(1)Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author..
(2) EFFECT OF CONCENTRATE SUPPLEMENTATION ON HERBAGE CONSUMPTION ,. MILK PRODUCTION AND COMPOSITION ,. AND ON LIVEVEIGHT AND CONDITION SCORE CHANGE IN EARLY LACTATION. A thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science Animal Science Department Massey University,. Palmerston North. NE� ZEALAND. �ISITIPORN SUKSOMBAT. 1988.
(3) ii. ABSTRACT. Each o f 1 5 s e t s o f i d en t i cal twins was graz i ng t r ea t me n t s ,. the. pas ture. concen t ra t e f e d t r ea tmen t ( CF ) . pas t u r e o n ly. and. those. fed. a l l oc a t ed. t reat me n t. to. ( PF ). Cows i n P F t r e a t m en t. two. and t h e were. fed. cows i n CF t re a tmen t wer e s u p pl emen t ed of. w i t h c o n c e n t ra t e s .. The. p e r enn i al rye g r ass .. The ex per imen t was c a r r i e d ou t f o r 1 4 weeks. ( 1 4 t h S e p t em b e r-2 1 s t. swards. used. were. p r ed om i n an t ly. December 1 987 ) o f the ear ly g r a z i ng s e a s o n. o f 1 987 .. T h e expe r i men t was carried ou t in two w i t h an. a l l owance. 1 9 87 a n d Pe r i od 21s t to. 30th. II. pe r i o d s ,. P e r i od. I. o f 20 kgDM/ cow/day f rom 1 3 t h t o 27 t h Oc t o b e r wi th a n allowance. November. 1 98 7 .. of. M i lk. 25. kgDM/c ow/day. yield ,. f ro m. m i lk c o mpos i t i on ,. an i ma l l i vewe i g h t and cond i t i on s core were meas u r e d .. H e r bage i n t ake was es t ima t e d by and was. 10 . 0. and. 9.0. sward. cu t t i n g. t e chni q u e. kgDM/ cow/day f o r supplemen t ed c ows , and. 1 1 . 8 and 1 2.2 kgDM/cow/day for. unsupplemen t e d cows i n Pe r i od s and. II. r e s p e c t ively .. Suppleme n t e d. cows. c o n s umed. I 6.7. kgDM/c ow / day concen t ra t e s i n b o t h p e r i od s .. T h e r e was a s i gni f i cant increase concen t r a t e s u p p lemen t a t i on .. The. in. mi lk. Yields. of. f a t i n P e r i o d II .. milk. due. to. average res p o n s e was 0 . 40 kg. m i l k/kg c onc en t r a t e OM ea t en or 0.68 kg m i lk/kg e a t en .. yield. e x t ra. feed. DM. cons t i tuen t s were i n c r e as e d ex ce p t f o r.
(4) iii. Concen t ra t e f e e ding had no e f f ec t o n lac t o s e. c oncen t ra t i ons. increased .. Sup p lemen t ed. bu t. m i lk. cows. m i lk. pro t e i n. and. milk. concen t r a t i on. was. l i vewe i g h t. and. more. gai ned. fat. cond i t i on s core t han unsupplemen t ed cows .. Concen t r a t e supp leme n t i n c reased kgDM/kgDM ea t en .. concen t ra t e. H e r bage. kgDM/kgDM. i n t ake. concen t ra t e. e a t en was. and. t o tal. 0 . 69. d e c reased. ea t e n .. MJME/MJME by. Res i dual. i n c r e a s e d by concen t r a t e s u p p l emen t a t i on .. i n t ak es. an. by. concen t r a t e. ave rage. herbage. 0 . 65. mass. 0 . 34 was.
(5) iv. ACKNO'ilLEDGEHENTS. I w i sh. to. t hank. Dr . c . v .. guidance ,. i nvaluea b l e. my. Holmes ,. as s i s t ance ,. adv i c e. s u p e rv i s o r , and. for. en cour agemen t. t hroughou t my s t ud i e s .. I a l s o w i s h t o t hank the following people :. Pro fessor B . R .. Vatki n f o r encouraging me t o s t udy i n. New. Zealand .. The s t af f s of Da i ry Research. Uni t. for. the i r. a s s i s t ance. during the expe r i me n t done. J.M.. Ren d e l and. V.. S e r e e p rasert for helpful. s ugges t i ons. and guidance wi t h s t a t i s t i cal p r o cedures .. M . F�. Sco t t and R . A .. Vatson f o r t h e i r help w i t h. che m i cal. analys e s .. V.. Cha tupo te f o r h i s as s i s t an ce i n d rawing g raphs .. The New. Zealand. Government. for. the. scholar s h i p. that. allowed m e t o c a r ry o u t my s t ud i e s .. The Dai ry Farming Promo t i on Organ i s a t ion o f. allowing m e to s t udy in New Zealand .. Thai land. for.
(6) V. F i na l ly , t o my w i f e , Piyarat , their. p a t i ence ,. comprehens i on ,. and support. my. son , and. t hroughou t a l l t h e period o f my Mas t e ra t e s t udy .. Sukr i t ,. for. encouragemen t.
