Effects of porcine stress syndrome genotype on maternal traits in swine

Studies were conducted to evaluate maternal performance differences between females with different porcine stress syndrome (PSS) genotypes. Two data sets were used to conduct this evaluation. The first involved 870 records from 333 females from a synthetic line of pigs selected for their PSS susceptibility. The second data set involved 3100 records from 841 purebred Landrace females. Only records from normal (NN) and carrier (Nn) dams were included;The first study revealed that Nn females farrowed 0.91 and 0.69 more (P \u3c 0.05) live pigs than NN and positive (nn) females, respectively. No difference in litter birth weight of pigs born alive or proportion of pigs surviving from birth to transfer was observed between any dam PSS genotypes;Normal females had 0.57 more (P \u3c 0.05) pigs at birth than did nn females. Normal sows raised 0.49 more (P \u3c 0.05) pigs to 21 d than did nn females. Normal sows produced 6.20 kg and 2.86 kg heavier (P \u3c 0.05) 21-d litter weights than did nn and Nn females, respectively. The proportion of pigs surviving from transfer to 21 d favored (P \u3c 0.05) NN dams by 13.1% and 9.3%, respectively, compared to nn and Nn dams. Normal females had 0.24 more pigs per litter at 42 d although the difference was not significant. Normal and Nn dams produced (P \u3c 0.05) 8.22 kg and 5.16 kg, respectively, heavier litters at 42 d. A 7.69% and 4.48% survival rate to 42 d advantage (P \u3c 0.05) was found in litters of NN and Nn sows, respectively, when compared to nn sows. Normal and Nn dams had similar survival rates of their litters to 42 d;The results from the study involving NN and Nn purebred Landrace dams revealed no significant differences for number born alive, number at 21 d, 21-d litter weight, survival rate to 21 d, and farrowing interval. This data set was also used to estimate genetic parameters for these traits. Heritabilities ranged from 0.04 to 0.06 for number born alive, from 0.21 to 0.32 for number at 21 d, and from 0.14 to 0.21 for 21-d litter weight depending on the method of adjusting for environmental factors. Heritabilities of 0.21 and 0.02 were found for survival rate to 21 d and farrowing interval, respectively

Prolapse Incidence in Swine Breeding Herds Is a Cause for Concern

Beginning in the fall of 2014 there has been a general and widespread increase in the incidence of prolapse in the U.S. swine herd. The purpose of this manuscript is to review the incidence, causative factors and treatment of rectal, vaginal, uterine and preputial prolapses. Rectal and vaginal prolapses are most common in swine when compared to other prolapse types. The cause of prolapses supports a fixation mechanism failure overcome by pressure on or weakening of support tissue. The fundamental factors affecting the incidence for prolapses are many and include factors related to nutrition, physiology, hormones, genetics, environment and other disease factors such as chronic diarrhea, cough, and dystocia. Treatment of prolapsed swine includes surgical and therapeutic management that can lead to complete recovery. However, in most cases, euthanasia is the final result. Economic loss was calculated at approximately $5220 dollars/year/1000 sows

Digital Evaluation of Structural Phenotypes Common among Higher Parity Crossbred Sows

Two independent, commercial, crossbred sow populations were selected to compare feet and leg structure in order to identify commonalities among them that may contribute to their long herd life. Digital imagery was used to measure the angle of the knee, pasterns and hock joints as well as the overall rear stance in sows ranging from parity 5 to 14. Parity and population effects were evaluated for each angle analyzed. Significant population effects (P\u3c 0.05) were observed for the angle of the knee. Significant parity effects (P\u3c0.05) were observed for the angle of rear leg stance. Similar leg conformation values across populations and parities for the front and rear pasterns and the hock may suggest that these values are within an acceptable range to allow for long herd life

Changes in Feet and Leg Joint Angles in Gilts Divergently Selected for Residual Feed Intake during their First Gestation

This study attempted to characterize any potential changes in feet and leg characteristics due togestation stage, genetic line difference or lameness status during the gilt’s first gestation.Joint angles for knee, hock, front and rear pastern were measured in 40 Yorkshire gilts divergently selected for residual feed intake (RFI) on days 30, 60 and 90 of gestation. On the same days, gilts were scored for walking lameness (i.e. lame ornon-lame) Significant differences (P \u3c 0.05) between gestation dayand lameness status were identified in the knee and both pasterns. Significant differences (P \u3c 0.05) in RFI line were also observed in both pasterns. These measurements suggest that as gestationprogresses, structural changesoccur. Similarly, differences between RFI linesmay be due to some underlying genetic effect that has not previously been identified. In this study, lame sows were also observed to have greater joint angles for the knee, front and rear pasterns; however, such differences were minimal and their biological relevance is unclear

