Weaning weight of pigs and litter sampling with reference to litter size

1937 ◽  
Vol 27 (4) ◽  
pp. 485-502 ◽  
Author(s):  
A. D. Buchanan Smith ◽  
H. P. Donald
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
General Relation ◽  
Gene Effects ◽  
Weaning Weight ◽  
Subsequent Performance ◽  
Rate Of Growth ◽  
The Mean ◽  
Significant Regression ◽  
The Individual

1. Following an examination of weaning weight with respect to litter size, it is concluded that no general relation between the two exists. Although a significant regression of weight on litter size was found, it appears probable that in herds where the relation between fertility and milk yield is different, such a regression will not necessarily be found.2. A sampling experiment was carried out to determine the extent to which a sample might be expected to represent the whole litter. A correlation of 0·96 was found between the mean growth rate of samples consisting of the four pigs nearest the average at weaning and the mean of the whole litter. This represents a loss of 8 per cent of the information. With three or two pigs chosen in the same way the loss was greater. Samples of four pigs chosen at random did not give results significantly different from those of the four pigs nearest the average. The choice of the heaviest four pigs resulted in a loss of 15 per cent of the information.3. The slight difference between the results from the random sample and the sample of the four average pigs indicated that there must have been only a small correlation, between weaning weight and subsequent rate of growth. An analysis of post-weaning rate of growth showed that the intra-class correlation of pigs of the same weaning weight was 0·15. Individual weight at weaning would therefore appear to be of slight value in estimating subsequent performance.4. Intra-litter correlations of growth rate for litter classes eight and nine were found to be 0·3 and 0·5. These values are higher than those found by others, probably as a result of the inclusion of the pre-weaning period in the calculation of the growth rates. There would appear to be grounds for believing that at least a fifth of the individual variance may be accounted for by additive gene effects.

Analysis of post-weaning growth in pigs

1939 ◽  
Vol 29 (2) ◽  
pp. 274-294 ◽  
Author(s):  
A. D. Buchanan Smith ◽  
H. P. Donald
Keyword(s):  
Litter Size ◽  
Carcass Quality ◽  
Small Animals ◽  
Absolute Rate ◽  
Rate Of Growth ◽  
The Mean ◽  
The Individual ◽  
Relationship Of ◽  
The Relationship ◽  
Graphical Illustration

1. The post-weaning growth of 135 litters has been analysed with a view to determining the relationship of certain arbitrary subdivisions with each other. For this purpose, the weight increases during three periods of 28 days have been denned in two ways—first, by age, the periods being 10–14, 14–18, and 18–22 weeks, and secondly, by weight, the periods beginning at 40, 80 and 120 lb. and continuing as before for 4 weeks.2. When the periods are defined by age, the mean increase per pig per litter is affected by weaning weight, but not by litter size (Table III). The variability of the individual increases becomes greater as the pigs become older and heavier (that is, passing from one period to a later one), but less within a period as the rate of growth increases (Table IV). It was not affected by litter size.3. The distribution of individual weights became increasingly skew with age. This is regarded as a graphical illustration of the fact that while absolute rate of growth is increasing, initially small animals must fall farther and farther behind (Graph 3).4. The correlations between the average litter increases in different periods were calculated for litter sizes 6–11. In general, the coefficient for periods 1 and 2 was about 0·4, and for periods 2 and 3 about 0·6 (Table VI). This is interpreted to mean that, when judged by results over the whole time under observation, litters with a high correlation between the increases in weight during short periods are not properly comparable with those with a low correlation. By this method, differences in rate of growth having an important influence on carcass quality may be obscured.

Liquid diets fed prior to weaning enhance performance of weaned piglets

2000 ◽  
Vol 2000 ◽  
pp. 119-119
Author(s):  
P.J. Blanchard ◽  
P. Toplis ◽  
L. Taylor ◽  
H.M. Miller
Keyword(s):  
Growth Rate ◽  
Current Practice ◽  
Negative Control ◽  
Milk Replacer ◽  
Weaned Piglets ◽  
Creep Feeding ◽  
Weaning Weight ◽  
Subsequent Performance ◽  
Creep Feed ◽  
The Uk

Creep feeding enhances weaning weight (King et al., 1998) and may also enhance early post-weaning growth rate, both of which are positively correlated to subsequent performance (Miller et al., 1999). When preweaning feeds are offered, current practice in the UK is to feed either dry feed from day 14 to weaning or acidified milk replacer from days 3 to 18. Intakes of dry feed pre-weaning are generally low whereas liquid feeds are consumed more readily. Our objectives were 1) to offer creep feed as a gruel to test whether this would enhance intake of creep and provide an alternative to milk replacer, and 2) to provide all three forms of supplementary feeding together to determine whether this further increased performance. Piglets receiving no supplementary pre-weaning feed were the negative control.

