Animal Factors Condition Milk Performance and Quality of Grazing Dairy Cows
الموضوعات :
1 - Centro de Investigaciones Agrarias de Mabegondo, INGACAL, Apdo, 10-15080, La Coruna, Spain
الکلمات المفتاحية: body condition score, body weight, energy balance, milk quality, potential milk yield, rumen function,
ملخص المقالة :
The base of this review is to consider the relevant role that animal factors (potential milk yield, body weight, body condition score, state of lactation, parity and fertility) play on milk performance (considering the energy balance and the rumen function across the full lactation curve of animals) and milk quality (milk protein content, milk fat content, milk lactose content, vitamins, minerals, immunoglobulins, cells in milk, pathogenic bacteria and inhibitors) of grazing dairy cows (taking into account the substitution rate and the milk response at pasture of animals under different supplementation regimes). All this, looking for high individual milk production and paying attention to grassland management as the key point for sustainability of grazing dairy systems in order to maintain high pasture dry matter intake in the swards with high grass quality (high pasture levels of crude protein, water soluble carbohydrates and digestibility of organic matter but low pasture levels of acid and neutral detergent fibers) all over the grazing season to satisfy cow needs at all times thought the lactation curve of dairy cows. It is also necessary to consider the use of supplementation at pasture (normally at the peak of lactation, when cows are generally in a state of negative energy balance and the provision of silage / concentrate can help to alleviate this situation) to keep the animals within the desired levels of milk production. It seeks, thereby, to achieve an efficient conversion of grass into milk, in a competitive and profitable way taking into consideration the current context in which pasture-based milk production systems are developed in mostly of temperate regions worldwide and focusing our interest in the milk premium price got by dairy farmers in a humid area as Galicia (NW Spain)when we consider the quantity and the quality of the milk delivered to the dairy industry.
Aharoni Y., Brosh A. and Ezra E. (1999). Effects of heat load and photoperiod on milk yield and composition in three dairy herds in Israel. Anim. Sci. 69, 37-47.
Auldist M.J., Coats S., Rogers G.L. and McDowell G.H. (1995). Changes in the composition of milk from healthy and mastitic dairy cows during the lactation cycle. Australian J. Exp. Agric. 35, 427-431.
Auldist M.J. and Hubble I. (1998). Effects of mastitis on raw milk and dairy products. Australian J. Dairy Tech. 53, 28-36.
Auldist M.J., Walsh B.J. and Thomson N.A. (1998). Seasonal and lactational influences on bovine milk composition in New Zealand. J. Dairy Res. 65, 401-411.
Bargo F., Muller L.D., Delahoy J.E., Cassidy T.W. (2002). Milk response to concentrate supplementation of high producing dairy cows grazing at two pasture allowances. J. Dairy Sci. 85, 1777-1792.
Bargo F., Muller L.D., Kolver E.S. and Delahoy J.E. (2003). Invited review: production and digestion of supplemented dairy cows on pasture. J. Dairy Sci. 86, 1-42.
Barkema H.W., Van Der Ploeg J.D., Schukken Y.H., Lam T.J.G.M., Benedictus G. and Brand A. (1998). Management style and its association with bulk milk somatic cell count and incidence rate of clinical mastitis. J. Dairy Sci. 82, 1655-1663.
Bartlett J.C. and Chapman D.G. (1961). Detection of hydrogenated fats in butter fat by measurement of cis-trans conjugated unsaturation. Agric. Food Chem. 9, 50-53.
Bauman D.E. and Currie W.B. (1980). Partitioning of nutrients during pregnancy and lactation: a review of mechanisms involving homeostasis and homeorhesis. J. Dairy Sci. 63, 1514-1529.
Beam S.W. and Butler W.R. (1997). Energy balance and ovarian follicle development prior to first ovulation postpartum in dairy cows receiving three levels of dietary fat. Biol. Reprod. 56, 133-142.
Beam S.W. and Butler W.R. (1998). Energy balance, metabolic hormones and early postpartum follicular development in dairy cows fed prilled lipid. J. Dairy Sci. 81, 121-131.
Beam S.W. and Butler W.R. (1999). Effects of energy balance on follicular development and first ovulation in post-partum dairy cows. J. Reprod. Fertil. 54, 411-424.
Beever D.E. (1993). Rumen function. Pp. 187-215 in Quantitative Aspects of Ruminant Digestion and Metabolism. J.M. Forbes and J. France, Eds. CAB International, Wallingford, USA.
Berzaghi P., Herbein J.H. and Polan C.E. (1996). Intake, site, and extent of nutrient digestion of lactating cows grazing pasture. J. Dairy Sci. 79, 1581-1589.
Black R.E., Williams S.M., Jones I.E. and Goulding A. (2002). Children who avoid drinking cow milk have low dietary calcium intakes and poor bone health. Am. J. Clin. Nutr. 76, 675-680.
