University of Alberta

Calf Conference 2016

A conference dedicated to feeding, growth, health and

management of pre-weaned calves

Dairy Research and Technology Centre

Edmonton Research Station

June 8, 2016

Calf Conference 2016

Program

10:00am – 10:15am

Registration & Coffee

10:15am – 11:15am

Session A

Session B

Guided facility tour and

student posters

Workshop on Automated Calf

Feeders – Mr. Jan Ziemerink

11:15am – 12:00pm

Session A

Session B

Workshop on Automated Calf

Feeders – Mr. Jan Ziemerink

Guided facility tour and

student posters

12:00pm – 12:45pm

Lunch

12:45pm – 12:50pm

Welcome – Dr. Masahito Oba

12:50pm – 1:40pm

Practical aspects of automated calf feeding and health related

issues with automated feeding – Dr. Bob James

1:40pm – 2:30pm

Early life nutrition for growth, health and future production –

Dr. Jim Drackley

2:30pm – 3:10pm

Dietary factors influencing calf gut development – Dr. Michael

Steele

3:10pm- 3:15pm

Closing remarks – Dr. Divakar Ambrose

Table of Contents

Research Overview

DRTC Research Program

Student Abstracts

Conference Presentations

How to manage automatic calf feeders successfully

Mr. Jan Ziemerink

Practical aspects of automated calf feeding and health related issues with automated

feeding

Dr, Bob James

Early life nutrition for growth, health, and future production

Dr. James Drackley

Weaning biology and strategies

Dr. Michael Steele

Research Program

Research at the Dairy Research and Technology Centre is focused on three strategic

priorities: 1) improving longevity of cows; 2) enhancing the efficiency of milk production

and conversion of forages, cereals and oilseeds to milk and meat in an environmentally

sustainable manner; 3) understanding the biology of gut development and early-life

nutrition and their impact on the animals outcomes later in life. There is a particular

emphasis on the influence of nutrition and physiology on gene expression in the gut, and

reproductive system. Studies in digestive physiology are targeted at maximizing nutrient

delivery to the intestine and mammary gland through the manipulation of ruminal

fermentation to optimize forage and grain digestion plus microbial protein synthesis.

Reproductive physiology research is focused on understanding the causes of subfertility

in dairy cows and developing applied solutions to improve reproductive performance.

Gut physiology is focused on the neonate and how feeding regimes influence the

development and health of the animal. An increased understanding of the reproductive

tract and gastrointestinal tract, liver, adipose tissue, and skeletal muscle is a prerequisite

to future progress in extending cow longevity, and enhancing the efficiency of milk

synthesis and its nutritional quality for humans.

Researchers: Dr. Divakar Ambrose [Reproductive Physiology & Management]

Dr. Burim Ametaj [Health & Immunology]

Dr. Clover Bench [Animal Behaviour]

Dr. Leluo Guan [Functional Genomics and Microbiology]

Dr. Masahito Oba [Nutrition & Feed Utilization]

Dr. Michael Steele [Calf Nutrition & Molecular Physiology]

Dr. Zhiquan Wang [Quantitative Genomics]

We acknowledge the support from the following agencies supporting work at the DRTC:

Alberta Innovates BioSolutions (AI-Bio), Alberta Agriculture and Forestry, Alberta

Livestock and Meat Agency (ALMA), Alberta Milk, Animal InfraMetrics Inc., BC Dairy

Association, Dairy Cattle Genetics Research and Development (DairyGen) of Canadian

Dairy Network Genome Canada, Dairy Farmers of Manitoba, Diamond V, DSM

Nutritional Products, Ltd., Grober Animal Nutrition, Growing Forward 2, InterAg (NZ),

Lallemand, Natural Sciences and Engineering Research Council (NSERC), Sask Milk,

Trouw Nutrition, WestGen.

The Dairy Research and Technology Center (DRTC) is an integral

part of the Dairy Research and Extension Consortium of Alberta

(DRECA), an agreement among Alberta Milk, the University of

Alberta, Alberta Agriculture and Forestry and the University of

Calgary. Our mission is to enhance the growth and sustainability of

Canada’s Dairy Industry through quality research, teaching and

extension.

