Evaluation of Iodine Value Product and Dietary Linoleic Acid as a Predictor of Carcass Iodine Value under Commercial Conditions

A 134 d experiment housed in a commercial research barn using 1,213 pigs randomly allotted to 1 of 6 dietary treatments [choice white grease(CWG)or corn oil(COIL)included at 2, 4, and 6%]found that: dietary linoleic acid is a superior predictor of carcass iodine value(IV)than iodine value product (IVP) and dietary linoleic acid must be limited to meet carcass IVstandards. Using dietary linoleic acid to predict carcass iodine value will allow producers to meet carcass IVstandards more accurately. It can be used as a tool to enable the use of various fat sources while maintaining packer standards for carcass IV. To achieve a maximum carcass of IV of 74, total linoleic acid in the diet should not exceed 3.8% and daily linoleic acid should not exceed 88 grams

Controls of Litter Size—Do Conclusions Drawn from Institutional Research Herds Always Have Relevance to Commercial Swine Production?

Increasing litter size in pigs has been an ongoing concern of many producers because it has the greatest impact on profitability of the swine enterprise. To study the biology of conceptus growth and survival, many models have been used by researchers. It was determined that a major component in limiting litter size results from the impacts of limitations in uterine space (i.e. uterine capacity). Placental efficiency, which is the ratio of a fetus’s weight compared with that of its placenta, has been shown to impact litter size, and is heritable. Selection for breeding animals having a high placental efficiency at term, has been shown to increase litter size. Furthermore, although piglet weight was only slightly decreased in offspring of boars and gilts selected for increased placental efficiency, placental size was profoundly reduced. This reduction in placental size was coupled with an increase in vascularity, thus nutrient and oxygen uptake by the conceptus could be accomplished over a decreased surface area of attachment to the uterine wall. Reproductive data obtained to date have been gathered largely from university swine herds that may have little relevance to commercially used US pig breeds. In contrast to the constant evaluations of physiological changes associated with increased litter size at universities, swine seed stock producers have selected for many generations simply on increased litter size and have not bothered to evaluate the resulting physiological changes associated with increased fecundity. Therefore, it was the objective of this study to investigate the reproductive characteristics of a commercially relevant swine herd in Iowa (PIC Camborough Line) at selected gestational ages. Multiparous sows (ranging from 1 to 14 parities) were slaughtered on days 25, 36, and 44 of gestation, time periods corresponding to intervals which are before, during, and after the time when uterine capacity becomes limiting. At the laboratory, the uterine horns were measured and ovulation rate was determined. Conceptuses were removed and fetal and placental weights were determined. Uterine horn length and ovulation rate did not differ between the three gestational groups. Conceptus number decreased from 15.8 ± 0.6 on day 25 to 12.9 ± 0.5 and 12.1 ± 0.4 on day 36 and day 44 (litter size in this population averages ~11.5 liveborn piglets/litter). Conceptus survival to day 25 was 60.2 ± 0.1%, which then decreased to 50.1 ± 0.1% on day 36 and 46.3 ± 0.1% on day 44. There was a positive correlation between conceptus number and ovulation rate on day 25 but by day 36 this association was lost. Conceptus number was not associated with uterine length on day 25, but by day 36 there was a positive association that remained through day 44. On all three gestation days there was a negative association between conceptus number and placental weight, but no association between conceptus number and fetal weight was observed, indicating that larger litters are comprised of conceptuses having small placentae, but the same sized fetuses. These data indicate that, compared with commonly reported values for university herds (16-18 ovulations), ovulation rate in these mixed parity production animals is extremely high, whereas conceptus survival as estimated from the number of conceptuses divided by the number of ovulations was very low. Additionally, although conceptus number was related to the ovulation rate on day 25, by day 36 the limitations of uterine size began to reduce conceptus number irrespective of ovulation rate. These data suggest that ovulation rate is not a limiting factor in litter size in this line of commercially relevant pigs. In contrast, the higher than expected ovulation rate observed in these pigs resulted in significant embryo losses and early uterine crowding. The consequences of this early conceptus crowding may have detrimental impacts on prenatal and postnatal growth rate and survival