Booth R.G., Kon S.K., Dann W.J. and Moore T. (1935). A study of seasonal variation in butter fat. II. A seasonal spectroscopic variation in the fatty acid fraction. Biochem. J. 29, 133-137.
Bourgeois L. (2002). Common agricultural policy and grasslands: the case study of France. Grassl. Sci. Eur. 7, 5-15.
Britt J.H. (1994). Follicular development and fertility: potential impacts of negative energy balance. Pp. 103-112 in Proc. Natio. Reprod. Symp. Pittsburgh, USA.
Brownlee A. (1956). The development of rumen papillae in cattle fed on different diets. Brit. Vet. J. 112(9), 369-375.
Bruinenberg M.H., Zom R.L.G. and Valk H. (2002). Energy evaluation of fresh grass in the diets of lactating dairy cows. Nether. J. Agric. Sci. 50, 67-81.
Bryant A. and Donnelly P. (1974). Yield and composition of milk from cows fed pasture herbage supplemented with maize and pasture silages. New Zealand J. Agric. Res. 17, 299-304.
Buckley F., Dillon P., Crosse S., Flynn F. and Rath M. (2000). The performance of Holstein-Friesian dairy cows of high and medium genetic merit for milk production on grass-based feeding systems. Livest. Prod. Sci. 64(3), 107-119.
Bullen J.J., Rogers H.J. and Leigh L. (1972). Iron binding proteins in milk and resistance to Escherichia coli infections in infants. Br. Med. J. 1, 69-75.
Burke F., O’Donovan M., Murphy J.J., O’Mara F.P. and Mulligan F.J. (2008). Effect of pasture allowance and supplementation with maize silage and concentrates differing in crude protein concentration on milk production and nitrogen excretion by dairy cows. Livest. Sci. 114, 325-335.
Butler W.R., Everett R.W. and Coppock C.E. (1981). The relationships between energy balance, milk production and ovulation in postpartum Holstein cows. J. Anim. Sci. 53, 742-748.
Butler W.R. and Smith R.D. (1989). Interrelationships between energy balance and postpartum reproductive function in dairy cattle. J. Dairy Sci. 72, 767-783.
Butler W.R. (2000). Nutritional interactions with reproductive performance in dairy cattle. Anim. Reprod. Sci. 60, 449-457.
Butler S.T., Stakelum G.K., Murphy J.J., Delaby L., Rath M. and O'Mara F.P. (2003). The relationship between milk production potential and herbage intake of grazing dairy cows. Anim. Sci. 77, 343-354.
Calvo Lacosata J.H., Marcos Carretero S., Jurado García J.J. and Serrano Noreña M. (2004). Association of the heart fatty acid-binding protein (FABP3) gene with milk traits in Manchega breed sheep. Anim. Genet. 35, 347-349.
Canfield R.W. and Butler W.R. (1990). Energy balance and pulsatile LH secretion in early postpartum dairy cattle. Dom. Anim. Endocrinol. 7, 323-330.
Canfield R.W. and Buther W.R. (1991). Energy balance, first ovulation and the effects of naloxone on LH secretion in early postpartum dairy cows. J. Anim. Sci. 69, 740-746.
Canfield R.W., Sniffen C.J. and Butler W.R. (1990). Effects of excess degradable protein on postpartum reproduction and energy balance in dairy cattle. J. Dairy Sci. 73(9), 2342-2349.
Combellas J., Baker R.D. and Hodgson J. (1979). Concentrate supplementation and the herbage intake and milk production of heifers grazing Cenchrus ciliaris. Grass Forage Sci. 34, 303-310.
Coulon J.B. and Rémond B. (1991). Variations in milk output and milk protein content in response to the level of energy supply to the dairy cow: a review. Livest. Prod. Sci. 29, 31-47.
Coulon J.B., Verdier I., Pradel P.H. and Almena M. (1998). Effect of lactation stage on the cheese making properties of milk and the quality of Saint-Nectaire-type cheese. J. Dairy Res. 65, 295-305.
Davison T., McGowan M., Mayer D., Young B., Johnson N., Hall A., Matschoss A., Goodwin P., Goughan J. and Lake M. (1996). Managing Hot Cows in Australia. Department of Primary Industries. Queensland, Australia.
Delaby L., Faverdin P., Disenhaus C., Michel G. and Peyraud J.L. (2009). Effect of feeding strategies on the Holstein and Normande dairy cows performance and their evolution during the lactation. Animal. 3(6), 891-905.
Delaby L., Horan B., O’Donovan M., Gallard Y. and Peyraud J.L. (2010). Are high genetic merit dairy cows compatible with low input grazing systems? Grassl. Sci. Eur. 15, 928-930.
Delaby L. and Peyraud J.L. (1994). Influence de la nature du concentré énérgetique sur les performances des vaches laitières au pâturage. Pp. 113-116 in Proc. 1th Rencontres des Recherches sur les Ruminants, Décembre. Paris.
