AN APPRAISAL OF CERTAIN SOURCES OF ENVIRONMENTAL VARIATION IN THE PRODUCTIVITY OF YORKSHIRE SOWS

1961 ◽  
Vol 41 (2) ◽  
pp. 220-229 ◽  
Author(s):  
G. H. Bowman ◽  
J. P. Bowland ◽  
H. T. Fredeen
Keyword(s):  
Litter Size ◽  
Weight Change ◽  
Gestation Length ◽  
Statistical Control ◽  
Weight Changes ◽  
University Of Alberta ◽  
Highly Correlated ◽  
The University ◽  
Least Squares Estimates ◽  
Size At Birth

Analysis of the records of 616 Yorkshire litters farrowed over a 20-year period in the University of Alberta swine herd indicated that litter performance was not associated with differences in weight changes of the sow during gestation or with gestation length. Gestation weight change was negatively correlated with breeding weight and lactation weight changes. Age of sow, breeding weight and litter order were highly correlated and were mutually dependent in their effect on litter performance. Least squares estimates of year, season, breeding weight of sow, and weight change during lactation effects were obtained for several performance traits of the litter. Year differences were large but erratic for all traits. Seasonal differences appeared to be important only for litter size with fall litters averaging 0.78 more pigs at weaning than spring litters. Weight of sow at breeding exerted an important influence on litter performance. Weight change during lactation appeared to be a function of litter size.Study of the relative influence of age and weight of gilts at breeding on first litter size at birth and weaning indicated that breeding weight exerted the greater influence.It is concluded that comparisons between litters in the same herd and born within the same year and season must provide for statistical control of variation in weight of dam at breeding. If inter-year comparisons are desired additional statistical control is essential.

INTERRELATIONS BETWEEN SOME REPRODUCTIVE TRAITS IN SWINE

1972 ◽  
Vol 52 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. H. FAHMY ◽  
C. S. BERNARD
Keyword(s):  
Litter Size ◽  
Survival Rates ◽  
Reproductive Traits ◽  
The Other ◽  
Gestation Length ◽  
Percentage Survival ◽  
Weaning Pig ◽  
Highly Correlated ◽  
Daily Gain ◽  
Size At Birth

The associations between 15 preweaning traits in pigs were studied to determine which had the most important effects on litter weights at birth and weaning. The traits were litter size at birth and weaning, number born alive, percentage survival to birth and weaning, pig and litter weights at birth and weaning, daily gain from birth to weaning, gestation length, number of teats, weights of dam at farrowing and at weaning, and the change in dam weight during lactation. Of the 105 correlations, 66 were statistically significant, though many were markedly low. Litter weights at birth and weaning were significantly and relatively highly correlated with most of the other traits, whereas number of teats was correlated only with survival rates at birth and weaning and pig birth weight. The results showed that the importance of litter size was almost twice that of pig weight in determining litter weights at birth and weaning. The results in general indicated that most of the economically important traits related to swine reproductivity are favorably associated.

Reproductive attributes of local pig (Votho) of Nagaland, India

2016 ◽  
Author(s):  
N. Savino ◽  
Z. Chusi ◽  
A. Dhali ◽  
P. Perumal
Keyword(s):  
Mortality Rate ◽  
Litter Size ◽  
Field Survey ◽  
Gestation Length ◽  
Reproductive Parameters ◽  
Litter Weight ◽  
Significant Difference ◽  
Size At Birth ◽  
Selection Of ◽  
Age At First Farrowing

The present study was conducted to measure the reproductive attributes of Naga local pigs (Votho) in Kohima, Peren and Phek district of Nagaland. The reproductive parameters were measured through field survey and reproductive records of owner. The reproductive parameters such as age at first fertile service (AFFS), age at first farrowing (AFF), gestation length, farrowing interval, litter size at birth, litter size at weaning, litter weight at birth, litter weight at weaning, mortality rate and stillbirth rate were measured. The result revealed that there was a significant difference among the different districts of Nagaland in AFFS, AFF and litter weight at birth. Parameters such as AFFS, AFF and litter weight at birth were significantly higher and gestation length, farrowing interval, litter size at weaning, litter weight at birth, litter weight at weaning were non-significantly higher in Kohima than in Peren and Phek District. Similarly, parameters such as litter size at birth, mortality rate were non-significantly higher in Peren district and stillbirth was non- significantly higher in Phek district than other districts of Nagaland. These reproductive attributes analyses may be useful in selection of breeding stock for future parents and select the place for breeding programme for indigenous local Naga pigs.

