Efficiency of timed pregnancies in C57BL/6 and BALB/c mice by mating one male with up to four females

2020 ◽  
Vol 54 (5) ◽  
pp. 461-468 ◽  
Author(s):  
Martina Dorsch ◽  
Isabell Wittur ◽  
Wiebke Garrels
Keyword(s):  
Pregnancy Rate ◽  
Litter Size ◽  
Accurate Estimate ◽  
F1 Hybrids ◽  
Weaning Weight ◽  
Oestrus Cycle ◽  
Wide Range

For a wide range of biomedical approaches, an accurate estimate of the age of embryos or pups is important. Overnight mating is the method that is mostly used to establish timed pregnancies. The oestrus cycle in mice repeats every four to five days. So, not all females will get pregnant because they are not in oestrus. Therefore, the aim of this study was to analyse whether polygamous mating could increase the rate of timed pregnancies per breeding cage and female. We compared overnight timed mating regimes with up to four females per male, using C57BL/6 and BALB/c mice as well as F1 hybrids of these two strains. The number of vaginal plugs, number of females that gave birth and weaned litter (including size and weaning weight) were recorded. Our results showed that the plug and pregnancy rate decreased, but the productivity per breeding cage increased for polygamous mating regimes. The proportion of females with vaginal plugs and females that gave birth was significantly higher in monogamous mating. The proportion of plugged females that gave birth, as well as litter size and weaning weight, were not influenced by the mating regime. After analysing 513 breeding cages with a total of 1090 females, we found that polygamous mating with up to three females per male can increase the number of timed pregnancies. However, in the mating regime with more than three females, the rate of timed pregnancy as well as number of pups per female declined.

scholarly journals 269 Effects of high phytase supplementation in lactation diets on sow and litter performance

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 101-102
Author(s):  
Kelsey L Batson ◽  
Hilda I Calderon Cartagena ◽  
Robert D Goodband ◽  
Jason C Woodworth ◽  
Mike D Tokach ◽  
...  
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Feed Intake ◽  
Control Diet ◽  
Small Scale ◽  
Body Weight Change ◽  
Weaning Weight ◽  
Commercial Trial ◽  
Quadratic Response ◽  
Dietary Treatments

Abstract A total of 109 sows (Line 241; DNA, Columbus, NE) were used in a study to evaluate the effect of increasing phytase concentration in lactation diets on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos 2700; DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The same STTD P and Ca concentrations were formulated for the phytase diets considering a release of 0.132 STTD P and 0.094 STTD Ca in both diets. Diets were fed from d 107 of gestation until weaning (d 18 ± 2). Litters were cross-fostered within treatment until 48 h post-farrowing to equalize litter size. Linear and quadratic response to phytase concentration was evaluated using the lmer function in R. There was no evidence for difference in sow body weight change, farrowing performance, wean-to-estrus interval, or litter size among dietary treatments. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P=0.093) as phytase increased. Although not significant (linear, P =0.226), farrowing duration decreased as phytase increased. Litter weaning weight increased (quadratic, P=0.039) and overall litter gain increased (quadratic, P=0.047) with 1,000 FYT of phytase. In summary, sow feed intake tended to increase linearly with increasing phytase; however, feeding 1,000 FYT/kg maximized overall litter gain and weaning weight. This small-scale study suggests sow and litter performance benefits due to high inclusions of dietary phytase; however, a commercial trial with more sows is warranted to confirm these results.

scholarly journals 142 Reproductive performance of land race hair sheep ewes in different breeding seasons under a semi-continuous production

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 76-76
Author(s):  
Stephan Wildeus ◽  
Dahlia O’Brien
Keyword(s):  
Pregnancy Rate ◽  
Litter Size ◽  
Production System ◽  
Continuous Production ◽  
Transrectal Ultrasound ◽  
Late Gestation ◽  
Production Cycle ◽  
Hair Sheep ◽  
Mating Period ◽  
Lamb Survival