Why and how we estimate the growth rate of fish? Practical aspect: Does the preservative size of barbel Barbus barbus is defined properly in Poland?

2017 ◽  
Vol 1 (1) ◽  
pp. 53-57
Author(s):  
Mariusz Klich
Keyword(s):  
Growth Rate ◽  
Thermal Conditions ◽  
Practical Aspect ◽  
Practical Application ◽  
Field Surveys ◽  
Size Limit ◽  
Rate Of Growth ◽  
Barbus Barbus ◽  
The Individual ◽  
Maturation Age

Based on fish scales, we can determine the age of fish, as well as the rate of growth of the individual from birth until the time of capture. The paper presents a method for determining the rate of growth of fish and the example of their practical application to determine the protective size limit of fish, on the example of barbel in Poland. The available data on the growth rate of barbel in Polish rivers, based on 12 field surveys carried out in 1948–2004 was compared. The growth rate of barbel in different habitats is variable. Barbel growth depends on the size of the river and thermal conditions. The results were compared with maturation age of barbel. Protective size limit definited for barbel, which is 40 cm, is correct. All populations of barbel can reproduce at least once before they reach the preservative size. Most of the populations may reproduce at least two or three times.

scholarly journals A critical statistical study of experimental data on the effect of minute electric currents on the growth rate of the coleoptile of barley

1926 ◽  
Vol 99 (695) ◽  
pp. 122-130 ◽  
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Statistical Study ◽  
Pure Line ◽  
Similar Data ◽  
Electric Currents ◽  
Rate Of Growth ◽  
The Mean ◽  
Positive Results ◽  
Case Based

A study of the effect of very minute electric currents on the rate of growth of the coleoptile of barley was published recently by one of us (F. G. G.) in collaboration. In this paper the mean rate of a number of control coleoptiles was compared with the mean rate of a number exposed to a minute electric discharge. The growth rate of individual coleoptiles showed, naturally, considerable divergences, so the mean result was in each case based on the observation of a large number of coleoptiles, the increments of growth of individual coleoptiles being stated as percentages of the rate of growth during the first hour of observation. It was assumed that the distribution of growth rates in a comparatively large sample of a pure-line barley would conform with the normal distribution; the probable errors of the mean results were therefore calculated in the ordinary way. During the continuation of this work positive results have been obtained in further experimental sets, but a number of these, though significant in the mass, were individually without significance. This suggested that a careful statistical study of the data on which the results were based might show how the accuracy of the method could be increased. Such a study has accordingly been undertaken, and it seems probable that methods employed are likely to be of use in the treatment of similar data.

scholarly journals THE GROWTH AND DURATION OF LIFE OF CELOSIA CRISTATA SEEDLINGS AT DIFFERENT TEMPERATURES

1934 ◽  
Vol 17 (6) ◽  
pp. 763-781 ◽  
Author(s):  
Thomas I. Edwards ◽  
Raymond Pearl ◽  
Sophia A. Gould
Keyword(s):  
Growth Rate ◽  
Maximum Yield ◽  
Total Duration ◽  
Growth Curves ◽  
Growth Period ◽  
Hypocotyl Length ◽  
Rate Of Growth ◽  
Life Duration ◽  
Celosia Cristata ◽  
The Mean

Daily measurements of hypocotyl length were made on Celosia cristata seedlings cultured in darkness under aseptic conditions at six constant temperatures between 14.5° and 40.5°C. At 40.5° roots did not penetrate the agar and only the hypocotyls that were supported by the wall of the test tube could be measured. The growth curves were of the generalized logistic type, but of different degrees of skewness. The degree of symmetry of the growth curves was influenced by temperature. At the lower temperatures the maximal growth rate came relatively late in the grand period of growth; at successively higher temperatures it came progressively earlier. The mean total time rate of growth (millimeter per diem) was found to be a parabolic function of the temperature. The maximum rate of growth was found from the curve to be at 30.48°C. The maximum observed rate of growth, and the maximum yield, were found to be at 30°C. At all temperatures above 14.5° the maximum growth activity fell in the second quarter of the whole growth period. At all temperatures tested other than 30°, and at all parts of the growth cycle, the growth yield as measured by height of hypocotyl at any given equivalent point was less than at 30°. The total duration of life of the seedlings, and the duration of life after the end of the growth period (intermediate period) were inversely proportional to the mean total growth rate. The observations on Celosia cristata seedlings are thus in accord with the "rate of living" theory of life duration. The optimal temperature for life duration is the minimum temperature, within the range of these observations.

