THE INFLUENCE OF ALTERED WEANING MANAGEMENT ON PIGLET GROWTH AND SOW REPRODUCTIVE PERFORMANCE

1989 ◽  
Vol 69 (1) ◽  
pp. 33-37 ◽  
Author(s):  
J. GILBERTSON ◽  
P. A. THACKER ◽  
R. N. KIRKWOOD
Keyword(s):  
Reproductive Performance ◽  
Treatment Effect ◽  
Crude Protein ◽  
Pulse Frequency ◽  
Free Access ◽  
Control Groups ◽  
Creep Feed ◽  
Body Weights ◽  
Piglet Growth ◽  
And Control

An experiment was undertaken to investigate the influence of split-weaning of litters 7 d before full weaning on the growth of piglets and the reproductive performance of sows. The litters of 27 Yorkshire × Landrace sows were assigned to be either split-weaned (heaviest piglets removed at 21 d of lactation; n = 13) or to act as controls (all piglets weaned at 28 d of lactation; n = 14). The influence on sow and litter performance was monitored. During lactation, mean sow feed intakes in the split-weaned and control groups were 6.9 ± 0.1 and 6.7 ± 0.2 kg d−1, respectively. The diet was formulated to provide 12.3 MJ DE kg−1 and 15.7% crude protein. Nursing piglets were allowed free access to a 20% crude protein creep feed from 7 d of age. Weaned piglets were fed ad libitum a commercial starter diet containing 18% crude protein. Split-weaning had no effect on either the weaning to estrus interval or subsequent litter size (4.5 ± 0.1 vs. 4.3 ± 0.4 d and 12.7 ± 0.9 vs. 13.0 ± 0.9 pigs, for split-weaned and control sows, respectively). However, while control sows lost weight between 21 and 28 d of lactation, the split-weaned sows gained weight (P < 0.02). There was no treatment effect on body weights of nursing piglets but weaning of the heavy piglets at 21 d resulted in a lower (P < 0.05) body weight at 28 d. On days 21 and 28, four sows from each group were blood sampled via indwelling vena caval cannulae at hourly intervals for 10 h. Also, samples were taken every 15 min for 4 h on these days. No treatment effect was noted for mean serum concentrations of luteinizing hormone (LH) or follicle stimulating hormone (FSH). Similarly, there was no effect on LH pulse frequency or amplitude. It is concluded that, in the absence of excessive sow weight loss or prolonged weaning to estrus intervals, the introduction of a split-weaning regime will not enhance sow or litter performance. Key words: Split-weaning, piglet growth, sow performance

Reproductive performance of pigs selected for components of efficient lean growth

1994 ◽  
Vol 1994 ◽  
pp. 14-14
Author(s):  
J. C. Kerr ◽  
N. D. Cameron
Keyword(s):  
Growth Rate ◽  
Reproductive Performance ◽  
Crude Protein ◽  
Large White ◽  
Digestible Energy ◽  
Lean Growth ◽  
Creep Feed ◽  
Daily Food ◽  
Litter Traits ◽  
And Control

This study determined the correlated responses in reproductive performance after five generations of divergent selection for components of efficient lean growth rate in Large White pigs.Data were collected from five generations of pigs divergently selected for daily food intake (DFI), lean food conversion (LFC), lean growth rate on ad-libitum feeding (LGA) and lean growth rate on restricted or scale feeding (LGS). In each selection group, there were high, low and control lines, each consisting of 10 boars and 20 gilts. Animals were mated at around 9.5 months of age. Pregnant gilts were fed 2.5 kg daily and farrowed sows up to 3.5 kg twice daily of a 160 g/kg DM crude protein and 132 MJ/kg DM digestible energy ration. Animals were farrowed at 414 (s.d. 19.7) days of age, on average. No cross fostering was practised. Piglets were offered creep feed containing 235 g/kg DM crude protein and 160 MJ/kg DM digestible energy from 14 days and were weaned at an average of 35 (s.d. 3) days. Litter traits were measured on 1220 selected Large White gilts, with 13030 piglet birth weights and 9951 weaning weights.

scholarly journals Effects of Intrauterine Infusion of a Chitosan Solution on Recovery and Subsequent Reproductive Performance of Early Postpartum Dairy Cows with Endometritis: A Pilot Field Trial

