Nutrition Commons^™

Effect Of Varying Rumen Degradable And Undegradable Protein On Milk Production And Nitrogen Efficiency In Lactating Dairy Cows Under Summer Conditions, Jeffrey D. Kaufman

Masters Theses

The objective is to determine the effect of reducing nitrogen input through feeding low rumen degradable protein (RDP) and rumen undegradable protein (RUP) proportions on milk production, nitrogen efficiency and metabolism in heat-stressed cows. Forty-eight mid-lactating, Holstein cows were assigned to treatments using a randomized block design in a 2x2 factorial arrangement of treatments (n = 12/treatment). Treatments included two levels of RDP (10 and 8%) and two levels of RUP (8 and 6%). From d 1 to 21, a common diet (10% RDP-8% RUP) was fed to cows followed with their respective treatment diets fed from d 22 to …

Effect Of Brown Midrib Corn Silage And Dried Distillers Grains Plus Solubles On Lactational Performance And Nitrogen Utilization By Dairy Cows, Hugo A. Ramirez

Department of Animal Science: Dissertations, Theses, and Student Research

Thirty six Holstein cows, four ruminally cannulated, (mean ± SD, 111 ± 35 DIM; 664 ± 76.5 kg BW) were used in replicated 4×4 Latin squares to investigate the effects of brown midrib (bm3) and conventional (DP) corn silages, and the inclusion of dried distillers grains plus solubles (DDGS) on milk production and N utilization. In each 28 d period cows were assigned to one of four treatments: DP plus 0% DDGS (CON); bm3 plus 0% DDGS (BMR); DP corn silage plus 30% DDGS (DP+DG); and bm3 plus 30% DDGS (BMR+DG). Dry matter intake was greater (P < 0.01) for cows consuming bm3 (25.8 VS 24.4 ± 0.47 kg), likewise for DDGS (24.3 and 25.9 ± 0.47 kg/d for 0 and 30%). Compared to DP hybrid, NDFD was higher (P < 0.01) for bm3 (32.5 VS 38.1 ± 1.79%). There was a hybrid × DDGS interaction (P < 0.01) for total concentration of volatile fatty acids (VFA) and rumen pH as the highly digestible treatment BMR+DG resulted in the highest VFA and the lowest pH. Milk yield was not affected by treatment and averaged 30.6 ± 1.09 kg/d. Milk protein yield (MPY) was greater (P < 0.01) for bm3 and DDGS treatments. There was a hybrid by DDGS interaction (P = 0.02) for milk fat yield (MFY) resulting in 1.03, 1.08, 0.84 and 0.78 ± 0.045 kg/d for DP, BMR, DP+DG and BMR+DG. Fat corrected milk (FCM) was affected by DDGS (P < 0.01) and averaged 30.0 and 26.4 ± 1.0kg/d (0% and 30% inclusions). Urinary N excretion was similar among treatments; however fecal N was lower (P = 0.03) for diets containing bm3 corn silage which caused lower (P = 0.02) manure N. These results indicate that bm3 corn silage and DDGS increase DMI, NDFD and MPY; however high inclusion of corn silage with 30% DDGS reduces FCM. Nitrogen excretion was reduced when cows consumed bm3.

Acetonaemia In Dairy Cows, F C. Wilkinson

Journal of the Department of Agriculture, Western Australia, Series 4

ACETONAEMIA is a common disease of newly calved cows in the dairying districts of Western Australia.

Affected cows practically dry off and lose a lot of body condition; these are the main causes of loss to the owners.

A Simple Feeding Guide : Balanced Rations For Dairy Cows, K Needham

Journal of the Department of Agriculture, Western Australia, Series 4

MANY technical articles have been written on the nutrition of dairy cattle and the methods employed in compounding a balanced ration have often been explained.

This article aims to present the principles of compounding a balanced ration in a simplified form, and suggests rations which should be easily adopted on any dairy farm.

Don't Neglect Those Dry Cows, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

WHEN a dairy cow becomes pregnant she is normally milking and has some months to go before being dried off.

It is usual at this stage for dairy farmers to provide the best feed available.

Mineral Supplements, Laurence C. Snook

Journal of the Department of Agriculture, Western Australia, Series 4

TJRODUCTIVE dairy cows have a high mineral requirement. A deficiency can cause lowered milk production and poor health may result if it is not corrected.

Can Heifers Be Fed Too Well?, Laurence C. Snook

Journal of the Department of Agriculture, Western Australia, Series 4

DURING recent years, emphasis has been given to the results of experiments conducted overseas, which appear to show that when heifers are generously fed, this reduces their ability to produce milk in later life.

As a result, some dairymen now believe that heifer calves should be kept lean rather than in prime condition.

It has become common to hear statements to the effect that generous feeding encourages calves to become "beefy," at the expense of the milk-producing attributes which are essential in a dairy cow.