Abstract A system for semi-continuous lamb production was evaluated using Barbados Blackbelly and St. Croix hair sheep ewes under 8-mo accelerated mating. Ewes were managed in a forage-based production system using rotational grazing. Two flocks of ewes (n = 30–35), equally representing the breeds, were bred 4 mo apart. Ewes were synchronized by feeding melengestrol acetate for 10 d, and mated in two single sire groups to like breed sires in November (NOV), March (MAR), and July (JUL) in a 25-d mating period. Pregnancy was recorded by transrectal ultrasound 22 d after breeding. Ewes were supplemented with corn/soybean meal during late gestation (0.75% of BW) and during lactation (1.5% of BW). They lambed on pasture with limited supervision, and lambs were weaned at 2 mo of age. Lambs had access to the supplement provided to ewes. Ewe performance (pregnancy rate, litter size, lamb survival, and birth and weaning weight) was recorded during a 2 yr production cycle, and analyzed for the effect of mating season. Pregnancy rate was not statistically different (P > 0.1) between season, and ranged from 93.9% in NOV, to 85.9 and 86.6% in MAR and JUL. Litter size (lambs born/ewe lambing) was higher (P < 0.05) in NOV (2.09) than MAR (1.68) and JUL (1.82). Lamb survival at birth was reduced (P < 0.001) in JUL (86.5%) compared to NOV (99%) and MAR (100 %), but was not different between seasons for survival to weaning (86 to 90%). Lamb birth weights were higher (P < 0.05) in MAR (3.16 kg) than JUL (2.99 kg), with NOV (3.05 kg) intermediate, while lamb weaning weights were higher (P < 0.001) in NOV (13.6 kg) compared with MAR (11.9 kg) and JUL (11.4 kg) mating. Data suggest that dual flock, accelerated mating of landrace hair sheep ewes can produce lamb cohorts of similar size in 4 mo intervals under a low-input, forage-based production system.

scholarly journals PSIX-19 The impact of piglet nursing location along the sow udder line on piglet gain and subsequent weaning weight

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 183-184
Author(s):  
Shannon L Dierking ◽  
Harold J Monegue ◽  
Merlin D Lindemann
Keyword(s):  
Weight Gain ◽  
Litter Size ◽  
Biological Function ◽  
Critical Factor ◽  
Lactation Period ◽  
Weaning Weight ◽  
Nutrient Density ◽  
And Performance ◽  
The Impact ◽  
Gland Development

Abstract Piglet weaning weight is a critical factor that influences post-weaning growth and performance. Weaning weight is a function of birth weight and the amount and nutrient density of the milk consumed during lactation. Milk production is influenced by sow mammary gland development and diet consumption but may also be a biological function of teat location along the udder line. The objective of this study was then to determine the effects of piglet nursing location along the udder on overall piglet gain and weaning weight. A total of 1,078 individual piglets were observed during the nursing period at three time points during lactation. The teat pairs along the udder line were labeled from anterior to posterior (1-7, respectively) to define nursing location. At the end of the lactation period, the observed piglet nursing location was evaluated for both actual weaning weight and overall piglet weight gain during lactation. Data were evaluated by analysis of variance with the statistical model utilizing litter size as a covariate. As expected, when litter size was utilized as a covariate, there was a significant effect on piglet weaning weight (P < 0.0001), and there was both a linear and quadratic effect of location (L, P < 0.0001; Q, P = 0.0009) on both weaning weight and lactation piglet gain. Heavier piglets were weaned from more anterior teats (teat pairs 1-4), with the numerically heaviest piglets weaned from teat pair 4 (6.12 kg), with the lowest weight piglets being weaned from teat pair 7 (5.17 kg). Piglet weight gain during lactation was impacted by litter size (P < 0.0001), but nursing location did not affect lactation weight gain (P = 0.57). Due to the differences in piglet weights at weaning, it can be concluded that piglet nursing location influences overall piglet weaning weight.

Influence of litter size and breed of sire on carcass weight and quality of lambs

1970 ◽  
Vol 12 (2) ◽  
pp. 281-290 ◽  
Author(s):  
H. P. Donald ◽  
J. L. Read ◽  
W. S. Russell
Keyword(s):  
Litter Size ◽  
Carcass Weight ◽  
Wide Range ◽  
Kidney Fat

SUMMARYIn order to obtain a wide range of live weights, two Oxford Down, two Southdown, and two Soay rams of recent feral origin, were used to sire lambs from 169 crossbred ewes. These ewes had been bred from Blackface ewes mated to Border Leicester, Dorset Hora, Clun Forest, Finnish Landrace and Tasmanian Merino rams. Of the 282 lambs weaned by the crossbred ewes, 61 were singles, 166 twins, 51 triplets and 4 quadruplets. Carcass data were obtained from all but three of them.Oxford Down cross lambs were, in terms of fitted values, 10 kg heavier and 4 days younger than Soay cross lambs and 6 kg heavier and 2 days younger than Southdown cross lambs when slaughtered. Twins and triplets were 1·4 and 2·1 kg, respectively, lighter than singles and were 37 and 58 days older than singles. Ewes of the heaviest groups produced heavier lambs in a shorter time than ewes of the lightest groups.The Soay cross lambs showed a higher killing-out percentage, less tail fat, and more kidney fat, than the Southdown and Oxford Down cross lambs.Carcass characters made little if any difference to the price paid for the lambs which depended mainly on weight. Receipts from lambs were highest when the most fertile ewes were mated to the largest rams.

