The sex ratio of a gilt’s birth litter can affect her fitness as a breeding female

2018 ◽  
Vol 58 (9) ◽  
pp. 1567 ◽  
Author(s):  
J. Seyfang ◽  
R. N. Kirkwood ◽  
A. J. Tilbrook ◽  
C. R. Ralph
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Reproductive Potential ◽  
Group Housing ◽  
Pork Industry ◽  
Welfare Issue ◽  
Breeding Herd ◽  
Uterine Environment ◽  
Animal Welfare Issue ◽  
Selection Of

Lifetime reproductive performance and behaviour are established in utero driven by genetics and the steroidal milieu of the uterine environment. Developing males synthesise androgens that can be absorbed by females in the litter. Consequently, the proportion of males in a litter has the potential to affect both lifetime reproductive performance and behaviour of female littermates. Although reproductive potential is understandably important for gilt selection, behaviour is becoming progressively more important as group housing of sows increases. Aggression can be a cause for removal from the breeding herd, and can also negatively affect reproductive performance and herd longevity. This review covers existing evidence of masculinisation in rodents and sheep, the mechanism causing masculinisation, and the knowledge gaps surrounding masculinisation in pigs. Premature culling of gilts is an economic and animal welfare issue in the pork industry resulting in low retention of gilts and reduced productivity. The selection of gilts needs to be improved to incorporate both lifetime reproductive potential and behaviour. We determined that there is cause to investigate the effect of the birth litter sex ratio of a gilt on her suitability for selection into the breeding herd.

scholarly journals Genomic Tools and Genetic Improvement of Crossbred Friesian Cattle

2021 ◽  
Vol 8 (1) ◽  
pp. 89-107
Author(s):  
Md Anisur Rahman ◽  
Nasrin Sultana Juyena ◽  
Mohammed Shamsuddin ◽  
Mohammad Musharraf Uddin Bhuiyan
Keyword(s):  
Reproductive Performance ◽  
Genetic Improvement ◽  
Reproductive Potential ◽  
Reproductive Traits ◽  
Production Traits ◽  
Genomic Tools ◽  
The Given ◽  
Friesian Cattle ◽  
Selection Of ◽  
Friesian Cows

Any genetic improvement in dairy cattle requires information on productive and reproductive performance in the given population. Animals have been selected to improve their productivity in order to increase the profitability to the farmer. As a result, selection of animals is made for higher production and a shortened productive life. The reproductive performance of Friesian cows under intensive and semi-intensive management system in Bangladesh is poor. Animal selection has historically been based on production traits, and not much attention was given to AI recording. Many attempts were taken scatterly to increase productive and reproductive potential of Bangladeshi cattle for different periods with variable achievements. Therefore, in this review article we have addressed the new tools and information that could be used to determine the level of productive and reproductive performance and to evaluate genetic factors using admixture analysis of cows bred by AI sires which affect reproductive traits of crossbred Friesian dairy cows reared in selected areas in Bangladesh. Res. Agric., Livest. Fish.8(1): 89-107, April 2021

scholarly journals CAUSES OF VARIATION IN REPRODUCTIVE PERFORMANCE OF WEST AFRICAN DWARF GOAT

2021 ◽  
Vol 21 ◽  
pp. 29-36
Author(s):  
O. A. Adebambo ◽  
A. O. Samuel ◽  
A. D. Onakade
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Reproductive Potential ◽  
Monozygotic Twins ◽  
Dry Season ◽  
Multiple Births ◽  
Seasonal Effect ◽  
Wet Season ◽  
Significant Survival ◽  
West African Dwarf Goat