The effects of group size and subtherapeutic antibiotic alternatives on growth performance and morbidity of nursery pigs: a model for feed additive evaluation

The objectives of this experiment were to evaluate the effects of alternatives to antibiotic growth promoters (AGP), two group sizes, and their interaction on nursery pig performance to serve as a model for future AGP alternative studies. A 41-d experiment was conducted in a commercial wean-to-finish barn; 1,300 piglets weaned at 21 d of age (weaned 2 or 4 d prior to experiment; 6.14 ± 0.18 kg BW; PIC 1050 sows and multiple sire lines) were blocked by sire, sex, and weaning date, then assigned to eight treatments: four dietary treatments each evaluated across two group sizes. The four dietary treatments were: negative control (NC), positive control (PC; NC + in-feed antibiotics), zinc oxide plus a dietary acidifier (blend of fumaric, citric, lactic, and phosphoric acid) (ZA; NC + ZnO + acid), and a Bacillus-based direct-fed-microbial (DFM) plus resistant potato starch (RS) (DR; NC + DFM + RS). The two group sizes were 31 or 11 pigs/pen; floor space was modified so area/pig was equal between the group sizes (0.42 m2/pig). There were 7 pens/diet with 11 pigs/pen and 8 pens/diet with 31 pigs/pen. Data were analyzed as a randomized complete block design with pen as the experimental unit. Diagnostic assessment of oral fluids, serum, and tissue samples was used to characterize health status. Pigs experienced natural challenges of acute diarrhea and septicemia in week 1 and porcine reproductive and respiratory syndrome virus (PRRSV) in weeks 4–6. There was a significant interaction between diet and group size for ADG (P = 0.012). PC increased ADG in large and small groups (P \u3c 0.05) and ZA increased ADG only in large groups (P \u3c 0.05). Small groups had improved ADG compared to large groups when fed NC or DR diets (P \u3c 0.05). Similarly, PC increased ADFI (P \u3c 0.05). Compared to NC, ZA improved ADFI in large groups only (P \u3c 0.05; diet × group size: P = 0.015). Pigs fed PC had greater G:F than NC (P \u3c 0.05), and small groups had greater G:F than large groups (P \u3c 0.05). There was no effect of ZA or DR on G:F. Pigs fed PC required fewer individual medical treatments than NC and pigs fed ZA were intermediate (P = 0.024). More pigs were removed from large than small groups (P = 0.049), and there was no effect of diet on removals (P \u3e 0.10). In conclusion, careful study design, protocol implementation, sample collection, and recording of important information allowed us to characterize the health status of this group of pigs and determine treatment effects on growth performance and morbidity

The impact of PRRSV on feed efficiency, digestibility and tissue accretion in grow-finisher pigs

The economic losses caused by Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) infection are estimated to cost the US swine industry more than $640 million annually (USDA, 2008). While significant advances have been made through research efforts to enhance our understanding of PRRSV at the animal health, immunological and genomic level, this disease still remains a significant issue in the US swine industry. Although we clearly know that PRRSV attenuates ADG of production pigs, its direct impact on feed efficiency, nutrient and energy digestibility, and whole body lean and fat accretion in grow finisher pigs has been poorly characterized. Therefore, the overall objective of this project was to characterize the impact PRRSV challenge has on grow-finisher pig feed efficiency, energy and nutrient digestibility, and tissue accretion rates

Evaluation of Iodine Value Product and Dietary Linoleic Acid as a Predictor of Carcass Iodine Value under Commercial Conditions

A 134 d experiment housed in a commercial research barn using 1,213 pigs randomly allotted to 1 of 6 dietary treatments [choice white grease(CWG)or corn oil(COIL)included at 2, 4, and 6%]found that: dietary linoleic acid is a superior predictor of carcass iodine value(IV)than iodine value product (IVP) and dietary linoleic acid must be limited to meet carcass IVstandards. Using dietary linoleic acid to predict carcass iodine value will allow producers to meet carcass IVstandards more accurately. It can be used as a tool to enable the use of various fat sources while maintaining packer standards for carcass IV. To achieve a maximum carcass of IV of 74, total linoleic acid in the diet should not exceed 3.8% and daily linoleic acid should not exceed 88 grams.</p

Controls of Litter Size—Do Conclusions Drawn from Institutional Research Herds Always Have Relevance to Commercial Swine Production?

