$title PAKLIVE: Pakistan Punjab Livestock Model (PAKLIVE,SEQ=55) $onText This model examines the role of livestock in the agricultural sector in the Punjab and how it is effected by variations in farm size, water availability, credit, crop prices and labor. World Bank, Pakistan Punjab Livestock Project. Tech. rep., The World Bank, 1977. Keywords: linear programming, agricultural economics, livestock sector, agricultural development $offText $sTitle Set Definitions Set c 'crops' / wheat, basrice, irrrice 'irradiated rice' maize, oilseed, gram cotton, sugar, berseem, kharfodder / h 'livestock types' / bullocks, bufflocows, cattlecows / f 'seasonal inputs' / landuse, irrwat 'irrigation water' labor, tdn 'total digestible nutrients' protein, draftpower, credit / n(f) 'nutrients' / tdn, protein / dp(f) 'draftpower' / draftpower / ta 'seasons and annual' / annual, kharif, rabi / t(ta) 'seasons' / kharif, rabi /; Scalar fsize 'farm size (acres)' / 12.5 / watercost 'cost of purchased water (rs per inch)' / 20 / laborcost 'cost of hired labor (rs per man-day)' / 10 / maxcredit 'maximum annual credit (rs)' / 20000 / lrr 'livestock reproduction ratio' / 1.25 / wpup 'maximum water purchaseable (inches)' / 17.5 / draftcost 'cost of hired draftpower (rs per workday)' / 30 /; Parameter bullockr(c) 'bullock requirements in the third season (work-days)' / wheat 8, oilseed 2, sugar 1, berseem 2/ bullocka(h) 'livestock availability in third season (work-days)' / bullocks 40 / waf(t) 'maximum water available at no cost (inches per acre)' / kharif 56, rabi 32 / rationcost(n) 'cost of purchased rations (rs per kg)' / tdn 1.3, protein 5 / cprice(c) 'crop prices (rs per maund)' / wheat 41.15, basrice 89.38, irrrice 39.92, maize 37.04 oilseed 59.26, gram 37.04, cotton 127.27, sugar 5.96 / gmargin(h) 'gross margin from livestock (rs)' / bufflocows 900, cattlecows 600 / eff(n) 'storage efficiency of nutrients' / tdn .5 / maxflab(t) 'maximum seasonal family labor (man-days)' / kharif 390, rabi 530 / watavail(t) 'max water available on farm at no cost (inches)' crev(c) 'crop revenue (rs per acre)'; Table cinput(*,ta,c) 'input-output matrix for crops' * landuse : acres * irrwat : inches * labor : man-days * draftpower: work-days * tdn : kgs * protein : kgs * credit : rs per year * yield : maund/acre per year wheat basrice irrrice maize oilseed gram cotton sugar berseem kharfodder landuse.kharif .1 1. 1. 1. .3 .3 1. 1. .3 1. landuse.rabi 1. .1 .6 1. .4 1. .8 .1 irrwat.kharif 65. 60. 25. 30. 25. 15. irrwat.rabi 20. 20. 15. 10. 45. 35. labor.kharif 7. 21. 21. 22. 4. 2. 11. 15. 3. 18. labor.rabi 16. 9. 9. 5. 10. 8. 10. 62. 15. 6. tdn.kharif -530. -510. -450. -60. -350. -2400. tdn.rabi -450. -650 -85. -215. -130. -1775. -1940. protein.kharif -6. -8. -31. -1. -6. -242. protein.rabi draftpower.kharif 12. 8. 8. 3. 3. 3. draftpower.rabi 6. 1. 1. 7. 1. 3. 7. 30. 6. credit.annual 150. 180. 220. 100. 120. 70. 145. 500. 65. 120 yield.annual -16 -11.4 -21 -10 -6 -6 -10 -375 ; Table linput(*,ta,h) 'livestock inputs-outputs' * labor : man-days * draftpower : work-days * tdn : kgs * protein : kgs * credit : rs per year bullocks bufflocows cattlecows labor.kharif 17.5 19 14 labor.rabi 26.5 29 21.5 draftpower.kharif -100 draftpower.rabi -175 tdn.(kharif,rabi) 1550 1050 750 protein.(kharif,rabi) 155 105 75 credit.annual 300 250 180 ; crev(c) = - cprice(c)*cinput("yield","annual",c); watavail(t) = fsize*waf(t); display crev, watavail; $sTitle Model Definition Positive Variable xcrop(c) 'cropping activities (acres)' wpurchase(t) 'water purchased (inches)' xrations(n,t) 'purchased rations (kg)' xlabor(t) 'hired labor (man-days)' xtransf(n,t) 'fodder transfer (kgs)' dhire 'hire of draftpower (workday)' xlivestk(h) 'livestock production (animals)'; Variable rev 'revenue from livestock and crops (rs)' lcost 'cost of hired labor (rs)' dcost 'cost of hired draftpower (rs)' wcost 'cost of purchased water (rs)' rcost 'cost of purchased rations (rs)' return 'net return'; Equation draft(dp,t) 'draftpower constraint (work-day)' land(t) 'land use by season (acre)' water(t) 'irrigation water use by season (inches)' labor(t) 'total labor required by season (man-day)' nutbal(n,t) 'seasonal purchase of nutrients (kgs)' bullock 'bullock use during third season (work-days)' credit 'credit requirements (rs)' totalrev 'total revenue from crops and livestock (rs)' costlabor 'cost of hired labor (rs)' costdraft 'cost of hired draftpower (rs)' costwater 'cost of purchased water (rs)' costrat 'cost of purchased rations (rs)' obj 'net return (rs)'; totalrev.. rev =e= sum(c, crev(c)*xcrop(c)) + sum(h, gmargin(h)*xlivestk(h)); costdraft.. dcost =e= draftcost*dhire; costlabor.. lcost =e= laborcost*sum(t, xlabor(t)); costwater.. wcost =e= watercost*sum(t, wpurchase(t)); costrat.. rcost =e= sum(n, rationcost(n)*sum(t, xrations(n,t))); obj.. return =e= rev - lcost - wcost - rcost - dcost; land(t).. sum(c, cinput("landuse",t,c)*xcrop(c)) =l= fsize; water(t).. sum(c, cinput("irrwat",t,c)*xcrop(c)) =l= watavail(t) + wpurchase(t); labor(t).. sum(c, cinput("labor",t,c)*xcrop(c)) + sum(h, linput("labor",t,h)*xlivestk(h)) =l= maxflab(t) + xlabor(t); draft(dp,t).. sum(c, cinput(dp,t,c)*xcrop(c)) =l= - sum(h, linput(dp,t,h)*xlivestk(h)); bullock.. sum(c, bullockr(c)*xcrop(c)) =l= sum(h, bullocka(h)*xlivestk(h)) + dhire; credit.. sum(c, cinput("credit","annual",c)*xcrop(c)) + sum(h, linput("credit","annual",h)*xlivestk(h)) + rcost + lcost + wcost + dcost =l= maxcredit; nutbal(n,t).. - sum(c, cinput(n,t,c)*xcrop(c)) + eff(n)*xtransf(n,t--1) + xrations(n,t) =g= sum(h, linput(n,t,h)* xlivestk(h)); xcrop.up("sugar") = 2; wpurchase.up(t) = wpup; Model pakistan / all /; solve pakistan using lp maximizing return; Parameter ivl 'imputed value of family labor (rs)'; ivl = rev.l/sum(t, sum(c, cinput("labor",t,c)*xcrop.l(c)) + sum(h,linput("labor",t,h)*xlivestk.l(h))); display ivl;