03629naa a2200469 a 450000100080000000500110000800800410001902200150006002400360007510000170011124501130012826000090024150000860025052021710033665000180250765000230252565000220254865300120257065300140258265300510259665300150264765300250266265300180268765300210270565300360272665300280276265300120279065300310280265300100283365300110284365300390285465300300289365300330292365300320295665300290298865300290301770000190304670000180306570000170308370000170310077300420311710525502019-02-11       2015    bl uuuu     u00u1 u    #d  a1751-732X.7 a10.1017/S1751731114003243.2DOI1 aBANCHERO, G.  aColostrum production in ewesba review of regulation mechanisms and of energy supply.h[electronic resource]  c2015  aArticle history: Received 19 June 2014; Accepted 1 December 2014; published 2015.  aIn sheep production systems based on extensive grazing, neonatal mortality often reaches 15% to 20% of lambs born, and the mortality rate can be doubled in the case of multiple births. An important contributing factor is the nutrition of the mother because it affects the amount of colostrum available at birth. Ewes carrying multiple lambs have higher energy requirements than ewes carrying a single lamb and this problem is compounded by limitations to voluntary feed intake as the gravid uterus compresses the rumen. This combination of factors means that the nutritional requirements of the ewe carrying multiple lambs can rarely be met by the supply of pasture alone. This problem can overcome by supplementation with energy during the last week of pregnancy, a treatment that increases colostrum production and also reduces colostrum viscosity, making it easier for the neonatal lamb to suck. In addition, litter size and nutrition both accelerate the decline in concentration of circulating progesterone that, in turn, triggers the onsets of both birth and lactogenesis, and thus ensures the synchrony of these two events. Furthermore, the presence of colostrum in the gut of the lamb increases its ability to recognize its mother, and thus improves mother–young bonding. Most cereal grains that are rich in energy in the form of starch, when used as supplements in late pregnancy will increase colostrum production by 90% to 185% above control (unsupplemented) values. Variation among types of cereal grain in the response they induce may be due to differences in the amount of starch digested post-ruminally. As a percentage of grain dry matter intake, the amount of starch entering the lower digestive tract is 14% for maize, 8.5% for barley and 2% for oats. Supplements of high quality protein from legumes and oleiferous seeds can also increase colostrum production but they are less effective than cereal grains. In conclusion, short-term supplementation before parturition, particularly with energy-rich concentrates, can improve colostrum production, help meet the energy and immunological requirements for new-born lambs, and improve lamb survival.  aCAMPO NATURAL  aFISIOLOGÍA ANIMAL  aPRODUCCIÓN OVINA  aCEREALS  aCOLOSTRUM  aDISMINUCIÓN DE CONCENTRACIÓN DE PROGESTERONA  aGESTACIÓN  aGESTACIÓN MÚLTIPLE  aLACTOGÉNESIS  aMOMENTO DE PARTO  aMORTALIDAD NEONATAL DE CORDEROS  aPRODUCCIÓN DE CALOSTRO  aPROTEIN  aREQUERIMIENTOS DE CALOSTRO  aSHEEP  aSTARCH  aSUPERVIVENCIA NEONATAL DE CORDEROS  aSUPLEMENTACIÓN CON GRANO  aSUPLEMENTACIÓN CON PASTOREO  aSUPLEMENTACIÓN ENERGÉTICA  aSUPLEMENTACIÓN PREPARTO  aSUPLEMENTACIÓN PROTEICA1 aMILTON, J.T.B.1 aLINDSAY, D.R.1 aMARTIN, G.B.1 aQUINTANS, G.  tAnimalgv. 9, n. 5, p. 831-837. 2015.