Analysis was carried out on the reproductive performance of 59 WAD (Foula djullon) goats over 8 year period 1982-1990) under intensive management. The data involving a total of 176 kiddings comprising 311 kids were analysed to provide some information on the reproductive potential and the distribution of the Sexes on the WAD goats for an appraisal of its utilization for future genetic and environmental studies and the improvement of the breed in Nigeria. The results showed no significant seasonal effect on the kidding pattern. Singles, twins and triplets were 33.44, 48,23 and 16,40% respectively. Kidding interval varied from 91 to 2.10 days, annual kidding rate was 1..68 with mean kid birth weight of 1.5 +0.138, 1.49 +0.65 and 1.31+0.095kg for single twins and multiple births respectively. The average sex ratio was 48.79+0.18. The least squares constants showed that the age of dam, kidding interval and Season of kidding have significant effect on the sex ratio with more males born by those after 3 years of age particularly during the dry season 't shorter kidding intervals or 191-220 days. Calculated frequency of sex combination of males to females was 0.4005, 0.4662 and 0.1333 trizygotic, dizygotic and monozygotic twins among the triplets - The frequency was 0.67 for monzygotic twinning among the twin births. Although preweaning mortalities of 12.26, 16.33 and 19.36% were recorded for single, twin and multiple births respectively, highly significant survival rate was recorded in the dry season (84.40+0.75) than in the wet season 81,18 +0.75 whilst the kidding interval was between 200 - 240 days in about 56% of the population studied. The current emphasis on the presence  of monozygotic twins with a frequency of 67% among twin birth and 13.3% among the triplets is to assist in utilizing this trait in the goat for studies that could enhance the modification of the environment or improve the genetic potentials of the breed.

СОВЕРШЕНСТВОВАНИЕ СТАД СКОТА СИММЕНТАЛЬСКОЙ ПОРОДЫ ПО МОЛОЧНОЙ И МЯСНОЙ ПРОДУКТИВНОСТИ

2020 ◽  
Author(s):  
N.V. SIVKIN ◽  
N.V. STREKOZOV ◽  
V.I. CHINAROV
Keyword(s):  
Milk Yield ◽  
Live Weight ◽  
Breeding Value ◽  
Early Age ◽  
Group I ◽  
Breeding Herd ◽  
Simmental Cattle ◽  
Meat Productivity ◽  
Selection Of ◽  
Meat Type

В симментальской породе предусматривается разведение скота, сбалансировано сочетающего молочную и мясную продуктивность. Однако в практике совершенствования племенных стад в подборах быков доминируют улучшатели удоя, что во многом предопределяет результаты селекции и продуктивный тип животных. Объектом нашего исследования стало стадо чистопородного симментальского скота в условиях стойловой системы беспривязного и привязного содержания коров. Для изучения эффективности использования быков-производителей разного племенного достоинства сформировали 2 опытные группы: I состояла из бычков, полученных от отцов с племенной ценностью (ПЦ) по удою 100 кг и более, а во II с ПЦ от 0 до 100 кг молока. Симментальские бычки, отобранные для контрольного убоя, достигали весовых кондиций 500 кг и более в 17,5 мес при среднесуточном приросте 911 г. При использовании на маточном поголовье быков-производителей с улучшающим эффектом по удою 100 кг и более, их сыновья (I группа), на фоне более высоких суточных приростов (на 30 г) и раннем возрасте достижения живой массы 500 кг (на 18 дней) имели массу и выход туши на 21,4 кг и 2,7 ниже, чем у бычков II группы. При формировании молочно-мясного типа быки-производители с умеренной племенной ценностью по удою обеспечивали получение потомства, сочетающего молочную и мясную продуктивность в экономически значимых пропорциях.The Simmental breed provides for the breeding of cattle that combines milk and meat productivity in a balanced proportion. However, in the practice of improving breeding herds, the selection of bulls is dominated by milk yield improvers, which largely determines the results of selection and the productive type of animals. The object of our research was a breeding herd of purebred Simmental cattle in variety feeding and housing practices. To study the effectiveness of using bulls-producers of different breeding values, 2 experimental groups were formed: I consisted of bulls received from fathers with a breeding value (BV) of milk yield 100 kg or more, and II with a BV from 0 to 100 kg of milk. Simmental bulls selected for control slaughter reached weight standards of 500 kg or more in 17.5 months with an average daily increase of 911 g. When used on breeding of bulls with an improving effect on the yield of 100 kg or more, their sons (group I), against the background of higher daily gains (30 g) and an early age of reaching a live weight of 500 kg (18 days), had a mass and carcass yield of 21.4 kg and 2.7 lower than that of group II bulls. When forming a dairy-meat type, producing bulls with a moderate breeding value for milk yield provided for the production of offspring that combined dairy and meat productivity in economically significant proportions.