Increasing litter size in pigs has been an ongoing concern of many producers because it has the greatest impact on profitability of the swine enterprise. To study the biology of conceptus growth and survival, many models have been used by researchers. It was determined that a major component in limiting litter size results from the impacts of limitations in uterine space (i.e. uterine capacity). Placental efficiency, which is the ratio of a fetus’s weight compared with that of its placenta, has been shown to impact litter size, and is heritable. Selection for breeding animals having a high placental efficiency at term, has been shown to increase litter size. Furthermore, although piglet weight was only slightly decreased in offspring of boars and gilts selected for increased placental efficiency, placental size was profoundly reduced. This reduction in placental size was coupled with an increase in vascularity, thus nutrient and oxygen uptake by the conceptus could be accomplished over a decreased surface area of attachment to the uterine wall. Reproductive data obtained to date have been gathered largely from university swine herds that may have little relevance to commercially used US pig breeds. In contrast to the constant evaluations of physiological changes associated with increased litter size at universities, swine seed stock producers have selected for many generations simply on increased litter size and have not bothered to evaluate the resulting physiological changes associated with increased fecundity. Therefore, it was the objective of this study to investigate the reproductive characteristics of a commercially relevant swine herd in Iowa (PIC Camborough Line) at selected gestational ages. Multiparous sows (ranging from 1 to 14 parities) were slaughtered on days 25, 36, and 44 of gestation, time periods corresponding to intervals which are before, during, and after the time when uterine capacity becomes limiting. At the laboratory, the uterine horns were measured and ovulation rate was determined. Conceptuses were removed and fetal and placental weights were determined. Uterine horn length and ovulation rate did not differ between the three gestational groups. Conceptus number decreased from 15.8 ± 0.6 on day 25 to 12.9 ± 0.5 and 12.1 ± 0.4 on day 36 and day 44 (litter size in this population averages ~11.5 liveborn piglets/litter). Conceptus survival to day 25 was 60.2 ± 0.1%, which then decreased to 50.1 ± 0.1% on day 36 and 46.3 ± 0.1% on day 44. There was a positive correlation between conceptus number and ovulation rate on day 25 but by day 36 this association was lost. Conceptus number was not associated with uterine length on day 25, but by day 36 there was a positive association that remained through day 44. On all three gestation days there was a negative association between conceptus number and placental weight, but no association between conceptus number and fetal weight was observed, indicating that larger litters are comprised of conceptuses having small placentae, but the same sized fetuses. These data indicate that, compared with commonly reported values for university herds (16-18 ovulations), ovulation rate in these mixed parity production animals is extremely high, whereas conceptus survival as estimated from the number of conceptuses divided by the number of ovulations was very low. Additionally, although conceptus number was related to the ovulation rate on day 25, by day 36 the limitations of uterine size began to reduce conceptus number irrespective of ovulation rate. These data suggest that ovulation rate is not a limiting factor in litter size in this line of commercially relevant pigs. In contrast, the higher than expected ovulation rate observed in these pigs resulted in significant embryo losses and early uterine crowding. The consequences of this early conceptus crowding may have detrimental impacts on prenatal and postnatal growth rate and survival.</p

The effects of group size and subtherapeutic antibiotic alternatives on growth performance and morbidity of nursery pigs: a model for feed additive evaluation