(7) vi. TABLE OF CONTENTS. TITLE PAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i. ABSTRACT. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ii. ACKNOVLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i v. LI ST OF TABLE S .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. x. LI ST O F F I GURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x i i. L I ST OF P LATE S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x i i i. 1 INTRODUCTI ON. .. .. .. .. .. .. .. .. .. .. 2 REVI E\1 O F L ITERATURE . .. .... .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. 2 . 1 EFFECTS OF SU PPLEMENTARY FEED G IVEN TO GRA ZING COVS 2 . 1 . 1 E f f e c ts on Feed I n t ake and Subs t i t u t i on Ra t e 2 . 1 . 1 . 1 Ty pe of supplements . .. 2 . 1 . 1 . 2 Leve l of f e e d i ng . .. 2 . 1 . 1 . 3 Qual i t y o f feeds . .. .. .. 2 . 1 . 1 . 4 Phys i o l og i cal s t a t e. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 2 . 1 . 2 E f f e c t on Residual Herbage Mass. ... . .. 2 . 1 . 3 E f fe c t on M i lk Y i e ld and Compos i t i on . . .. 2 . 1 . 3 . 1 Type o f suppleme n ts 2 . 1 . 3 . 2 Level o f f eed i ng . . . 2 . 1 . 3 . 3 Qual i t y o f f eeds. .. .. .. .. .. .. .. .. .. .. .. ..... .... ... .. .. .. .. .. .. .. .. .. .. ... .. .. . .. . . . .. .. .. .. 2 . 1 . 3 . 4 S tage o f l ac t a t i on and level o f. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. •. .. .. •. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 1. .. .. .. .. .. .. · .. .. .. .. . .. .. .. .. .. .. .. .. 2 . 1 . 4 E f f e c ts o n Li vewe i gh t and Body Cond i t i on Score. 3 3 3 3 4 6 6 7 7. .8. . .9 11 13 14.
(8) vii. 2 . 2 E FFECTS O F LEVEL O F FEEDING I N EARLY LACTATION . . .. .. .. . . . 16. 2 . 2 . 1 E f f e c ts on M i lk Y i e l d and Compos i t i on . . . . . . . . . . . 1 7 2 . 2 . 1 . 1 Immed i a t e e f fe c t . . . . . . . . . . . . . . . . . . . . . . . . . 1 7 .. 2 . 2 . 1 . 2 Car ryove r e f f e c t . . . . .. .. ......... .. ... .. . . .. .. .. . . . 18. 2 . 2 . 2 E f f e c t s on Livewe i gh t and/ o r Body Cond i t i o n . . . . 2 0 .. 2 . 2 . 2 . 1 Imme d i a t e e f fe c t .. .. .. .. .. ....... .... .. 2 . 2 . 2 . 2 Car ryover e f f e c t . . . . . . .. .. .. . . . . . . . 20 .. ............. .. .... 2 . 3 FACTORS CONTROLLING HERBAGE INTAKE B Y GRAZING DAIRY. .. .. . 21 . 22. 2 . 3 . 1 Volun t ary Food I n t ake . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 .. .. 2 . 3 . 1 . 1 Me tab o l i c f ac t o rs . . . . . . .. .. ......... .. 2 . 3 . 1 . 2 Phys i cal fac t o rs . . . . . . . . . . . . . . . . . .. 2 . 3 . 1 . 3 Behav i o u r a l fac t ors . . . . . . . . . . . . . . .. 2 . 3 . 2 Pas t ure Fac t o rs .. .. ... .. ... .. .. .. .. ................... 2 . 3 . 2 . 1 Herbage mass . . . . . . . . . . . . . . . . . .. .. .. .. . . . . 23 .. ..... . . .. .. .. .. ... .. .. . 24 . 27. . . . . 28. . . . . . . . . . . . 28. 2 . 3 . 2 . 2 Herbage a l l owance . . . . . . . . . . . . . . . . . . . . . . 3 0 .. �. .. .. 2 . 3 . 2 . 3 Herbage d i g e s t i b i l i ty . . . . . . . . . . . . . . . . . . . . 3 1 .. 2 . 3 . 3 An i mal Fac t o rs .. .. .............. .. ........... .. .. .. .. . . . .32. 2.3 . 3 . 1 S i z e , l ivewe igh t , body cond i t i on , age . . . . 3 2 .. 2 . 3 . 3 . 2 E f f e c t o f p r egnancy . . .. 2 . 3 . 3 . 3 E f f e c t o f lac t a t i on . . .. .. .. .. .. . . . . . . . . . . . . . . . . 33 .. . ... .......... .. .. 2 . 3 . 4 E f f e c t of Suppl emen t ary F e e d i ng . . . . . . . . . . . . . 2 . 4 OBJECTIVE OF THE STUDY . . . . . . . . . . . . . . . . . . . . . .. .. .. .. . . 34. . . . 35. . . . . . . . . . 36.
