Determining sow performance and mineral digestibility with phytase supplementation of the lactating sow ration

Posted in: Ontario Pork, Pork Insight Articles by admin on March 9, 2010 | No Comments

One potential way for producers to save on feed costs is to introduce phytase into the pigs diets. Phytase binds up phosphorus making it poorly available so it doesn’t negatively impact land, it also renders calcium, iron, zinc, manganese and copper poorly available. Tests have shown that 0.1 % reduction in calcium and phosphorus have no impact on carcass traits or meat quality. In lactating sows, no work has been done concerning the response due to phytase supplementation with respect to: 1) digestibility of trace minerals, 2) response of milk production and quality, and 3) piglet performance. These things are important to understand before farmers begin introducing phytase into diets. To test phytase use on sows a group of 36 sows were assigned one of four mineral phytase treatments when they were in farrowing crates. The four treatments were:1) phytase and a trace mineral premix, 2) no phytase and a trace mineral premix, 3) only phytase and no trace mineral premix, and 4) neither phytase or a trace mineral premix. Farrowing data was recorded as well as blood, feces and milk samples were taken for analysis. Also sow feed and water intake was recorded along with weaning data. Results showed that in the short term sows did not need typical levels of calcium and phosphorus and any trace mineral supplementation they receive. No production parameters were found to be impacted by the treatments. Phytase supplementation did not improve digestibility of phosphorus, calcium or the trace
minerals, as it has in other studies. It is unclear at this point why that was the case but there is at least one significant confounding factor, being dry matter intake. For some reason, the sows consuming treatments that received reduced calcium and phosphorus and no trace mineral supplementation tended to consume more feed than those that received normal mineral
supplementation. To learn why this is more studies will need to be done on a larger group of sows.

Epidermal Growth Factor-Expressing Lactococcus lactis Enhances Intestinal Development of Early-Weaned Pigs

Posted in: Nutrition, Ontario Pork, Pork Insight Articles by admin on February 10, 2010 | No Comments

Stress and incomplete gastrointestinal development in early-weaned piglets represent significant challenges in commercial swine farming. Orally ingested recombinant epidermal growth factor (EGF) has been shown to remain biologically active in the gastrointestinal tract as well as stimulate intestinal development, reducing the incidence of pathogen infection and diarrhea. We have previously shown that the food-grade bacterium Lactococcus lactis can be genetically altered to express biologically active EGF when fed to early-weaned mice. In this study, we assigned 8 pigs to
each of 4 groups that were given EGF-expressing L. lactis (EGF-LL), empty vector-expressing L. lactis (EV-LL), recombinant human EGF, or unsupplemented bacterial media, all of which were delivered as 50-mL i.g. doses twice per
day. All pigs were killed after 14 d to examine intestinal morphology. Pigs in the EGF-LL group had greater jejunal and duodenal villus heights (P,0.0001) and intestinal length (P = 0.049) than pigs in the control group. Immunohistochemistry with antibodies against proliferating cell nuclear antigen (PCNA) revealed that the proliferation of intestinal cells was significantly greater in the EGF-LL group than in the control group. PCNA expression and intestinal length also were greater in the EV-LL group, which received L. lactis that did not express EGF, than in the control group (P = 0.049), further supporting the use of naturally occurring intestinal microbes as desirable vectors for recombinant protein delivery. Our data demonstrates the feasibility of delivering a growth factor using common probiotic bacteria to farm animals for commercial practice.

