AGE, WEIGHT, BACKFAT AND TIME OF MATING EFFECTS ON PERFORMANCE OF GILTS

1990 ◽  
Vol 70 (2) ◽  
pp. 469-481 ◽  
Author(s):  
L. G. YOUNG ◽  
G. J. KING ◽  
J. S. WALTON ◽  
I. McMILLAN ◽  
M. KLEVORICK
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Reproductive Performance ◽  
Coefficient Of Variation ◽  
Sexual Maturity

An experiment was conducted involving 429 gilts that were managed to stimulate estrus after 140 d of age, bred at first, second or third observed estrus and to study factors relating to estrus and reproductive performance to weaning of the first litter. The average at first estrus followed by the coefficient of variation (%) in parentheses were: age 167.2 d (11.8); weight 106.8 kg (15.5); backfat 19.1 mm (17.8); backfat/weight 0.18 (16.2) and weight/age 0.64 (11.5). Sixty-two and one-half percent of the gilts exhibiting estrus did so between 140 and 170 d of age. Fifty-eight percent of the gilts exhibited estrus prior to 180 d of age and were less than 110 kg liveweight. There were relatively low correlations between indices of growth rate and fatness with age at first estrus. Reproductive performance was not enhanced by delaying breeding to second or third estrus after puberty. Key words: Pigs, reproduction, sexual maturity, age, weight, backfat

scholarly journals A Comparison of Variability in Two Cassin’s Auklet (Ptychoramphus aleuticus) Colonies Using Spline-based Nonparametric Models

2013 ◽  
Vol 4 (1) ◽  
pp. 63-85
Author(s):  
Dean Koch
Keyword(s):  
Growth Rate ◽  
Reproductive Performance ◽  
Coefficient Of Variation ◽  
Small Scale ◽  
Regression Spline ◽  
Ecological Variability ◽  
Nonparametric Models ◽  
Cassin's Auklet ◽  
Ptychoramphus Aleuticus ◽  
Over Time

While variability in the reproductive performance of a population over time is a familiar and useful concept to ecologists, it can be difficult to capture mathematically. Commonly used ecological variability statistics, such as the standard deviation of the logarithm and coefficient of variation, discard the time-ordering of observations and consider only the unordered response variable values. We used a relatively new methodology, the cubic regression spline (a flexible curve fitted to a scatterplot of data), both to illustrate trends in reproductive performance over time and to explore the utility of the cubic regression spline roughness penalty (J) as a statistic for measuring variability while retaining time-ordering information. We concluded that although J measures variability in a mathematical sense, it can be inappropriate in a population ecology context because of sensitivity to small-scale fluctuations. To illustrate our methodology, we used the CRS approach in an analysis of historical data from two Cassin’s Auklet colonies located on Frederick and Triangle Islands in coastal BC, developing a model for the annual mean nestling growth rate on each island over seven contiguous years. Model selection indicated a complex (nonlinear) trend in growth rate on both islands. We report higher variability in the resident bird population of Triangle Island than Frederick Island, based on a comparison of the fitted curves, and the values of the coefficient of variation and population variability summary statistics.

A DIFFERENCE IN WEIGHT REDUCES FIGHTING WHEN UNACQUAINTED NEWLY WEANED PIGS FIRST MEET

1987 ◽  
Vol 67 (4) ◽  
pp. 951-960 ◽  
Author(s):  
JEFFREY RUSHEN
Keyword(s):  
Growth Rate ◽  
Aggressive Behavior ◽  
Key Words ◽  
Coefficient Of Variation ◽  
Weaned Pigs ◽  
Common Procedure ◽  
Variation Formula ◽  
Weight Variation ◽  
The Common ◽  
The Difference

The mixing of weaned pigs from different litters was observed so that the effect of a large difference in bodyweight on fighting could be examined. When 5- to 6-wk-old pigs met in pairs for 1 h, fights were longer and biting more frequent if the difference in weight between the pigs was small (< 0.5 kg) than if it was large (> 3.0 kg). In groups of four 5- to 6-wk-old pigs taken from different litters, fighting was more prolonged during 2 h after mixing if there was little weight variation in the group (coefficient of variation [Formula: see text]) than if there was large weight variation (coefficient of variation [Formula: see text]). When groups of four pigs were formed by taking one large and one small pig from each of two litters, the longest duration of fighting occurred between the two large pigs. Significantly less fighting occurred between the large and small pigs and between the two smaller pigs. Subordinate pigs were less likely to retaliate against the dominant pigs if the weight difference was large. It seemed that the presence of large pigs in the group inhibited fighting between equally matched smaller pigs. I suggest the common procedure of mixing pigs matched for weight exacerbates the initial fighting but how this affects growth rate will depend on the level of competition over food. Key words: Pigs, aggressive behavior, weight variation, mixing

Productivity of farmed wapiti in Alberta

1994 ◽  
Vol 74 (2) ◽  
pp. 297-303 ◽  
Author(s):  
B. A. Friedel ◽  
R. J. Hudson
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Reproductive Performance ◽  
Multiple Birth ◽  
Production Ratio ◽  
Farm Survey ◽  
Calf Mortality ◽  
The Mean ◽  
Calving Rate ◽  
On Farm