EVALUATION OF MILK VARIABLES AS MEASURES OF MILK EFFECT ON PREWEANING PERFORMANCE OF BEEF CATTLE

1971 ◽  
Vol 51 (1) ◽  
pp. 21-30 ◽  
Author(s):  
H. B. JEFFERY ◽  
R. T. BERG
Keyword(s):  
Milk Yield ◽  
Average Daily Gain ◽  
Curvilinear Relationship ◽  
Total Solids ◽  
University Of Alberta ◽  
Milk Components ◽  
Beef Herds ◽  
Highly Correlated ◽  
The University ◽  
Relationship Of

A study with 176 (1966) and 201 (1967) cows from the University of Alberta beef herd was conducted to investigate the effectiveness of a number of milk variables for explaining variance in preweaning gain of beef calves. The seven milk variables calculated over 24 hours were yield of milk, total energy, total protein and total solids, and percentages of butterfat, protein and solids-not-fat. These variables were measured for two periods, August and October, and averages for the two periods were calculated. Mean 24-hour milk yield ranged from 3.8 to 6.1 kilograms. Percentage of butterfat, protein and solids-not-fat, respectively, ranged from 4.10 to 5.77, 3.28 to 3.93, and 8.67 to 9.50. The intercorrelations among yield of milk, energy, protein and total solids were high and positive, ranging between 0.85 and 0.99. Correlations of milk yield with percent milk components were small and predominantly negative. Intercorrelations of percent milk components ranged from 0.09 to 0.55. Correlations of mean milk yield variables and average daily gain (ADG) of calf to weaning for the two periods ranged from 0.73 to 0.78. In most instances, total milk yield was equally or more highly correlated with ADG than the other milk yield variables. Correlations of percent milk components with ADG were low, and in most instances not significant. In 1966 data, little additional variation in ADG was explained by the inclusion of other milk variables over that explained by milk yield alone. In 1967, the inclusion of milk percent components accounted for from 2 to 7% of variance in ADG over milk yield alone. Average milk yield for the two periods of milking was more consistent than a single milking in explaining variance in ADG over both years. The response of ADG of calf to milk yield was essentially a linear relationship, but there were indications that the curvilinear relationship of ADG and milk yield should not be ignored in beef herds of relatively high milk production.

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.

FACTORS AFFECTING GESTATION LENGTH IN THE PIG

1979 ◽  
Vol 59 (1) ◽  
pp. 83-87 ◽  
Author(s):  
I. GARNETT ◽  
G. W. RAHNEFELD
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Weight Change ◽  
Average Daily Gain ◽  
Weight Ratio ◽  
Gestation Length ◽  
Small Litter ◽  
Factors Affecting ◽  
Number Of Factors ◽  
Breeding Groups

The effects of a number of factors on gestation length were examined in two groups of swine. The first group consisted of a Lacombe line (L) selected for post-weaning average daily gain (ADG), a control-Yorkshire (Y) line and a group of Yorkshire females (Y1) bred to Lacombe boars to produce L × Y litters. The second group of females were from twice-yearly farrowings following termination of the selection study. The effect of litter size, although statistically significant for all breeding groups, was small. Litter weight had a small but significant effect for the L and Y breeds. Sex ratio of the litter had no effect on gestation length. Consistent with previous results, the Lacombe was found to have a longer gestation length than the Yorkshire. When age effect was taken into account there was a small but significant parity effect between first and second litter. The effect of sow body weight at breeding (BW), body weight change during gestation (GWG), and weight change expressed as a proportion of breeding weight (RATIO) were examined in the group II females. A small but significant effect of RATIO was found in the Lacombe breed. There was found to be no sex effect on litter size. Heritability estimates for gestation length from daughter dam regression were 0.47, 0.72 and 0.69 for the L, Y and Y1 groups, respectively.

