APLICACIÓN DEL MODELO CNCPS (CORNELL) EN PEQUEÑOS RUMIANTES
Prof. Antonello Cannas Department of Agricultural Sciences, University of Sassari, Sardinia, Italy
Outline § The development of the SRNS § Prediction of requirements with the SRNS § SRNS prediction of feed nutritive value § SRNS nutritive values
§ SRNS evaluation § SRNS application § NDF and other CHO optimal values
Why developing the SRNS? Sheep & goat models:
• more empirical, less flexible than recent cattle systems • Have simplified body reserve models • Do not consider dairy sheep (except for INRA) • Do not account for: – the effect of intake on feed digestibility (except for AFRC, 1995), animal requirements (except for CSIRO, 2007), microbial efficiency
– the effect of rumen pH and N balance – the effects of fiber and non fiber bacteria on digestion – environmental effects on requirements (except for CSIRO, 2007)
Ewes and goats are not cows 10 2mes smaller !
Sheep and goats have a lower fermenta2ve capacity (rumen volume/Mcal maintenance energy) than ca5le
§ To compensate, they must:
§ be more selec2ve
§ eat more per day (as % of BW) than cows: lacta@ng ewes and goats : 3.5-‐7.0% of BW lacta@ng cow : 2.0-‐4.0% of BW
§ have higher feed passage rate à lower fiber diges@bility § Ruminate feed par2cles more finely - are more limited by the diet large par@cle size - Higher grain diges@bility
The SRNS • Approach used: – to use the framework of the CNCPS – to modify its submodels not suitable for S & G: • summarizying the vast literature available on small ruminants • finding scaling factors to apply research on cattle to small ruminants • carrying new experiments only when strictly necessary ⇒ little money is available for S & G research
The SRNS • Submodels of the CNCPS modified: – – – – – –
ME & MP requirements: from CSIRO, INRA, AFRC Composition of the gain for growing animals: CSIRO, modified Body gains or losses of adults: new equations Passage rate: new equations Fecal output of CP, fat , ash : CNCPS, corrected DMI prediction: equations of Pulina et al (1998) and AFRC (goats)
• Submodels of the CNCPS not modified: – The whole supply submodel (but new passage rates) – Amino Acid submodel ⇒ under work
The SRNS Cannas A., Tedeschi L., Fox D.G., Van Soest P.J., Pell A.N. 2004. Journal of Animal Science, 82:149-169 Tedeschi, L.O., Cannas, A., Fox D.G. 2010. Small Ruminant Research, 89, 174–184.
• NRC (2007) based its requirements for sheep on Cannas et al. (2004)
• SRNS software web site: http://nutritionmodels.com/srns.html free use for university students
• Multilingual: English, Italian, Spanish, Portoguese, Turkish, Korean
Outline
§ The development of the SRNS § Prediction of requirements with the SRNS § SRNS prediction of feed nutritive value § SRNS nutritive values
§ SRNS evaluation § SRNS application § NDF and other CHO optimal values
Sources of variations of MEm in lactating cattle Variable
% increase MEm
Source
Breed
0 à 30
Age
0 à -16
CNCPS CSIRO
Sex
0 à 15
AFRC, CSIRO
Diet quality
0 à 10
AFRC, CSIRO, INRA
Urea cost
0 à 14
CNCPS
Feeding level
0 à 40
CSIRO
-20 à 20
CNCPS - NRC
Cold stress
0 à 75
CSIRO – CNCPS
Heat stress
0 à 35
CNCPS
Activity confined
0 à 12
CNCPS
Grazing activity
8 à 55
CNCPS
Previous nutrition (BCS)
SRNS: ME maintenance requirements MEm (Mcal/d) = (SBW0.75 × 0.062 × K × a2 × exp(- 0.03 × AGE) + 0.09 × MEI × km + ACT + NEmcs + UREA)/km where: SBW = shrunk BW a2 = acclimatization AGE = age of the animals K = BMR adjustment 0.09 × MEI = ⇑ in maintenance req. as nutrient intake ⇑ ACT = Activity (flat and sloped distance) NEmcs = cold stress (°C, wind, rain) UREA = cost of urea production and excretion Km = 0.644
SRNS: ME maintenance requirements MEm (Mcal/d) = (SBW0.75 × 0.062 × K × a2 × exp(- 0.03 × AGE) + 0.09 × MEI × km + ACT + NEmcs + UREA)/km
K = BMR adjustment • Sheep: K = 1 è a1 × K = 0.062 Mcal • Goats: Based on Sahlu et al. (2004) K = 1.25 for dairy goats è a1× K = 0.0775 Mcal K = 1.05 for other goats è a1 × K = 0.0651 Mcal
MP maintenance requirements CleanWool 0.147 × FBW + 3.375 15.2 × DMI + + 0.6 × 365 0.67 0.67
Sheep !