Calving and weaning rates of 1084 wapiti hinds (females) were collected in the 1990 season by an on-farm survey of 50 producers in Alberta, to determine the reproductive performance of farmed wapiti. A calving rate of 81 and 96% for 2-yr-old and adult hinds, respectively, gave a provincial herd average of 93%. Weaning rates of 73% for 2-yr-old and 91% for adult hinds resulted in an 88% weaning rate overall. One set of triplets and three sets of twins gave a multiple birth ratio of one in 271 calvings. Overall calf mortality was 5.2% in the survey, with a trend (P = 0.07) for 2-yr olds to experience higher calf mortalities (9.5%) than adult hinds (4.4%). Dystocia accounted for two-thirds of the total calf mortalities reported in the survey. Although 2-yr olds calved later than adult hinds (11 June vs. 6 June), hind pre-rut weight influenced calving dates. Male calves were heavier (94 vs. 85 kg, (P = 0.0001) than female calves at 100 d due to their faster growth rate (753 vs. 686 g d−1, P = 0.0001). Growth rate and consequently weaning weights were positively influenced by hind pre-rut weight. The mean length of the breeding season was 111 d with producers exposing an average of 21 hinds per breeding stag on 1.2 ha of pasture per wapiti yr−1. The calf production ratio at 200 d was 52.5 kg calf per 100 kg hind for individual females weaning a calf, and was 46.2 kg calf per 100 kg of hind exposed on a herd basis. Pre-rut weaning was associated with improved calving (3.3%), weaning rates (2.6% in adult hinds and 13.4% in young hinds), decreased calf mortality (3.2%), advanced calving dates (5 d), and improved growth to 200 d (8%). Key words: Game farming, wapiti, reproduction, calving, weaning, growth

scholarly journals Assessment of the Growth and Reproductive Performance of Cloned Pietrain Boars

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Performance ◽  
Reproductive Performance ◽  
Semen Quality ◽  
Small Body ◽  
Economic Benefits ◽  
Large Animal ◽  
Significant Difference ◽  
F1 Progeny

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.

Akodon molinae (Rodentia Cricetidae), a new laboratory animal: breeding, management and reproductive performance

1980 ◽  
Vol 14 (2) ◽  
pp. 129-131 ◽  
Author(s):  
Maria Susana Merani ◽  
Marta Susana Lizarralde
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Laboratory Animal ◽  
Post Partum ◽  
Animal Breeding ◽  
Haemorrhagic Fever ◽  
Sex Ratio At Birth ◽  
Breeding Management ◽  
Laboratory Colony

Akodon molinae, a vole mouse widely distributed in central Argentina, shows remarkable chromosome polymorphisms. It is one of the natural reservoirs of the actiologic agent of haemorrhagic fever, and a laboratory colony could be of great help in investigating this disease. Pregnancy lasted 23 (range 21-25) days. Litters of 4-5 young were born to monogamous breeding pairs about every 30 days, with weaning at 26 days post partum. The sex ratio at birth was 505 males to 500 females: at weaning it was 460 to 440. Sexual maturity was attained at about 16 weeks of age in males and 12-20 weeks in females. Akodon molinae is easy to handle, but fighting and killing or neglect of young are problems.

THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: REPRODUCTIVE PERFORMANCE

1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
Author(s):  
MOHAMED H. FAHMY ◽  
JACQUES J. DUFOUR
Keyword(s):  
Body Weight ◽  
Mortality Rate ◽  
Key Words ◽  
Litter Size ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Ovulation Rate ◽  
Genetic Groups ◽  
Linear Regressions ◽  
Size At Birth

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities

Erratum: Size at onset of sexual maturity and growth rate in crustacean populations

1975 ◽  
Vol 53 (3) ◽  
pp. 360-360
Author(s):  
Adrian M. Wenner ◽  
Craig Fusaro ◽  
Allan Oaten
Keyword(s):  
Growth Rate ◽  
Sexual Maturity

Exteroceptive Factors, Sexual Maturation and Reproduction in the Female Rat

1979 ◽  
Vol 13 (3) ◽  
pp. 283-286 ◽  
Author(s):  
M. L. Norris ◽  
C. E. Adams
Keyword(s):  
Reproductive Performance ◽  
Sexual Maturation ◽  
Sexual Maturity ◽  
Mature Male ◽  
Female Rat ◽  
Vaginal Opening ◽  
Sexually Mature

Summary Keeping a sexually mature male with a weanling female rat advanced neither the time of vaginal opening nor that of 1st oestrus. In 2 of 3 experiments females kept singly after weaning reached sexual maturity significantly earlier than did grouped females. The reproductive performance of females mated at 1st oestrus was not significantly different from that of older primiparae. 26 rats gave birth to an average of 9·3 young at 59·5 days of age, and 22 of them reared 96% of the young to weaning.

scholarly journals Vegetative growth of Umbrella Leaf Palm, Johannesteijsmannia lanceolata in Angsi Forest Reserve, Malaysia

1970 ◽  
Vol 12 ◽  
pp. 11-20
Author(s):  
M. Z. Rozainah ◽  
U. R. Sinniah
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Vegetative Growth ◽  
Forest Reserve ◽  
Vegetative Phenology

A study of an acaulescent palm, Johannesteijsmannia  lanceolata J. Dransfield was carried out in Angsi Forest Reserve Negeri Sembilan Malaysia for a period of 19 months A total of 32 adults, 24 juveniles and 32 seedlings from 3 different plots were censused every two weeks. The results showed that the average numbers of new leaves entering the crown with in the study period (19months) were: 3.3, 2.6 and 1.3 for 2.1, 1.6 and 0.8 leaves per year for adult juvenile and seedling, respectively. From the calculation it was discovered that the time spent by each leaf in the crown before it died was 8.8 years for adult and 8.4 years for juvenile. Key words: Johannesteijsmannia; Growth rate; Vegetative phenology; Arecaceae doi: 10.3126/eco.v12i0.3190 Ecoprint: An International Journal of Ecology 12: 11-20, 2005

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