Dairy sheep farming and nutrition U. Bernabucci Department of Animal Production University of Tuscia – Viterbo

Main Dairy Sheep Breeds reared in Italy Massese Breed Sarda Breed Comisana Breed Department of Animal Production See:

Schematic representation of the productive cycle of dairy sheep in Central Italy in relation with pasture availability Dry Lactation Primiparous Pluriparous Months Grazing forage availability JJJ Department of Animal Production

Structural characteristics of dairy sheep farms Department of Animal Production

Forages Pasture Hay Silage Department of Animal Production

Forage management in the dairy sheep farming system Environment and landscape Agronomic management Animal management Soil Characteristics Agronomic operations Grazing technique Animal health Quantity of forage Biomass Forage species Climatic and topographic condition Animal pressure Productive level Quality of the animal products Forage quality

Department of Animal Production

Forages Pasture Department of Animal Production

Grazing forage availability during the year estimated by grass height Department of Animal Production

HayStrawGrassland areasSilageTemporary grassland

Department of Animal Production

DM CPNDFADF ADLNSC FUMP/kg Mixed Gramineae Clover Mixed field Nutritive value of pastures (% of DM; means ± SD) Department of Animal Production

DM CPNDFADF ADLNSC FUMP/kg Mixed Gramineae Clover Mixed field Nutritive value of pastures (% of DM; means ± SD) Department of Animal Production

Nutritive value of pasture during the year (% of DM; means ± SD) DM CPNDFADF ADLNSC FUMP/kg Oct-Dec Jen-Mar Apr-Jun Jul-Sept Grazing on straw :low energy and protein values Department of Animal Production

Protein, NDF and forage unit for milk production contents of pasture (% on DM) Department of Animal Production

Forages Hay Department of Animal Production

DM CPNDFADF ADLNSC FUMP/kg Italian ryegrass Mixed , Alfalfa Nutritive value of hays (% of DM; means ± SD) Department of Animal Production

Forages Silage Department of Animal Production

DM CPNDFADF ADLNSC FUMPpH NH 3 Italian ryegrass Corn Clover Alfalfa NH 3 = % NH 3 -N / Total - N Nutritive value of silage (% of DM; means ± SD)

Relative utilisation of forages in the diet of dairy sheep during the year HayPastureSilage Department of Animal Production

Concentrate utilisation Department of Animal Production

Concentrate fed during the year  No changes in characteristics just in the amount fed Department of Animal Production

Requirements Department of Animal Production

Requirements of energy and protein for dairy sheep FUMP CP (g) 40 kg of LW kg of LW kg of LW FUMP = Fodder Unit for milk production LW = Live weight Maintenance Department of Animal Production

Requirements of energy and protein for dairy sheep Days before lambing Weight of lambs at birth FUMPCPFUMP CP FUMP CP FUMP = Fodder Unit for milk production; CP = crude protein (g) Pregnancy values to be added to ‘Maintenance’

Requirements of energy and protein for dairy sheep Milk composition Requirements per litre Fat, % Protein, % FUMP CP Lactation values to be added to ‘Maintenance’ FUMP = Fodder Unit for milk production; CP = crude protein (g)

Critical phases in the dairy sheep production system Department of Animal Production

Oct Sept Milk yield and energy requirements of dairy ewes Lambs Milk FUMP Department of Animal Production

Pluripaorus: Early lactation and first 2 months of lactation Primipaorus: Last phases of pregnancy: -  pasture availabilityNutritive lack - no  in hay and silage useRapid decline in milk yield - no  in concentrate useDecline in BCS Milk Grass Department of Animal Production

Improve grazing management and hay and silage use Possible solutions: -  grazing time -  hay and silage use -  concentrate use Example of diet: kg of silage kg of hay kg of concentrate Concentrate containing > 16% of CP Department of Animal Production

End of lactation - SPRING: -  pasture availability -  pasture nutritive value Flushing is not necessary -  concentrates utilisation Mating of pluripaorus ewes Milk Grass Department of Animal Production