(9) vi i i. 3 MATERIALS AND METHODS. .. .. .. .. .. .. .. .. .. .. .. .. 3 . 1 PRE-EXPERIMENTAL CONDITIONS 3 . 1 . 1 Cl i ma t ological Da t a .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 3 . 1 . 2 An i mals and T r e a tmen t s. . .. .. . . .. .. .. .. 3 . 1 . 3 An i ma l , Sward and Feed Manageme n t s 3 . 1 . 4 Pas t ures and Concen t ra t e s 3 . 2 MEASUREMENTS .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. 3 . 2 . 1 F e e d Measu remen t s . . . . .. 3 . 2 . 2 An i ma l Measuremen t s 3 . 2 . 2 . 1 I n t ake. .. .. .. .. 3 . 2. 2 . 2 Li vewe igh t. .. .. .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..... 3 . 2 . 2 . 3 Body cond i t i on. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. . .. . .. .. .. .. .. .. .. .. .. .. .. .. . .. 3 . 2 . 2 . 4 M i lk produc t i on and compos i t i on . .. 3 . 3 STATI STI CAL ANALYSI S . .. 4 RE SULT S. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. ... .. .. .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 4:2 . 1 Pregraz ing Cond i t i o ns 4 . 2 . 2 Her bage In take. .. .. .. .. .. .. .. 4 . 2 . 3 Res i dual Herbage Mas s 4 . 3 ANI MAL PERFORMANCE S 4 . 3 . 1 Gene ral. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. . .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .... ... .. .. .. .. .. .. .. . .. . .. .. . .. .. .. .. .. . . . .. ... . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. ... .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. .. ... .. .. . .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. . .. .. 37. 39 41 42 42 42. . 44. .. .. 37. . 38 .. .. .. .. .. 4 . 1 CHEMICAL ANALYSI S AND GRO S S ENERGY DETERMINATI ON OF 4 . 2 SWARD CHARACTERI STICS. .. .. ... .. . . 35. .. 44 45 45 46. 49. . 49. . 50 .. . 50. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 53 57 59. . 59 .. 4 . 3 . 2 Yi e l d s o f M i l k , M i lk Fat , M i lk Pro t e i n a n d . . . . . . 6 0 4 . 3 . 3 Mi lk Compos i t i ons. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 4 . 3 . 4 L i v eweigh t and Body Cond i t i o n Score. .. .. .. .. .. .. . .. .. .. .. .. . . .. .. .. .. .. .. . .. .. .. .. .. 62 64.
(10) ix. 5 DISCUSSION. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 5 . 1 EFFECT OF CONCENTRATE SUPPLEMENTATI ON O N HERBAGE. .. .. .. .. .. .. .. .. •. .. 80 80. 5 . 1 . 1 Measureme n t o f He rbage In t ake . . . . . . . . . . . . . . . . . . . B O 5 . 1 . 2 Herbage In t ake and Subs t i t u t i o n Ra t e. .. 5 . 1 . 3 Explan a t ion o f Reduced Herbage I n t ake 5 . 1 . 4 E f f e c t o n Res i d u a l Herbage Mass. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 5 . 2 EFFECT OF CONCENTRATE SUPPLEMENTATION ON MILK. .. . 82. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 84 90 93. 5 . 2 . 1 M i lk Y i e ld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3 5 . 2 . 2 Y i e lds o f M i l k Cons t i t uen t s . . . . . . . . . . . . . . . . . . . . 1 1 1 5 . 2 . 3 Re s i dual E f f e c t on Y i elds o f M i lk and I t s . . . . . . 1 1 1 5 . 2 . 4 Compos i t i on o f M i lk. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 5 . 3 EFFECT OF CONCENTRATE SUPPLEMENTATI ON ON LIVEWEIGHT. 6 CONCLUSI ON. .. .. 7 B I B LI OGRAPHY. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . ... . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .... .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 113 116. . . 1 18 .. .. .. .. 120.
(11) X. LIST OF TABLES. Table. 3 . 1 Common Abbrev i a t i ons . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Table. 3 . 2 C l i ma t ol ogi cal data t hrougho u t the expe r i me n t . . . . . . 3 9. Table. 3 . 3 Da t a f o r cows a t t he s t a r t o f t h e expe r i m en t . . . . . . . 40. Ta ble. 3 . 4 Summary o f the expe r i men t al des c r i p t ion . . .. Tab le. 4 . 1 Da t a f o r the analyses of feeds used i n t h e expe r i men t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1 .. .. . . . . .. .. .. .. . . 38. . . 41. .. Table. 4 . 2 Mean values and resul t s o f ANOVA f o r t he amoun t s o f p r egra z i ng pas t u r e mas s ( kgDM / ha ) f o r t h e two t reatmen t s in P e r i o d s I and II . . . . . . . . . . . . . . . . . . . . . 52. Table. 4 . 3 M ean values and resul t s o f ANOVA for t he amoun t s o f he rbage , concen t ra t e and t o tal DM a l l owan c e ( kgDM/ cow/day ) f o r t he t w o t re a t men t s i n P e r i od s I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 .. Table. .. 4 . 4 Mean values and resul t s o f ANOVA f o r t h e amoun t s o f ME o f f ered f rom herbage , concen t ra t e and t o t a l ME allowance ( MJ / cow/day) for t he t w o t rea t men t s i n P e r i ods I and I I . . . .. . . . . . . . . . . . . . . . . 54 .. Table. .. .. .. .. .. .. .. .. .. 4 . 5 Mean values and resul t s o f ANOVA for t he amoun t s o f DM consumed from t he pas t ure, concen t ra t e and t o t al apparen t DM i n t ake ( kg/ cow/ day ) for t h e two t r ea tmen t s in P e r i ods I and I I . . . . . . . . . . . . . . . . . . 56 .. Table. .. .. .. .. .. .. .. 4 . 8 M ean values and resul t s o f ANOVA f o r t h e amoun t s o f res i dual he rbage mass ( RHM, kgDM /ha ) f o r t h e two t reat me n t s in P e r i ods I and I I . . . . . . . . . . . . . . . 60 .. Ta ble. .. 4 . 7 I n c rease in t o t al DM and M E i n t akes cau s e d b y t h e consum p t i on o f 1 kgDM o r 1 M J M E a s con cen t ra t e s i n Per i ods I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8 .. Table. .. 4 . 6 M ean values and resul t s o f ANOVA for t he amoun t s o f ME cons umed from t he he rbage , concen t ra t e and t o t al ME cons umed ( MJ / cow/day ) f o r the two t re a t men t s in P e r i ods I and II . . . . . . . . . . . . . . . . . 57 .. Table. .. .. 4 . 9 Y i elds o f mi lk, mi lk f a t, mi lk p r o t e i n a n d m i lk l a c t o s e ( kg/ cow/day ) f o r the two t re a t men t g r o u p s i n P e r i ods I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Table 4 . 10 Concen t ra t i on o f f a t , p r o t e i n and l ac t os e ( % ) f o r t h e t w o t reatmen t groups i n P e r i od s I and I I . . . . . . . 6 5.