Delaby L., Peyraud J.L., Bouttier A. and Pecatte J.R. (1999). Effect of grazing conditions and supplementation on herbage intake by dairy cows. Renc. Rech. Rumin. 6, 139-142.
Delagarde R., Peyraud J.L. and Delaby L. (1999). Influence of carbohydrate or protein supplementation on intake, behaviour and digestion in dairy cows strip grazing low nitrogen fertilized perennial ryegrass. Ann. Zootech. 48, 81-96.
Delagarde R., Valk H., Mayne C.S., Rook A.J., González-Rodríguez A., Baratte C., Faverdin P. and Peyraud J.L. (2011). GrazeIn: a model of herbage intake and milk production for grazing dairy cows. 3. Simulations and external validation of the model. Grass Forage Sci. 66, 61-77.
DePeters E.J. and Cant J.P. (1992). Nutritional factors influencing the nitrogen composition of bovine milk: a review. J. Dairy Sci. 75(8), 2043-2070.
Dillon P., Crosse S. and O’Brien B. (1997). Effect of concentrate supplementation of grazing dairy cows in early lactation on milk production and milk processing quality. Irish J. Agric. Food Res. 36, 145-159.
Dillon P. (2006). Achieving high dry matter intake from pasture with grazing dairy cows. Pp. 1-26 in Fresh Herbage for Dairy Cattle: the Key to a Sustainable Food Chain. A. Elgersma, J. Dijkstra and S. Tamminga, Eds. Springer.
Dillon P., Roche J.R., Shalloo L. and Horan B. (2005). Optimising financial return from grazing in temperate pastures. Pp. 131-147. in 20th Int. Grassland Cong. Cork, Ireland.
Dillon P., Berry D.P., Evans R.D., Buckley F. and Horan B. (2006). Consequences of genetic selection for increased milk production in European seasonal pasture based systems of milk production. Livest. Sci. 99, 141-158.
Dirksen G.U., Liebich H.G. and Mayer E. (1985). Adaptative changes of ruminal mucosa and their functional and clinical significance. Bov. Pract. 20, 116-121.
Dixon R.M. and Stockdale C.R. (1999). Associative effects between forages and grains: consequences for feed utilisation. Australian J. Agric. Res. 50, 757-773.
Ferguson J.D. and Chalupa W. (1989). Impact of protein nutrition on reproduction in dairy cows. J. Dairy Sci. 72, 746-766.
Fox P.F. and McSweeney P.L.H. (1998). Milk Lipids. Dairy Chemistry and Biochemistry. Blackie Academic Profession/Chapman and Hall. New York, USA.
Fulkerson W.J., Wilkins J., Dobos R.C., Hough G.M., Goddard M.E. and Davison T. (2001). Reproductive performance in Holstein-Friesian cows in relation to genetic merit and level of feeding when grazing pasture. Anim. Sci. 73, 397-406.
Garnsworthy P.C. and Jones G.P. (1987). The influence of body condition at calving and dietary protein supply on voluntary food intake and performance in dairy cows. Anim. Prod. 44, 347-353.
Garton G.A. (1963). The composition and biosynthesis of milk lipids. J. Lipid Res. 4, 237-254.
Gaucheron F. (2005). The minerals of milk. Reprod. Nutr. Dev. 45, 473-483.
Gibb M.J., Ivings W.E., Dhanoa M.S. and Sutton J.D. (1992). Changes in the components of autumn calving Holstein-Friesian cows over the first 29 weeks of lactation. Anim. Prod. 55, 339-360.
Gibson J.P. (1989). Selection on the major components of milk: alternative methods of deriving economic weights. J. Dairy Sci. 72, 3176-3189.
Goff J.P. and Horst R.L. (1997). Effects of the addition of potassium or sodium, but not calcium, to prepartum rations on milk fever in dairy cows. J. Dairy Sci. 80, 176-186.
González Rodríguez A., Vázquez Yáñez O.P. and Roca-Fernández A.I. (2010). Alimentación de las vacas lecheras en las zonas húmedas españolas. Ganadería. 67, 54-60.
Grainger C. and Mathews G.L. (1989). Positive relation between substitution rate and pasture allowance for cows receiving concentrates. Australian J. Exp. Agric. 29, 355-360.
Grummer R.R. (1991). Effect of feed on the composition of milk fat. J. Dairy Sci. 74, 3244-3257.
Heck J.M.L., Van Valenberg H.J.F., Dijkstra J. and Van Hooidonk A.C.M. (2009). Seasonal variation in the Dutch bovine raw milk composition. J. Dairy Sci. 92, 4745-4755.
Hernández Urdaneta A., Coppock C.E., McDowell R.E., Gianola D. and Smith N.E. (1976). Changes in forage concentrate ratio of complete feeds for dairy cows. J. Dairy Sci. 59, 695-671.