Growth of Juvenile Chum Salmon (Oncorhynchus keta) Under Different Feeding Regimes

1969 ◽  
Vol 26 (6) ◽  
pp. 1631-1645 ◽  
Author(s):  
R. J. LeBrasseur
Keyword(s):  
Growth Rate ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Rate Of Growth ◽  
Total Length ◽  
Chum Salmon Oncorhynchus Keta ◽  
Feeding Regimes ◽  
Size Groups ◽  
Juvenile Chum Salmon ◽  
The Mean

Juvenile chum salmon were fed on six different concentrations of size-selected zooplankton for 8 weeks. Zooplankton were caught daily and sorted through sieves into size-groups roughly as follows: 6–20 mm total length, mainly euphausiids; 2.5–4.5 mm, mainly copepods; and ≤ 1.5 mm, mainly small copepods. The rate of growth in weight of the fish was found to be dependent upon the concentration of the ration. Fish which were offered no food lost weight, and fish which were offered excess food increased in weight by 5.4% per day. The mean growth rate of the fish held on fixed rations ranged from 2.2 to 5.7% per day and was found to be independent of the type of prey. Electivity experiments showed that all the fish selected copepods 1.6–4.5 mm long in proportion to their abundance and rejected copepods ≤ 1.5 mm. The euphausiids were selected only by fish which had previously fed on euphausiids. The effect of variations in the availability of prey is discussed.

Relationships among uterine and placental factors in prolific ewes and their relevance to variations in foetal weight

1980 ◽  
Vol 30 (1) ◽  
pp. 115-124 ◽  
Author(s):  
S. M. Rhind ◽  
J. J. Robinson ◽  
I. McDonald
Keyword(s):  
Litter Size ◽  
Late Pregnancy ◽  
Ovulation Rate ◽  
Total Weight ◽  
Under Nutrition ◽  
Foetal Mortality ◽  
The Mean ◽  
The Individual

ABSTRACTObservations were made on the distribution of ovulations between the two ovaries, the distribution of foetuses between the two uterine horns, the total numbers of cotyledonary burrs, and the weights and numbers of foetal cotyledons for each foetus in 80 Finnish Landrace × Dorset Horn ewes killed between 50 and 145 days of gestation. While ovulations were randomly distributed between right and left ovaries, viable foetuses were more evenly distributed between right and left uterine horns. Migration of embryos between the horns contributed to this relative balance but early foetal mortality, which increased with ovulation rate, tended to upset it. The mean number of foetal cotyledons per foetus depended on litter size and distribution, and at any fixed litter size was substantially reduced in those ewes with six or more ovulations. Foetal weights were also relatively low in these ewes. The total weight of cotyledons per foetus decreased by about 12% for each increase of one in number of foetuses, as compared with a 20% decrease in number of cotyledons but only a 7 to 11 % decrease in the weight of the individual foetuses. Comparisons between foetuses within the same litter led to similar trends in the ratios of cotyledon numbers, cotyledon weights and foetal weights. It is suggested that the presence of some very small lambs in large litters should not be attributed to maternal under-nutrition in late pregnancy.

scholarly journals The effect of litter size upon foetal growth rate and the placental transfer of calcium and phosphorus in superovulated Scottish half-bred ewes

1973 ◽  
Vol 29 (3) ◽  
pp. 437-446 ◽  
Author(s):  
A. R. Twardock ◽  
H. W. Symonds ◽  
B. F. Sansom ◽  
G. J. Rowlands
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Placental Transfer ◽  
Ovulation Rate ◽  
Foetal Growth ◽  
The Mean ◽  
Calcium And Phosphorus

1. The ovulation rate of forty-eight Scottish half-bred ewes was increased by using pregnant mare's serum gonadotrophin thus inducing litters of one to four foetuses.2. The effects of increased litter size upon the foetal growth rate and upon the rate of transfer of calcium and phosphorus across the placenta were studied at 108–112, 122–126 and 136–140 d gestation.3. The number of foetuses had little effect upon foetal weight at 112 d, the mean weights of a singleton, twin, triplet or quadruplet being similar. However, by 140 d mean foetal weight decreased markedly as litter size increased.4. Failure of individual quadruplets to grow as fast as a singleton was associated with a limitation in the capacity of the placenta for transferring minerals. The maximum rates of transfer of Ca and P, whatever the number of foetuses, were approximately 2·8 and 1·4 g/d respectively. These rates were attained by 112 d when quadruplets were being carried, by 126 d for triplets, and by 140 d for twins.

