple regression analysis revealed non-significant t-test value with GL. However, Average litter weight at 21 days (ALW21) was highly significant (P<0.01) suggesting that such can be used to predict GL. Weight of doe (WOD) was highly significant (P<0.01) showing that such parameter is important for predicting GL. A high R2 value was obtained indicating that the variability in GL is explained by the linearity of the preweaning litter traits and WOD. However the correlation coefficient R, (0.89) revealed a high degree of association between the preweaning litter traits in the rabbits and the weight of doe in a linear form. The F-value was significant at P<0.05 indicating that WOD and the preweaning litter traits in rabbits have significant contribution to the variation in GL. The correlations among traits were positive and significant for majority of the traits, which include live birth number (LBN), ADG21, ALW21, KWV, LS21, and LW21. However SBN had negative correlation with other traits.

Differences in food resource allocation in a long-term selection experiment for litter size in mice 1. Developmental trends in body weight and food intake against time

2000 ◽  
Vol 71 (1) ◽  
pp. 31-38 ◽  
Author(s):  
W. M. Rauw ◽  
P. Luiting ◽  
M. W. A. Verstegen ◽  
O. Vangen ◽  
P. W. Knap
Keyword(s):  
Resource Allocation ◽  
Body Weight ◽  
Food Intake ◽  
Litter Size ◽  
Genetic Factors ◽  
Food Resource ◽  
Control Line ◽  
Individual Data ◽  
Allocation Pattern ◽  
Maturation Rate

AbstractDifferences in the metabolic resource situation between non-reproductive male and female mice of a line selected for high litter size at birth (average of 22 born per litter) and a non-selected control line (average of 10 born per litter) were investigated in two replicates. Brody curves were fitted to individual data on body weight against age and linear regression lines were fitted to individual data on cumulative food intake against age. Mature body weight and mature daily food intake were higher in selected mice than in control mice and higher in males than in females. Selected males matured faster than selected females and control mice. In general, differences in growth and food intake curves between species or lines can mostly be explained by differences in mature size. Therefore, parameters were subsequently scaled by individual estimates of mature body weight. Differences that remain after scaling are a consequence of what have been called specific genetic factors. Scaled mature food intake was higher in selected mice than in control mice and higher in females than in males. Scaled maturation rate was higher in selected mice than in control mice and higher in selected males than in selected females. This shows that in the present study, specific genetic factors have been detected for both body weight and food intake, which suggests that selection for increased litter size has disproportionally changed the resource allocation pattern.

scholarly journals Effects of selection on growth, body composition and food intake in mice: II. Correlated responses in reproduction

1984 ◽  
Vol 44 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Forbes D. Brien ◽  
Gillian L. Sharp ◽  
William G. Hill ◽  
Alan Robertson
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Food Intake ◽  
Litter Size ◽  
Reproductive Performance ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Primary Reason ◽  
Correlated Responses ◽  
Fat Percentage

SummaryFemale reproductive performance is reported in mice selected for ten generations for one of three criteria: either appetite (A), fat percentage (F) or total lean mass (P). For each criterion lines were selected for high (H) or low (L) performance, with contemporary unselected controls (C). In the A and P lines, litter size changed in the direction of the selected criterion, the changes being larger and more rapidly established in the A than in the P lines. At generation 10, the differences in litter size between high and low lines were 2·6 live young born in the A lines, and 1·0 live young born in the P lines. The differences in 6-week weight between the high and low lines were 3·5 g in the A lines, 6·5 g in the P lines. Changes in ovulation rate were the primary reason for changes in litter size, the differences between the high and low lines being 3·8 corpora lutea for the A lines, and 3·1 corpora lutea for the P lines. Fitting body weight at mating as a covariate within lines in the analysis of ovulation rate and live foetus number removed the differences between the high and low selected P lines, but not those in the A lines. The high and low selected A and P lines did not differ in prenatal survival. There were no consistent differences in litter size, ovulation rate or pre-natal survival in the F lines.

