scholarly journals Method of individual forecasting of sow reproductive performance on the basis of a non-linear canonical model of a random sequence

2020 ◽  
Vol 27 (4) ◽  
pp. 309-313
Author(s):  
I. P. Atamanyuk ◽  
V. Y. Kondratenko ◽  
A. S. Kramarenko ◽  
O. E. Novikov ◽  
V. Y. Lykhach
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Random Sequence ◽  
Markov Property ◽  
Canonical Model ◽  
Production Cycle ◽  
Size Change ◽  
Lower Estimation ◽  
Non Linear ◽  
Sow Reproduction

Improvement of sow reproductive performance is a key factor determining the efficiency of the pig production cycle and profitability of pork production. This article presents the solution of an important scientific and practical problem of individual forecasting of sow reproduction . The population used for the present study is from a pig farm managed by the Limited Liability Company (LLC) ‘Tavriys’kisvyni’ located in Skadovsky district (Kherson region, Ukraine). The experimental materials used for this study consisted of 100 inds. of productive parent sows of the Large White breed.The litter size traits – the total number of piglets born (TNB), number of piglets born alive (NBA) and number of weaned piglets (NW) – were monitored in the first eight parities over an eleven year period (2007–2017). The method of the forecasting of sow litter size is developed based on the non-linear canonical model of the random sequence of a litter size change. The proposed method allows us to take maximum account of stochastic peculiarities of sow reproductive performance and does not impose any restrictions on the random sequence of a litter size change (linearity, stationarity, Markov property, monotony, etc.). The block diagram of the algorithm presented in this work reflects the peculiarities of calculation of the parameters of a predictive model. The expression for the calculation of an extrapolation error allows us to estimate the necessary volume of a priori and a posteriori information for achieving the required quality of solving the forecasting problem. The results of the numerical experiment confirmed the high accuracy of the proposed method of forecasting of sow reproduction. The method offered by us almost doubles the accuracy of forecasting of sow litter size compared to the use of the Wiener and Kalman methods. Thus, average forecast error decreases across the range of features TNB (1.71), NBA (1.68) and NW (1.25 piglets). Apparently, this may reflect a higher level of manifestation of the genetically determined level of individual sow fertility at the moment of piglet weaning. The higher adequacy of the developed mathematical model with regard to NW can be also due to the fact that the relations between sow litter size in different farrowings primarily have a non-linear character, which is taken into maximum account in our offered model. Given non-linearity, on the other hand, turns out to be a significant factor determining a lower estimation of the repeatability value for NW compared to the estimations for TNB and NBA. The use of the developed method will help to improve the efficiency of pig farming.

Studies in sow reproduction 1. The effect of nutrition between weaning and remating on the reproductive performance of primiparous sows

1972 ◽  
Vol 15 (3) ◽  
pp. 259-264 ◽  
Author(s):  
P. H. Brooks ◽  
D. J. A. Cole
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Post Partum ◽  
Large White ◽  
The Mean ◽  
Sow Reproduction

SUMMARYFollowing weaning of their first litter at 42 days post partum, 36 Landrace × (Landrace × Large White) sows were fasted for 24 hr then allocated to one of three feed levels, 1·8, 2·7 and 3·6 kg food/day, until the day after mating. During pregnancy all the sows received 1·8 kg food/day.The incidence of infertility and anoestrus was greatest for sows fed 1·8 kg/day and least for sows fed 3·6 kg·day. Sows fed 1·8 kg/day took significantly (P < 0·01) longer (21·6 + 3·0 days) to return to oestrus than sows fed 3·6 kg/day (9·2 ± 2·2 days). The mean litter size for sows fed 1·8, 2·7 and 3·6 kg food/day was 9·4 ± 0·9, 10·1 ± 0·8 and 11·5 ± 0·6 piglets respectively, but these differences were not significant.