The pattern of growth in the early lifecycle of individual Sepia pharaonis

2004 ◽  
Vol 55 (4) ◽  
pp. 415 ◽  
Author(s):  
Jonathan W. Minton
Keyword(s):  
Growth Rate ◽  
Growth Phase ◽  
Growth Curves ◽  
Maximum Size ◽  
Control Group ◽  
Sepia Pharaonis ◽  
Second Growth ◽  
The Mean ◽  
R Value ◽  
The Individual

The pattern of growth in the early lifecycle of the pharaoh cuttlefish, Sepia pharaonis, was investigated by rearing hatchlings at 26°C in two separate trials. In each trial, the mean weight and mantle length (ML) was recorded in 5-day intervals. In addition, in each trial the growth of 20 group-reared cuttlefish was measured as a control to compare against the individual data. After 60 days of growth, the mean size for individuals in trial 1 was 2.75 g (maximum size 3.32 g) and in trial 2 was 12.76 g (maximum size 14.99 g) at 90 days. Each individual went through distinct growth phases during the first 90 days after hatching. The first growth phase matched exponential curves with an R-value of 0.98 or better, and the second growth phase corresponded with linear and power growth curves at an R-value of 0.98 or better. In trial 1, the mean growth rate for individuals during the first phase was 5.91% BW day–1 and the control group growth rate was 6.36% BW day–1. In trial 2, the mean growth rate for individuals during the first phase was 6.06% BW day–1 and the control group growth rate was 6.70% BW day–1.

scholarly journals ON THE RELATION BETWEEN LITTER SIZE, BIRTH WEIGHT, AND RATE OF GROWTH, IN MICE

1935 ◽  
Vol 19 (2) ◽  
pp. 249-263 ◽  
Author(s):  
W. J. Crozier ◽  
E. V. Enzmann
Keyword(s):  
Litter Size ◽  
Time Course ◽  
Inbred Strains ◽  
General Character ◽  
Single Individual ◽  
Time Curve ◽  
Relative Growth Rates ◽  
Rate Of Growth ◽  
Fractional Increase ◽  
The Individual

We have been concerned with the connection between size of litter and weight of litter at birth, especially in mice. The weight at birth represents, it is to be presumed (at least in mice, and for certain other cases), the weight at a particular developmental stage. The connection between number in litter (N) and weight of litter (W) has been interpreted as due to the partition of nourishment between mother and young, and on an equal basis among the several embryos of a litter. The "heterogonic" relationship which the data exhibit between N and W shows that the constant K, defined by log W = K log N + const., is independent of the species, and has an essentially constant value (0.85±) in all multiparous mammals; it is therefore regarded as a partition coefficient. In the case of power function relationships between masses of components of a single individual, the respective "drawing powers" of the several organs are diverse, and diverse magnitudes of K are encountered. With developing embryos, the intrinsic drawing powers of the tissues concerned in embryos and mothers are in each case of the same general character, at least among mammals; the constancy of K reflects this. A parallel for the case as it appears in the consideration of relative growth rates of organs in a single individual, and in which the varying magnitudes of the heterogonic growth constant K are presumed to reflect diverse drawing powers of the respective tissues, would be given by intrauterine growth of a litter containing individuals with diverse capacities for growth, —that is, individuals differing genetically with respect to the factors determining the magnitudes of w1. We have been dealing with the growth of litters in inbred strains. It is to be presumed that in the case of the growth of a litter containing two categories of individuals so far as concerns intrinsic drawing powers with respect to the nourishment provided by the mother, it would be possible to investigate the way in which K is open to modification. Although difficult, from the standpoint of classifying the individual young, it would appear to be distinctly worth while to make such an experiment, and we have planned it for the future. It is pointed out that for genetic purposes the ideal weight of a litter of 1 is obtainable from a series of measurements of N and W, free from disturbances affecting the apparent value of this quantity as observed in single births. This weight of an ideal litter of 1 should be employed to disentangle the effects of heterosis and fertility factors from those having to do with individual weight at birth. During the suckling period the relation ΔW/W = K (ΔN/N) is maintained for young mice, but with modifications in the case of small and large suckling litters due to (1) the time course of milk yield, and (2) the effect of litter size upon this. It is shown that a growth curve can be obtained for an ideal litter of I, under the condition of milk supply that on each day the mother is able to provide a constant fractional increase of milk for each additional young mouse in the litter. The rate of growth then adheres to the time curve of capacity for production of milk.

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