Research Facilities:

DRTC is a 146-cow tie-stall facility where cows can be fed individually. Milk production

and health data are recorded electronically. Forages fed to the cattle include silage grown

at the 500 acre Edmonton Research Station and purchased hay. Experiments include both

intensive metabolic research as well as the integration of this fundamental research in

applied production studies. Biological samples are transported to the Agriculture Forestry

Centre (North Campus) for analysis.

Dairy Research and Technology Centre:

Manager: Harold Lehman 780-492-7691

Full time management and operations staff 6

Cows milked 138

Daily average milk production (kg/cow/day)

- Fat (%)

- Protein (%)

38

3.8

3.2

Tons of cereal silage harvested at the Edmonton Research Station last

year (2015)

2188

Percent of the cows registered with Holstein Canada 100%

Hours for 2 people on the morning milking/feeding shift 3:00-11:00

Hours for 2 people on the afternoon milking/feeding shift 10:00-6:00

Hours for 1 person day shift 6:00-2:00

Stalls in the new barn, milking barn

Stalls in the old barn, dry cow stalls

146

19

Current index of milk, fat and protein production (BCA) 269-246-269

Number of ingredients, batches and recipes available in the TMR feed

mixing system

13-10-40

Kg of TMR fed to high producing cows (dry matter basis) 25

Kg of TMR fed to the low producing cows (dry matter basis) 21

Assessment of ovarian function through in-line milk progesterone analysis

postpartum, and insemination outcomes in dairy cows.

Bruinjé, T.C.1, Gobikrushanth, M.

1, Ambrose, D.J.

1,2

1Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton,

AB; 2Livestock Research Branch, Alberta Agriculture and Forestry, Edmonton, AB Canada.

tcbruinje@ualberta.ca; dambrose@ualberta.ca

Poor reproductive efficiency of lactating dairy cows is a well-known challenge to the dairy

industry. The early onset of ovulation and luteal activity after calving improves fertility but

abnormalities in ovarian function during this period are poorly understood. Two studies were

conducted to evaluate if luteal activity and progesterone (P4) concentrations in milk are

associated with the success of artificial insemination (AI). Towards this end, milk P4 data

collected at set intervals starting 20 d postpartum, through in-line milk analysis (Herd Navigator,

Delaval Inc), were assessed from two dairy farms in Alberta. In the first study, 785 Holstein

cows had their luteal activity (LA) estimated based on P4 > 5ng/mL. Cows that initiated LA at ≤

35d and >35d postpartum were considered to have ovulated early (Early-Ov) and late (Late-Ov),

respectively. Luteal activity until 1st AI, lasting 7 to 19 d was defined as normal and LA lasting

<7d or >19d as abnormal. From calving to 1stAI, luteal phases were classified as at least one

normal LA (1NormLA), at least two normal LA (2NormLA), at least one abnormal LA

(1AbnLA) and at least two LA, whether normal or abnormal (2TotLA). Outcomes of 1st and 2

nd

AI were evaluated. In the second study, 605 AI events that had a confirmed luteolysis (P4

declined to < 5ng/mL preceding AI) and a confirmed ovulation (P4 increased to > 5ng/mL after

AI) were evaluated for P4 concentrations. The day of luteolysis was d-2 and AI occurred on d0.

Progesterone concentrations on d-2, 5, 10, 14, and maximum P4 (Peak) within 21d (17 ± 2d)

were evaluated, in addition to the rate of daily change in P4 (𝑒. 𝑔.𝑑0+𝑑5

5). Outcome of AI was

considered as pregnant (LA >45d), open (LA ≤19d), or embryo loss (LA >20d but ≤45d).

Statistical analyses were performed by mixed-effects logistic regression (GLMER) of R (Study

1) and MIXED procedures of SAS (Study 2).

Overall, 71% of the cows had 1NormLA, 28% had 2NormLA, 51% had 1AbnLA and 56% had

2TotLA in the first study. The probability of pregnancy following 1st AI was increased in cows

that had 1NormLA (odds ratio (OR): 3.21, P=0.001), 2NormLA (OR: 1.63, P<0.03) and 2TotLA

(OR: 2.31, P<0.01) and in primiparous cows comparing to multiparous cows (OR: 1.56, P<0.01).