Review of advances in metabolic bioavailability of amino acids

Posted in: Ontario Pork, Pork Insight Articles by admin on January 1, 2010 | No Comments

The animal’s amino acid requirement and the potential of feedstuffs to supply those amino acids in metabolically available form (amino acid bioavailability) are intertwined. Although standardized ileal amino acid digestibility is currently most widely used as an estimate of dietary protein quality, numerous factors influence these estimates. Slope ratio assays are considered the standard against which other methods of amino acid availability are judged because they measure the effect of protein quality on the entire metabolism of the animal. However, practical use of slope ratio growth assays is limited. Recently, the slope ratio assay utilizing the indicator amino acid oxidation technique has been developed to determine the
metabolic availability (MA) of amino acids in pigs and humans This review will discuss how the indicator amino acid oxidation (IAAO) technique can: 1) address some of the problems associated with the slope ratio assay; 2) be used to determine the metabolic availability (MA) of amino acids in animal feedstuffs; 3) become a valuable measure of amino acid bioavailability; and 4) be applied in practical swine nutrition.

Systematic comparison of the empirical and factorial methods used to estimate the nutrient requirements of growing pig

Posted in: Pork Insight Articles, Swine Innovation by admin on December 18, 2009 | No Comments

Empirical and factorial are two ways to determine nutritional requirements for animals. The three purposes of this study, done by L. Hauschild et al, were to estimate nutrient requirements for a pig population using empirical and factorial methods, establish a relationship between the requirements that relate the two methods, and to study the limitations of these methods when used to determine the nutrient requirements for individual pigs and groups of pigs. Empirical and factorial methods were used to estimate the ratio of lysine to Net energy (Lys:NE). Optimum ratios were then determined using a systematic analysis. Sixty-eight individual pigs were then simulated using experimental data. For the empirical method,  population responses were recorded by using 11 different Lys:NE diets. Average daily gain and feed conversion ratio were used as the performance criteria. Optimal Lys:NE requirements for growing pigs were found to be different depending on the method used. The factorial method does not allow estimates of Lys:NE that maximize the response of similar populations in a given time and weight interval. The empirical method was able to attain optimal population responses, although the estimation requirements are fixed and cannot be used for a population or a growing phase. This study shows that the two common  methods to calculate nutrient requirments have different results, and important limitations that must be considered when the goal is to optimize response in a individual or group of pigs.

A multiplex RT-PCR assay for the rapid and differential diagnosis of classical swine fever and other pestivirus infections

Posted in: Production by admin on November 30, 2009 | No Comments

Classical swine fever is a highly contagious viral disease causing severe economic losses in pig production almost worldwide. All pestivirus species can infect pigs, therefore accurate and rapid pestivirus detection and differentiation is of great importance to assure control measures in swine farming. Here we describe the development and evaluation of a novel multiplex, highly sensitive and specific RT-PCR for the simultaneous detection and rapid differentiation between CSFV and other pestivirus infections in swine. The universal and differential detection was based on primers designed to amplify a fragment of the 50 noncoding genome region for the detection of pestiviruses and a fragment of the NS5B gene for the detection of classical swine fever virus. The assay proved to be specific when different pestivirus strains from swine and ruminants were evaluated. The analytical sensitivity was estimated to be as little as 0.89 TCID50. The assay analysis of 30 tissue homogenate samples from naturally infected and non-CSF infected animals and 40 standard serum samples evaluated as part of two European Inter-laboratory Comparison Tests conducted by the European Community Reference Laboratory, Hanover, Germany proved that the multiplex RT-PCR method provides a rapid, highly sensitive, and cost-effective laboratory diagnosis for classical swine fever and other pestivirus infections in swine.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/03781135

Meta-analysis of phosphorus utilisation by broilers receiving corn-soyabean meal diets: influence of dietary calcium and microbial phytase

