Factors governing the shape of the growth curve of body weight and the age at slaughter of Suffolk × Welsh lambs

1966 ◽  
Vol 8 (3) ◽  
pp. 435-444 ◽  
Author(s):  
J. S. Broadbent ◽  
J. H. Watson

Curves of growth in live-weight, from birth to 16 weeks of age, of 362 Suffolk × Welsh lambs were analysed for the effect of sex, birth type, sire and test centre environment and related to variation in age at slaughter.The relative pre-natal disadvantages of twin lambs resulted in their curves of growth differing from those of single-born animals, particularly in males. Test centre environment exerted a marked effect in such cases. At one centre, male twins showed marked compensatory growth.Differences in growth existed between the 14 sire progeny groups. As the linear component of the growth curves decreased, the quadratic values became increasingly negative. Deceleration of growth was most marked in slowest growing progeny groups and this was accentuated by a poor test centre environment.These factors combined to influence age at slaughter, which was also related to birth weight of the lamb. Lambs at the best test centre reached slaughter weight 10 and 16 days earlier than lambs at the two remaining centres. Sires produced differences in age at slaughter of 10 to 14 days, within centres.

2017 ◽  
Vol 47 (4) ◽  
Author(s):  
Felipe Amorim Caetano Souza ◽  
Tales Jesus Fernandes ◽  
Raquel Silva de Moura ◽  
Sarah Laguna Conceição Meirelles ◽  
Rafaela Aparecida Ribeiro ◽  
...  

ABSTRACT: The analysis of the growth and development of various species has been done using the growth curves of the specific animal based on non-linear models. The objective of the current study was to evaluate the fit of the Brody, Gompertz, Logistic and von Bertalanffy models to the cross-sectional data of the live weight of the MangalargaMarchador horses to identify the best model and make accurate predictions regarding the growth and maturity in the males and females of this breed. The study involved recording the weight of 214 horses, of which 94 were males and 120 were non-pregnant females, between 6 and 153 months of age. The parameters of the model were estimated by employing the method of least squares, using the iteratively regularized Gauss-Newton method and the R software package. Comparison of the models was done based on the following criteria: coefficient of determination (R²); Residual Standard Deviation (RSD); corrected Akaike Information Criterion (AICc). The estimated weight of the adult horses by the models ranged between 431kg and 439kg for males and between 416kg and 420kg for females. The growth curves were studied using the cross-sectional data collection method. For males the von Bertalanffymodel was found to be the most effective in expressing growth, while in females the Brody model was more suitable. The MangalargaMarchador females achieve adult body weight earlier than the males.


1948 ◽  
Vol 38 (3) ◽  
pp. 243-302 ◽  
Author(s):  
L. R. Wallace

SUMMARYIn the investigation described, we have observed a t monthly intervals throughout gestation the changes taking place in a series of similar ewes, in lamb to the same ram, and each receiving the same standard diet.In following the live-weight growth curves of the ewes it was found that on a constant level of feeding the weight gains became greater during each succeeding month of pregnancy, and at corresponding stages were larger for ditocous than for monotocous ewes. This was found to be due to the fact that, although on our diet the ewes did gain slightly in actual body weight, the main increases in live weight resulted from the growth of the gravid uterus itself, and this increases in weight far more rapidly in the later stages of gestation, and is also heavier where twins are carried.


1940 ◽  
Vol 30 (4) ◽  
pp. 511-569 ◽  
Author(s):  
C. P. McMeekan

It is impracticable to give a detailed summary of the many findings of.this experiment; attention is confined, therefore, to the major aspects and the general principles emerging.1. By quantitative control of the plane of nutrition, twenty closely inbred pigs have been made to conform to four major variations in the shape of the growth curve from birth to 200 lb. live weight. A high rate throughout (High-High), a high followed by a low rate (High-Low), a low followed by a high rate (Low-High) and a low rate throughout the period (Low-Low) afforded comparison between animals of the same weight but different age and between animals of the same weight and age but with differently shaped growth curves. The relative effects of the treatments upon the development of body proportions and anatomical composition have been studied.