The probability of pregnancy following 2nd

AI was higher in cows that had 2NormLA (OR: 1.57,

P<0.05) and 2TotLA (OR: 1.80, P<0.01). Cows that had 1AbnLA had lower chances of

pregnancy (OR: 0.66, P=0.01) and tended to have more embryo losses following 2nd

AI (55%,

P=0.08). Multiparous cows were at a higher risk of Late-Ov (32.58%, P=0.04), while Early-Ov

cows had a lower risk of embryo loss following 2nd

AI (OR: 0.70, P=0.05). In the second study,

cows that became pregnant tended (P=0.10) to have lower P4 at the day of luteolysis (d-2) than

cows that remained open. Pregnant cows had greater P4 than open cows at d10 and d14; they

also had higher Peak P4, and greater rates of daily increase from d-2 to 14, d-2 to Peak, d5 to 10,

d5 to 14 and d5 to Peak. Primiparous cows had greater P4 and greater rate of daily increase in P4

than multiparous cows. Mean P4 concentrations and rate of daily increase in P4 are reported in

Tables 1 and 2, respectively.

Take home messages: An early onset of ovulation and luteal activity postpartum and an

increased frequency of normal luteal activities until first AI increase the probability of

pregnancy. Milk P4 concentration during the post-ovulatory period following AI, and the rate of

P4 increase after ovulation, is greater in cows that conceive, regardless of whether or not

pregnancy is sustained beyond 20 days after ovulation.

Table 1: Mean milk progesterone concentrations (ng/mL) relative to day of luteolysis by insemination outcomes and parity

Variables d-2 (n=599) d5 (n=592) d10 (n=576) d14 (n=538) Peak (n=605)

Insemination outcomes

Pregnant 3.3±0.12 3.9±0.9 9.6±1.5* 18.3±1.9* 23.4±1.3*

Open 3.4±0.14* 3.8±0.9 8.3±1.5 16.7±1.8 20.3±1.3

P-value 0.10 0.56 <0.001 <0.01 <0.001

Parity

Primiparous 3.5±0.1 4.8±0.3 10.8±0.6 19.7±0.7 23.6±1.2

Multiparous 3.3±0.1 3.0±0.3 7.7±0.5 16.0±0.6 21.2±1.1

P-value <0.03 <0.03 <0.001 <0.001 <0.001

*P-value did not differ from embryo loss group

Table 2: Rate of daily increase (ng/mL/day) in P4 relative to day of luteolysis by insemination outcomes and parity

Variables d-2 to 5

(n=592)

d-2 to 10

(n=558)

d-2 to 14

(n=538)

d-2 to Peak

(n=605)

d5 to 10

(n=568)

d5 to 14

(n=529)

d5 to Peak

(n=592)

d10 to 14

(n=517)

d10 to Peak

(n=569)

d14 to Peak

(n=511)

AI outcomes

Pregnant 0.08±0.13 0.3±0.03 0.9±0.1* 1.0±0.07* 1.1±0.1* 1.6±0.1* 1.5±0.07* 2.2±0.1 1.5±0.09 1.2±0.2

Open 0.04±0.13 0.4±0.02 0.8±0.1 0.9±0.07 0.9±0.1 1.4±0.1 1.3±0.07 2.0±0.1 1.6±0.06 1.2±0.2

P-value 0.29 0.43 <0.002 <0.001 <0.001 <0.01 <0.01 0.22 0.14 0.79

Parity

Primiparous 0.2±0.05 0.3±0.03 1.0±0.04 1.0±0.04 1.2±0.09 1.6±0.07 1.4±0.07 2.2±0.11 1.6±0.09 1.0±0.09

Multiparous -0.1±0.05 0.4±0.03 0.8±0.04 0.9±0.04 0.9±0.08 1.4±0.07 1.3±0.06 2.0±0.09 1.6±0.07 1.3±0.06

P-value <0.001 0.55 <0.001 <0.001 <0.001 <0.001 0.05 0.13 0.76 <0.001

*P-value did not differ from embryo loss group

Characterizing novel fertility traits and their association with reproductive

performance indicators in dairy cattle

Gobikrushanth, M.1, Dutra, P.A.