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.

scholarly journals The density of females of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) affects their reproductive performance on pupae of Bombyx mori L. (Lepidoptera: Bombycidae)

2010 ◽  
Vol 82 (2) ◽  
pp. 323-331 ◽  
Author(s):  
Fabricio F. Pereira ◽  
José C. Zanuncio ◽  
José E. Serrão ◽  
Teresinha V. Zanuncio ◽  
Dirceu Pratissoli ◽  
...  
Keyword(s):  
Life Cycle ◽  
Relative Humidity ◽  
Sex Ratio ◽  
Bombyx Mori ◽  
Reproductive Performance ◽  
Climatic Chamber ◽  
Glass Tubes ◽  
Bombyx Mori L

Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) is a gregarious and polyphagous parasitoid mainly of Lepidoptera pupae. The objective of this paper as to study the developent of parasitoid on Bombyx mori L. (Lepidoptera: Bombycidae) pupae exposed to one, nine, 18, 27, 36, 45 or 54 female P. elaeisis, respectively. The females of the parasitoid remained in contact with pupae for 24 hours in glass tubes (14.0 x 2.2 cm), packed in a climatic chamber regulated at 25 ± 2°C, 70 ± 10% relative humidity and photo phase of 12 hours. With the exception of density 1:1 (72.72%), in other densities parasitism was 100%. Adults of P. elaeisis did not emerge from pupae at densities of 1:1 and 9:1, but 100.0% of parasitoid emergence was observed at the density of 45:1 and 54.54% at 54:1. The duration of the life cycle of this parasitoid ranged from 20 to 28 days. P. elaeisis produced 49 to 589 descendants per pupa of B. mori. The sex ratio of P. elaeisis ranged from 0.93 ± 0.01 to 0.97 ± 0.01 without differences with 18, 27, 36, 45 and 54 females/host. This parasitoid should be reared with the density of 45 females per pupa of B. mori.

scholarly journals Assessment of reproductive potential in patients after myomectomy

2021 ◽  
Vol 8 (1) ◽  
pp. 35-39
Author(s):  
Yan Van ◽  
Yuliya A. Romadanova ◽  
Alla A. Bakhvalova ◽  
Ekaterina V. Fedina ◽  
Aleksandr A. Zinov’yev ◽  
...  
Keyword(s):  
Surgical Approach ◽  
Ovarian Function ◽  
Reproductive Potential ◽  
Morphological Structure ◽  
Clinical Situation ◽  
Functional Restoration ◽  
Hormonal Profile ◽  
Abdominal Myomectomy ◽  
Time Required ◽  
Selection Of

The aim of the study is to assess the restoration of anatomical and functional integrity of the uterus and identify changes in hormonal profile in women after laparoscopic and abdominal myomectomy. Material and methods. 58 patients aged 36,2 5,9 years old with uterine myoma underwent myomectomy: 31 patients underwent laparoscopic myomectomy and 27 patients underwent abdominal myomectomy. The selection of surgical approach didnt depend on the size, the number and localization of uterine myomas and the patients concomitant pathology. The hormonal profile of the patients including AMH level was assessed befor myomectomy and in the 6 months after the operation. Postoperative assessment was performed on day 5th8th after surgery and in 1 and 6 months after myomectomy. Results. No significant differences were found in the processes of reparation of the uterus and in hormonal profile of the patients after laparoscopic or abdominal myomectomy. The time required for the patients reabilitation and for the restoration of the ovarian function and uterine morphological structure was similar in both groups. Conclusion. The hormonal profile of the patients and the anatomical and functional restoration of myometrium after myomectomy doesnt depend on the surgical approach if myomectomy is performed by an experienced surgeon after the correct assessment of the clinical situation.

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