Hijink J.W.F., Le Du Y.L.P., Meijs J.A.C. and Meijer A.B. (1982). Supplementation of the Grazing Dairy Cow. Institute for Livestock Feeding and Nutrition Research. Lelystad, The Netherlands.
Hilditch T.P. and Jasperson H. (1941). Milk fats from cows fed on fresh pasture and on ensiled greed fodder. I. Observations on the component fatty acids. J. Soc. Chem. Ind. 60, 305-310.
Hilditch T.P. and Jasperson H. (1945). The polyethenoid acids of the C18 series present in milk and grass fats. J. Soc. Chem. Ind. 64, 109-111.
Hoden A., Fiorelli J.L., Jeannin B., Huguet L., Muller A. and Weiss P. (1987). Le pâturage simplifié pour vaches laitières: synthèse de résultats expérimentaux. Fourrages. 111, 239-257.
Hoden A., Peyraud J.L., Muller A., Delaby L. and Faverdin P. (1991). Simplified rotational grazing management of dairy cows: effects of rates of stocking and concentrates. J. Agric. Sci. 116, 417-428.
Hoffman K., Muller L.D., Fales S.L. and Holden L.A. (1993). Quality evaluation and concentrate supplementation of rotational pasture grazed by lactating cows. J. Dairy Sci. 76, 2651-2663.
Holdaway R.J. (1990). A comparison of methods for the diagnosis of bovine subclinical mastitis within New Zealand dairy herds. Ph D Thesis. Massey Univ., New Zealand.
Holden L.A., Muller L.D., Lykos T. and Cassidy T.W. (1995). Effect of corn silage supplementation on intake and milk production in cows grazing grass pasture. J. Dairy Sci. 78, 154-160.
Holmes C.W., Brookes I.M., Garrick D.J., MacKenzie D.D.S., Parkinson T.J. and Wilson G.F. (2002). Introduction to dairy production in New Zealand. Pp. 1-20 in Milk Production from Pasture. C.W. Holms, Ed. Massey Univ. Palmerston North, New Zealand.
Holt C. (1997). The milk salts and their interaction with casein. Pp. 233-256 in Advanced Dairy Chemistry. 1. Lactose, Water, Salts and Vitamins. P.F. Fox, Ed. NY Blackie Academic and Professional Publishers. New York, USA.
Holter J.B., Slotnick M.J., Hayes H.H. and Bozak C.K. (1990). Effect of prepartum dietary energy on condition score, pospartum energy, nitrogen partitions and lactation production responses. J. Dairy Sci. 73, 3502-3511.
Hoover W.H. and Stokes S.R. (1991). Balancing carbohydrates and proteins for optimum rumen microbial yield. J. Dairy Sci. 74, 3630-3644.
Horan B., Dillon P., Berry D.P., O'Connor P. and Rath M. (2005). The effect of strain of Holstein-Friesian, feeding system and parity on lactation curves characteristics of spring-calving dairy cows. Livest. Prod. Sci. 95, 231-241.
Iverson S.J. and Oftedal O.T. (1995). Phylogenetic and ecological variation in the fatty acid composition of milks. Pp. 789-827. in The Handbook of Milk Composition. R.G. Jensen, Ed. Academic Press Inc. Orlando, USA.
Jarrige R. (1989). Ruminant Nutrition, Recommended Allowances and Feed Tables. John Libbey, Eurotext,London, Paris.
Jenness R., Regehr E.A. and Sloan R.E. (1964). Comparative biochemical studies of milks. II. Dialyzable carbohydrates. Comp. Biochem. Physiol. 13, 339-52.
Jenness R. (1974). The composition of milk. pp. 3-107 in: Lactation A Comprehensive Treatise. B.L. Larson and V.L. Smith, Eds. Academic Press. New York, USA.
Jensen R.G. (2002). The composition of bovine milk lipids: January 1995 to December 2000. J. Dairy Sci. 85, 295-350.
Jha R., Nagarajan H.K. and Prasanna S. (2005). Land fragmentation and its implications for productivity: evidence from Southern India. ASARC Work. paper. Available in: http://rspas.anu.edu.au/papers/asarc/WP2005_01.pdf. Accessed Mar. 2011.
Johnson A.H. (1978). The composition of milk. Pp. 1-57 in: Fundamentals of Dairy Chemistry. B.H. Webb, A.H. Johnson andJ.A. Alford, Eds. AVI Publishing Company. Westport, USA.
Johnson A.O., Semenya J.G., Buchowski M.S., Enwonwu C.O. and Scrimshaw N.S. (1993). Correlation of lactose maldigestion, lactose intolerance and milk intolerance. Am. J. Clin. Nutr. 57, 399-401.
Journet M. and Demarquilly C. (1979). Grazing. Pp. 295-321 in Feeding Strategy for the High Yielding Cow. W.H. Broster and H. Swan, Eds. Canada Publishing Co. St. Albans, Canada.
