The inoculation with Azospirillum brasilense has the potential to reduce the use of mineral fertilizers with efficient capacity to promote plant growth and yield. Most studies on the Azospirillum–plant association have been conducted on cereals and annual grasses. More studies are needed in perennial pastures, such as bermudagrass (Cynodon dactylon (L.) Pers.) that require substantial nitrogen (N) fertilization to maximize their production potential. Therefore, pastures based on Tifton 85 bermudagrass in association with annual ryegrass (Lolium multiflorum Lam.), which were inoculated with A. brasilense and fertilized with increasing amounts of N fertilizer and grazed by lactating Holstein cows were evaluated. Three grazing systems were evaluated: (i) Tifton 85, inoculated + 180 kg N/ha per year; (ii) Tifton 85 + 230 kg N/ha per year; and (iii) Tifton 85 + 280 kg N/ha per year. Forage samples were collected before and after grazing to evaluate the responses of the plants and animals. The forage yields of the systems were 21.0, 20.8 and 22.1 t DM/ha per year and the stocking rates were 3.9, 3.8 and 4.0 animal unit/ha per day, respectively. Crude protein, total digestible nutrients and neutral detergent fibre concentrations were 162, 560 and 667 g/kg, respectively. Inoculation in pastures planted with Tifton 85 bermudagrass in combination with ryegrass (plus 180 kg N/ha per year) had a positive effect, providing forage yield and nutritional value equivalent to those with fertilization with 230 kg N/ha per year.

Organic farming conserves natural resources, promotes biodiversity, guarantees animal welfare and obtains healthy products from raw materials through natural processes. In order to evaluate possibilities of increasing organic animal production, this study proposes a farm-scale multicriteria method for assessing the conversion of dairy goat systems to the organic model. In addition, a case study in the Northern Sierra of Seville, southern Spain, is analysed. A consensus of expert opinions and a field survey are used to validate a list of potential indicators and issues for assessing the conversion, which consider not only the European Community regulations for organic livestock farming, but also agroecological principles. As a result, the method includes 56 variables integrated in nine indicators: Nutritional management, Sustainable pasture management, Soil fertility and contamination, Weed and pest control, Disease prevention, Breeds and reproduction, Animal welfare, Food safety and Marketing and management. The nine indicators are finally integrated in a global index named OLPI (Organic Livestock Proximity Index). Application of the method to a case study with 24 goat farms reveals an OLPI value of 46.5% for dairy goat farms located in mountain areas of southern Spain. The aspects that differ most from the agroecological model include soil management, animal nutrition and product marketing. Results of the case study indicate that the proposed method is easy to implement and is useful for quantifying the approximation of conventional farms to an organic model.

The objective of this work was to examine the effect of different levels of grazing on muscle nutritional fatty acid (FA) profile, including the beneficial n-3 polyunsaturated fatty acids (PUFA) and cis-9, trans-11 (cis-9, trans-11) 18:2 conjugated linoleic acid (CLA). Thirty male Galician Blond (GB) breed calves were randomly assigned to the following three grazing treatments: (1) continuous pasture grazing for 250 days (P); (2) 197-day grazing followed by a 50-day short period of concentrate-based finishing (PC) and (3) 57-day grazing followed by a 165-day long period of concentrate-based finishing (C). Calves kept sucking their mothers up to the time of slaughter. The slaughter weight was similar for all treatments (about 330 kg). Samples of the longissimus thoracis muscle were used for assessment of chemical composition by near infrared reflectance spectroscopy and FA profiles by gas chromatography. Muscle from C calves was fatter and had higher content in total FA, monounsaturated FA (MUFA), cis-9 18:1 than muscle from P calves, whereas PC muscle had generally intermediate values. No significant treatment difference for total saturated FAs (SFA) was found. Content of potentially beneficial n-3 PUFA (18:3n-3, 20:3n-3, 20:5n-3 and 22:6n-3), cis-9, trans-11 CLA and n-6:n-3 ratio were lower and PUFA : SFA ratio were higher in P than in both C and PC calves. Calves fed exclusively on pasture synthesised higher amounts of beneficial FA than calves finished on concentrate. A 50-day period of concentrate-based finishing was sufficient to offset the synthesis of beneficial FA from pasture grazing.

Two experiments were conducted to determine if type of stocking system influenced the intake and live-weight gain (LWG) of cattle co-grazed with sheep on sown ryegrass/white clover pasture.

