Corner, R. A.

Kenyon, Paul R.

Morris, Stephen T.

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings 21st International Grassland Congress / 8th International Rangeland Congress Optimal Sward Height for Production in Twin and Triplet Ewes Stephen T. Morris Massey University, New Zealand Paul R. Kenyon Massey University, New Zealand R. A. Corner Massey University, New Zealand Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/3-1/29 The 21st International Grassland Congress / 8th International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 瞯 ]462　 瞯 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅰ 　Grasslands/Rangelands Resources and Ecology ——— Soil‐Plant‐Animal InterrelationshipsOptimal sward height for production in twin and triplet ewesS .T . Morris , P . R . Kenyon , R A . CornerInstitute o f Veterinary , A nimal and Biomedical Sciences , Massey University , Priv ate Bag 11‐222 , Palmerston North , NewZealand . E‐mail :s .t .morris＠ massey .ac .nzKey words : lamb grow th , lamb birth weight , nutritionIntroduction Low birthweight lambs are associated with lower survival rates and lower weaning weights thereby limitingpotential returns to sheep farmers . The nutritional requirements for both singleton‐ and twin‐bearing ewes are well establishedand Morris et al . (２００４) identified ４ cm as the optimal sward height for single‐ and twin‐bearing / rearing ewes under continuousgrazing systems . However , the feeding requirements of triplet bearing / rearing ewes under pastoral grazing conditions have onlyrecently been researched in New Zealand .Materials and methods In study one , ９６ tw in‐and ９０ triplet‐bearing Romney ewes were randomly assigned on day ６４ ofpregnancy ( P６４) to four replicated sward height treatments (２ , ４ , ６ and ８ cm sward height ) . At parturition ( L１ ) the eweswere reassigned to two (４ cm and ８ cm) replicated sward heights until weaning at L８７ . In study two , ８０ tw in‐and ５６ triplet‐bearing ewes were randomly assigned to two replicated sward heights (２ and ４ cm) from P７０ to P１０７ . At P１０７ the ewes werere randomised to the two swards heights until parturition generating four sward height treatments (２‐２ , ２‐４ , ４‐２ and ４‐４ cm) .After parturition ewes were offered ４ cm pastures .Results Study one ewes grazing the ２ cm sward height during pregnancy were significantly ( P ＜ ０ .０１ ) lighter at P９９ and P１３２and at L１ than ewes grazing ４ , ６ or ８ cm swards . These ewes also had significantly lower dry matter intakes , condition scoresand ultrasonic backfat depths ( data not shown) . Lambs born to ewes grazing the ２ cm swards during pregnancy were alsolightest at birth ( P ＜ ０ .０１ ) but sward height during pregnancy or lactation had no effect on lamb weaning weight or lambsurvival to weaning . In study two lambs born to ewes grazing ２ cm during pregnancy were lighter at birth and weaning thanewes grazing ４ cm swards during pregnancy ( Table １ ) . Switching feeding level from ２ cm to ４ cm sward height at P１０７resulted in lamb birth and weaning weights similar to those lambs born to ewes grazing ４ cm swards throughout pregnancy .Sward height had no effect on ewe maternal behaviour score . Lambs born to ewes grazing ２ cm swards throughout pregnancyexhibited behaviours associated with a greater drive to maintain contact with their dam than lambs born to well‐fed ewes duringthe same period in both mid and late pregnancy . These types of behaviour have previously been associated with lower lambsurvival rates .Table 1 E f f ect o f lamb birth rank and sward height o f f ered to ewes during p regnancy on lamb birth and weaning weight(kg) ( ± SE) . Di f f ering superscrip ts are signi f icantly di f f erent ( P ＜ ０ .０５ ) .Birth weight Weaning weightTwin ４ 晻.５b ± ０ .１ ２５ x. ２b ± ０ .３T riplet ３ 晻.８a ± ０ .１ ２１ x.７a ± ０ .１Sward height２ － ２ l３ 晻.９a ± ０ .１ ２２ x.２a ± ０ .５２ － ４ l４ 晻.２ab ± ０ .１ ２３ x.５ab ± ０ .５４ － ２ l４ 晻.０a ± ０ .１ ２３ x.４ab ± ０ .５４ － ４ l４ 晻.４b ± ０ .１ ２４ x.７b ± ０ .５Conclusions These results achieved on low land predominately ryegrass / white clover swards suggest that ewes rearing twins andtriplets should be grazed on pastures of ４ cm or better during pregnancy to achieve optimal birth weights , however there is nonutritional benefit in feeding above ４ cm in terms of lamb live weight . If feed is limiting ewes can be fed on ２ cm swards for thefirst two thirds of pregnancy provided ４ cm swards are available in last third of pregnancy .ReferencesCorner , R .A . , Kenyon , P . R . Stafford , K . J . , West , D . M . , Lopez‐Villalobos , N . Morris , S .T . , Oliver , M .H . ,(２００７) . The effect of nutrition from mid‐ to late‐pregnancy on the performance of twin‐ and triplet‐bearing ewes and theirlambs . A ustralian Journal o f Ex perimental A griculture ( in press) .Morris , S .T . , Kenyon , P .R . , (２００４) . The effect of litter size and sward height on ewe and lamb performance . New ZealandJournal o f A gricultural Science ４７ :２７５‐２８６ .

Optimal Sward Height for Production in Twin and Triplet Ewes

https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=2608&amp;context=igc

Optimal Sward Height for Production in Twin and Triplet Ewes

Abstract

Similar works

Full text

Available Versions

University of Kentucky