Kefford B., Christian M.P., Sutherland B.J., Mayes J.J. and Grainger C. (1995). Seasonal influences on cheddar cheese manufacture: influence of diet quality and stage of lactation. J. Dairy Res. 62, 529-537.
Kellaway R. and Porta S. (1993). Feeding concentrates. Supplement for dairy cows. Pp 76 in Research and Development Corporation. R. Hopkins, Ed. Victoria, Australia.
Kennedy J., Dillon P., Faverdin P., Delaby L., Buckley F. and Rath M. (2002). The influence of cow genetic merit for milk production on response to level of concentrate supplementation in a grass-based system. J. Dairy Sci. 75, 433-445.
Kennedy J., Dillon P., Delaby L., Faverdin P., Stakelum G. and Rath M. (2003). Effect of genetic merit and concentrate supplementation on grass intake and milk production with Holstein-Friesian dairy cows. J. Dairy Sci. 86, 610-621.
Kennedy E., O’Donovan M., Murphy J.P., Delaby L. and O’Mara F. (2005). Effect of grass pasture and concentrate-based feeding systems for spring-calving dairy cows in early spring on performance during lactation. Grass Forage Sci. 60, 310-318.
Keown J.F., Everett R.W., Empet N.B. and Wadell L.H. (1986). Lactation Curves. J. Dairy Sci. 69, 769-781.
Kertz A.F., Reutzel L.F. and Thomson G.M. (1991). Dry matter intake from parturition to mid-lactation. J. Dairy Sci. 74, 2290-2295.
Kibon A. and Holmes W. (1987). The effect of height of pasture and concentrate composition on dairy cows grazed on continuously stocked pastures. J. Agric. Sci. Camb. 109, 293-301.
Knapp D.M. and Grummer R.R. (1990). Effect of supplemental dietary fat on lactating dairy cattle under conditions of heat stress. J. Dairy Sci. 73(1), 219-222.
Kuhn N.J., Carrick D.T. and Wilde C.J. (1980). Lactose synthesis: possibilities of regulation. J. Dairy Sci. 63, 328-336.
Leaver J.D. (1985). Milk production from grazed temperate pastures. J. Dairy Res. 52, 313-344.
Ling E., Kon S. and Porter J. (1961). The composition of milk and the nutritive value of its components. Pp. 195-263 in Milk: The Mammary Gland and its Secretion. S. Kon and A. Cowie, Eds. Academic Press. New York, USA.
Lock A.L.F., Destaillats F., Kraft J. and German J.B. (2008). Introduction to the Proceedings of the Symposium Scientific update on dairy fats and cardiovascular diseases.J. Am. Coll. Nutr. 27, 720-722.
Mabrook M.F. and Petty M.C. (2003). A novel technique for the detection of added water to full fat milk using single frequency admittance measurements. Sens. Act. B: Chem. 96, 215-218.
Malagelada J.R. (1995). Lactose intolerante. New England J. Med. 333(1), 53-54.
Marion G.B., Norwood J.S. and Gier H.T. (1968). Uterus of the cow after parturition: Factors affecting regression. Am. J. Vet. Res. 29, 71-75.
Mayer E., Liebich H.G., Arbitman R., Hagemeister H. and Dirksen G. (1986). Nutritionally induced changes in the ruminal papillae and in their capacity to absorb short chain fatty acids in high producing dairy cows. Pp. 806-817 in Proc. 14th World Buiat. Cong. Dublin, Ireland.
Mayne C.S. (1991) Management Issues for the Grassland Farmer in the 1990s. British Grassland Society Occasional.
Mayne C.S. and Peyraud J.L. (1996). Recent advances in grassland utilization under grazing and conservation. Grassl. Sci. Eur. 1, 347-360.
Meijs J.A.C. (1981). Herbage intake by grazing dairy cows. Agricultural Research Reports 909. Center Agricultural Publishing and Documentation. Wageningen, Netherlands.
Meijs J.A.C. and Hoekstra J.A. (1984). Concentrate supplementation of grazing dairy cows. 1. Effect of concentrate intake and herbage allowance on herbage intake. Br. Grassl. Soc. 39, 59-66.
Moore T. (1939). Spectroscopic changes in fatty acids. Biochem. J. 33, 1635-1638.
MosqueraLosada M.R. and González Rodríguez A. (1998). Effect of annual stocking rates in grass and maize + rye systems on production by dairy cows. Grass Forage Sci. 53, 95-108.
Muller L.D. and Fales S.L. (1998). Supplementation of cool season grass pastures for dairy cattle. Pp. 335-350 in Grass for Dairy Cattle. J.H. Cherney and D.J.R. Cherney, Eds. CAB International. New York, USA.
O’Brien B., Dillon P., Murphy J.J., Mehra R.K., Guinee T.P., Connolly J.F., Kelly A. and Joyce P. (1999). Effects of stocking density and concentrate supplementation of grazing dairy cows on milk production, composition and processing characteristics. J. Dairy Res. 66, 165-176.