Genetic and phenotypic aspects of doe productivity in four breeds of rabbits

1988 ◽  
Vol 110 (1) ◽  
pp. 191-197 ◽  
Author(s):  
M. H. Khalil ◽  
E. A. Afifi ◽  
M. E. Emara ◽  
J. B. Owen
Keyword(s):  
Litter Size ◽  
Environmental Parameters ◽  
Direct Selection ◽  
Phenotypic Correlation ◽  
Gestation Length ◽  
Environmental Correlations ◽  
Litter Traits ◽  
Genetic And Phenotypic Correlations ◽  
Mortality Percentage ◽  
Size At Birth

SummaryData on 841 purebred Bauscat, White Flander, Giza White and Baladi Red litters provided estimates of genetic, phenotypic and environmental parameters for gestation length, litter size at birth and at weaning, mortality and sex ratio at weaning. A total of 170 daughters (paternal half-sisters) of 76 sires were available for the analysis. No important differences were detected among breeds for litter traits studied except litter size at weaning (P < 0·001). Year of kindling affected (P < 0·001) gestation length, litter size at birth and mortality percentage. No clear patterns of the effect of parity and month of kindling on litter traits were observed. The sire of the doe and doe within sire affected most of the traits studied. Estimates of heritability indicated that the sire's genetic contribution to litter traits are much higher during the pre-natal period than for the suckling period. Estimates of repeatability for litter traits studied were relatively low. Genetic and phenotypic correlations between gestation length and other litter traits were relatively low. Litter size traits were positively correlated both genetically and phenotypically. Estimates of genetic and phenotypic correlation between litter size traits and preweaning mortality were generally negative. Phenotypic and environmental correlations were generally very similar in size and sign. Predicted direct selection was shown to give greater improvement in litter size at birth than indirect selection through litter size at weaning.

scholarly journals Effect of rebreeding interval on reproductive performance and body weight changes of does during pregnancy

2021 ◽  
Vol 32 (1) ◽  
pp. 142-152
Author(s):  
G. T. Iyeghe-Erakpotobor ◽  
E. O. Oyedipe ◽  
L. O. Eduvie ◽  
D. Ogwu
Keyword(s):  
Body Weight ◽  
Pregnancy Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Feed Intake ◽  
The Other ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Tropical Conditions ◽  
Size At Birth

The effect of rebreeding interval on the reproductive performance and body weight changes of does during pregnancy was investigated using 24 multiparous crossbred (New Zealand White X California) does. The does were placed on three treatments comprising mating at 14, 21 and 28 days postpartum. The docs were served 250g-concentrate meal (23% CP und 2600 kcal ME/kg) daily, while water was given ad libitum. Parameters monitored were doe willingness to mate, doe weights during pregnancy, feed intake, pregnancy rate, litter size and weight at birth, alive at birth and up to 21 days postpartum and stillbirth rate. Kits were weaned at 4 weeks of age. Results obtained showed that does mated 14 days postpartum lost more weight in the second week of pregnancy than the other groups. Rebreeding interval did not significantly (P>0.05) affect doe weight gain in the 19, 3" and 4th weeks of pregnancy. Does mated 14-d postpartum had significantly (P<0.05) higher feed intake during the l", 2nd and 3rd weeks of pregnancy. Feed:guin ratio was higher for does mated 21 d postpartum than for other treatments. Pregnancy rate was higher in the 14-d group and lowest in the 28-d group. Willingness to mate also decreased with increasing rebreeding interval. Litter size at birth, number of kits alive at birth and up to 28 days postpartum were not affected (P>0.05) by rebreeding interval as was the case for litter birth weight and percent stillbirths. Does mated 14 days postpartum however, had numerically more kits alive at birth and up to 28 days postpartum than the other groups. Litter weights were slightly higher for does mated 14 and 21 days postpartum than 28 days. It is concluded from this study that mating does 14 days postpartum under tropical conditions could increase the number of kits weaned per doe and hence increase profitability of the rabbit production enterprise. 

scholarly journals Effect of flushing on reproductive performance of rabbits.

2021 ◽  
Vol 32 (1) ◽  
pp. 134-141
Author(s):  
G. T. Iyeghe-Erakpotobor
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Feed Intake ◽  
Protein Level ◽  
Mortality Rates ◽  
Weight Changes ◽  
Protein Requirement ◽  
Size At Birth