HEAVY TRAFFIC APPROXIMATIONS FOR A SYSTEM OF INFINITE SERVERS WITH LOAD BALANCING

1999 ◽  
Vol 13 (3) ◽  
pp. 251-273 ◽  
Author(s):  
Philip J. Fleming ◽  
Burton Simon
Keyword(s):  
State Space ◽  
Heavy Traffic ◽  
Joint Probability ◽  
Mass Function ◽  
Accurate Estimate ◽  
The State ◽  
Probability Mass Function ◽  
Traffic Loads ◽  
Wide Range ◽  
Heavy Traffic Approximations

We consider an exponential queueing system with multiple stations, each of which has an infinite number of servers and a dedicated arrival stream of jobs. In addition, there is an arrival stream of jobs that choose a station based on the state of the system. In this paper we describe two heavy traffic approximations for the stationary joint probability mass function of the number of busy servers at each station. One of the approximations involves state-space collapse and is accurate for large traffic loads. The state-space in the second approximation does not collapse. It provides an accurate estimate of the stationary behavior of the system over a wide range of traffic loads.

scholarly journals The effects of breed, sire and environmental factors on the birth and weaning weight of lambs

2020 ◽  
Vol 108 (4) ◽  
pp. 70-78
Author(s):  
S. Kramarenko ◽  
◽  
A. Kramarenko ◽  
S. Lugovoy ◽  
D. Balan ◽  
...  
Keyword(s):  
Birth Weight ◽  
Environmental Factors ◽  
Litter Size ◽  
Analysis Of Variance ◽  
Significant Influence ◽  
Research Data ◽  
Weaning Weight ◽  
Factors Influencing ◽  
Size Type

The effects of breed, sire and environmental factors on the birth and weaning weight of lambs The aim of this study was to determine the effect of some important factors influencing on the birth and weaning weight variability in lambs. Data from 2603 ewes was included in the analysis, where 3961 lambs were obtained during the five years of the research. Data was tested using analysis of variance (ANOVA) with the GLM procedure of Minitab Release 13.1. Our results presented significant influence on the year of lambing, breed, ram genotype, age of a dam, type of a birth (litter size), sex of a lamb and on the birth weight and weaning weight of lambs. Keywords: birth and weaning weight of lambs; ram genotype; year of lambing; age of ewes; litter size (type of birth); sex of a lamb; the Ascanian fine-fleece breed.

scholarly journals Tissue-specific cis-regulatory divergence implicates a fatty acid elongase necessary for inhibiting interspecies mating in Drosophila

2018 ◽  
Author(s):  
Peter A. Combs ◽  
Joshua J. Krupp ◽  
Neil M. Khosla ◽  
Dennis Bua ◽  
Dmitri A. Petrov ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Candidate Genes ◽  
Molecular Mechanisms ◽  
Sister Species ◽  
F1 Hybrids ◽  
Rna Seq ◽  
Fatty Acid Elongase ◽  
Tissue Specific ◽  
Regulatory Changes ◽  
Wide Range

AbstractPheromones known as cuticular hydrocarbons are a major component of reproductive isolation in Drosophila. Individuals from morphologically similar sister species produce different sets of hydrocarbons that allow potential mates to identify them as a suitable partner. In order to explore the molecular mechanisms underlying speciation, we performed RNA-seq in F1 hybrids to measure tissue-specific cis-regulatory divergence between the sister species D. simulans and D. sechellia. By focusing on cis-regulatory changes specific to female oenocytes, we rapidly identified a small number of candidate genes. We found that one of these, the fatty acid elongase eloF, broadly affects both the complement of hydrocarbons present on D. sechellia females and the propensity of D. simulans males to mate with those females. In addition, knockdown of eloF in the more distantly related D. melanogaster led to a similar shift in hydrocarbons as well as lower interspecific mate discrimination by D. simulans males. Thus, cis-regulatory changes in eloF appear to be a major driver in the sexual isolation of D. simulans from multiple other species. More generally, our RNA-seq approach proved to be far more efficient than QTL mapping in identifying candidate genes; the same framework can be used to pinpoint cis-regulatory drivers of divergence in a wide range of traits differing between any interfertile species.

