It’s spring silly sea­son at Ellinbank Re­search

North East & Goulburn Murray Farmer - - NEWS -

AGRI­CUL­TURE Vic­to­ria re­searchers at Ellinbank are still in the mid­dle of the spring silly sea­son, with some ex­per­i­ments wind­ing up and oth­ers just be­gin­ning.

First cab off the rank this spring was an early lac­ta­tion nutri­tion ex­per­i­ment as part of the “First 100 Days” re­search pro­gram.

In this ex­per­i­ment, which is led by Vicky Russo and Dr Bill Wales and runs un­til Jan­uary, four dif­fer­ent strate­gies for pro­vid­ing grain sup­ple­ments dur­ing early lac­ta­tion are be­ing tested in four groups of 24 cows.

Flat feed­ing rates of ei­ther “high” or “medium” amounts of grain for the first 140 days of lac­ta­tion are be­ing com­pared to sys­tems in which a high amount of grain is re­duced to a “low” amount when cows were judged to have switched from a fat mo­bil­i­sa­tion phase to one of fat de­po­si­tion.

Two dif­fer­ent ways of ap­prox­i­mat­ing the tim­ing of this tran­si­tion were com­pared: in one treat­ment di­ets were changed when 70 days in milk was reached.

In the fi­nal group, di­ets were changed when cows stopped los­ing weight and started gain­ing it ir­re­spec­tive of days in milk ( as judged by daily mea­sure­ments of live weight).

Re­sults from this ex­per­i­ment should be­come avail­able early in the New Year.

Next, the se­cond graz­ing ex­per­i­ment as part of the “Smart Feed­ing” re­search pro­gram was con­ducted in Oc­to­ber.

An ex­per­i­ment us­ing 40 cows was led by Meaghan Dou­glas and my­self to mea­sure the ef­fect of time away from pas­ture on graz­ing be­hav­iour, dry mat­ter in­take and the change in the avail­abil­ity and qual­ity of pas­ture as graz­ing pro­gressed.

The cows were al­lo­cated into five treat­ment groups of eight and re­leased back to their pad­dock se­quen­tially.

Over 15 days, one group was walked straight to the pad­dock while oth­ers were sent back at 45-minute in­ter­vals over three hours, in the same or­der each time, thus mim­ick­ing what of­ten oc­curs on com­mer­cial farms.

Some cows, there­fore, were away from the pad­dock for six hours per day plus walk­ing and milk­ing time.

To mea­sure graz­ing be- haviour, cows were fit­ted with jaw move­ment sen­sors and ac­tiv­ity mon­i­tors to record the time cows spent graz­ing each day, the to­tal num­ber of bites the cows took each day, and the rate at which cows grazed.

In ad­di­tion, the n- alkane tech­nique was used to mea­sure the to­tal daily dry mat­ter in­take of cows.

Mea­sure­ments were also made of pas­ture mass and qual­ity prior to graz­ing, and then im­me­di­ately prior to each new group of cows en­ter­ing the pad­dock.

Pre­lim­i­nary analy­ses of the re­sults showed that cows re­turn­ing to the pad­dock first pro­duced around 6.2kg more milk per day than cows re­turn­ing three hours later.

This was de­spite spend­ing ap­prox­i­mately the same amount of time graz­ing.

Pre­sum­ably the cows re­turn­ing to the pad­dock last har­vested a smaller amount of pas­ture per bite, re­sult­ing in a lower in­take of lower qual­ity pas­ture, but this data is still be­ing col­lated.

Last but not least, an ex­per­i­ment was com­menced in early No­vem­ber as part of the “Cool Cows” pro­gram led by Dr Leah Marett and Richard Wil­liams.

This ex­per­i­ment, which uses 24 cows, has the aim of in­ves­ti­gat­ing four dif­fer­ent sup­ple­ments for their po­ten­tial to form di­ets with a lower heat of fer­men­ta­tion that may be use­ful for feed­ing cows in hot weather.

Sup­ple­ments that will be tested in­clude wheat, bar­ley, maize and canola meal.

In­for­ma­tion from this ex­per­i­ment could ul­ti­mately lead to spe­cial “sum­mer sup­ple­ments” to help re­lieve the milk loss in­curred dur­ing heat stress.

These di­ets will be tested in cows that have been pre­vi­ously iden­ti­fied as be­ing ei­ther tol­er­ant or sus­cep­ti­ble to heat events, to check for pos­si­ble in­ter­ac­tions be­tween the ef­fects of nutri­tion and ge­net­ics.

SILLY SEA­SON AT ELLINBANK: Not only is it the spring silly sea­son at Ellinbank Re­search Cen­tre, it’s also Christ­mas.

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.