MPM =
Goats !
0.03 × BW 0.6 × Hair 0.147 × FBW + 3.375 15.2 × DMI MPM = + + 0.6 × 365 0.67 0.67
• 1st term : endogenous CP from scurf & wool, g/d • 2nd term : urinary endogenous CP, g/d • 3rd term : fecal endogenous CP, g/d SRNS = MPm increases as DMI increases to account for higher visceral costs
SRNS energy and protein requirements of adult sheep Assuming clean wool production per year equal to 4% of BW Milk with 6.5% fat, 5% true protein (kg/d) 0 1 2 3
Energy requirements (ME, Mcal/d) 50 kg FBW 1
Protein requirements (MP, g/d)
70 kg FBW 2
50 kg FBW 1
70 kg FBW 2
TOTAL
maint.
TOTAL
maint.
TOTAL
maint.
TOTAL
maint.
1.61 3.53 5.35 7.15
1.61 1.90 2.05 2.20
2.07 4.04 5.85 7.65
2.07 2.40 2.55 2.70
48 147 247 346
48 61 74 87
59 158 257 357
59 72 85 98
based on the hypothesis that DMI is equal to 1.2, 1.8, 2.4, and 3.0 kg/d for dry ewes or lactating ewes producing 1, 2 and 3 kg/d of milk , respectively, and that total daily MEI equals total requirements. 1
based on the hypothesis of DMI is equal to 1.5, 2.1, 2.7, and 3.3 kg/d for dry ewes or lactating ewes producing 1, 2 and 3 kg/d of milk , respectively, and that total daily MEI equals total requirements. 2
NEL total requirements in lactation: ewes Milk with 6.5% fat, 5.0% true protein
70 kg of BW SNRS 1
INRA 2007 2
INRA 2017 2
(kg/d)
TOTAL
maint.
TOTAL
TOTAL
0 1 2 3
1.33 2.60 3.77 4.93
1.33 1.55 1.64 1.74
1.36 2.42 3.48 4.55
1.42 2.48 3.55 4.61
based on the hypothesis of DMI equal to 1.5, 2.1, 2.7, and 3.3 kg/d for 3-y old dry ewes or lactating ewes producing 1, 2 and 3 kg/d of milk, respectively, and that total daily MEI equals total requirements. Assuming NE of milk equal to 1.063 Mcal/kg. 1
2
assuming NE of milk equal to 1.063 Mcal/kg
Heat exchange in animals Conduction
Convection Solar radiation
Muscle+fat layer Skin surface
HEAT
TOTAL INSULATION = IT + IE IT = Thermal insulation
Wool or hair
of internal tissues IE = External thermal insulation from wool or hair
Evaporation Convection
Conduction Radiation
Sheep Total maintenance requirements expressed as index thermoneutral conditions index = 100)
Wind (km/h) Rain (mm/d) Adults, dry Temp. +5 °C Temp. 0 °C Temp. -5 °C Adults, in lactation Temp. +5 °C Temp. 0 °C Temp. -5 °C
Wool 25 mm 0 30 0 30 0 30
Wool 50 mm 0 30 0 30 0 30
115 129 144
134 149 164
234 267 300
247 280 313
100 103 183 195 100 114 208 220 109 124 233 245
100 100 100
100 100 104
125 137 149
133 145 157
100 100 107 114 100 100 116 123 100 100 125 132
Growth requirements
Soccer’s World Cup, 2006 (won by Italy)
NEL total requirements in lactation: ewes Milk with 6.5% fat, 5.0% true protein
70 kg of BW SNRS 1
INRA 2007 2
INRA 2017 2
(kg/d)
TOTAL
maint.