O’Donnell J.A. (1989). Milk fat technologies and market: A summary of the wisconsin milk marketing board 1988 milk fat roundtables. J. Dairy Sci. 72, 3109-3115.
Olori V.E., Brotherstone S., Hill W.G. and McGuirk B.J. (1997). Effect of gestation stage on milk yield and composition in Holstein-Friesian dairy cattle. Livest. Prod. Sci. 52, 167-176.
Opatpatanakit Y., Kekkaway R.C. and Lean L.J. (1993). Substitution effects of feeding rolled barley grain to grazing dairy cows. Anim. Feed Sci. Technol. 42, 25-38.
Parodi P.W. (2009). Review: has the association between saturated fatty acids, serum cholesterol and coronary heart disease been over emphasized? Int. Dairy J. 19, 345-361.
Park Y.W., Juarez M., Ramos M. and Haenlein G.F.W. (2007). Physico-chemical characteristics of goat and sheep milk. Small Rumin. Res. 68, 88-113.
Papalois M., Leach F.W., Dungey S., Yep Y.L. and Versteeg C. (1996). Australian milk fat survey physical properties. Austral J. Dairy Tech. 51, 114-116.
Parodi P.W. (1977). Conjugated octadecadienoic acids of milk fat. J. Dairy Sci. 60, 1550-1553.
Peaker M. (1977). The aqueous phase of milk: ion and water transport. Symp. Zool. Soc. Lond. 41, 113-134.
Peyraud J.L., Astigarraga L. and Faverdin P. (1996). Digestion of fresh perennial ryegrass fertilized at two levels of nitrogen by lactating dairy cows. Anim. Feed Sci. Technol. 64, 155-171.
Peyraud J.L. and González Rodríguez A. (2000). Relations between grass production, supplementation and intake in grazing dairy cows. Grassl. Sci. Eur. 5, 269-282.
Peyraud J.L. and Delaby L. (2001). Ideal concentrate feeds for grazing dairy cows. Responses to supplementation in interaction with grazing management and grass quality. Pp. 203-220 in Recent Advances in Animal Nutrition. P.C. Garnsworthy and J. Wiseman, Eds. University Press. Nottingham, UK.
Peyraud J.L., Van Den Pol-Van Dasselaar A., Dillon P. and Delaby L. (2010). Producing milk from grazing to reconcile economic and environmental performances. Grassl. Sci. Eur. 15, 865-890.
Phillips C.J.C. and Leaver J.D. (1985). Supplementary feeding of forage to grazing dairy cows. 2. Offering grass silage in early and late season. Grass Forage Sci. 40, 193-200.
Pomeranz Y. (1985). Functional Properties of Food Components. Academic Press. London. UK.
Pyorola S. (2003). Indicators of inflammation in the diagnostics of mastitis. Vet. Res. 34, 565-587.
Rao M.K. and Sundaresan D. (1979). Influence of environment and heredity on the shape of lactation curves in Sahiwal cows. J. Agric. Sci. 92, 393-401.
Rauw W.M., Kanis E., Noordhuizen Stassen E.N. and Grommers F.J. (1998). Undesirable side effects of selection for high production efficiency in farm animals: a review.Livest. Prod. Sci. 56, 15-33.
Ray D.E., Halbach T.J. and Armstrong D.V. (1992). Season and lactation number effects on milk production and reproduction of dairy cattle in Arizona. J. Dairy Sci. 75, 2976-2983.
Ribeiro Filho H.M.N., Delagarde R. and Peyraud J.L. (2005). Herbage intake and milk yield of dairy cows grazing perennial ryegrass pastures or white clover / perennial rye grass pastures at low and medium herbage allowance. Anim. Feed Sci. Technol. 119, 13-27.
Riel R.R. (1963). Physico chemical characteristics of Canadian milk fat. Unsaturated fatty acids. J. Dairy Sci. 46, 102-106.
Robaina A.C., Grainger C., Moate P., Taylor J. and Stewart J. (1998). Responses to grain feeding by grazing dairy cows. Australian J. Exp. Agric. 38, 541-549.
Roca-Fernández A.I. (2011) Sustainable milk production systems in humid areas using farm resources. Ph D Thesis. Univ., Santiago de Compostela, Spain.
Roca-Fernández A.I., O’Donovan M., Curran J. and González- Rodríguez A. (2011). Effect of pre grazing herbage mass and daily herbage allowance on perennial ryegrass swards structure, pasture dry matter intake and milk performance of Holstein -Friesian dairy cows. Spanian J. Agric. Res. 9(1), 86-99.
Roca-Fernández A.I. and González-Rodríguez A. (2012). Effect of dietary and animal factors on milk fatty acids composition of grazing dairy cows: a review. Iranian J. Appl. Anim. Sci. 2(2), 97-109.