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Hiroaki Okawa ◽  
Missaka M.P. Wijayagunawardane ◽  
Peter L.A.M. Vos ◽  
Osamu Yamato ◽  
Masayasu Taniguchi ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Polymorphonuclear Leukocytes ◽  
Prostaglandin F2α ◽  
Chitosan Solution ◽  
Control Group ◽  
Control Groups ◽  
Early Postpartum Period ◽  
Early Postpartum ◽  
And Control

This study investigated the efficacy of intrauterine infusion of a chitosan solution (CHT) on uterine recovery in early postpartum dairy cows with or without endometritis, and their subsequent reproductive performance. In Experiment 1, cows with endometritis at 3 weeks postpartum were administered CHT (n = 5) and prostaglandin F2α (PGF2α) (n = 4). Untreated cows (n = 7) served as the control group. In Experiment 2, 18 cows with a normally recovered uterus at the fresh cow check (mean, 35 days postpartum) were assigned to the CHT (n = 10) and control (n = 8) groups, and intrauterine infusion was conducted in the CHT group. Overall, in Experiment 1, the percentage of polymorphonuclear leukocytes significantly declined in the CHT group (32.3 ± 10.2 to 5.5 ± 2.4, p < 0.05) from week 3 to week 5, but no decline occurred in the PGF2α and control groups. In Experiment 2, the CHT and control groups showed no significant differences in reproductive parameters, suggesting the absence of adverse effects of CHT on fertility. These results suggest that intrauterine infusion of CHT in the early postpartum period effectively accelerates uterine recovery from endometritis and might be a suitable replacement for PGF2α administration.

scholarly journals Measuring the sensitivity of difference-in-difference estimates to the parallel trends assumption

2021 ◽  
pp. 263208432110613
Author(s):  
Landon Gibson ◽  
Frederick Zimmerman
Keyword(s):  
Sensitivity Analysis ◽  
Treatment Period ◽  
Treatment Effect ◽  
Statistical Tests ◽  
Sensitivity Analyses ◽  
Difference In Difference ◽  
Control Groups ◽  
Pre Treatment ◽  
Background Difference ◽  
And Control

Background. Difference-in-Difference makes a critical assumption that the changes in the outcomes, over the post-treatment period, are similar between the treated and control groups—the parallel trends assumption. Evaluation of this assumption is often done either by graphical examination or by statistical tests in the pre-treatment period. They result in a binary conclusion about the validity of the assumption. Purpose. This paper proposes a sensitivity analysis that quantifies the departure from parallel trends necessary to meaningfully change the estimated treatment effect. Results. Sensitivity analyses have an advantage over traditional parallel trends tests: they use all available data and thereby work even if only one pre-period is available, and they quantify the strength of unobserved confounder(s) required to change the conclusions of a study. Conclusions. We apply the sensitivity analysis metrics developed by Cinelli and Hazlett (2020) and illustrate them on two studies.

Effect of heat stress for specific period on juvenile traits, feed efficiency and some heat stress parameters in different genetic groups of broilers

2018 ◽  
Author(s):  
B. L.N. Reddy ◽  
K. S. Rajaravindra ◽  
U. Rajkumar ◽  
M. R. Reddy
Keyword(s):  
Heat Stress ◽  
Feed Efficiency ◽  
Control Groups ◽  
Naked Neck ◽  
Genetic Groups ◽  
Significant Difference ◽  
Body Weights ◽  
Pure Lines ◽  
And Control ◽  
Stress Parameters

To evaluate the effect of heat stress an experiment was conducted in which one cross (PB-1X Naked neck), two pure lines ( PB-1 and Naked neck) and corresponding control populations were generated simultaneously on the same day.120 chicks in PB-1X Naked neck (Control 120), 91 chicks in Naked neck pure( Control 82) and 81 chicks in PB-1 pure ( Control 80)were generated. Temperatures were raised (up to 40°C) by providing the two halogen lamps in each of the heat stressed genetic groups from 4-6 weeks of age. Body weights were recorded at 0, 2,4, 6 and 7 weeks of age along with conformational traits like breast angle and shank length at 6 weeks of age. 2ml of blood was collected at 6weeks of age from all the 6 genetic groups (10 birds from each) to estimate the heat stress parameters. Feed efficiency was recorded at 6 weeks and 7 weeks of age. Significant differences were found for SOD, CAT, ALP and GPx between heat stressed and control genetic groups. Higher estimates were found in heat stressed genetic groups as compared to corresponding control groups. For juvenile body weights in stressful conditions there is significant difference between genetic groups. Lower juvenile body weights were recorded in heat stressed genetic groups as compared to control groups. Lower feed efficiency was recorded in heat stressed genetic groups as compared to corresponding control groups.

