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tendency is more marked the higher the number of botanical species in the pasture, on condition that botanical heterogeneity is accompanied by a corresponding spatial differentiation of the various essences. In fact, structural differentiation of pasture facilitates identification and prehension of the most appetising essences or parts of the plant. Species which are erect in their growth, such as most forage grasses, offer a better chance of the sheep selecting morphological parts of the single plant than do creeping species, such as some spontaneous or cultivated legumes (Table 7) (Avondo and Lutri, 2004). Table 7 – Protein and digestible organic matter content of the whole plant and of selected parts of various pasture essences (Avondo and Lutri, 2004). Digestible organic Crude Protein matter % DM % DM Whole Selected Whole Selected Botanical essence Grasses Growth habit Plant part plant part Barley Erect 18.2 25.4 68.1 72.0 Bromus spp Erect 15.8 23.7 69.1 73.7 Mixed pasture Erect 10.1 16.8 62.6 69.8 Mixed pasture Erect 8.8 11.3 73.4 76.6 Mixed pasture Legumes Erect 10.8 16.7 - - Vetch Creeping 20.9 22.2 66.4 69.1 Clover Creeping 21.4 26.5 75.1 75.6 Mixed pasture Creeping 16.4 18.0 68.4 68.2 Mixed pasture Creeping 16.8 20.7 - - In general, as biomass increases so does intake capacity. However, even with high herbage availability, as pasture quality gets worse, due to the biological evolution toward maturity, searching for less lignified plant parts or essences results in a reduction in time spent eating. If biomass levels are high and the grass is over 30 cm high, then sheep may trample the grass to reach the tips. As a result some of the biomass is wasted and the sheep spend less time grazing. If, however, the biomass levels are high but the pasture is short and dense, then intake increases because bite prehension is facilitated. Ideally, in order to avoid the negative effects of excessive selective activity by the sheep, the pasture should be dense and not more than 8 -10 cm in height. This can be done by choosing the right type of pasture and maintaining an adequate stocking rate. Herbage quality can be expressed in terms of digestibility, filling value, crude protein (CP) or structural carbohydrate content. It affects pasture intake. Good quality herbage can enable the "potential" intake to be reached. This is an intake that allows the animal to satisfy its requirements without physical limitations. Generally the levels of intake observed in highly digestible pastures are higher than in lignified pastures. It is also true that if the pasture is highly digestible then the 98
animals can reduce intake, as they reach the state of satiety earlier, due to the effects of metabolic control. The correlation between chemical components and intake for the different types of pasture is rather weak. It is difficult to clearly assess the pasture conditions of natural pasture with the type of undifferentiated data on its chemical composition which are available. Mean data does not, indeed, explain all the qualitative differences between essences and certainly does not consider the spatial distribution of these essences, even though they may be of significant importance in selective behaviour. Most attempts to predict pasture intake by sheep based on feed chemical and nutritional composition have emphasised the important role played by NDF content (Lanari et al., 1993), as this influences rumen wall distension. Table 8 reports some intake prediction equations based on NDF content. The correlation is always negative. Table 8 - Regression equations between dry matter intake (g/kg metabolic weight) and pasture NDF content. Category of forage Regression equation All forages Alfalfa hays Miscellaneous hays All forages Grass forages Polyfytes hays Miscellaneous hays I = 107.4 – 0.644 NDF I = 104.6 – 0.488 NDF I = 117.4 – 0.760 NDF I = 134.5 –1.10 NDF I = 95.3 + 6.70 NDF – 0.0668 NDF 2 I = 136.5 – 0.12 NDF I = 96.5 – 0.38 NDF – 0.0000004 NDF 4 Effect of supplementary feeding on herbage intake 99 Macchioni et al., 1990 Macchioni et al., 1990 Macchioni et al., 1990 Reid et al., 1988 Rohweder et al., 1978 Dulphy et al., 1990 Lanari et al., 1993 When feed supplements are used there is nearly always a reduction in pasture intake, because of the substitution effect (S). S is the variation in herbage intake per unit of supplement provided and it can vary greatly, from 0 to 1. In certain conditions it may, indeed, be even lower than 0 or greater than 1. Obviously, the lower the S value, the higher the total feed intake. Intake response to a supplement is strongly influenced by the quantity and quality of the available herbage. When there is little biomass available or its quality is poor, the supplement causes an increase in total dry matter intake and an improvement in animal performance; in these cases S is very low or null. In conditions where there is a large amount of available biomass or its quality is high, the efficacy of supplement is almost nullified due to the high S level. Figure 3 shows the S values found by Molle et al. (1997), when a corn grain supplement was given to dairy sheep grazing for 5 hours/d on good quality ryegrass sward of different height and biomass. One can see S values higher than 1. When biomass reaches DM yields higher than 2 t/ha, all the herbage was substituted by concentrates.