TOTAL
TOTAL
0 1 2 3
1.33 2.60 3.77 4.93
1.33 1.55 1.64 1.74
1.36 2.42 3.48 4.55
1.42 2.48 3.55 4.61
based on the hypothesis of DMI equal to 1.5, 2.1, 2.7, and 3.3 kg/d for 3-y old dry ewes or lactating ewes producing 1, 2 and 3 kg/d of milk, respectively, and that total daily MEI equals total requirements. Assuming NE of milk equal to 1.063 Mcal/kg. 1
2
assuming NE of milk equal to 1.063 Mcal/kg
Cost of gain vs. maturity (CSIRO, 1990) FAT set A Fat set B Protein set A Protein set B
Content in EBG (g/kg)
700 600 500 400 300 200 100 0 0.00
0.20
0.40
0.60
0.80
1.00
With this approach the cost of growth of all sheep and goat breeds can be predicted with the same model
Relative size (P) P = current BW/ mature BW
Mature BW P for 30 kg lamb
Sarda female
Sarda male
Merino female
Merino male
45
65
60
84
0.67 (30/45)
0.46 (30/65)
0.50 (30/60)
0.36 (30/84)
500
NRC (1981)
NE required (kcal/100 g ADG)
450 AFRC (1998)
400 350
SRNS Female
300
SRNS - Male
250 200
Sahlu & NRC(2007) Dairy & Meat
150 100 0
10
20
30
40
Sahlu & NRC (2007) Indigenous
BW (kg)
Simulation of the relationship between BW and NE requirements for 100 g/d of ADG. For the SRNS a mature weight of 55 kg for females and 85 kg for males was considered
CNCPS Sheep: body reserves model (Cannas & Boe, 2003)
BW = a + b BCS Breed
production
Meat/wool Aragonesa Awassi Milk Bergamasca Meat/wool Boutsko Milk Churra Milk Karagouniko Milk Laxta Milk Manchega Milk Merino Meat/wool Scottish Black. Meat Serres Milk Western range Meat/wool a = mature weight at BCS = 0 * original relationship is curvilinear
a
b
BW at BCS 2.5
Authors
* Texeira et al., 1989 8.95 42.66 11.80 57.40 Treacher e Filo, 1995 8.10 63.90 Susmel et al., 1995 7.36 37.90 Zy goyannis et al., 1997 5.57 44.00 Frutos et al., 1997 9.27 56.80 Zygoyannis et al., 1997 7.10 48.65 Oregui et al., 1997 10.9 67.30 Molina et al., 1998 7.27 41.38 Guerra et al., 1969 10.56 59.69 Russel et al., 1969 8.62 48.25 Zygoyannis et al., 1997 8.10 61.10 Sanson et al., 1993 b = BW variation for 1 BCS variation
22.52 27.90 43.60 19.50 30.12 33.60 30.90 39.50 2 3.20 33.29 26.70 40.85
full BW, kg
SRNS
120
70 kg FBW at BCS 2.5
100
50 kg FBW at BCS 2.5
60 kg FBW at BCS 2.5 40 kg FBW at BCS 2.5
80 60 40 20
Simulation of body reserve model in sheep
0 0
1
2
3
4
5
4
5
BCS (scale 0-5) 70 kg FBW at BCS 2.5 60 kg FBW at BCS 2.5 50 kg FBW at BCS 2.5 40 kg FBW at BCS 2.5
40
body FAT, kg
35 30 25 20 15 10 5 0 0
1
2
3
BCS (scale 0-5)
Outline
§ The development of the SRNS § Prediction of requirements with the SRNS § SRNS prediction of feed nutritive value § SRNS nutritive values
§ SRNS evaluation § SRNS application § NDF and other CHO optimal values
SRNS feed energy and protein value § based on the CNCPS dynamic rumen model § Predict nutrient supply from carbohydrate and protein fractions and their digestion and passage rates
§ Predicts separately rumen N requirements and balance and whole body MP balance
§ Variable microbial efficiency § Predicts variable ME and MP values from feed analysis
SRNS: feed fermented in the rumen depends on degradation rate (kd) and passage rate (Kp) UNDEGRADED
Intake Kd
Kp
Intestine
DEGRADED
Degradation rate (%/h) = rate at which feed fractions ferment Passage rate (%/h) = rate at which a feed particle escapes the rumen tract
SRNS: 4 carbohydrate fractions Organic Acids & Sugars
CHO A: kd 175 - 300%/h
NFC Starch & pectins
available NDF unavailable NDF
Lignin
CHO B1:
kd
CHO B2:
kd 3 - 6%/h
CHO C: kd 0 %/h
25 - 40%/h
SRNS = 5 protein fractions A
Non protein N Soluble CP
Kd istantaneous
NPN
citoplas m
B1
175-300%/h
sol. citopl.