In experiment 1 (134 days), yearling heifers (no. = 9) plus ewe hoggets (no. = 27) were co-grazed (1: 1 M0·75) using continuous (C-CS) or rotational (R-CS) stocking. In experiment 2 (126 days), a cattle alone (no. = 9) treatment was included under each stocking system (C-C and R-C). Initial live weight of heifers was 266 (s.e. 4·5) and 232 (s.e. 4·4) kg and that of hoggets was 54 (s.e. 0·9) and 47 (s.e. 0·7) kg in experiments 1 and 2, respectively. In both experiments, the area offered daily to R-CS group was manipulated to promote a weekly live-weight change in sheep similar to that on the C-CS treatment. C-C cattle in experiment 2 were grazed at similar sward surface height (SSH) to C-CS, and R-C cattle at similar pre- and post-grazing SSH to R-CS. SSH was measured daily on all treatments and regulated on the continuously stocked treatments by addition and removal of non-experimental animals. Organic matter intake (OMI) was determined from the ratio of n-alkanes in faeces and herbage. Animals were weighed weekly.

Mean SSH on continuously stocked pastures was 5·10 (s.e. 0·03) and 4·26 (s.e. 0·02) cm for C-CS in experiments 1 and 2, respectively, and 4·27 (s.e. 0·02) cm for C-C in experiment 2. The mean pre- and post-grazing SSH for R-CS was 15·9 (s.e. 0·12) and 5·60 (s.e. 0·07) cm, respectively in experiment 1, and 15·2 (s.e. 0·08) and 4·82 (s.e. 0·03) cm, respectively in experiment 2. On R-C swards pre- and post-grazing SSH was 14·9 (s.e. 0·08) and 4·87 (s.e. 0·03) cm, respectively.

In experiment 1, cattle continuously co-grazed with sheep grew significantly more slowly than those rotationally co-grazed with sheep (804 (s.e. 41·6) v. 1039 (s.e. 47·7) g/day, P < 0·01). Sheep LWG did not differ between stocking treatments (150 v. 138 g, P > 0·05 for C-CS and R-CS respectively). These findings were confirmed in the second experiment in which C-CS cattle only grew at 0·69 of the daily LWG achieved by R-CS cattle (706 v. 1028, (s.e. 72) g/day; P < 0·05) at similar sheep LWG (155 v. 147, (s.e. 6·5) g/day respectively). LWG of C-C and R-C cattle was similar (916 v. 1022, (s.e. 72) g/day; P > 0·05). LWG per ha in both experiments was higher on R-CS than on C-CS treatments, and on cattle alone than on CS treatments. Treatment effects on OMI and final fasted live weight were similar in pattern to LWG.

It is suggested that the observed disadvantage to cattle when co-grazed with sheep under continuous stocking and the lack of effect when rotationally co-grazed reflected a difference in the two stocking systems in providing opportunities for complementary/competitive use of pasture resources.

A comparison was made between two different finishing systems with Belgian Blue bulls. Two groups of bulls were grazed during an initial 140-day period and then finished indoors with concentrates. There were two stocking rates during the grazing period: a medium at six bulls per ha (MGFI) and a high at eight bulls per ha (HGFI). A third group of bulls was finished indoors on a concentrate diet during the whole finishing period (FI). The experiment was repeated over 2 years consecutively. The pasture which was grazed at the medium stocking rate was characterized by a higher sward height (P < 0·01), more refusals (P < 0·001), less Lolium perenne (P < 0·05) and more Trifolium repens (P<0·05) than that grazed at eight bulls per ha. The live-weight gain was 1·15 kg/day during the grazing period for the MGFI bulls and 1·00 kg/day when they were taken indoors. The increase in stocking rate reduced the gain at grass (1·00 kg/day, P < 0·001) and improved the gain indoors (1·24 v. 1·01 kg/day, P < 0·001). In the groups which were initially grazed when compared with the indoor system, the fattening period was longer (236·0 and 241·0 v. 186·9 days, P<0·01) and the live-weight gain lower (1·11 and 1·10 v. 1·44 kg/day, P < 0·001 for MGFI, HGFI and Fl respectively). The dressing proportion was greater also (P < 0·05), and there were higher concentrations of muscles (P < 0·05) and bones (P < 0·05) in the carcass of the bulls which were grazed initially. With these bulls, the lean meat was darker (P<0·05) and lost more water although there were no effects on the myoglobin content or on shear force. The net profit was in favour of the groups which were grazed.