scholarly journals Bootstrap bias correction for average treatment effects with inverse propensity weights

2019 ◽  
Vol 52 (2) ◽  
pp. 187-200
Author(s):  
GUBHINDER KUNDHI ◽  
MARCEL VOIA
Keyword(s):  
Propensity Score ◽  
Treatment Effect ◽  
Bias Correction ◽  
Treatment Effects ◽  
Potential Problem ◽  
Average Treatment Effect ◽  
Omitted Variables ◽  
Control Groups ◽  
Average Treatment ◽  
And Control

The estimated average treatment effect in observational studies is biased if the assumptions of ignorability and overlap are not satisfied. To deal with this potential problem when propensity score weights are used in the estimation of the treatment effects, in this paper we propose a bootstrap bias correction estimator for the average treatment effect (ATE) obtained with the inverse propensity score (BBC-IPS) estimator. We show in simulations that the BBC-IPC performs well when we have misspecifications of the propensity score (PS) due to: omitted variables (ignorability property may not be satisfied), overlap (imbalances in distribution between treatment and control groups) and confounding effects between observables and unobservables (endogeneity). Further refinements in bias reductions of the ATE estimates in smaller samples are attained by iterating the BBC-IPS estimator.

scholarly journals Lasso adjustments of treatment effect estimates in randomized experiments

2016 ◽  
Vol 113 (27) ◽  
pp. 7383-7390 ◽  
Author(s):  
Adam Bloniarz ◽  
Hanzhong Liu ◽  
Cun-Hui Zhang ◽  
Jasjeet S. Sekhon ◽  
Bin Yu
Keyword(s):  
Treatment Effect ◽  
Multivariate Regression ◽  
Asymptotic Variance ◽  
Ordinary Least Squares ◽  
Randomized Experiments ◽  
Control Groups ◽  
The Difference ◽  
Selection Operator ◽  
Simple Difference ◽  
And Control

We provide a principled way for investigators to analyze randomized experiments when the number of covariates is large. Investigators often use linear multivariate regression to analyze randomized experiments instead of simply reporting the difference of means between treatment and control groups. Their aim is to reduce the variance of the estimated treatment effect by adjusting for covariates. If there are a large number of covariates relative to the number of observations, regression may perform poorly because of overfitting. In such cases, the least absolute shrinkage and selection operator (Lasso) may be helpful. We study the resulting Lasso-based treatment effect estimator under the Neyman–Rubin model of randomized experiments. We present theoretical conditions that guarantee that the estimator is more efficient than the simple difference-of-means estimator, and we provide a conservative estimator of the asymptotic variance, which can yield tighter confidence intervals than the difference-of-means estimator. Simulation and data examples show that Lasso-based adjustment can be advantageous even when the number of covariates is less than the number of observations. Specifically, a variant using Lasso for selection and ordinary least squares (OLS) for estimation performs particularly well, and it chooses a smoothing parameter based on combined performance of Lasso and OLS.

scholarly journals Scientific And Economic Justification Of Application Of Symbiotic Polycomponent Fodder Additive In Feeding High Productive Cows

2021 ◽  
Vol 901 (1) ◽  
pp. 012026
Author(s):  
V G Kosolapova ◽  
N P Buryakov ◽  
O G Mokrushina ◽  
A V Kosolapov ◽  
D E Aleshin
Keyword(s):  
Milk Fat ◽  
Crude Protein ◽  
Feed Consumption ◽  
Feed Additive ◽  
Control Group ◽  
Control Groups ◽  
Lactating Cows ◽  
Blood Biochemical ◽  
And Control ◽  
Experimental Group