B2 insol. citopl.
True protein
5-12%/h
Insolubile CP
B3
NDF
0.15 - 2%/h
NDIP
C ADIP
0%/h
Kd (%/h) of CHO of some feeds § Degradation rates are pool and feed specific, based on research data § Can be altered by degree of processing and rumen pH § same feed library of cattle Feed
A
B1
B2
Corn grain, whole
115
7.5
4
Corn grain, ground
200
10
4
Corn grain, flaked
300
30
6
Barley, ground
300
25
5
Corn silage, medium particles
250
20
6
Corn silage, fine particles
300
28
9
SRNS passage rates (Kp) (Cannas and Van Soest, 2000); equations developed on cattle, sheep and goats (few) data Kp forage, diet 17% CP Kp concentrate, diet 17% CP
9
Kp forage, diet 10% CP
8
Kp concentrate, diet 10% CP
Kp (%/h)
7 6
5 4
3 2
1 0 0.0
0.5
1.0
1.5
Dietary NDFI (% BW)
2.0
2.5
CNCPS - SRNS ⇑ requirements " ⇑ DM and NDF intake " ⇑ feed passage rate " ⇓ digestibility − much stronger decrease in slowly fermented fractions (e.g. fiber or insoluble N) than fastly fermented fractions (e.g. starch or soluble protein) − no decrease in digestibility in the feed fractions with very high degradation rate (e.g. sugar or NPN) − certain feed fractions are not digested at all (lingin and lingin bound substances)
Energy value: forages NEL System CP, % DM Ash , % DM NDF, % DM ADL , % DM
Ray-grass 2 14.7 10.5 52.7 4.5
Ray-grass 4
Ray-grass 5
10.6 8.7 63.4 5.0
9.4 9.2 70.6 8.0
Alfalfa 1 18.7 11.4 43.6 7.5
Alfalfa 3 15.0 10.7 56.0 9.0
1.173 1.360 1.343 1.302 1.278
1.071 1.150 1.345 1.265 1.230
NEL, Mcal/kg DM INRA NRC (2001) SRNS F70, 1.0M SRNS F70, 2.4M SRNS F30, 3.1M
1.258 1.390 1.437 1.370 1.346
1.156 1.290 1.345 1.261 1.236
1.122 1.320 1.085 1.003 0.980
F70 and F30 = percentage of forage in the diet; 1M, 2.4 M and 3.1 M = levels of feeding in multiples of maintenance. NRC (2001) = dairy cattle
Protein value: concentrates System
Units
Maiz USA
Pulpa de remolacha 11.3 0.9 47.7
Hna. Soja 44 50.1 1.9 14.2
Hna. Girasol
CP Ash NDF
% DM % DM % DM
9.4 4.2 10.2
INRA SRNS F70, 1.0M SRNS F70, 2.4M SRNS F30, 3.1M
DIP, % CP DIP, % CP DIP, % CP DIP, % CP
45 51 43 43
55 44 41 41
65 68 60 60
76 69 62 62
INRA SRNS F70, 1.0M SRNS F70, 2.4M SRNS F30, 3.1M
PDIA * MP escape * MP escape * MP escape *
52 40 47 47
49 42 45 45
185 144 184 185
78 85 110 110
* g/kg of DM F70 and F30 = percentage of forage in the diet; 1M, 2.4 M and 3.1 M = levels of feeding in multiples of maintenance.
34.2 2.7 44.8
Protein value: concentrates
INRA INRA SRNS F70, 1.0M SRNS F70, 2.4M SRNS F30, 3.1M
PDIME PDIMN MP microb. MP microb. MP microb.
43 21 121 110 99
Pulpa de remolacha 11.3 0.9 47.7 g/kg DM 63 33 103 94 84
INRA INRA SRNS F70, 1.0M SRNS F70, 2.4M SRNS F30, 3.1M
PDIE PDIN MP total MP total MP total
95 73 161 157 146
112 82 145 139 129
System CP Ash NDF
Units % DM % DM % DM
Maiz USA 9.4 4.2 10.2
* g/kg of DM F70 and F30 = percentage of forage in the diet; 1M, 2.4 M and 3.1 M = levels of feeding in multiples of maintenance.
