Improvement of biosustainability of a goat feeding system with key supplementation

A one-year study was conducted to measure the effects of balanced supplemen tation to improve biosustainability of a 110 head goat herd in Mexico in te rms of economic feasibility on limited pasturing range land complemented wi th an alfalfa hay forage bank and grazing corn stubble. Average weight of a dult females was 52.410+/-5 kg, yearlings 40.0+/-3 kg at first kidding. Ave rage total lactation milk production was 455+/-21 kg in 210 days. Feeding s trategy included balanced concentrate (BC) from December to May, gradually changing the supplementation when grazing started, by offering a multinutri tional block (MB) and complex catalytic granulate feed (CCF), which was use d at the beginning of range pasture and continued, when goats were fed on c orn stubble starting October. The initial BC was composed of corn, barley, wheat bran, soybean oil meal, but the latter was withdrawn from the mixture in May (3 Meal ME and 12% CP; 10% from May on), offered twice a day. Anima ls on pasture from May until November were supplied ad libitum with MB prep ared from molasses, urea, salt, cottonseed meal, limestone, cement kin dust , corn stubble, and a mineral mixture, composed of triple superphosphate an d a commercial mineral mix for ruminants and salt. Beginning in August, 200 g of CCF was added from a mixture of molasses, urea, salt, limestone, cott onseed meal, rice polishing, corn, poultry litter, commercial mineral salts , ammonium sulfate, cement kiln dust, and animal lard. Late pasture on corn stubble was from October to December. CCF was kept with the diet. Average voluntary feed intake (VFI) was 1.880 kg DM/d with an annual total of 828 k g; of which 248 kg DM was provided by alfalfa hay from a forage bank corres ponding to 30% of the total feed intake; 182 kg or 22% of the diet was conc entrate (BC, MB, CCF), and 398 kg or 48% was from range land (grasses, shru bs and tree leaves) or corn stubble pasturing. Balancing concentrate dimini shed the protein intake from 2.10 times requirements to 1.19. Changes in su pplementation according to forage availability permitted nutritional optimi zation of the system. It was possible to improve biosustainability (forages produced on the farm) from 33% before to 48%; while increasing milk produc tion from 400 to 455 kg/year and diminishing production cost from 20 to 17 US cents per liter of milk. (C) 2000 Published by Elsevier Science B.V. All rights reserved.