(12) xi. Table 4 . 1 1 Mean values and resu l t s o f ANOVA f o r t he i n i t i al and f i na l l i vewe i gh t ( kg/ cow ) , t h e ini t i a l and f i nal body cond i t i on s c o r e ( un i t s ) , li vewe i gh t c hange ( grm /day ) and cond i t i on s co r e change ( uni t s / mon t h ) for t he two t rea t me n t groups i n P e r i o d s I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .·. .. . 67. Table. 5 . 1 Changes i n i n t ake o f pas t u re and r e s idual h e rbage ' mass per un i t of add i t i onal Hay, S i lage o r Concen t ra t e expres s ed as kgDM/kg s u pplemen t DM, MJME/MJME supplemen t or kgDM/ha by gra z i ng cows . . . . 8 6. Tab l e. 5 . 2 Change i n y i e lds o f m i lk ( kg/ kgDM supplemen t ) and i t s cons t i tuen t s ( grm/ kgDM s u p p lemen t ) p e r un i t o f add i t i onal Hay, S i lage o r Concen t ra t e t o graz i ng cows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. Table. 5 . 3 Change in concen t ra t i ons o f m i lk cons t i t uen t s (%) , l i vewe igh t ( grm/kgDM supp lemen t ) , and body cond i t i on s c ore ( un i t s / mo n t h ) per uni t o f add i t i onal Hay, S i lage o r Concen t ra t e t o g ra z i ng d a i ry cows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9 .. .. Tab l e. 5 . 4 Changes in animal p e r f o rmance p e r kg ex t ra f eed D M ea t en by graz i ng d a i ry cows . . . . . . . � . . . . . . . . 104. Table. 5 . 5 Calcu l a t e d ene rgy balance f o r t he two t re a t men t s i n P e r i o d s I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 0.
(13) xii. LIST OF FIGURES. F igure. 4 . 1 E f f e c t of concen t ra t e s u pp l emen t a t ion on m i lk produc t i on over t he e x p e r i men t a l per i od . . .. F igu re. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 4 . 6 E f f e c t o f concen t r a t e s u pplemen t a t ion on concen t ra t i on o f m i lk p r o t e i n . . . . . . . . . . . . .. .. 4 . 7 E f f e c t o f concen t ra t e supplemen t a t ion on concen t r a t i on o f m i l k l a c t o s e . . . . . . . . ... .. . 68. . 69 .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 71. .. .. 73. . . . 74. 4 . 9 Trend in l i vewe i gh t change over the exp e r i men t a l pe r i od . . . . . .. . . . . . .... . . ... .. .. .. .... .. .. . . 72. 4 . 8 Rela t i on s h i p be tween changes i n l i vewe i g h t and changes in body cond i t i on s c ore over 14 weeks of expe r i men t . . . . . . . . . . . . ... .. F i gure. .. .. .. F i gure. .. 4 . 5 E f f e c t o f concen t ra t e s u pplemen t a t ion on concen t ra t i on o f m i l k f a t . . . . . ........ .. F igu re. .. .. .. F i gu r e. .. 4 . 4 E f f e c t o f concen t ra t e supplemen t a t ion o n m i lk . . . . . . .... ..... . . lac t os e y i eld . . . . . . .. F i gu r e. .. 4 . 3 E f f e c t o f concen t ra t e s u pplemen t a t i on o n m i lk pro t e i n y i e ld . . . . . .. .... . . . . . . . . . 70 .. F i gu r e. .. 4 . 2 E f f e c t o f concen t r a t e s u p p lemen t a t i on on m i lk f a t y i e ld . . . . . . . .. ... .. . .... . . . . .. F igure. .. .. .. .. .. 75. 76. F i gu r e 4 . 10 Trend i n body cond i t i on score change over t he exp e r i men t a l per i od . . .. .. . . . . . . . 77 .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
(14) xii i. LIST OF PLATES. P l a t e 4 . 1 E f f e c t o f concen t ra t e supplemen t a t i on on r e s i dual herbage mass ( a ) unsu p p lemen t e d group ( b ) s u p p l emen t e d group . . . . . . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. P l a t e 4 . 2 E f f e c t o f concen t ra t e s u p p l emen t a t i on on r e s i dual herbage mass ( a ) u n s u p p lemen t ed group ( b ) s u p p l emen t e d group ( Cl o s e d u p ) . . . . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 78. 79.