Effect of litter size on herbage intake at pasture by ewes and their progeny

1991 ◽  
Vol 53 (2) ◽  
pp. 191-197 ◽  
Author(s):  
S. A. Vulich ◽  
E. G. O'Riordan ◽  
J. P. Hanrahan
Keyword(s):  
Body Weight ◽  
Organic Matter ◽  
Food Intake ◽  
Litter Size ◽  
Dry Matter ◽  
Experimental Period ◽  
Weekly Intake ◽  
Dry Matter Digestibility ◽  
Herbage Intake

AbstractThirty-four mature ewes (17 rearing twins and 17 rearing singles) were used to examine the effect of litter size on herbage intake at pasture by ewes over the course of lactation; intake by their lambs during weeks 13 to 15 of lactation was also evaluated. Daily organic matter intake (OMI) was estimated using the n-alkane technique. Ewes and lambs rotationally grazed 19 × 0·15-ha paddocks during the experimental period which extended from week 2 of lactation to weaning at week 15 of lactation. Sward conditions were maintained steady throughout with daily OM allowance per ewe varying between 4·6 and 5·7 kg and dry matter digestibility between 763 and 858 g/kg DM.Throughout lactation OMI and OMI per kg body weight were higher for twin-rearing ewes (P < 0·05) than for ewes rearing singles: 2·50 and 2·26 kg/day, and 38 and 32 g/kg per day, respectively. Intake reached a maximum on weeks 6 to 7 of lactation. From weeks 13 to 15 of lactation, OMI and OMI per kg body weight for single- and twin-reared lambs were 1·09 and 1·14 kg/day, and 31 and 36 g/kg per day, respectively.The combined food intake per dam-offspring unit for weeks 13 to 14 of lactation for a ewe plus her single lamb was 2·8 kg OM per day compared with 4·3 kg OM per day for a ewe plus her two lambs. The repeatability of average weekly intake by ewes was 0·39 over the course of lactation and 0·40 for lambs over the 13 to 15 week period. Repeatability estimates for ewes increased slightly when data from weeks 3 to 7 and weeks 13 to 14 was analysed separately (0·42 and 0·53, respectively).

scholarly journals Effect of some factors on growth of lambs from crossing between the Improved Wallachian and East Friesian

2011 ◽  
Vol 51 (No. 2) ◽  
pp. 54-60 ◽  
Author(s):  
J. Kuchtík ◽  
IDobeš
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Growth Traits ◽  
Operating Conditions ◽  
First Year ◽  
Phenotypic Correlations ◽  
Body Weights ◽  
Sources Of Variation ◽  
Daily Gain ◽  
Individual Body

The effect of some factors (genotype, sex, litter size, age of dam at lambing, month of lambing and year of birth of lamb) on the growth of lambs &ndash; crossbreds between the Improved Wallachian (IW) and East Friesian (EF) breed was evaluated in operating conditions during two successive years. Three genotypes were evaluated: IW 50 EF 50, EF 75 IW 25 and EF 87.5 IW 12.5. The evaluation of the effect of genotype on growth showed that this factor did not have a significant effect on the majority of growth traits under study. In the period from birth to 100 days of age the highest daily gain was found in IW 50 EF 50 (263 g). The daily gains of EF 75 IW 25 and EF&nbsp;87.5 IW 12.5 in this period were lower but identical (244 g). Age of dam had a significant effect on the majority of growth traits under study. Sex of lamb had a significant effect on body weight at 100 days of age and also on the majority of daily gains under study. The factors litter size, month of lambing and year of lamb birth were the most significant sources of variation of daily gains. As far as the non-genetic factors were concerned, the highest daily gains from birth to 100 days of age were recorded in males (259 g), in singles (260 g), in lambs from 4-years-old ewes (269 g), in lambs born in January (263 g) and in lambs born in the first year of evaluation (256 g). The analysis of phenotypic correlations indicated that body weight at birth showed a positive and highly significant (P&nbsp;&le; 0.01) effect on the majority of growth traits under study. All phenotypic correlations between individual body weights were positive and high (P &le; 0.01). The majority of phenotypic correlations between individual daily gains under study were also positive and high (P &le; 0.01). &nbsp;