Roca-Fernández A.I., González-Rodríguez A. and Vázquez-Yáñez O.P. (2012a). Effect of pasture allowance and cows’ lactation stage on perennial ryegrass sward quality, pasture dry matter intake and milk performance of Holstein-Friesian cows. Span-ian J. Agric. Res. 10(2), 393-408.
Roca-Fernández A.I., González-Rodríguez A., Vázquez-Yáñez O.P. and Fernández-Casado J.A. (2012b). Effect of forage source (grazing vs. silage) on conjugated linoleic acid content in milk fat of Holstein-Friesian dairy cows from Galicia (NW Spain). Spanish J. Agric. Res. 10(1), 116-122.
Roca-Fernández A.I. (2013). Sward factors influence on pasture dry matter intake of grazing dairy cows: a review. Iranian J. Appl. Anim. Sci. 3, 629-652.
Rook A.J., Huckle C.A. and Penning P.D. (1994). Effects of sward height and concentrate supplementation on the ingestive behaviour of spring-calving dairy cows grazing grass-clover swards. Appl. Anim. Behav. Sci. 40, 101-112.
Rowney M. and Christian M. (1996). Effect of cow diet and stage of lactation on the composition of milk fat for cheese manufacture. Aust. J. Dairy Tech. 51, 118-122.
Sakata T. and Tamate H. (1978). Rumen epithelial cell proliferation accelerated by rapid increase in intraruminal butyrate. J. Dairy Sci. 61, 1109-1113.
Sakata T. and Tamate H. (1979). Rumen epithelium cell proliferation accelerated by propionate and acetate. J. Dairy Sci. 62, 49-52.
Sander E.G., Warner R.G., Harrison H.N. and Loosli J.K. (1959). The stimulatory effect of sodium butyrate and sodium propionate on the development of rumen mucosa in the young calf. J. Dairy Sci. 42, 1600-1605.
Schopper D. and Claus R. (1986). Progesterone concentrations in milk fat around ovulation in the dairy cow: differences between observed and silent heat. Zuchthygiene. 21, 237-240.
Sears P.M. and Wilson D.J. (2003). Mastitis. Vet. Clin. North Am. Food Anim. Pract. 19, 11-12.
Shalloo L., O’Donnell S. and Horan B. (2007). Profitable dairying in an increased EU milk quota scenario. Pp. 20-44 in Proc. Nat. Dairy Conf. Kilkenny, Ireland.
Shuster D.E., Harmon R.J., Jackson J.A. and Hemken R.W. (1991). Suppression of milk production during endotoxin-induced mastitis. J. Dairy Sci. 74, 3763-3774.
Stakelum G. (1986a). Herbage intake of grazing dairy cows. 1. Effect of autumn supplementation with concentrates and herbage allowance on herbage intake. Iranian J. Agric. Res. 25, 31-40.
Stakelum G. (1986b). Herbage intake of grazing dairy cows. 2. Effect of herbage allowance, herbage mass and concentrate feeding on the intake of cows grazing primary spring grass. Iranian J. Agric. Res. 25, 41-51.
Stakelum G. and Connolly J. (1987). Effect of body size and milk yield on intake of fresh herbage by lactating dairy cows indoors.Iranian J. Agric. Res. 26, 9-22.
Stakelum G., Dillon P. and Murphy J. (1988). Supplementary feeding of grazing dairy cows. Pp. 25-27. in Moorepark dairy farmers Conf. Teagasc. Fermoy, Co. Cork, Ireland.
Stakelum G. (1993). Achieving high performance from dairy cows on grazed pastures. Irish Grassl. Anim. Prod. Assoc. J. 27, 9-18.
Staples C.R., Thatcher W.W. and Clark J.H. (1990). Relationship between ovarian activity and energy status during the early postpartum period of high producing dairy cows. J. Dairy Sci. 73, 938-947.
Staples C.R., Thatcher W.W., García Bojalil C.M. and Lucy M.C. (1992). Nutritional influences on reproductive function. Pp. 382-392 in Large Dairy Herd Management. H.H. Van Horn and C.J. Wilcox, Eds. American Dairy Science Association. Champaign, USA.
Stockdale C.R., Callaghan A. and Trigg T.E. (1987). Feeding high energy supplements to pasture fed dairy. Effects of stage of lactation and level of supplement. Australian J. Agric. Res. 38, 927-940.
Stockdale C.R. and Trigg T.E. (1985). Effect of pasture allowance and level of concentrate feeding on the productivity of dairy cows in late lactations. Australian J. Exp. Agric. 25, 739-744.
Stockdale C.R. (1994). Persian clover and maize silage. II. Effects of variations in clover and silage consumption on the productivity of dairy cows at various stages of lactation. Australian J. Agric. Res. 45, 1767-1782.