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(2) EFFECT OF CONCENTRATE SUPPLEMENTATION ON HERBAGE CONSUMPTION ,. MILK PRODUCTION AND COMPOSITION ,. AND ON LIVEVEIGHT AND CONDITION SCORE CHANGE IN EARLY LACTATION. A thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science Animal Science Department Massey University,. Palmerston North. NE� ZEALAND. �ISITIPORN SUKSOMBAT. 1988.
(3) ii. ABSTRACT. Each o f 1 5 s e t s o f i d en t i cal twins was graz i ng t r ea t me n t s ,. the. pas ture. concen t ra t e f e d t r ea tmen t ( CF ) . pas t u r e o n ly. and. those. fed. a l l oc a t ed. t reat me n t. to. ( PF ). Cows i n P F t r e a t m en t. two. and t h e were. fed. cows i n CF t re a tmen t wer e s u p pl emen t ed of. w i t h c o n c e n t ra t e s .. The. p e r enn i al rye g r ass .. The ex per imen t was c a r r i e d ou t f o r 1 4 weeks. ( 1 4 t h S e p t em b e r-2 1 s t. swards. used. were. p r ed om i n an t ly. December 1 987 ) o f the ear ly g r a z i ng s e a s o n. o f 1 987 .. T h e expe r i men t was carried ou t in two w i t h an. a l l owance. 1 9 87 a n d Pe r i od 21s t to. 30th. II. pe r i o d s ,. P e r i od. I. o f 20 kgDM/ cow/day f rom 1 3 t h t o 27 t h Oc t o b e r wi th a n allowance. November. 1 98 7 .. of. M i lk. 25. kgDM/c ow/day. yield ,. f ro m. m i lk c o mpos i t i on ,. an i ma l l i vewe i g h t and cond i t i on s core were meas u r e d .. H e r bage i n t ake was es t ima t e d by and was. 10 . 0. and. 9.0. sward. cu t t i n g. t e chni q u e. kgDM/ cow/day f o r supplemen t ed c ows , and. 1 1 . 8 and 1 2.2 kgDM/cow/day for. unsupplemen t e d cows i n Pe r i od s and. II. r e s p e c t ively .. Suppleme n t e d. cows. c o n s umed. I 6.7. kgDM/c ow / day concen t ra t e s i n b o t h p e r i od s .. T h e r e was a s i gni f i cant increase concen t r a t e s u p p lemen t a t i on .. The. in. mi lk. Yields. of. f a t i n P e r i o d II .. milk. due. to. average res p o n s e was 0 . 40 kg. m i l k/kg c onc en t r a t e OM ea t en or 0.68 kg m i lk/kg e a t en .. yield. e x t ra. feed. DM. cons t i tuen t s were i n c r e as e d ex ce p t f o r.
(4) iii. Concen t ra t e f e e ding had no e f f ec t o n lac t o s e. c oncen t ra t i ons. increased .. Sup p lemen t ed. bu t. m i lk. cows. m i lk. pro t e i n. and. milk. concen t r a t i on. was. l i vewe i g h t. and. more. gai ned. fat. cond i t i on s core t han unsupplemen t ed cows .. Concen t r a t e supp leme n t i n c reased kgDM/kgDM ea t en .. concen t ra t e. H e r bage. kgDM/kgDM. i n t ake. concen t ra t e. e a t en was. and. t o tal. 0 . 69. d e c reased. ea t e n .. MJME/MJME by. Res i dual. i n c r e a s e d by concen t r a t e s u p p l emen t a t i on .. i n t ak es. an. by. concen t r a t e. ave rage. herbage. 0 . 65. mass. 0 . 34 was.
(5) iv. ACKNO'ilLEDGEHENTS. I w i sh. to. t hank. Dr . c . v .. guidance ,. i nvaluea b l e. my. Holmes ,. as s i s t ance ,. adv i c e. s u p e rv i s o r , and. for. en cour agemen t. t hroughou t my s t ud i e s .. I a l s o w i s h t o t hank the following people :. Pro fessor B . R .. Vatki n f o r encouraging me t o s t udy i n. New. Zealand .. The s t af f s of Da i ry Research. Uni t. for. the i r. a s s i s t ance. during the expe r i me n t done. J.M.. Ren d e l and. V.. S e r e e p rasert for helpful. s ugges t i ons. and guidance wi t h s t a t i s t i cal p r o cedures .. M . F�. Sco t t and R . A .. Vatson f o r t h e i r help w i t h. che m i cal. analys e s .. V.. Cha tupo te f o r h i s as s i s t an ce i n d rawing g raphs .. The New. Zealand. Government. for. the. scholar s h i p. that. allowed m e t o c a r ry o u t my s t ud i e s .. The Dai ry Farming Promo t i on Organ i s a t ion o f. allowing m e to s t udy in New Zealand .. Thai land. for.
(6) V. F i na l ly , t o my w i f e , Piyarat , their. p a t i ence ,. comprehens i on ,. and support. my. son , and. t hroughou t a l l t h e period o f my Mas t e ra t e s t udy .. Sukr i t ,. for. encouragemen t.