Hna. Soja 44 Hna. Girasol 30 50.1 34.2 1.9 2.7 14.2 44.8 58 176 54 49 44
40 145 36 32 29
243 361 198 233 229
118 223 121 142 139
Protein value: whole diets System
Units
Ray-grass 2
Ray-grass 4
Ray-grass 5
Alfalfa 1
Alfalfa 3
Diet F70, 1.0 M INRA INRA SRNS
PDIE, g/d PDIN, g/d MP total, g/d
87 102 106
80 100 97
78 101 90
90 104 102
84 104 100
Diet F70, 2.4 M INRA INRA SRNS
PDIE, g/d PDIN, g/d MP total, g/d
217 256 269
200 250 243
194 252 226
225 260 267
210 260 256
Diet F30, 3.1 M INRA INRA SRNS
PDIE, g/d PDIN, g/d MP total, g/d
337 351 370
328 346 366
325 346 364
341 367 361
333 366 365
INRA suggests to use the lowest between PDIE and PDIN
Outline § The development of the SRNS § Prediction of requirements with the SRNS § SRNS prediction of feed nutritive value § SRNS nutritive values
§ SRNS evaluation § SRNS application § NDF and other CHO optimal values
SRNS evaluations Pred MB = RMS r2 References (P) O – P PE SHEEP 1 All OMd, g/100 g 19 60.2 61.3 -‐1.1 3.6 0.83 Cannas et al. (2004) Cannas et al. (2004) All 2 OMd, g/100 g 12 56.6 53.3 3.3 6.5 1 Lact. SBW var., g/d 15 22 28 -‐5.8 30 0.73 Cannas et al. (2004) 2 14 -‐57 110 53.4 84.1 0.84 Cannas et al. (2004) Lact. SBW var., g/d 19 -‐-‐ -‐-‐ 0.174 -‐-‐ 0.82 NRC (2007) Lact. NEL, Mcal/d Grow.3 ADG, g/d 42 198 180 18 41 0.84 Cannas et al. (2006a,b) 3 156 189 179 10 -‐-‐ 0.70 NRC (2007) Grow. ADG, g/d 3 8 285 282 2.4 21.4 0.76 Linsky (2008) Grow. ADG, g/d 8 275 295 19.8 59.2 0.30 Linsky (2008) Grow.3 Fat, g/kg EBG 3 146 152 5.8 19.3 0.10 Linsky (2008) Grow. Prot., g/kg EBG 8 48 -‐-‐ -‐-‐ 0.9 -‐-‐ 0.88 NRC (2007) Grow. MP for gain, g 8 1.33 1.29 0.04 0.05 0.95 Linsky (2008) Grow. DMI, kg/d GOATS Lact. MEI, Mcal/d 21 4.04 4 0.04 0.23 0.99 Cannas et al. (2007b) 6 -‐ 0.10 0.99 Cannas et al. (2007b) Lact. NE milk, Mcal/d 21 1.664 1.746 3 0.082 0.20 2 0.87 Cannas et al. (2007b) Lact. NE bal., Mcal/d 21 0.361 0.286 0.075 3 1 Grow. ADG, g/d 31 136.1 142.5 -‐6.4 32.5 0.85 Cannas et al. (2007a) 1 2 3 rumen N balance positive; rumen N balance negative; (0.09 x MEI) correction of MEm not Stage Variable, units
used
N
Obs (O)
Outline § The development of the SRNS § Prediction of requirements with the SRNS § SRNS prediction of feed nutritive value § SRNS nutritive values
§ SRNS evaluation § SRNS application § NDF and other CHO optimal values
SRNS report
SRNS report
SRNS report
Ruminant Nutri2on System (Tedeschi, 2018) Include caGle, sheep, goats Methane predic2ons
Nuraghe (Sardinia) 1800-1300 year B.C. About 8000 of them in the whole Island
Outline § The development of the SRNS § Prediction of requirements with the SRNS § SRNS prediction of feed nutritive value § SRNS nutritive values
§ SRNS evaluation § SRNS application § NDF and other CHO optimal values
CHO during pregnancy and lactation of sheep and goats
§ Well defined reference values for NDF, starch, sugars, fiber particle size in dairy cattle
§ No feeding systems suggest optimal, max and min NDF and NSC (or NFC) values during the pregnancy and lactation of ewes and goats Serious limitation when balancing the diets of small ruminants
Pregnancy
Energy and NDF during pregnancy of sheep and goats § Sheep and goats are prolific and have short pregnancy: high requirements in a short period § Common to observe subclinical ketosis and pregnancy toxemia § Strong association between negative energy balance, increased ketone bodies and diseases in the transition period (end of pregnancy, early lactation) § Marked negative energy balance during pregnancy reduces milk production § Proper nutrition during pregnancy necessary for optimal milk production and health during the lactation
Ewes (BW 92 kg) fed silages plus concentrates (Olsen, 2016)
Mean: 1.0% NDFi intake as % BW
Database on pregnant ewes (mean -30 d to lambing) Mean St.dev. Min. Max.