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Proceedings of the 11 th Annual GRE
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Table of Contents Program of Events
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Program of Events Thursday, Novembe
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Speakers at the symposium site in B
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Gold: Sponsors Babcock Institute fo
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“YOU WANT TO MILK WHAT?” IMPORT
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already have their milking faciliti
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efficient or just selling milk (or
Page 17 and 18:
production doubles. However, there
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Total production (pounds) Percentag
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Milk production (pounds) Average mi
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Percentage of ewes in each system 1
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5. Ice Cream and Butter: • raw mi
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3. Fresh Cheeses made from pasteuri
Page 29 and 30:
The Vermont Cheese Council (www.vtc
Page 31 and 32:
1 x Brine Tank (10’ long x 3 ft.
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LAMB REARING STRATEGIES: FARMER PAN
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BONNIEVIEW FARM’S LAMB REARING ST
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REARING LAMBS AT 3-CORNER FIELD FAR
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PROFITABILITY OF SMALL RUMINANT FAR
Page 41 and 42:
Table I. General Farm Description L
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Table 4. Business Balance Sheet Ass
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Table 5. Income Statement Income Av
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Lifestyle is a definite reason for
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Grossman et al., 1999). Animals wit
Page 51 and 52:
Physiological Factors Affecting Lac
Page 53 and 54:
Recently, it has been hypothesized
Page 55 and 56:
(co)variate in the genetic model us
Page 57 and 58: show that milk production increases
Page 59 and 60: Figure 6 - Lactation curves of ewes
Page 61 and 62: milk yield (g/d) 3000 2500 2000 150
Page 63 and 64: a genetic potential to produce more
Page 65 and 66: when compared with the control grou
Page 67 and 68: probability (%) 70 60 50 40 30 20 1
Page 69 and 70: considered “healthy” if every S
Page 71 and 72: Finally, udder health has to be con
Page 73 and 74: De Maria Ghionna C., Dell’Aquila.
Page 75 and 76: Manalu, W., Sumaryadi, M.Y., Sudjat
Page 77 and 78: Rupp R., Boichard D., Barbat A., As
Page 79 and 80: Introduction MILK FAT SYNTHESIS AND
Page 81 and 82: The variety of fatty acids allows t
Page 83 and 84: Germany); we have shown previously
Page 85 and 86: Manipulating Milk Fatty Acid Compos
Page 87 and 88: increase in rumen output of vacceni
Page 89 and 90: Luna et al., 2005; Nudda et al., 20
Page 91 and 92: Cabiddu, A., M. Decandia, M. Addis,
Page 93 and 94: MANAGING YOUR OWN RETAIL SHOP: MARK
Page 95 and 96: The Reality our feta demonstrates t
Page 97 and 98: Meat and meat dishes: 1. Legs: whol
Page 99 and 100: 5. We have daily visits from chefs
Page 101 and 102: HOW TO GRAZE DAIRY SHEEP AND SUPPLE
Page 103 and 104: significantly increase milk product
Page 105 and 106: All parameters are significantly di
Page 107: Table 6 - Dry matter intake and mil
Page 111 and 112: Milk fat and protein concentrations
Page 113 and 114: fat concentration can be used as a
Page 115 and 116: (1998), working with adult Sarda ew
Page 117 and 118: equirements. The relationship found
Page 119 and 120: that there have not been enough stu
Page 121 and 122: Grazing methods Grazing methods are
Page 123 and 124: How should the number of paddocks b
Page 125 and 126: Table 16 - Description of four past
Page 127 and 128: a) concentrates supplied during mil
Page 129 and 130: References Arnold G.W., and Dudzins
Page 131 and 132: supplemented with corn grain. Optio
Page 133 and 134: succeeding add on pastures smaller
Page 135 and 136: diverse forage have much to do with
Page 137 and 138: dairy farming. In fact, Vermont agr
Page 139 and 140: thermized (holding at a temperature
Page 141 and 142: speaking, the risks associated with
Page 143 and 144: FARMER PANEL ON LABOR HOW TO ATTRAC
Page 145 and 146: • Animal Health Products • Spec
Page 147 and 148: Cultivating Healthy Communities UVM
Page 149 and 150: 139
Page 151 and 152: Hudson Valley Camemberts Pure Sheep
Page 153 and 154: Premier Dairy Service, LLC Argyle,
Page 155 and 156: www.vermontagriculture.com 145
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