(7) vi. TABLE OF CONTENTS. TITLE PAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i. ABSTRACT. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ii. ACKNOVLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i v. LI ST OF TABLE S .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. x. LI ST O F F I GURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x i i. L I ST OF P LATE S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x i i i. 1 INTRODUCTI ON. .. .. .. .. .. .. .. .. .. .. 2 REVI E\1 O F L ITERATURE . .. .... .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. 2 . 1 EFFECTS OF SU PPLEMENTARY FEED G IVEN TO GRA ZING COVS 2 . 1 . 1 E f f e c ts on Feed I n t ake and Subs t i t u t i on Ra t e 2 . 1 . 1 . 1 Ty pe of supplements . .. 2 . 1 . 1 . 2 Leve l of f e e d i ng . .. 2 . 1 . 1 . 3 Qual i t y o f feeds . .. .. .. 2 . 1 . 1 . 4 Phys i o l og i cal s t a t e. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 2 . 1 . 2 E f f e c t on Residual Herbage Mass. ... . .. 2 . 1 . 3 E f fe c t on M i lk Y i e ld and Compos i t i on . . .. 2 . 1 . 3 . 1 Type o f suppleme n ts 2 . 1 . 3 . 2 Level o f f eed i ng . . . 2 . 1 . 3 . 3 Qual i t y o f f eeds. .. .. .. .. .. .. .. .. .. .. .. ..... .... ... .. .. .. .. .. .. .. .. .. .. ... .. .. . .. . . . .. .. .. .. 2 . 1 . 3 . 4 S tage o f l ac t a t i on and level o f. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. •. .. .. •. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 1. .. .. .. .. .. .. · .. .. .. .. . .. .. .. .. .. .. .. .. 2 . 1 . 4 E f f e c ts o n Li vewe i gh t and Body Cond i t i on Score. 3 3 3 3 4 6 6 7 7. .8. . .9 11 13 14.
(8) vii. 2 . 2 E FFECTS O F LEVEL O F FEEDING I N EARLY LACTATION . . .. .. .. . . . 16. 2 . 2 . 1 E f f e c ts on M i lk Y i e l d and Compos i t i on . . . . . . . . . . . 1 7 2 . 2 . 1 . 1 Immed i a t e e f fe c t . . . . . . . . . . . . . . . . . . . . . . . . . 1 7 .. 2 . 2 . 1 . 2 Car ryove r e f f e c t . . . . .. .. ......... .. ... .. . . .. .. .. . . . 18. 2 . 2 . 2 E f f e c t s on Livewe i gh t and/ o r Body Cond i t i o n . . . . 2 0 .. 2 . 2 . 2 . 1 Imme d i a t e e f fe c t .. .. .. .. .. ....... .... .. 2 . 2 . 2 . 2 Car ryover e f f e c t . . . . . . .. .. .. . . . . . . . 20 .. ............. .. .... 2 . 3 FACTORS CONTROLLING HERBAGE INTAKE B Y GRAZING DAIRY. .. .. . 21 . 22. 2 . 3 . 1 Volun t ary Food I n t ake . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 .. .. 2 . 3 . 1 . 1 Me tab o l i c f ac t o rs . . . . . . .. .. ......... .. 2 . 3 . 1 . 2 Phys i cal fac t o rs . . . . . . . . . . . . . . . . . .. 2 . 3 . 1 . 3 Behav i o u r a l fac t ors . . . . . . . . . . . . . . .. 2 . 3 . 2 Pas t ure Fac t o rs .. .. ... .. ... .. .. .. .. ................... 2 . 3 . 2 . 1 Herbage mass . . . . . . . . . . . . . . . . . .. .. .. .. . . . . 23 .. ..... . . .. .. .. .. ... .. .. . 24 . 27. . . . . 28. . . . . . . . . . . . 28. 2 . 3 . 2 . 2 Herbage a l l owance . . . . . . . . . . . . . . . . . . . . . . 3 0 .. �. .. .. 2 . 3 . 2 . 3 Herbage d i g e s t i b i l i ty . . . . . . . . . . . . . . . . . . . . 3 1 .. 2 . 3 . 3 An i mal Fac t o rs .. .. .............. .. ........... .. .. .. .. . . . .32. 2.3 . 3 . 1 S i z e , l ivewe igh t , body cond i t i on , age . . . . 3 2 .. 2 . 3 . 3 . 2 E f f e c t o f p r egnancy . . .. 2 . 3 . 3 . 3 E f f e c t o f lac t a t i on . . .. .. .. .. .. . . . . . . . . . . . . . . . . 33 .. . ... .......... .. .. 2 . 3 . 4 E f f e c t of Suppl emen t ary F e e d i ng . . . . . . . . . . . . . 2 . 4 OBJECTIVE OF THE STUDY . . . . . . . . . . . . . . . . . . . . . .. .. .. .. . . 34. . . . 35. . . . . . . . . . 36.