Depiction of Lying Down and Standing up Sequences in Multiparous Sows

The objective of this study was tocreatea pictorial lying down-standing up sequence depiction in multiparous sows.Eighty-five multiparous sows were moved from their home stallto a testingstall where they were video recorded for one lying down–standing up event on 30, 60 and 90 days of gestation. The digital video camera was positioned on the adjacent stall so the sows’ profile was visible while recording. Observations ceased when the sow successfully lied down or if 2.5 hours elapsed since recording began. Normal standing and lying pictorial depictions were created, and deviations fromthenormal lying down and standing up sequences were also pictorially depicted. This is the first published pictorial depictions on mulitparous sows on the standing-lying-standing sequence

Effect of Ad libitum Feeding of Gilt Developer Diets Differing in Standard Ileal Digestive Lysine Concentrations on Growth Traits

An experiment was conducted to determine the optimum dietary lysine concentration for optimum growth rate of replacement gilts during the growing-finishing period. A total of 2,960 gilts (Large White x Landrace), 42.3±7.0 kg average BW were allotted to randomized completely block design (RCBD). Three grower and finisher diets were formulated to contain low lysine (0.68 and 0.52% standard ileal digestible (SID) lysine), medium lysine (0.79 and 0.60% SID lysine), and high lysine (0.90 and 0.68 % SID lysine) at data recording day (142, 160 and 200 d of age). Covariate of body weight at 100 days was included in the models and it had significant influence on growth traits (P \u3c 0.05). Gilts fed the high lysine treatment had increased body weight (BW), flank-to-flank, backfat thickness, loin depth, fat-free-lean, and average daily gain (ADG) (P \u3c 0.05) when compared to gilts fed the medium and low lysine treatments. The results indicated that gilts require higher dietary lysine concentrations to maximize growth rate and high lysine diet may useful to impact growth traits when fed to developing gilt from 142 to 200 kg BW

Time Taken for Lame and Non-lame Sows to Stand and Lie

This study aimed to characterize the postures and movements of the lying down sequence in multiparous sows,and to identify possible differences between lame and non-lamesows. Eighty-five multiparous sows were moved from their gestation housingto a gestation stall where they were video recorded for one lying down–standing up event on days 30, 60 and 90 of gestation. The digital video camera was positioned on the adjacent stall so the sows’ profile was visible while recording. Observations ceasedwhen the sow successfully lied down and stood up or if 2.5 hours elapsed since recording began. Prior to recording, sows were scored for lameness on a 3-point scale, (1 = normal to 3 =severely lame).From thevideo,postures and movements that occurred during the lying-standing sequence were identified. Lameness was not associated with any of the traits studied. However, a tendency to spend less time standing was observed in lame sows suggesting that lameness recorded in thisstudy was notsevere enough to affect the sequence

Quantitation of Gait and Stance Alterations Due to Monosodium Iodoacetate–induced Knee Osteoarthritis in Yucatan Swine

Knee osteoarthritis is one of the most common causes of chronic pain worldwide, and several animal models have been developed to investigate disease mechanisms and treatments to combat associated morbidities. Here we describe a novel method for assessment of locomotor pain behavior in Yucatan swine. We used monosodium iodoacetate (MIA) to induce osteoarthritis in the hindlimb knee, and then conducted live observation, quantitative gait analysis, and quantitative weight-bearing stance analysis. We used these methods to test the hypothesis that locomotor pain behaviors after osteoarthritis induction would be detected by multiparameter quantitation for at least 12 wk in a novel large animal model of osteoarthritis. MIA-induced knee osteoarthritis produced lameness quantifiable by all measurement techniques, with onset at 2 to 4 wk and persistence until the conclusion of the study at 12 wk. Both live observation and gait analysis of kinetic parameters identified mild and moderate osteoarthritis phenotypes corresponding to a binary dose relationship. Quantitative stance analysis demonstrated the greatest sensitivity, discriminating between mild osteoarthritis states induced by 1.2 and 4.0 mg MIA, with stability of expression for as long as 12 wk. The multiparameter quantitation used in our study allowed rejection of the null hypothesis. This large animal model of quantitative locomotor pain resulting from MIA-induced osteoarthritis may support the assessment of new analgesic strategies for human knee osteoarthritis