Author(s):  
Ayhan Ceyhan ◽  
Ahmet Şekeroğlu ◽  
Mustafa Duman

In this study, growth performance of Akkaraman lambs and some fertility parameters of Akkaraman sheep raised in semi extensive farm conditions were investigated. A total of 6300 heads Akkaraman ewes (6000 ewes and 300 rams) housed in 34 farms located in central villages of Niğde province were evaluated between 2012 and 2016. The data of birth weight of 30161 lambs, body weight of 29517 lambs aged 90 days old and some fertility parameters of 30000 heads ewes were used. The average lambing rate of ewes was found 90.1%. The twining rate of ewes was 20.8%; the average litter size was 1.12 lambs. Birth weights of Akkaraman sheep lambs was 4.23 kg, average 90th day live weights were 23.05 kg. Effects of year, birth type, dam age, and sex were found statistically significant on birth and 90-day live weights of the Akkaraman lambs. As a result, it was concluded that the fertility of Akkaraman sheep and growth characteristics of lambs raised by public under semi-extensive conditions could be improved and the economic situation of sheep farms could be better by the implementation such improvement project.


1958 ◽  
Vol 50 (2) ◽  
pp. 198-210 ◽  
Author(s):  
P. N. Wilson

1. Fifty-five kids of the East African dwarf goat were used in the experiment. The kidding percentage was 107·8%, and the twinning percentage 12·7%; the proportion of twin births increased in the latter stages of the experiment, related to the longer period the late-kidding dams had spent on the rising plane of nutrition.2. The percentage of female kids to total kids born was 56·4%, male kids 43·6%. The mean birth weight of female kids was 4·5 lb., compared to 5·2 lb. for male kids.3. The sex difference in live-weight increase increased markedly after 16 weeks of age. The growth of females slowed down to approximately ½ lb. per head per week, whereas that of males continued to increase at the rate of approximately 1 lb. per head per week. H-plane female kids reached 33 lb. at 31 weeks, H-plane males achieved the same weight at 20 weeks of age.4. The effect of plane of nutrition on the live weights of experimental kids of both sexes was statistically significant as from the third week of age. H-plane kids reached 33 lb. live weight at approximately 26 weeks of age, L-plane kids at about 48 weeks.5. The kids initially placed on a L-plane of nutrition exhibited a marked resilience when switched to the H-plane. The live-weight gains after switching were for females as great as, and for males greater than, the gains made by kids on a H-plane of nutrition throughout the growing period.This recuperative capacity of animals changed from L to H levels of diet, at or before the point of inflexion of the growth curve, has now been clearly established for all types of farm livestock examined, the pig, the sheep, the chicken and the goat. Both sexes exhibited this capacity to recover from initial low-plane feeding.


1980 ◽  
Vol 31 (3) ◽  
pp. 223-235 ◽  
Author(s):  
C. S. Taylor

ABSTRACTThe inter-species relationship between mature body weight and time taken to mature in body weight was studied empirically in nine domestic species with data ranging from early embryonic to late postnatal growth. When examined in terms of genetic size scaling, the results showed that metabolic age provided a readily useable comparative age scale which would allow results obtained from one species to advance the study of growth and nutrition in other species.A standardized growth curve was therefore calculated for each species in terms of degree of maturity in body weight and metabolic age. The two standardized regression curves gave mean growth curves that estimated expected degree of maturity at a given metabolic age and expected metabolic age at a given degree of maturity. The two mean curves scarcely differed.Deviations of each species from these mean curves were analysed. There were significant standardized differences between species in earliness of maturing. Rabbits were estimated to mature in 30% less time than expected for their size, a deviation which (if repeatable) could be of great potential importance to animal production.