The effect of postulating diet intake on embryonic and fetal survival, and litter size in gilts

1991 ◽  
Vol 71 (3) ◽  
pp. 675-681 ◽  
Author(s):  
G. W. Dyck
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Semen Quality ◽  
Weight Maintenance ◽  
Weight Changes ◽  
Fetal Survival ◽  
Breed Difference ◽  
Breed Differences ◽  
Diet Intake ◽  
Daily Gain

The effect on reproductive performance of restriction of diet intake to body weight maintenance for 10 d after mating (R), versus a daily gain of 0.4 kg (C) was assessed in 264 Landrace (L) × Yorkshire (Y) gilts in a rotational crossbreeding program over 4 yr. Gilts were slaughtered during gestation at 30 d (49 gilts) and 60 d (52 gilts), or farrowed (163 gilts). Diet intake had no effect on survival at 30 d (C, 85.1% and R, 82.5%; P > 0.10) and 60 d (C, 81.8% and R, 82.4%, P > 0.10), or on litter size (C, 9.9 and R, 9.9 piglets born alive; P > 0.10). Breed difference in survival approached significance at 30 d (Y × LY, 88.3% vs. L × YL, 80.2%; P = 0.086), and decreased at 60 d (Y × LY, 83.3% and L × YL, 81.4%; P > 0.10). Breed differences in the number of piglets born alive were not significant (Y × LY, 10.2 and L × YL, 9.6 piglets; P > 0.10). Deaths during gestation and parturition averaged 25.6% (16.2% by 30 d; 1.7%, 30 to 60 d; 3.2%, 60 d to parturition; and 4.5%, during parturition (stillbirths)). The 17.9% death loss up to 60 d of gestation was due in part to a greater death loss associated with higher ovulation rates (R2 = 6.60) but was not influenced by individual sires, semen quality attributes, duration of estrus or body weight changes. Thus, in the crossbred gilt, the majority of death losses occur by 30 d of gestation, and do not appear to be affected by changes in diet intake early in gestation. Key words: Gilts, diet intake, embryonic survival, stillbirth, litter size

scholarly journals The effect of chosen factors of the growth of lambs crosses of the breeds Charollais, Suffolk and Improved Valachian

2005 ◽  
Vol 53 (2) ◽  
pp. 39-44
Author(s):  
Igor Dobeš ◽  
Jan Kuchtík
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
The Other ◽  
Time Interval ◽  
Other Hand ◽  
Live Body Weight ◽  
Body Weights ◽  
Daily Gain ◽  
Highly Uniform ◽  
Growth Ability

The aim of our study was to evaluate the effects of chosen factors (crossbreds, sex, litter size, age of ewes and interaction between sex and litter size) on the growth of lambs crossbreds of the breeds Charollais (Ch), Suffolk (Sf) and Improved Valachian (IV). The evaluation was performed in the year 2004 on the farm Růžďka and involved altogether 96 lambs. The growth ability was evaluated at the following crossbreds: Ch x Sf (n = 28), (Ch x Sf) x Sf (n = 28), IV x Sf (n = 21) and (IV x Sf) x Sf (n = 19). All lambs under study were born indoor in January. Lambs were kept indoor till the end of the evaluation. From the evaluation of effects of crossbreds, sex and age of ewes on the live body weights and daily gains of lambs above all result that these factors showed a significant effect only on the live body weight at birth. On the other hand, the factors of litter size and interaction between sex and litter size showed a highly significant (P < 0.01) effect on the live body weights of lambs at birth, at 70 and at 100 days of age as well as on their daily gains within the intervals from birth to 70 and 100 days of age. It can be concluded that the daily gains were highly uniform but relatively low in all crossbreds under the study within the time interval from birth to the age of 100 days, while the non-significantly highest daily gain was recorded in the crossbreds of IV x Sf (211 g). On the other hand the lowest ones were observed in the crossbreds of CH x Sf and (IV x Sf) x Sf (199 g).

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