1, Felton, C.A.

2, Bruinjé, T.C.

1, Colazo, M.G.

2, Butler, S.T.

3, and

Ambrose, D.J.1,2

1Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton,

AB, Canada T6G 2P5; 2Livestock Research Branch, Alberta Agriculture and Forestry,

Edmonton, AB, Canada T6H 5T6; 3

Teagasc, Animal & Grassland Research and Innovation

Centre, Moorepark, Fermoy, Co Cork, Ireland.

Phenotypes that are relevant to fertility in dairy cattle could be categorized into traditional and

novel fertility traits. The most commonly used traditional traits are first service conception rate

and days open. Recent studies investigated the association between novel fertility traits such as

anti-Müllerian hormone (AMH) concentrations and reproductive outcomes in dairy cattle. The

objectives of this study were to: (1) characterize variations in insulin like growth factor-I (IGF-I),

luteinizing hormone (LH), estradiol, AMH, antral follicle count (AFC) and endometrial thickness

within a population of dairy cows, and (2) determine repeatability for LH, AMH and AFC (3)

explore associations between each of the aforementioned novel fertility traits with first service

conception rate, number of services, days open and pregnancy by 150 and 250 days in milk

(DIM). One hundred lactating Holstein cows from the Dairy Research Technology Centre

(DRTC) at the University of Alberta were enrolled in this pilot study. Blood samples were

collected approximately at (I) 7 DIM to determine plasma concentrations of IGF-I and (II) 14

and 75 DIM to determine plasma concentrations of AMH. All cows received one injection of

PGF2α starting approximately at 52 DIM (cloprostenol, 500 µg, d 0) followed by GnRH

(gonadorelin, 100 µg, d 3; Presynch) on 55 DIM and were subjected to an Ovsynch protocol at

62 DIM, with timed-AI (TAI) occurring at 72 DIM. Blood samples were collected immediately

before (0 h) and 2 h after the GnRH injection of Presynch and the second GnRH injection of

Ovsynch to determine plasma LH concentrations. Another set of blood samples was collected 0h

before the second GnRH injection of the Ovsynch protocol to determine plasma concentrations

of estradiol. Transrectal ultrasonography was used to determine (I) endometrial thickness

approximately at 71 DIM, after the second GnRH of Ovsynch, (II) AFC at both 14 and 73 DIM

and (III) to confirm pregnancy at 30 days post insemination. Data were analyzed using MEANS,

MIXED and CORR procedure of SAS. Later, all 100 cows were ranked based on the

measurements for each fertility trait, from highest to lowest, and those in the top (n=33) and

bottom (n=33) thirds were classified into HIGH- and LOW FERT groups within each trait. The

association between binomial outcomes and FERT groups were determined using the GLIMMIX

procedure and pregnancy by 150 and 250 DIM were determined using LIFETEST procedure of

SAS. The variabilities for IGF-I, LH, estradiol, AMH, AFC and endometrial thickness were 65,

67, 79, 64, 43 and 15%, respectively. The repeatability was 19% for plasma LH determined at

Presynch and Ovsynch (P=0.06), and it was 75 and 41% for plasma concentrations of AMH and

AFC determined at 14 and 73 DIM (P<0.05), respectively. The proportion of cows that ovulated

in response to the last GnRH of Ovsynch was significantly higher for cows categorized as HIGH

FERT, based on plasma concentration of LH determined during Ovsynch, than LOW FERT

(97.0 vs 78.8%; P=0.03). The first service conception rate tended to be higher for cows that were

categorized as HIGH FERT based on plasma concentrations of LH (42.4 vs 24.2%; P=0.06),

estradiol (45.4 vs 24.2%; P=0.10) and AMH (45.4 vs 24.2%; P=0.08) than those categorized as

LOW-FERT. Furthermore, cows categorized as HIGH FERT based on plasma concentrations of

estradiol and AMH tended to have fewer services per conception (2.2±0.2 vs 2.7±0.2) than those

categorized as LOW FERT. Similarly, cows that were categorized as HIGH FERT based on

plasma concentrations of AMH and estradiol had fewer days open than those categorized into