(9) vi i i. 3 MATERIALS AND METHODS. .. .. .. .. .. .. .. .. .. .. .. .. 3 . 1 PRE-EXPERIMENTAL CONDITIONS 3 . 1 . 1 Cl i ma t ological Da t a .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 3 . 1 . 2 An i mals and T r e a tmen t s. . .. .. . . .. .. .. .. 3 . 1 . 3 An i ma l , Sward and Feed Manageme n t s 3 . 1 . 4 Pas t ures and Concen t ra t e s 3 . 2 MEASUREMENTS .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. 3 . 2 . 1 F e e d Measu remen t s . . . . .. 3 . 2 . 2 An i ma l Measuremen t s 3 . 2 . 2 . 1 I n t ake. .. .. .. .. 3 . 2. 2 . 2 Li vewe igh t. .. .. .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..... 3 . 2 . 2 . 3 Body cond i t i on. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. . .. . .. .. .. .. .. .. .. .. .. .. .. .. . .. 3 . 2 . 2 . 4 M i lk produc t i on and compos i t i on . .. 3 . 3 STATI STI CAL ANALYSI S . .. 4 RE SULT S. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. ... .. .. .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 4:2 . 1 Pregraz ing Cond i t i o ns 4 . 2 . 2 Her bage In take. .. .. .. .. .. .. .. 4 . 2 . 3 Res i dual Herbage Mas s 4 . 3 ANI MAL PERFORMANCE S 4 . 3 . 1 Gene ral. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. . .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .... ... .. .. .. .. .. .. .. . .. . .. .. . .. .. .. .. .. . . . .. ... . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. ... .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. .. ... .. .. . .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. . .. .. 37. 39 41 42 42 42. . 44. .. .. 37. . 38 .. .. .. .. .. 4 . 1 CHEMICAL ANALYSI S AND GRO S S ENERGY DETERMINATI ON OF 4 . 2 SWARD CHARACTERI STICS. .. .. ... .. . . 35. .. 44 45 45 46. 49. . 49. . 50 .. . 50. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 53 57 59. . 59 .. 4 . 3 . 2 Yi e l d s o f M i l k , M i lk Fat , M i lk Pro t e i n a n d . . . . . . 6 0 4 . 3 . 3 Mi lk Compos i t i ons. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 4 . 3 . 4 L i v eweigh t and Body Cond i t i o n Score. .. .. .. .. .. .. . .. .. .. .. .. . . .. .. .. .. .. .. . .. .. .. .. .. 62 64.
(10) ix. 5 DISCUSSION. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 5 . 1 EFFECT OF CONCENTRATE SUPPLEMENTATI ON O N HERBAGE. .. .. .. .. .. .. .. .. •. .. 80 80. 5 . 1 . 1 Measureme n t o f He rbage In t ake . . . . . . . . . . . . . . . . . . . B O 5 . 1 . 2 Herbage In t ake and Subs t i t u t i o n Ra t e. .. 5 . 1 . 3 Explan a t ion o f Reduced Herbage I n t ake 5 . 1 . 4 E f f e c t o n Res i d u a l Herbage Mass. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 5 . 2 EFFECT OF CONCENTRATE SUPPLEMENTATION ON MILK. .. . 82. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 84 90 93. 5 . 2 . 1 M i lk Y i e ld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3 5 . 2 . 2 Y i e lds o f M i l k Cons t i t uen t s . . . . . . . . . . . . . . . . . . . . 1 1 1 5 . 2 . 3 Re s i dual E f f e c t on Y i elds o f M i lk and I t s . . . . . . 1 1 1 5 . 2 . 4 Compos i t i on o f M i lk. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 5 . 3 EFFECT OF CONCENTRATE SUPPLEMENTATI ON ON LIVEWEIGHT. 6 CONCLUSI ON. .. .. 7 B I B LI OGRAPHY. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . ... . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .... .. .. .. .. .. .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 113 116. . . 1 18 .. .. .. .. 120.
(11) X. LIST OF TABLES. Table. 3 . 1 Common Abbrev i a t i ons . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Table. 3 . 2 C l i ma t ol ogi cal data t hrougho u t the expe r i me n t . . . . . . 3 9. Table. 3 . 3 Da t a f o r cows a t t he s t a r t o f t h e expe r i m en t . . . . . . . 40. Ta ble. 3 . 4 Summary o f the expe r i men t al des c r i p t ion . . .. Tab le. 4 . 1 Da t a f o r the analyses of feeds used i n t h e expe r i men t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1 .. .. . . . . .. .. .. .. . . 38. . . 41. .. Table. 4 . 2 Mean values and resul t s o f ANOVA f o r t he amoun t s o f p r egra z i ng pas t u r e mas s ( kgDM / ha ) f o r t h e two t reatmen t s in P e r i o d s I and II . . . . . . . . . . . . . . . . . . . . . 52. Table. 4 . 3 M ean values and resul t s o f ANOVA for t he amoun t s o f he rbage , concen t ra t e and t o tal DM a l l owan c e ( kgDM/ cow/day ) f o r t he t w o t re a t men t s i n P e r i od s I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 .. Table. .. 4 . 4 Mean values and resul t s o f ANOVA f o r t h e amoun t s o f ME o f f ered f rom herbage , concen t ra t e and t o t a l ME allowance ( MJ / cow/day) for t he t w o t rea t men t s i n P e r i ods I and I I . . . .. . . . . . . . . . . . . . . . . 54 .. Table. .. .. .. .. .. .. .. .. .. 4 . 5 Mean values and resul t s o f ANOVA for t he amoun t s o f DM consumed from t he pas t ure, concen t ra t e and t o t al apparen t DM i n t ake ( kg/ cow/ day ) for t h e two t r ea tmen t s in P e r i ods I and I I . . . . . . . . . . . . . . . . . . 56 .. Table. .. .. .. .. .. .. .. 4 . 8 M ean values and resul t s o f ANOVA f o r t h e amoun t s o f res i dual he rbage mass ( RHM, kgDM /ha ) f o r t h e two t reat me n t s in P e r i ods I and I I . . . . . . . . . . . . . . . 60 .. Ta ble. .. 4 . 7 I n c rease in t o t al DM and M E i n t akes cau s e d b y t h e consum p t i on o f 1 kgDM o r 1 M J M E a s con cen t ra t e s i n Per i ods I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8 .. Table. .. 4 . 6 M ean values and resul t s o f ANOVA for t he amoun t s o f ME cons umed from t he he rbage , concen t ra t e and t o t al ME cons umed ( MJ / cow/day ) f o r the two t re a t men t s in P e r i ods I and II . . . . . . . . . . . . . . . . . 57 .. Table. .. .. 4 . 9 Y i elds o f mi lk, mi lk f a t, mi lk p r o t e i n a n d m i lk l a c t o s e ( kg/ cow/day ) f o r the two t re a t men t g r o u p s i n P e r i ods I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Table 4 . 10 Concen t ra t i on o f f a t , p r o t e i n and l ac t os e ( % ) f o r t h e t w o t reatmen t groups i n P e r i od s I and I I . . . . . . . 6 5.