Posted in: Pork Insight Articles by admin on November 26, 2009 | No Comments

With the price of phosphate driving up feed prices and the environmental concerns surrounding the use of phosphorus (P), it is beneficial to understand a birds response to dietary phosphorus in order to optimize its use. Due to the large volume of studies done on the bird response to dietary phosphorus, researchers were able to combine the results of multiple studies done between 1996 and 2006 to build a database of eight publications reporting 15 experiments, with a total of 203 treatments. This database was used to predict the birds response to dietary phosphate with the key variables being calcium (Ca) and microbial physate derived from Aspergillus niger, in terms of average daily feed intake (ADFI), average daily gain (ADG), gain to feed (G:F) and tibia ash concentration. The data was then put through a regression to find the implicaitons phosphorus had on ADG, ADFI, G:F, and tibia ash concentration. Dietary Ca affected the intercept and linear component for ADG, G:F and tibia ash concentration, whereas for ADFI, it affected only the intercept. The microbial physate additive effected the intercept, the linear coefficient and intercept coefficient for ADFI, ADG, and G:F. Microbial physate also effected the intercept and linear component for tibia ash concentration. An evaluation was then done on these models to test their performance. Results showed that ADFI, ADG and Tibia ash concentration were predicted fairly well (slope and intercept did not deviate from 0 to 1, respectively), whereas this was not the case for G:F. An increase in Ca had an aggravating affect on P deficiency for all criteria while additional physate had the opposite effect. It must be considered that even if the decrease in dietary Ca may improve P utilisation, it could in turn become limiting for bone mineralisation. In conclusion this meta-analysis provides options for reducing expensive and environmentally suspect P in diets without sacrificing growth, by manipulations of calcium and physate.

A clinical field trial to evaluate the efficacy of vaccination in controlling Salmonella infection and the association of Salmonella-shedding and weight gain in pigs

Posted in: Ontario Pork, Pork Insight Articles, Welfare by admin on November 23, 2009 | No Comments

A clinical field trial was performed to determine the effectiveness of an autogenous Salmonella Typhimurium bacterin compared with a commercial live S. Choleraesuis vaccine in pigs. The association between Salmonella shedding and weight gain was also investigated. Nine cohorts of weaned pigs, (330 to 350 pigs per cohort), were randomly assigned to 1 of 3 treatment groups (injection with S. Typhimurium bacterin, vaccination via water with S. Choleraesuis vaccine, or a control group receiving no vaccine). In each cohort, the average daily gain was calculated for a selected pen throughout the production stage. Pen (pooled) fecal samples were collected bi-weekly and cultured. The odds of Salmonella shedding in both vaccinated groups was higher than in the control group (P , 0.05). The prevalence of Salmonella shedding declined overall as pigs aged (P 5 0.04). However, the control pigs showed the smallest decrease in Salmonella shedding over the entire production stage, while prevalence of Salmonella shedding in the vaccinated groups decreased twice as much as the control group over the entire production stage. Salmonella Typhimurium var. Copenhagen DT104, S. Cerro, and S. Agona, which had been isolated on the study farm previously, were recovered from pigs in this study. Shedding of S. Typhimurium var. Copenhagen decreased over time in both vaccine treatment groups. On the other hand, S. Cerro shedding rate was lower in the control pigs compared with vaccinated pigs and S. Agona could be recovered only from the samples collected from S. Choleraesuis vaccinated pigs. The pigs from pens with a higher Salmonella recovery rate experienced slower growth compared with pigs from pens where Salmonella was not isolated. This latter finding indicates that there might be an economic incentive for producers to try to control endemic salmonellosis if effective programs could be developed.

Evaluation of the Risk Factors for Shedding Salmonella with or without Antimicrobial Resistance in Swine Using Multinomial Regression Method

Posted in: Environment, Ontario Pork, Pork Insight Articles by admin on November 11, 2009 | No Comments