Twenty eight (28) multiparous crossbred does were placed on four diets consisting of 16, 18, 20 and 24% CP for two weeks before mating and one week after mating to evaluate the effect of flushing on the reproductive performance of rabbits. The does were placed on 16% CP diet during pregnancy and 18% CP diet during lactation  Results obtained showed similar (P>0.05) weight changes and feed intake for all the groups though does fed the 16% CP diet lost weight. Does flushed with 18, 20 and 24% CP had slightly larger litter size at birth while 18% and 20% CP flushed does had slightly larger litter size alive at birth than 16 and 24% CP does. Litter size at 21 days postpartum was significantly (P<0.05) higher for does flushed with 20 and 24% CP than those flushed with 16 and 18% CP. Litter weights were significantly (p<0.05) higher for 20% and 24% CP flushed than 16 and 18% CP flushed does at 7 , 14- and 21-day postpartum. Stillbirths increased with increase in protein level up to 20% CP level before decreasing slightly ar 24% CP. Kit mortality rates at 0-7, 7-14 and 14-21 days postpartum were similar (P>0.05) but numerically lower for 20 and 24% CP flushed does. Total kit mortality rale (0-21 days postpurtum) was significantly (P<0.05) higher for does flushed with 16 and 18% CP diets. It is concluded from this study, that flushing multiparous does with 20 and 24% CP diets gave better reproductive performance than with 16 and 18% CP diets. Feeding 16% CP diel to does during pregnancy does not appear to meet their protein requirement for gestation 

scholarly journals Effect of re-mating intervals on growth and reproductive performance of rabbits

2013 ◽  
Vol 42 (2) ◽  
pp. 143-147
Author(s):  
BK Saha ◽  
MB Sarker ◽  
MH Alam ◽  
ME Kabir ◽  
MR Amin ◽  
...  
Keyword(s):  
Growth Rate ◽  
New Zealand ◽  
Litter Size ◽  
Milk Yield ◽  
Reproductive Performance ◽  
Gestation Length ◽  
Natural Lighting ◽  
Litter Weight ◽  
Nest Boxes ◽  
Size At Birth

The aim of this study was to know the effects of postpartum re-mating intervals on reproductive performances of does and growth of kits. Fifteen female New Zealand White crossbred rabbits were divided into three groups of equal numbers. They were re-mated within 24 hours, at 10 days and 28 days postpartum. Animals were individually caged in cells measuring 2'×2'×2'. Does were kept under natural lighting. Plastic nest boxes were supplied to does 3-4 days before parturition. They were reared up to four generation. Litter weight at birth was significantly (p<0.05) higher at 10 days postpartum than within 24 hours and at 28 days postpartum intervals. Higher growth rate was observed in 10 days postpartum group comparing to other re-mating groups. Milk yield of the dams were significantly (p<0.05) higher when dam re-mated at 10 days postpartum than those re-mated within 24 hours after parturition. Conception rate, gestation length of does, litter size at birth and weaning, litter weight at weaning, doe weight at mating, kidding, weaning and kid mortality did not differ significantly among the groups. Rabbit does re-mated at 10 days postpartum show maximum litter weight at birth, growth rate of kits and milk yield of dam.DOI: http://dx.doi.org/10.3329/bjas.v42i2.18497 Bang. J. Anim. Sci. 2013. 42 (2): 143-147

REPRODUCTIVE PERFORMANCE OF GILTS FROM LINES SELECTED FOR FEED UTILIZATION AND CARCASS SCORE

1972 ◽  
Vol 52 (2) ◽  
pp. 267-271
Author(s):  
M. H. FAHMY ◽  
C. S. BERNARD
Keyword(s):  
Least Squares ◽  
Litter Size ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Feed Utilization ◽  
Gestation Length ◽  
Litter Weight ◽  
Yorkshire Pigs ◽  
Score Line ◽  
Size At Birth

Eight reproductive traits were studied on 751 gilts of 3 lines of Yorkshire pigs derived from a common population by selecting for feed utilization (line 1), carcass score (line 2), and for both traits combined (line 3) during 10 generations. Least squares means for the traits were as follows: gestation length 115.2 days; litter size at birth 9.0 pigs (total) and 8.4 pigs (alive); litter size at weaning 6.8 pigs; number of teats 13.4; and litter weight at birth, 21, and 56 days, 9.3, 32.6, and 92.6 kg, respectively. Heritability estimates were calculated for each line by half-sib correlation and intra-sire regression of offspring on dam. The pooled estimate for the above eight traits was 0.45, 0.11, 0.09, 0.15, −0.12, 0.08, 0.14, and 0.14, respectively. Line effect was highly significant for all traits except litter size at birth. Means and heritabilities for line 3 were higher than those for lines 1 and 2, which did not differ greatly from each other. Variation from year to year had significant effects only on litter weight at different ages. The within years–within line regressions of the eight traits on inbreeding were not significant. The within line phenotypic correlations between each of feed utilization and carcass score and the eight traits were generally low and nonsignificant.

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