DMI, BW %BW 73.1 2.7 23.4 0.4 39.4 2.0 100.0 3.3
DMI, kg/d 1.9 0.6 1.2 2.9
NDFI, %BW NDF% DIP, d 1.2 43.2 117.4 0.3 9.1 13.0 0.8 31.0 90.0 1.7 61.6 130.0
Litter size 1.9 0.7 1.0 3.2
Total litter BW 10.4 5.2 3.3 16.8
ME int, Mcal/d 4.9 1.9 2.7 8.1
ME req, Mcal/d 4.0 1.4 2.1 5.6
NDFI, % bw DMI, % BW
3,5
Diet NDF during pregnancy(mean= 30 d from lambing)
3 NDFi or DMI , % BW
2,5 2
1,5 1
MEI
0,5
ME balance
MEI intake or balance, Mcal/d
10,0 8,0
0 20
30
40 50 NDF, % DM
60
70
6,0 4,0 2,0 0,0
-2,0
20
30
40 50 NDF, % DM
60
70
Diet NDF concentration during the pregnancy of sheep
NDFI, % BW = 0.646 + 0.02086 x NDF% - 0.2032 x litter size DMI, %BW = 4.392 - 0.01731 x NDF% - 0.5011 x litter size
R2 adj = 92.6% R2 adj = 80.6%
ME int, Mcal/d = 3.05 - 0.0582 NDF% - 1.450 x litter size + 0.09746 BW R2 adj= 93.7%
Diet NDF during pregnancy (Cannas, 2016) (70 kg BW) 4,5 4,0 3,5 3,0 2,5 2,0 1,5 1,0 0,5 0,0
Litter size
DMI, kg/d NEL int, Mcal/d NEL req, Mcal/d
1
1
1
35
50
65
2
2
2
3
3
3
35NDF (% 50 DM) 65 Diet
35
50
65
Max diet NDF around 40-45%; lower values in small body size sheep
Diet NDF during pregnancy
NDF intake, % BW
2,5 Sheep
2,0
Cattle
y = 0.0004x2 - 0.0125x + 0.874 R² = 0.72
1,5 1,0 0,5
y = 0.0006x2 - 0.0414x + 1.3791 R² = 0.84
0,0 20
30
40 50 NDF, % DM
60
70
Energy and NDF during pregnancy of sheep and goats
In late pregnancy: § diet NDF concentration < 40% is suggested, especially with twins § energy and NDF concentrations should be similar to those of lactation § High quality (immature, low NDF and lignin) forage sources are needed § Chopping the forages helps to keep high the intake
Lactation
Meeting of the Animal Science Modellersâ&#x20AC;&#x2122; Group -2016
Prediction of optimal NDF intake in Antonello Cannas
sheep
Antonello Cannas1, L. O. Tedeschi2, G. Molle3, A. S. Atzori1, C. Dimauro1, M. F. Lunesu1 1Department
of Agricultural Sciences, University of Sassari, Sardinia, Italy
2Department
of Animal Science, Texas A&M University, College Station, TX
3Dipartimento
di Ricerca nelle Produzioni Animali, Agris Olmedo, Sardinia, Italy
59
Intake models for sheep § Intake models for sheep (and goats..) mostly based on energy requirements, do not account for diet filling effect (Pulina et al., 2013) § Little reference values for optimal, minum or maximum dietary or forage NDF concentration or intake, forage and NDF particle size § Mostly empirical observations and suggestions
OBJECTIVES § to develop a model to predict optimal dietary NDF concentration and intake for sheep. Current focus: lactating ewes § The approach developed by of Mertens (1985; 1987) for dairy cattle was used and adapted to sheep
Dairy cows Max DMI with NDFI equal to 1.1-1.2% PV
Intake (% BW)
Ie = C/F
Ie = R/E
Diet NDF, % DM
BW
DMI % BW
DMI kg/d
Diet NDF % DM
NDF intake kg/d
NDF intake % BW
600
2.90
17.4
38.0
6.61
1.10
600
3.35
20.1
33.0
6.63
1.11
600
4.00
24.0
27.5
6.60
1.10