The objectives of this experiment were to evaluate the effects of alternatives to antibiotic growth promoters (AGP), two group sizes, and their interaction on nursery pig performance to serve as a model for future AGP alternative studies. A 41-d experiment was conducted in a commercial wean-to-finish barn; 1,300 piglets weaned at 21 d of age (weaned 2 or 4 d prior to experiment; 6.14 ± 0.18 kg BW; PIC 1050 sows and multiple sire lines) were blocked by sire, sex, and weaning date, then assigned to eight treatments: four dietary treatments each evaluated across two group sizes. The four dietary treatments were: negative control (NC), positive control (PC; NC + in-feed antibiotics), zinc oxide plus a dietary acidifier (blend of fumaric, citric, lactic, and phosphoric acid) (ZA; NC + ZnO + acid), and a Bacillus-based direct-fed-microbial (DFM) plus resistant potato starch (RS) (DR; NC + DFM + RS). The two group sizes were 31 or 11 pigs/pen; floor space was modified so area/pig was equal between the group sizes (0.42 m2/pig). There were 7 pens/diet with 11 pigs/pen and 8 pens/diet with 31 pigs/pen. Data were analyzed as a randomized complete block design with pen as the experimental unit. Diagnostic assessment of oral fluids, serum, and tissue samples was used to characterize health status. Pigs experienced natural challenges of acute diarrhea and septicemia in week 1 and porcine reproductive and respiratory syndrome virus (PRRSV) in weeks 4–6. There was a significant interaction between diet and group size for ADG (P = 0.012). PC increased ADG in large and small groups (P P P 0.05). Similarly, PC increased ADFI (P P P = 0.015). Pigs fed PC had greater G:F than NC (P P P = 0.024). More pigs were removed from large than small groups (P = 0.049), and there was no effect of diet on removals (P > 0.10). In conclusion, careful study design, protocol implementation, sample collection, and recording of important information allowed us to characterize the health status of this group of pigs and determine treatment effects on growth performance and morbidity.This article is published as Olsen, Kristin M., Nicholas K. Gabler, Chris J. Rademacher, Kent J. Schwartz, Wesley P. Schweer, Gene G. Gourley, and John F. Patience. "The effects of group size and subtherapeutic antibiotic alternatives on growth performance and morbidity of nursery pigs: a model for feed additive evaluation." Translational animal science 2, no. 3 (2018): 298-310. doi: 10.1093/tas/txy068.</p

The impact of PRRSV on feed efficiency, digestibility and tissue accretion in grow-finisher pigs

The economic losses caused by Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) infection are estimated to cost the US swine industry more than $640 million annually (USDA, 2008). While significant advances have been made through research efforts to enhance our understanding of PRRSV at the animal health, immunological and genomic level, this disease still remains a significant issue in the US swine industry. Although we clearly know that PRRSV attenuates ADG of production pigs, its direct impact on feed efficiency, nutrient and energy digestibility, and whole body lean and fat accretion in grow finisher pigs has been poorly characterized. Therefore, the overall objective of this project was to characterize the impact PRRSV challenge has on grow-finisher pig feed efficiency, energy and nutrient digestibility, and tissue accretion rates.This proceeding is published as N.K. Gabler, W.P. Schweer, J.F. Patience, L. Karriker, C. Sparks, G. Gourley, M. Fitzsimmons, K. Schwartz and T.E. Burkey (2013) The impact of PRRSV on feed efficiency, digestibility and tissue accretion in grow-finisher pigs. Allen D. Leman Swine Conference 40: 135-136. Posted with permission.</p

EC91-219 Nebraska Swine Report

This 1991 Nebraska Swine Report was prepared by the staff in Animal Science and cooperating departments for use in the Extension and Teaching programs at the University of Nebraska-Lincoln. Authors from the following areas contributed to this publication: Swine Nutrition, swine diseases, pathology, economics, engineering, swine breeding, meats, agronomy, and diagnostic laboratory. It covers the following areas: breeding, disease control, feeding, nutrition, economics, housing and meats