Abstract Research has been carried out on the use of the symbiotic “Rumimaster” in balanced diets of highly productive cows in the conditions of the breeding plant “Kirovskaya meadow-bog experimental station”. The experiment was carried out on two groups of animals in the middle of lactation with a duration of 90 days. The inclusion of the feed additive “Rumimaster” in the diet of experienced cows contributed to an increase in the gross production of natural and 4% fat milk by 124.5 kg and 128.4 kg, the yield of milk fat and milk protein by 5.2 and 4.1 kg, respectively. … The differences between the groups for these parameters were in the range of 5.1-5.7%. The productivity of cows for 305 days of lactation in the experimental group was higher than in the control by 7.5%. The symbiotic “Rumimaster” promoted the activation of digestion processes, which was reflected in the increase in the time of feed consumption and the duration of the chewing gum. The cows of the experimental group showed an increase in the level of digestibility of the main nutrients. In terms of the digestibility of crude protein and crude fiber, the experimental group of cows significantly exceeded the indicators of the control group by 3.3 and 3 absolute percent, respectively. The blood biochemical parameters of the animals of the experimental and control groups were within the physiological norm. The economic evaluation of the research results showed the effectiveness of the use of the symbiotic “Rumimaster” in the diets of lactating cows, which was expressed in the receipt of additional profit from one cow in the amount of 1,344.79 rubles for the period of experience and an increase in the profitability of milk production by 2.1 absolute percent.

scholarly journals A pilot study to determine the feasibility of a cluster randomised controlled trial of an intervention to change peer attitudes towards children who stutter

2018 ◽  
Vol 65 (1) ◽  
Author(s):  
Rizwana B. Mallick ◽  
Lehana Thabane ◽  
A.S.M. Borhan ◽  
Harsha Kathard
Keyword(s):  
Pilot Study ◽  
Treatment Effect ◽  
Dropout Rate ◽  
Control Group ◽  
Control Groups ◽  
Post Intervention ◽  
Peer Attitudes ◽  
Significant Difference ◽  
Randomised Controlled ◽  
And Control

Background: While randomised controlled trials (RCTs) are considered the gold standard of research, prior study is needed to determine the feasibility of a future large-scale RCT study. Objectives: This pilot study, therefore, aimed to determine feasibility of an RCT by exploring: (1) procedural issues and (2) treatment effect of the Classroom Communication Resource (CCR), an intervention for changing peer attitudes towards children who stutter. Method: A pilot cluster stratified RCT design was employed whereby the recruitment took place first at school-level and then at individual level. The dropout rate was reported at baseline, 1 and 6 months post-intervention. For treatment effect, schools were the unit of randomisation and were randomised to receive either the CCR intervention administered by teachers or usual practice, using a 1:1 allocation ratio. The stuttering resource outcomes measure (SROM) measured treatment effect at baseline, 1 and 6 months post-intervention overall and within the constructs (positive social distance, social pressure and verbal interaction). Results: For school recruitment, 11 schools were invited to participate and 82% (n = 9) were recruited. Based on the school recruitment, N = 610 participants were eligible for this study while only n = 449 were recruited, where there was n = 183 in the intervention group and n = 266 in the control group. The dropout rate from recruitment to baseline was as follows: intervention, 23% (n = 34), and control, 6% (n = 15). At 1 month a dropout rate of 7% (n = 10) was noted in the intervention and 6% (n = 15) in the control group, whereas at 6 months, dropout rates of 7% (n = 10) and 17% (n = 44) were found in the intervention and control groups, respectively. For treatment effect on the SROM, the estimated mean differences between intervention and control groups were (95% Confidence Interval (CI): -1.07, 5.11) at 1 month and 3.01 (95% CI: -0.69, 6.69) at 6 months. A statistically significant difference was observed at 6 months on the VI subscale of the SROM, with 1.35 (95% CI: 0.58, 2.13). Conclusion: A high recruitment rate of schools and participants was observed with a high dropout rate of participants. Significant differences were only noted at 6 months post-intervention within one of the constructs of the SROM. These findings suggest that a future RCT study is warranted and feasible.

scholarly journals The Effects of Ram Exposure, Progestogen and eCG on Reproductive Performance of Fat Tail Ewes in Non-Breeding Season