Adapatation of the model of Mertens to sheep § Sheep have a lower fermentative capacity (rumen volume / Mcal maintenance energy) than cattle. To compensate, sheep: § are more selective § eat more per day (as % of BW) than cows: • lactating ewe : 3.5-7.0% of its BW • lactating cow : 2.0-4.0% of its BW § have higher feed passage rate à lower fiber digestibility § NDFIC = NDF intake capacity (kg of NDF/d), considered constant and equal to 1.1% ± 0.1 of BW § is this valid for sheep? § is this valid, since the level of intake of intake of sheep is higher than that of cattle, the diet of sheep would have too low NDF concentrations
Diet DM and NDF during lactation
DMI%BW sheep DMI%BW cow
DMI%BW sheep DMI%BW cow
y = -0.0714x + 8.7298 R² = 0.33
8
3,5
7
3,0 y = 0.0287x + 1.1758 R² = 0.31 2,5
5
NDFI, % BW
DMI, % BW
6
2,0
4
1,5
3
1,0
2 y = -0.0183x + 4.1611 R² = 0.048
1
0,5
0 20
25
30
35
40
NDF, % DM
45
50
y = 0.0284x + 0.2327 R² = 0.53
55
0,0 20
25
30
35 40 NDF, % DM
45
50
55
Adapta2on of the model of Mertens to sheep § The 1.1% NDFI%bw of a 600 kg cow Mertens (1985, 1987) was used as reference value: § NDFIC was 6.6 kg of NDF, which is also equal to 5.444% of BW0.75 (i.e. 6.6/6000.75= 0.544)
§ The NDFIC capacity for other BW was es@mated as 5.444% of BW0.75 MW, kg
NDFI, % BW
50 100 200 400 600 800 1000
18.8 31.6 53.2 89.4 121.2 150.4 177.8
2.05 1.72 1.45 1.22 1.10 1.02 0.97
NDFI, % NDFI capacity, kg MW 1.02 1.72 2.90 4.87 6.60 8.19 9.68
5.444 5.444 5.444 5.444 5.444 5.444 5.444
2,0
y = 5.444 x-‐0.25
1,5
NDFI, % BW
BW, kg
2,5
1,0 0,5 0,0 0
200
400 600 BW, kg
800
1000
Adapta2on of the model of Mertens to sheep
Thus, the NDFIC of Mertens (1987) was scaled to sheep BW assuming it varied as a func2on of BW-‐0.25
By using 1.1% NDFI%bw à NDFIC, % BW = 5.444 x BW-‐0.25
§ The predic@ons are consistent with the values of Molle et al. (2014, 2016) (Obs = 2.38%, Pred = 2.30%) and Nielsen (2016) (Obs = 1.92%, Pred = 1.76%) if 1.2% NDFI%bw is used § the equa@ons of Mertens (1987) were then used to es@mate DMI and NDF op@mal concentra@on in sheep of different milk yield y using variable NDFIC, % BW
Maximum dietary NDF (% of DM) and corresponding DMI (% BW) on lactating ewes fed forages and concentrates (Cannas et al., 2016) Grass-Legume forage: 58% NDF, 1.20 NEL kg-1 Concentrate: 12% NDF, 1.90 NEL kg-1
Milk, kg/d 6.5% fat, 5.8% P 1.0 2.0 3.0 4.0 Milk, kg/d 6.5% fat, 5.8% P 1.0 2.0 3.0 4.0
45 kg BW (2.10 NDFI%bw )
60 kg BW (1.96 NDFI%bw )
NDF %
DMI % BW
Forage %
DMI kg/d
NDF %
DMI % BW
Forage %
DMI kg/d
54.7 41.7 33.7 28.3
3.8 5.0 6.2 7.4
93 65 47 35
1.7 2.3 2.8 3.3
58.0 45.9 37.9 32.3
3.4 4.3 5.2 6.1
100 74 56 44
2.0 2.6 3.1 3.7
75 kg BW (1.85% NDFI%bw)
90 kg BW (1.77% NDFI%bw)
NDF %
DMI % BW
Forage %
DMI kg/d
NDF %
DMI % BW
Forage %
DMI kg/d
58.0 49.1 41.2 35.5
3.2 3.8 4.5 5.2
100 81 64 51
2.4 2.9 3.4 3.9
58.0 51.6 43.9 38.2
3.0 3.4 4.0 4.6
100 86 69 57
2.7 3.1 3.6 4.1
Italics = it would cause weight gain.