(12) xi. Table 4 . 1 1 Mean values and resu l t s o f ANOVA f o r t he i n i t i al and f i na l l i vewe i gh t ( kg/ cow ) , t h e ini t i a l and f i nal body cond i t i on s c o r e ( un i t s ) , li vewe i gh t c hange ( grm /day ) and cond i t i on s co r e change ( uni t s / mon t h ) for t he two t rea t me n t groups i n P e r i o d s I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .·. .. . 67. Table. 5 . 1 Changes i n i n t ake o f pas t u re and r e s idual h e rbage ' mass per un i t of add i t i onal Hay, S i lage o r Concen t ra t e expres s ed as kgDM/kg s u pplemen t DM, MJME/MJME supplemen t or kgDM/ha by gra z i ng cows . . . . 8 6. Tab l e. 5 . 2 Change i n y i e lds o f m i lk ( kg/ kgDM supplemen t ) and i t s cons t i tuen t s ( grm/ kgDM s u p p lemen t ) p e r un i t o f add i t i onal Hay, S i lage o r Concen t ra t e t o graz i ng cows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. Table. 5 . 3 Change in concen t ra t i ons o f m i lk cons t i t uen t s (%) , l i vewe igh t ( grm/kgDM supp lemen t ) , and body cond i t i on s c ore ( un i t s / mo n t h ) per uni t o f add i t i onal Hay, S i lage o r Concen t ra t e t o g ra z i ng d a i ry cows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9 .. .. Tab l e. 5 . 4 Changes in animal p e r f o rmance p e r kg ex t ra f eed D M ea t en by graz i ng d a i ry cows . . . . . . . � . . . . . . . . 104. Table. 5 . 5 Calcu l a t e d ene rgy balance f o r t he two t re a t men t s i n P e r i o d s I and I I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 0.
(13) xii. LIST OF FIGURES. F igure. 4 . 1 E f f e c t of concen t ra t e s u pp l emen t a t ion on m i lk produc t i on over t he e x p e r i men t a l per i od . . .. F igu re. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 4 . 6 E f f e c t o f concen t r a t e s u pplemen t a t ion on concen t ra t i on o f m i lk p r o t e i n . . . . . . . . . . . . .. .. 4 . 7 E f f e c t o f concen t ra t e supplemen t a t ion on concen t r a t i on o f m i l k l a c t o s e . . . . . . . . ... .. . 68. . 69 .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 71. .. .. 73. . . . 74. 4 . 9 Trend in l i vewe i gh t change over the exp e r i men t a l pe r i od . . . . . .. . . . . . .... . . ... .. .. .. .... .. .. . . 72. 4 . 8 Rela t i on s h i p be tween changes i n l i vewe i g h t and changes in body cond i t i on s c ore over 14 weeks of expe r i men t . . . . . . . . . . . . ... .. F i gure. .. .. .. F i gure. .. 4 . 5 E f f e c t o f concen t ra t e s u pplemen t a t ion on concen t ra t i on o f m i l k f a t . . . . . ........ .. F igu re. .. .. .. F i gu r e. .. 4 . 4 E f f e c t o f concen t ra t e supplemen t a t ion o n m i lk . . . . . . .... ..... . . lac t os e y i eld . . . . . . .. F i gu r e. .. 4 . 3 E f f e c t o f concen t ra t e s u pplemen t a t i on o n m i lk pro t e i n y i e ld . . . . . .. .... . . . . . . . . . 70 .. F i gu r e. .. 4 . 2 E f f e c t o f concen t r a t e s u p p lemen t a t i on on m i lk f a t y i e ld . . . . . . . .. ... .. . .... . . . . .. F igure. .. .. .. .. .. 75. 76. F i gu r e 4 . 10 Trend i n body cond i t i on score change over t he exp e r i men t a l per i od . . .. .. . . . . . . . 77 .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
(14) xii i. LIST OF PLATES. P l a t e 4 . 1 E f f e c t o f concen t ra t e supplemen t a t i on on r e s i dual herbage mass ( a ) unsu p p lemen t e d group ( b ) s u p p l emen t e d group . . . . . . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. P l a t e 4 . 2 E f f e c t o f concen t ra t e s u p p l emen t a t i on on r e s i dual herbage mass ( a ) u n s u p p lemen t ed group ( b ) s u p p l emen t e d group ( Cl o s e d u p ) . . . . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 78. 79.
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