2021 ◽  
Author(s):  
Massoud - Talebkhan Garoussi ◽  
Omid Mavadati ◽  
Mohammad Ali Bahonar ◽  
Mehran Dabiri
Keyword(s):  
Breeding Season ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Control Group ◽  
Control Groups ◽  
Transabdominal Ultrasonography ◽  
Fat Tail ◽  
Equine Chorionic Gonadotropin ◽  
And Control ◽  
Lh Secretion

Abstract Sheep are considered short-day breeders. Exposure of rams to anestrus ewes results in an increase in LH secretion. The aims of this study was to determine whether the presence and exposure of rams can effect on reproductive performance such as: pregnancy rate, litter size, sex of lamb, fecundity rate and prolificacy rate of fat tail Iranian Shaal breed ewes in non-breeding season using progesterone (p4) analogue with or without equine chorionic gonadotropin (eCG). Totally, 100 ewes out of 138 non-cyclic ewes with <0.5ng/ml P4 were selected for this study. They were aged 2 to >7 years old. They were stratified to two groups (control and treatment). The ewes in treatment and control groups received 13 days a sponge containing 60 mg medroxyprogesterone acetate (MPA). The treatment group consists of 3 subgroups and each group contains 25 ewes equally. They were included: 1- P4, eCG and Ram exposure. 2- P4 and ram exposure. 3- P4 and eCG. Ewes in control group received only P4. The ewes were located in isolated corrals for 40 days. The ram to ewe ratio was 1 to 5. Twenty healthy rams were housed in an isolated pen from ewes with distance 1500 m during 40 days. Rams exposed three days before sponge withdraw (day 10). They were separated by considerable distance (2 meters) using fence. The related groups received 500 IU eCG on the day of sponge removal (day 13). The rams were released into the ewe flock after removing the sponge in treatment and control groups. Pregnancy diagnosis performed using transabdominal ultrasonography. The obtained data analyzed using SPSS version 16. The conception rate in treatment and control groups were differed significantly (P<0.01). The conception rate in P4+ram exposure+ eCG, P4+ramexposure and P4+ eCG were 96%(no.24), 80%(no.20) and 88%(no.22), respectively. However, the conception rate in control group was 60% (no. 15). The fecundity rates were 136%, 100% and 124% in treatment subgroups, however, it was 84% in control group, respectively. There were no significant differences among genus and weight of lambs in treatments subgroups and control group (P>0.05). It is concluded that ram exposure can increase significantly reproductive performance in non-breeding season fat tailed ewes Shaal breed.

scholarly journals Evaluation of the Single-Dose Toxicity of Capsaicin Pharmacopuncture in Rats

2020 ◽  
Vol 37 (3) ◽  
pp. 167-172 ◽  
Author(s):  
Ji Hye Hwang ◽  
Jaseung Ku ◽  
Chul Jung
Keyword(s):  
Animal Model ◽  
Single Dose ◽  
Saline Solution ◽  
Sprague Dawley ◽  
Control Groups ◽  
Male And Female ◽  
Sprague Dawley Rats ◽  
Body Weights ◽  
And Control ◽  
Safe Dose

Background: This study aimed to assess the toxicity of capsaicin (CP) pharmacopunture in an animal model.<br/>Methods: The toxicity of a single-muscular dose of CP (45.45 mg/mL) was evaluated in 6-week-old male and female Sprague-Dawley rats. A total of 20 rats were assigned to 2 groups which were sex and weight matched. All rats acclimatized for 1 week before receiving 1.0 mL of CP (45.45 mg/mL) or normal saline solution(control) intramuscularly. The general condition and mortality of the animals were observed. The rats were sacrificed 2 weeks after CP was administered and histopathology was performed.<br/>Results: No abnormal symptoms or deaths were observed, and there was no difference in body weights between the CP and control groups throughout the study. No significant differences in histopathology were observed between the groups.<br/>Conclusion: No toxicological changes related to the administration of CP were observed. This study indicated that the safe dose of CP in Sprague-Dawley rats was 1.0 mL of CP (45.45 mg/mL) or less. Further studies are needed to confirm the safety of CP in the human body.

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