Studies in sow reproduction. 2. The effect of lactation length on the subsequent reproductive performance of the sow

1975 ◽  
Vol 20 (3) ◽  
pp. 401-406 ◽  
Author(s):  
D. J. A. Cole ◽  
M. A. Varley ◽  
P. E. Hughes
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Curvilinear Relationship ◽  
Large White ◽  
Lactation Length ◽  
Average Litter Size ◽  
The Relationship ◽  
Sow Reproduction

SUMMARYForty litters were weaned from their Landrace × Landrace × Large White dams at 2-day intervals to give a range of lactation lengths from 4 to 42 days. A significant (P<0·001) negative curvilinear relationship was observed between lactation length and the interval from weaning to first oestrus. This period was increased by 4·2 days with the reduction of lactation from 42 to 4 days. The relationship between lactation length and the interval from farrowing to remating was significant (P<0·001) and positively linear over the whole range of observations. A decrease of 1 day in lactation length reduced this interval by 0·91 days. Very short lactations were associated with reduced litter size at the following farrowing; sows weaned after lactation lengths between 4 and 21 days had an average litter size of 9–6 piglets born per litter in the next parity, whereas sows weaned following lactation lengths between 21 and 42 days had an average of 12·7 piglets born in the next parity (P<0·01).

Studies in sow reproduction 4. The effect of level of feeding in lactation and during the interval from weaning to remating on the subsequent reproductive performance of the early-weaned sow

1976 ◽  
Vol 22 (1) ◽  
pp. 71-77 ◽  
Author(s):  
M. A. Varley ◽  
D. J. A. Cole
Keyword(s):  
Treatment Group ◽  
Litter Size ◽  
Reproductive Performance ◽  
Lactation Period ◽  
Weight Changes ◽  
Enzootic Pneumonia ◽  
Treatment Groups ◽  
Group Control ◽  
Sow Reproduction

SummarySeventy-five enzootic pneumonia-free female pigs (sows) were allocated at random to one of five treatment groups. Four of these groups were weaned following a 10-day lactation period and were fed either 2 or 4 kg per day in lactation and either 2 or 4 kg per day from weaning to remating, such that the patterns of feeding for the four groups in the two periods were: 4 kg, 4 kg (HH); 4 kg, 2 kg (HL); 2 kg, 4 kg (LH) and 2 kg, 2 kg (LL). A fifth treatment group (control) was weaned following a 42-day lactation period and was fed up to 6·3 kg/day, depending on litter size and 2·7 kg/day from weaning to remating. Level of feeding for the four early-weaned groups in both lactation and in the interval from weaning to remating significantly (P < 0·001) affected the weight changes of the sows during these periods. The interval from weaning to oestrus for the early-weaned sows (8·2 days) was significantly (P < 0·001) greater than for the control sows (4·5 days), but this interval was not affected by level of feeding either in lactation or in the remating period for the early-weaned sows. Litter size at the subsequent farrowing for the early-weaned sows (9·3 piglets) was significantly (P < 0·001) less than litter size for the control sows (12·0 piglets). Level of feeding in lactation or in the weaning to remating period had no effect on subsequent litter size of the early-weaned sows.

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 &gt; 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 &lt; 0.05) in NOV (2.09) than MAR (1.68) and JUL (1.82). Lamb survival at birth was reduced (P &lt; 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 &lt; 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 &lt; 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.

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

scholarly journals Effects of cooling on the reproductive performance of gilts

2016 ◽  
Vol 20 (2) ◽  
pp. 357-361
Author(s):  
J.O. Oyedeji ◽  
G.O. Imagbenikaro
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Reproductive Performance ◽  
Feed Intake ◽  
Cooling System ◽  
Large White ◽  
Feed Cost ◽  
Randomized Design ◽  
Significant Difference ◽  
Level Of Significance