Stockdale C.R. (1999). Effect of length of the period of supplementation with concentrates on pasture intake and performance of grazing dairy cows. Australian J. Exp. Agric. 39, 803-809.
Stockdale C.R. (2000). Levels of pasture substitution when concentrates are fed to grazing dairy cows in northern Victoria. Australian J. Exp. Agric. 40, 913-921.
Stockdale C.R. (2001). Body condition at calving and the performance of dairy cows in early lactation under Australian conditions: a review. Australian J. Exp. Agric. 41, 823-839.
Stockdale C.R. (2004). Effects of level of feeding of concentrates during early lactation on the yield and composition of milk from grazing dairy cows with varying body condition score at calving. Australian J. Exp. Agric. 44, 1-9.
Sutter F. and Beever D.E. (2000). Energy and nitrogen metabolism in Holstein-Friesian cows during early lactation. Anim. Sci. 70, 503-514.
Tas B.M., Taweel H.Z. and Smit H.J. (2005). Effects of perennial ryegrass cultivars on intake, digestibility, and milk yield in dairy cows. J. Dairy Sci. 88(9), 3240-3248.
Tekerli M., Akinci Z., Dogan I. and Akcan A. (2000). Factors affecting the shape of lactation curves of Holstein cows from the Balikesir province of Turkey. J. Dairy Sci. 83, 1381-1386.
Thomas P.C. (1983). Milk protein. Proc. Nutr. Soc. 42, 407-418.
Thomas P.C. and Rook J.A.F. (1983). Milk production. Pp. 558-622 in Nutritional Physiology of Farm Animals. J.A.F. Rook and P.C. Thomas, Eds. Longman. London, UK.
Urashima T., Saito T. and Nakamura T. (2001). Oligosaccharides of milk and colostrum in non-human mammals. Glycoconjugate J. 18, 357-371.
Van Arendon J.A.M., Nieuwhof G.J., Vos H. and Korver S. (1991). Genetic aspects of feed intake and efficiency in lactating dairy heifers. Livest. Prod. Sci. 29, 263-275.
Van Hung P.V., Macaulay G.T. and Marsh S. (2007). The economics of land fragmentation in the north of Vietnam. Australian J. Agric. Res. Econ. 51(2), 195-211.
Van Den Pol Van Dasselaar A., Vellinga T.V., Johansen A. and Kennedy E. (2008). To graze or not to graze, that’s the question. Grassl. Sci. Eur. 13, 706-716.
Van Soest P.J. (1994). Nitrogen metabolism.Pp. 290-311 in Nutritional Ecology of the Ruminant. P.J. Van Soest. Ed. Comstock Publishing Associates, Cornell University Press. Ithaca, New York, USA.
Van Vuuren A.M., Van der Koelen C.J. and Vroons de Bruin J. (1986). Influence of level and composition of concentrate supplements on rumen fermentation patterns of grazing dairy co-ws. Netherlands J. Agric. Sci. 34, 457-467.
Van Vuuren A.M. and Van Den Pol-Van Dasselaar A. (2006). Grazing systems and feed supplementation. Pp. 85-101 in Fresh Herbage for Dairy Cattle, the Key to a Sustainable Food Chain. A. Elgersma, J. Dijkstra and S. Tamminga, Eds. Wageningen UR Frontis Series Springer. Dordrecht, Netherlands.
Villa Godoy A., Hughes T.L., Emery R.S., Chapin L.T. and Fogwell R.L. (1988). Association between energy balance and luteal function in lactating dairy cows. J. Dairy Sci. 71, 1063-1072.
Visek W.J. (1984). Ammonia: its effects on biological systems, metabolic hormones, and reproduction. J. Dairy Sci. 67, 481-498.
Washburn S.P. and White S.L. (1997). Seasonal reproduction in Jerseys and Holsteins in confinement versus pasture systems. Pp. 32-33 in Proc. Dairy Field Day. North Carolina State Univ. Raleigh, North Carolina.
Westwood C.T., Lean I.J., Garvin J.K. and Wynn P.C. (2000). Effects of genetic merit and varying dietary protein degradability on lactating dairy cows. J. Dairy Sci. 83, 2926-2940.
Whitmore H.L., Tyler W.J. and Casida L.D. (1974). Effects of early post-partum breeding in dairy cattle. J. Anim. Sci. 38, 339-346.
Wiktorsson H. and Spörndly E. (2002). Grazing: an animal welfare issue for automatic milking farms. Pp 132-145 in 1th North American Conf., Wageningen Academic Publishers. Wageningen, Netherlands.
Wilkins R.J., Gibb M.J. and Huckle C.A. (1995). Lactation performance of spring-calving dairy cows grazing mixed perennial ryegrass / white clover swards of differing composition and height. Grass Forage Sci. 50, 199-208.
Zurek E., Foxcrot G. and Kennelly J. (1995). Metabolic status and first ovulation in pospartum dairy cows. J. Dairy Sci. 78, 1909-1920.