Starch in lactating sheep and goats In ewes: • Positive effect of starch in early lactation (Cannas et al., 2002; Bovera et al., 2004; Cannas et al., 2007; Cannas et al., 2013) • Positive effects of highly digestible fiber (e.g. beet pulps, soybean hulls and immature forage) in mid-late lactation (Cannas et al., 2002; Cannas et al., 2004; Bovera et al., 2004)
In goats: • Positive effect of starch both in early and in late lactation (Cannas et al., 2007)
Milk production in ewes fed different % of NSC and starch (Bovera et al., 2004) L = 20.7% starch 1600
H = 26.1% starch
*
Milk yield (g/d)
1400 1200 1000
L H
800 600 400 200 0 0
* = P < 0.05
1
2
3
4
Months of lactation
5
6
7
Modulation of dietary energy partitioning between milk production and body reserves in sheep and goats Ph.D. Project of Mondina Lunesu Chair: Antonello Cannas
Diets
Pellets HS
LS
Pellet (HS or LS)
65.7
65.7
Dehyd chopped alfalfa
28.0
28.0
Whole corn grains
2.4
2.4
Mature ryegrass hay
3.9
3.9
100.0
100.0
Ingredients, % as fed
TOTAL
Chemical composi2on CP, % DM
15.4
15.4
Ash, % DM
11.8
12.3
NDF, % DM
36.4
46.8
NFC, %DM
37.3
26.6
Starch, % NFC
64.6
39.62
Starch, % DM
24.1
10.5
Ingredients, % AF
HS
LS
Dehydrated alfalfa Corn meal Barley meal Wheat bran Soybean hulls Soybean meal 44 Sugarcane molasses Sodium bicarbonate Bentonite Magnesium oxide Minerals and vitamins
30.0 21.1 13.4 10.1 9.0 5.0 4.6 3.0 2.0 1.5 0.3
30.0 3.0 0.0 5.0 43.2 7.4 4.6 3.0 2.0 1.5 0.3
Appe@zer TOTAL
0.03 100.0
0.03 100.0
LS HS
LS HS
3,3 3,1 2,9 2,7 2,5
6.5% fat corrected milk produc2on, kg/d(P<0.01)
LS HS
i Prelim
SHEEP 3,8
27-‐
y 6-‐Ma
22-‐
e 4-‐Jun
BCS (P< 0.013)
3,6 3,4
BCS
2,1 1,9 1,7 1,5 1,3 1,1 0,9 0,7
BCS (P> 0.05)
BCS
3,4 3,2 3 2,8 2,6 2,4 2,2 2
GOATS 3,5
4.0% fat corrected milk yield, kg/d (P<0.02)
3,2
LS
3,0
HS
2,8
0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0
Ewes Goat
Insulin
Insulin (µg/L)
(µg/L)
20
40
60 80 DIM
100 120 140 15
Ew es
12
GH (ng/ml)
0
9
Growth Hormone (ng/ml)
6 3 0 0
20
40
60DIM80
100
120
140
NDF and STARCH during lactation
§ DMI and NDFI as % of BW higher in small size sheep and goats § Optimal NDF dietary concentration lower in small size sheep and goats § In early lactation the diet should be rich of starch, both in ewes and goats: 20-30% of DM § In mid-late lactation the diet should be rich of starch in goats (20-30% of DM) but low in starch (10-15% of DM) and rich in digestible fiber in sheep
CONCLUSIONS § Economical importance of sheep and goats is growing • should not be more the little brother § Better predictions are needed to account for the different environments and production systems § to improve sheep and goats’ performances and profitability § to reduce nutrient use and environmental impact § to reduce more food for humans
§ Much more effort is needed to develop feeding systems for sheep and goats
Alghero
Thank you for your attention !