The study examined the effect of cooling on the reproductive performance of gilts using 27 Large White Experimental Gilts on a Completely Randomized Design (CRD) with 3 systems of cooling, namely Wallow Cooling (WC), Sprinkler Cooling (SC) and Zero Cooling (ZC). Gilts were weighed at the commencement of the experiment and thereafter fed ad libitum from service to farrowing. Feed intake till farrow, feed cost, gilt weight at farrow, date of farrow, litter size and weight were recorded. The feed/piglet weight, feed intake/litter, feed cost/litter and birth weight/piglet were derived. The results showed that feed intake per litter and feed per piglet weight were highest for gilts placed on WC(P< 0.05), followed by SC and least for sow placed on ZC; gilt weight before farrow was highest for sow placed on SC (69.78±0.92), followed by ZC (69.33±0.94) and least for gilts placed on WC (67.33±0.87); litter sizes of gilts placed under the WC and SC systems were similar (5.6±0.41) while that under the ZC system was comparatively smaller (5.4±0.40);while the date of farrow was lowest in the ZC system (113.8±0.32) followed by SC (114.0±0.33) and highest under the WC (114.1±0.33). However, the feed intake per litter, feed per piglet weight, litter sizes of gilts, birth weight per piglet of gilts and the average date of farrow among gilts placed on WC, SC and ZC were not statistically different at 5% level of significance. Though, there is no significant difference in the performance among gilts placed on WC, SC and ZC, temperature regulation through provision of efficient cooling system in piggery would help to increase litter size, improve feed intake per litter and reduce the average cost of feeding gilt per day in maximizing reproductive performances in pigs.Keywords: Cooling, gilts, service, farrow, piggery, litter size, piglet and birth weight

scholarly journals An approach for experiment evaluations for multiple harvests crops based on non-linear regression

2021 ◽  
Vol 39 (3) ◽  
pp. 250-257
Author(s):  
Alessandro Dal’Col Lúcio ◽  
Maria Inês Diel ◽  
Bruno G Sari
Keyword(s):  
Linear Regression ◽  
Growth Models ◽  
Fruit Production ◽  
Production Cycle ◽  
Total Production ◽  
Biological Processes ◽  
Production Potential ◽  
Non Linear ◽  
Using Data ◽  
The Moment

ABSTRACT Biologically based growth models can be an alternative in identifying the productive response of multiple harvest vegetables. By interpreting the estimates of the parameters of the models, it is possible to estimate the total production, the rate of fruit production, and the moment when the crop reaches its maximum production potential. Besides, by estimating confidence intervals, these responses can be compared between genotypes or between different treatments. Therefore, the purpose of this manuscript is to present a literature review, and a detailed step-by-step, to interpreting the evolution of the production cycle of vegetables with multiple harvests crops based on non-linear regression. All the requirements that must be met in this type of analysis were presented in detail based on non-linear regression, providing the necessary steps for this type of analysis in details. Demonstration is given using data from strawberry cultivation along with the associated R scripts and interpretation of analysis output in material supplemental. This approach can allow for more relevant inferences than standard means analyses through better examination and modeling of the underlying biological processes.

Influence of farm, parity, season and litter size on the lactation curve parameters of white British dairy goats

1993 ◽  
Vol 57 (1) ◽  
pp. 99-104 ◽  
Author(s):  
J. C. Williams
Keyword(s):  
Standard Deviation ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Litter Size ◽  
Parameter Estimates ◽  
Model Parameters ◽  
Dairy Goats ◽  
Lactation Curve ◽  
Non Linear ◽  
Research Institute

AbstractThe following goat lactation model was fitted (using non-linear regression) to 407 lactations from five commercial goat dairies and one Research Institute goat herd: y = A exp (B(l + n'/2)n' + Cn' 2 - 1·01/n) where y = daily yield in kg; n = day of lactation (post parturition); and n' = (n -150)1100.Influence of farm, parity and season on the parameter estimates for 376 individual lactations was studied, using multiple linear regression. The models adopted were of the form: A = 1·366 + 1·122 × parity - 0·137 × parity2; ln(-B) = - 1·711 + 0·107 × parity + 0·512 season one; C = 0·037, with a standard deviation for A of 0·658, for ln(-B) of 0·636 and for C of 0·127.Influence of litter size on parameters was investigated for the Research Institute herd. There was no evidence of an effect on any of the model parameters.

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