SUMMER and FALL: -   pasture availabilityFlushing for primiparous ewes -   pasture nutritive valuePossible metabolic disorders -  concentrates utilisationImpairment of nutritional status Mating of primipaorus ewes Last phase of pregnancy of pluriparous ewes Grass Department of Animal Production

Improve hay, silage and concentrate use Possible solution: - utilisation of best hay - utilisation of silage -  concentrate (Flashing) Example of diet: kg of silage kg of hay kg of concentrate Concentrate containing > 13-14% of CP Department of Animal Production

Some considerations àImprove grazing management; àImprove hay and silage use; àWhen we feed silage (mais in particular) have to consider: àSilage =  protein --- Pasture =  protein àTo formulate concentrates in relation with forage availability and characteristics (pasture in particular) Low availability: 25% CP High availability: 18% CP  NSC (Grain) Department of Animal Production

Anyway, about forage it has to be considered possible environmental impact: Department of Animal Production

Major environmental impacts of semi-extensive dairy sheep farming system Grazing management Grazing Techniques High stocking rate High grazing pressure Continuous grazing Long grazing time Carrying capacity Annual cultivated forages (monoculture) Influence on soil fertility and stability Influence on biodiversity Foraging strategy Grazing areas degradation Department of Animal Production

Some considerations àTo formulate particular concentrates in relation with the physiological phase (last phase of pregnancy in particular) Example of special concentrate to prevent pregnancy toxaemia Department of Animal Production

Animals, housing and feeding 440 healthy and dry Comisana ewes were used. The parity ranged from 2 to 5. Animals were split in two homogeneous groups of 20 by body score, parity and genetic capability for milk production. 4The trial was performed under semi-extensive conditions. 4The ewes were fed the same diet during the first 100 days of pregnancy: - hay: ad libitum basis; - pasture: 7 hours a day; - barley: 100 g head -1 d -1 ; - commercial mixed feed (CMF): 200 g head -1 d -1. ( 1 ) Department of Animal Production

Treatment 4Fifty days before lambing to one of the two groups (T-group) 200 g head -1 d -1 of special CMF containing: - 5% of Na-propionate - 3.5% of Ca-salts of LCFAs - 3% of sorbitol mg/kg of niacin, was given in substitution of 200 g head -1 d -1 of traditional CMF. 4The other 20 ewes (C-group) were not treated. After lambing all ewes were fed the same diet. ( 2 ) Department of Animal Production

Body condition score (BCS) Days from lambing Department of Animal Production

Plasma  -OH butyrate (BOHB) and Non-Esterified Fatty Acids (NEFA) (mmol/l) Days from lambing Department of Animal Production

Least-square means of plasma metabolites in the last 28 days of pregnancy in ewes fed (T-group) or not (C-group) a special concentrate. N. of lambs born/ewe 1 2 Group C T C T N. of animals(7)(6) (13)(14) Glucose (mmol/l)2.41 B 2.30 B 1.97 A 2.17 B  -OH butyrate (mmol/l)0.657 A A B A NEFA (mmol/l)0.522 A A B A Ca (mmol/l)2.46 B 2.61 B 2.39 A 2.55 B Zn (  mol/l)15.21 a b a b Albumin (g/l)32.8 A 35.4 B 33.6 A 34.1 AB Bilirubine (  mol/l)4.13 B 3.28 A 4.45 B 3.42 A a, b = P<0.05; A, B = P<0.01 Department of Animal Production

Least-square means of live weight at birth (LW 0 ), live weight at 30 days of age (LW 30 ) and average daily gain (ADG) of ewes’ offspring in ewes fed (T-group) or not (C-group) a special concentrate. N. of lambs born/ewe 1 2 Group C T C T N. of animals(7)(6) (13) (14) LW 0 (kg) 4.68 B 4.92 B 4.12 A 4.18 A LW 30 (kg) B B Aa Ab ADG (kg)0.296 ab ab a b a, b = P<0.05; A, B = P<0.01 Sex ratio was not different between groups. No differences were observed for LW 0 between groups. The lower ADG was in C-group Treatment allowed to maintain normal lamb ADG