Nutrition, Genetics and physiology in pig industry

Differences in lean growth performance of pigs sampled from 1980 and 2005 commercial swine fed 1980 and 2005 representative feeding programs source: J.S. Fix, J.P. Cassady, E. van Heugten, D.J. Hanson and M.T. See. Differences in lean growth performance of pigs sampled from 1980 and 2005 commercial swine fed 1980 and 2005 representative feeding programs. Livestock Science. 2010. Vol. 128 (1-3): 108-114.

IN that paper by Fix - the 2000 NPB equations can not be used for pigs at 45 kg BW - it is way beyond the range of the data used in the 2000 trial. The b values in the regression equations for fat-free lean change with every 20 kg change in BW. Also the 2000 NPB equations - had very large RSD's - that data is the least accurate of all the trials included in the Johnson et al 2004 Journal of Animal Science paper. IN that paper the RSD for fat-free lean percentage for real time ultrasound 3.22 % when the total SD was 5 %. Based on data published in a 1999 publication - and disccussed in recent article -late march in Feedstuffs that the real time ultrasound equation predicts about 54 % of the actual difference in fat-free lean percentage of any two genetic lines. I Note in EC - only equations with RSD's of less than 2.5 % are acceptable and allowed to be used. An equation with an RSD of 3.22 % when total SD is 5 % - only accounts for 54.5 % of the between pig variation in carcass lean percentage ( across pigs from 7 to 57 mm in the trial). IN the lean gain trial - Newsham Hybrids submitted two genetic lines - line 1 and 2 - which were .41 inches or about 10.4 mm different in backfat depth ( over 4 within line SD's different) and called one single line. The measures were taken at line speeds and the machines only found a .14 to .17 in difference in backfat between the lines. This is the data used for the NPB 2000 equations used to predict fat -free lean in this trial. One should read article in Journal of Animal Science 2010 - on the evaluation of three optical probes to compare the equations developed when the measurements are taken accurately versus when they are not. The differences in fat-free lean gain in this trial between the genetic lines are much greater - almost two fold greater than predicted - but if one uses inaccurate equations - this prediction bias is to be expected.

Basically, the growth of an animal is based on several factors such as nutritions and genetic potentials. An animal with improved genetic potentials will need a much better nutrition. We need to provide the right amount of protein (amino acids) and energy for the animal to reach its genetic potentials. Nutrition will be dependent of the nutrient content of feeds and the physiological capability of the animal to digest and absorbed the nutrients, hence if the GI tract is not prepare properly you will not gained good growth even you have a high genetic potentials and high density feed (nutrition). A genetic improvement will command for additional research on the new nutrient requirements of such breed.

This is a topical area; the consumers want lean pork & breeders have been working hard to package this genetic potential. Nutrition plays a great role in realizing this potential in a profitable and sustainable manner. A challenge to nutritionists is to predict the nutrient requirements of such animals given they eat less and are sensitive to pathogen/environmental stresses. An important aspect in this regard is the question of whether we really know the Lys & other nutrients requirements of modern pig genotypes raised in production systems under constant public scrutiny. For example, pigs raised in antibiotic free feeding programs?. The fact is that the requirements we have now were derived using animals fed in-feed antibiotics? this practice has been banned in some jurisdictions & the same may occur elsewhere. It is prudent to expect gastrointestinal disturbances to increase under antibiotic free feeding regimen, however, what does this portend to the animal’s ability to achieve its genetic potential? Under such circumstances, are more nutrients going to support gastrointestinal physiological functions rather than prime muscle growth? Do gut and body nutrients requirements differ? Could there be nutrients sparing advantage in production systems using digestive feed additives such enzymes, probiotics, essential oils e.t.c.? Can we move towards developing models which take into account most of these factors?

In thailand (Khonkaen Universit) we have one Experiment for Nutrition and Genetice in pig. GRADE LEVELS OF LYSINE AT VARIOUS METHIONINE LEVELS IN FINISHING PIGS DIET ON GROWTH PERFORMANCE Suntorn Kakaisorn 1, Chaiyaphuk Hongladdaporn 1, Sawang Kullawong 1 and Suwit Terapuntuwat 2 1 Department of Animal Science, Faculty of Science and Technology, Loei Rajabubhat University, Loei-Chiangkan Rd., Loei, 42000 2 Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, 40002 ABSTRACT This experiment was conducted to determine three levels of lysine with three levels of methionine on growth performance of finishing pig. Treatment diets were calculated for 3 levels of lysine (0.780, 1.025 and 1.270 %) and 3 levels of methionine (0.240, 0.315 and 0.390 %). Thirty-three crossbred pigs (Large white X Landrace X Duroc, 67.00 kg average body weight) were used. Twenty-seven pigs were used as experimental diet ( 9 treatments, 3 pigs per treatment). Six pigs were given protein free diet for metabolic and endrogenus nitrogen loss determination. Pigs were kept in individual metabolism cage. The pigs given protein free diet had body weight loss 203.57 g/h/d. Daily weight gain, gain per feed, protein efficiency ratio, and net protein ratio of pigs under 9 treatment diets did not show significant different response. (P>0.05). However, pigs fed lysine 1.025 % and methionine 0.390 % showed highest average daily gain (817 g/h/d), gain per feed (351 g/kg), protein efficiency ratio (2.09) and net protein ratio (2.61). Methionine and total sulfur amino acid were calculated to be 38 % and 61 % of lysine, respectively. The levels of lysine and methionine in diet for 67 kg pig should be 1.025% and 0.390 %. Live weight pigs recommended effect of lysine and methionine levels on protein utilization should be further investigated. Key Words : lysine levels, methionine levels, growth performance, finishing pigs thank you Suntorn Kakaisorn