2011 ◽  
Vol 50 (No. 6) ◽  
pp. 243-248 ◽  
Author(s):  
M. Koyuncu ◽  
S. Kara Uzun ◽  
S. Ozis ◽  
S. Duru

Forty-seven Kivircik ram lambs, aged 2 months, raised and managed under an intensive system were used to measure the development of testis diameter and length, and scrotum circumference, length and volume, and their association with the development of body growth. The effects of age and body weight of lambs, type of birth and dam age on the development of the five testicular parameters from weaning at 2&ndash;6 months of age were investigated. In ram lambs, the respective least-squares means of testis measurements: testis diameter, testis length, scrotum circumference, scrotum length and scrotum volume were 2.55 &plusmn; 0.099 cm, 5.83 &plusmn; 0.165 cm, 15.23&nbsp;&plusmn; 0.650&nbsp;cm, 7.24 &plusmn; 0.287 cm and 87.57 &plusmn; 5.921 cm<sup>3 </sup>at 2 months; and 2.99 &plusmn; 0.099 cm, 6.59 &plusmn; 0.164 cm, 14.24&nbsp;&plusmn; 0.657 cm, 10.60 &plusmn; 0.290 cm and 157.49 &plusmn; 5.987 cm<sup>3</sup> at 6 months. The effect of birth type on testis diameter and the effect of dam age on testis length were significant (P &lt; 0.05 and P &lt; 0.01), besides the effects of lamb age and live weight of lambs on the whole testis measurements were significant (P &lt; 0.01). &nbsp;


1990 ◽  
Vol 50 (2) ◽  
pp. 271-275 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Constantinou

ABSTRACTThe study examined early measures of growth and their relationships with mature body size. Data on 792 purebred females of the Chios breed, born and reared on two experimental farms between 1978 and 1986, were analysed. Pedigree information and records on live weight at birth, at weaning, 105 days of age and at first and subsequent matings was recorded. There were flock-year differences for all traits studied (P < 0·01) and birth type was important for all traits except post-weaning growth rate. Dam lactation number had no significant effect on birth weight and pre-weaning growth rate, but it significantly affected all subsequent weights and post-weaning growth rate. Estimated heritabilities increased with age and ranged from 0·13 (s.e. 0·14) (birth weight) to 0·30 (s.e. 0·15) (mature weight). Genetic correlations were generally positive between weights and growth traits. Phenotypic correlations were positive and followed the pattern of the genetic correlations. The results suggest that selection for 105-day weight will result in increased mature weight.


1992 ◽  
Vol 54 (3) ◽  
pp. 389-393 ◽  
Author(s):  
M. Theriez ◽  
B. Touraine ◽  
P. Vigneron ◽  
M. Prud'hon

AbstractPure Merinos d'Aries male lambs were reared indoors (IN), with hay and concentrates, or outdoor (OUT) on improved Mediterranean range (Garrigues) and slaughtered when they reached 25 (light) or 32 (heavy) kg live weight. The alimentary tract weight was significantly affected by slaughter weight and by rearing method, which also significantly modified rumen contents. IN lamb body composition was higher in fat and energy and lower in water and protein than OUT lambs but differences induced by the rearing method were reduced when slaughter weight was increased. Allometric equations established for each environment were used to determine body composition and body gain composition at 20 and 25 kg empty body weight. Changes were very limited for IN lambs but protein and fat content of OUT lambs changed greatly as a result of the tremendous increase of grass availability towards the end of the fattening period.


1975 ◽  
Vol 20 (2) ◽  
pp. 199-205 ◽  
Author(s):  
D. Levy ◽  
Z. Holzer ◽  
Y. Folman

SummaryThe effects of roughage level (15 and 35% of the ration) and of slaughter weight (400,450 and 500 kg) were studied in an experiment of 2 x 3 factorial design. Daily live-weight gains and carcass gains were significantly higher on the lower roughage levels, but there was no difference in degree of fatness of the carcass. Dry-matter intake expressed as a percentage of body weight was 2·91 on 35% roughage compared with 2·53 and 15% roughage, i.e. 15% higher on the highroughage diet. This compensated the animals on the high-roughage diet for the lower energy content of their feed. Rate of gain increased with an increase in slaughter weight. The percentage of fat trim and of saleable meat increased, while that of bone decreased significantly with an increase in slaughter weight. The animals on the lowroughage diet were approximately 11% more efficient than the others in converting metabolizable energy into live weight.


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