The Influence of Fatness and Fat Change on the Performance of Breeding Gilts

1987 ◽  
Vol 1987 ◽  
pp. 63-63
Author(s):  
P.R. Eastham ◽  
C.T. Whittemore
Keyword(s):  
Treatment Group ◽  
Litter Size ◽  
Feeding Strategies ◽  
Not Given ◽  
Large White ◽  
Weaning Weight ◽  
Live Births ◽  
Creep Feed ◽  
Weight Gains ◽  
High Level

Weight gains can occur with substantial fat losses and therefore liveweight change is unlikely to form the basis of feeding strategies, whereas the fatness of the animal may be a more appropriate criterion. Eighty Large White x Landrace gilts were first mated at 123.5 kg ± 1.54 with a P2 of 14.5 mm ± 0.24 [Meritronics] and 12.7 mm ± 0.19 (Vetscan]. Half these gilts were fed to be fat [F] at parturition [target 20-24 mm P2) and half were fed to be thin [T] [target 10-14 mm P2). F gilts consumed more feed during pregnancy and gained more weight and backfat than T gilts [all differences between the 2 treatments were significant P˂0.001). The number of piglets born and the number of live births were not affected by feeding gilts to be fat or thin, but fat gilts produced significantly heavier piglets. After parturition, half of both F and T gilts were offered either 7 kg of food per day [H] or 3 kg per day [L] and half were sucked by litters of 5 piglets and half by litters of 10 piglets during a 28 day lactation. Piglets were not given creep feed. Fatness of the gilts at parturition, feed level during lactation and sucking litter size all significantly influenced both the absolute and the change in liveweight and backfat from farrowing to weaning. Weight and P2 changes are shown in Figures 1 and 2. The performance of the litter was also significantly affected by the fatness of the gilt at parturition and by the number of piglets sucking. Results for each treatment group are given in Table 1. Animals offered the high level of feed during lactation had a significantly shorter interval between weaning and conception. There were also positive relationships between readiness to rebreed and absolute liveweight and absolute fatness.

scholarly journals Echocardiography and Pulmonary Arterial Hypertension

2016 ◽  
Vol 68 (4) ◽  
Author(s):  
Eduardo Bossone ◽  
Rodolfo Citro ◽  
Alberto Ruggiero ◽  
Bettina Kuersten ◽  
Giovanni Gregorio ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Structural Changes ◽  
Pulmonary Arteries ◽  
Progressive Increase ◽  
Accurate Estimate ◽  
Therapeutic Interventions ◽  
Wide Range ◽  
Advanced Stages ◽  
Pulmonary Arterial

Pulmonary Arterial Hypertension (PAH) is an heterogeneous condition brought on by a wide range of causes. It is characterized by structural changes in small pulmonary arteries, that produce a progressive increase in pulmonary artery pressure and pulmonary vascular resistance, ultimately leading to right ventricle failure and death. Given the non-specific nature of its early symptoms and signs, PAH is often diagnosed in its advanced stages. Along with a careful clinical assessment and an accurate electrocardiogram/Chest X-ray interpretation, echocardiography is an essential test in the evaluation of patient with PAH. In fact it not only provides an accurate estimate of pulmonary pressure at rest and during exercise, but may also help to exclude any secondary causes, predict the prognosis, monitor the efficacy of specific therapeutic interventions and detect the preclinical stage of the disease.

In vitro-produced horse embryos exhibit a very narrow window of acceptable recipient mare uterine synchrony compared with in vivo-derived embryos

2019 ◽  
Vol 31 (12) ◽  
pp. 1904 ◽  
Author(s):  
Juan Cuervo-Arango ◽  
Anthony N. Claes ◽  
Tom A. E. Stout
Keyword(s):  
Pregnancy Rate ◽  
Pregnancy Loss ◽  
Oestrous Cycle ◽  
Ongoing Pregnancy ◽  
Ongoing Pregnancy Rate ◽  
Wide Range ◽  
In Pregnancy

In recent years, the number of equine invitro-produced embryos (IVP) has increased markedly; as yet, there are few reports on what constitutes an ‘ideal’ recipient for an IVP embryo. This study retrospectively investigated the effects of recipient mare oestrous cycle characteristics on the likelihood of pregnancy after transfer of IVP (n=264) and invivo-derived embryos (n=262). IVP embryos tolerated only a narrow window of recipient mare ‘synchrony’, with transfer on Day 4 after ovulation resulting in a higher likelihood of ongoing pregnancy (69%) than transfer on Days 3, 5 or 6 (53.2%, 41.3% and 23.1% respectively; P=0.02). In contrast, Day 8 invivo-derived embryos tolerated a wide range of uterine (a)synchrony, with no difference in pregnancy or pregnancy loss for recipients that ovulated between Day 4 and Day 9 before transfer. However, transferring invivo-derived embryos to recipients that had a longer oestrus preceding transfer resulted in higher Day 12 and ongoing pregnancy rate (P<0.01). This effect was not significant in IVP embryos. In conclusion, Day 6–8 IVP blastocysts survive best after transfer to Day 4 recipient mares; Day 8 invivo-derived embryos survive equally well in Day 4–9 recipients, but do better in mares that have a long preceding oestrus.

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