A multinomial logistic regression method was used to investigate the risk factors for antimicrobial resistance (AMR) in Salmonella isolated from faecal samples collected on 80 Ontario swine farms in Canada. The samples were classified into three groups including Salmonella-negative samples (S)), Salmonella-positive samples without AMR (S+AMR)) and Salmonella-positive samples with AMR (S+AMR+). The samples collected directly from pigs had a greater chance to be positive for Salmonella with AMR compared to those samples collected from the pen floor. The odds of culturing Salmonella with or without AMR was higher if pelleted feed was used compared with mash or liquid feed (P < 0.001). The faecal samples collected on farrow-to-finish farms had a significant lower chance of testing positive for Salmonella with multidrug resistance than the samples from grow-finisher farms (P = 0.004). The chance of culturing Salmonella without AMR on farms with a continuous system was higher than on farms with an all-in/all-out system (P = 0.009). However, there was no significant association between the flow system and recovery of Salmonella with AMR. The larger farms were more likely to be in S+AMR+ group than in S) group (P < 0.001) whereas herd size did not appear as a risk factor for being in S+AMR) group compared with S) group. These findings indicate that although on-farm antimicrobial use is one component of resistance, there might be other farm management factors that also affect the development of emerging resistant bacterial foodborne pathogens on swine farms. Finding different risk factors for shedding Salmonella with or without antimicrobial resistance would help to take the appropriate approach to each group if a control programme were to be implemented or an intervention applied.

Formulating diets for growing pigs: economic and environmental considerations

Posted in: Nutrition, Pork Insight Articles, Swine Innovation by admin on October 22, 2009 | No Comments

Traditionally a pig’s diets is created based on two pieces of criteria, growth and cost. A diet that focuses on maximizing growth and minimizing  costs overlooks some externalities such as environmental impacts. Nitrogen and phosphorus are two nutrients implemented in a pigs diet to enhance growth, although excessive amounts of these two nutrients in a diet will cause more of the nutrients to go undigested and excreted by the pig. When manure is disposed the excreted phosphorus and nitrogen build up in soils resulting in pollution of surface and ground water. This paper proposes a linear model which considers environmental impacts as well as economic impacts with the intentions of helping hog farmers and mill operators develop cost effective pig diets while not harming the environment. The authors developed a multi-criteria model that considers minimum nitrogen and phosphorus excretion and minimum costs. The models were based off real world diets and costs from Quebec and France and then compared. After making the comparisons the results showed that it is possible to limit the amount of harmful nutrients excreted while still keeping costs down. This information has value to producers, mill operators and also policy makers who can set limitations or incentives to help protect the environment from soil saturation.

Prevalence of Yersinia enterocolitica shedding and bioserotype distribution in Ontario finisher pig herds in 2001, 2002, and 2004

Posted in: Environment, Ontario Pork, Pork Insight Articles, Welfare by admin on October 10, 2009 | No Comments

We investigated characteristics of Yersinia enterocolitica infection in Ontario finisher pig herds. Our specific objectives were to estimate or test: prevalence of Y. enterocolitica shedding in finisher pigs, bioserotype distribution, agreement between the herd-level tests based on sampling pig and pooled fecal samples, whether bioserotypes cluster by farms, and whether Y. enterocolitica-positive herds cluster spatially. In total, 3747 fecal samples were collected from 100 farms over the years 2001, 2002, and 2004 (250 total herd visits). Fecal samples were tested by culture and positive isolates were biotyped and serotyped. Apparent pig-level prevalence of Y. enterocolitica was 1.8%, 3.2%, and 12.5% in 2001, 2002, and 2004, respectively. Estimated true pig-level prevalence of Y. enterocolitica was 5.1%, 9.1%, and 35.1% in 2001, 2002, and 2004, respectively. Herd-level prevalence was 16.3%, 17.9%, and 37.5% in 2001, 2002, and 2004, respectively. In all years, the most common bioserotype was 4, O:3, followed by bioserotype 2, O:5,27. Kappa between herdlevel status based on pig and pooled samples ranged between 0.51 and 0.68 for biotype 1A and bioserotype 4, O:3, respectively. For 4, O:3, a significant bias in discordant pairs was detected, indicating that pig samples were more sensitive than pooled samples in declaring a herd as positive. Farms tended to be repeatedly positive with the same bioserotype, but positive study farms did not cluster spatially (suggesting lack of between herd transmission and lack of a common geographic risk factor).