LOW FERT (133.0±11.6 vs 170.6±12.1; P=0.03, and 138.6±11.6 vs 171.5±11.7; P=0.06,

respectively). The proportion of cows that were pregnant by 150 DIM was numerically greater

for HIGH FERT cows than LOW FERT cows when they were categorized based on plasma

estradiol (54.5 vs 42.4%; P=0.19) and AMH (54.5 vs 42.4%; P=0.19) concentrations. On the

other hand, the proportion of cows pregnant by 250 DIM was significantly higher for HIGH

FERT than LOW FERT based on plasma concentrations of estradiol (97.0 vs 84.8%; P=0.02)

and AMH (97.0 vs 84.8%; P=0.02). In summary, the plasma concentrations of IGF-I, LH,

estradiol and AMH were highly variable and associated with the studied reproductive

performance indicators. However, the AFC and endometrial thickness had moderate to low

variability and were not associated with any of the reproductive performance indicators.

Identification of predictive biomarkers for 6 periparturient diseases of

transition dairy cows by metabolomics

G. Zhang, E. Dervishi, S. M. Dunn, and B. N. Ametaj*

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton,

AB, Canada T6G 2P5

Corresponding author: burim.ametaj@ualberta.ca

Transition dairy cows are commonly afflicted by periparturient diseases like ketosis, milk fever

(MF), lameness, metritis, subclinical mastitis (SCM), and retained placenta (RP). Mechanistic

details and etiopathology of the six aforementioned diseases are not well known yet. It is of

importance to investigate alterations of blood, urine, and milk metabolome before, during, and

after clinical appearance of these diseases in dairy cows. Early predictive biomarkers of these

diseases could help veterinarians and dairy producers to make early preventive strategies, which

could help to lower the animal sufferings, the incidence rates, and related economic losses. The

objective of this study was to identify predictive biomarkers for ketosis, MF, lameness, metritis,

SCM, and RP in transition dairy cows by using metabolomics-base technologies including

nuclear magnetic resonance (NMR) and mass spectrometry (MS). Blood, urine, and milk

samples were collected from 100 multiparous Holstein dairy cows. Twenty healthy controls

(CON) and 6 cows with clinical signs of each disease at -8, -4, disease, +4, and +8 wks relative

to parturition were selected. Direct injection and liquid chromatography and tandem mass

spectrometry (DI/LC-MS/MS), gas chromatography - mass spectrometry (GC-MS), inductively

coupled plasma mass spectrometry (ICP-MS) and NMR were utilized for quantification of

metabolites. Univariate and multivariate data analyses were conducted by MetaboAnalyst at each

time point to examine alterations of metabolites throughout the progress of the disease. Results

showed that alterations of metabolites such as amino acids, carbohydrates, lipids, organic acids,

ketones, amines, and minerals preceded occurrence of 6 diseases. Numerous metabolic pathways

were perturbed in sick cows during the onset and progression of disease. Predictive biomarker

models with high sensitivity and specificity were developed for each disease. By taking one drop

of blood or urine dairy producers in the near future can identify cows that might be affected by

periparturient diseases 4-8 wks before appearance of diseases and take preventive measurements

to avoid the disease occurrence and related economic and welfare issues. An ounce of prevention

is worth a pound of cure.

Feeding of heat-treated colostrum promotes bifidobacteria and obstructs

E. coli colonization in the small intestine of neonatal calves

Nilusha Malmuthuge, Yanhong Chen, Guanxiang Liang, Le Luo Guan*

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton,

Canada. T6G 2P5

*lguan@ualberta.ca

Although the feeding of heat-treated colostrum has been reported to decrease neonatal calf

diarrhea, the mechanisms behind this have not been well described. The present study

investigated the impact of heat-treated colostrum feeding on the bacterial colonization in calf

small intestine, within the first 12 hours of life. Newborn Holstein bull calves (n=32) were

separated from dams soon after birth and assigned to one of the three colostrum feeding

methods; fresh colostrum (FC, n=12), heat-treated colostrum (HC, n=12) and control (no

colostrum- NC, n=8). Colostrum feeding was completed within an hour after birth to FC and HC

calves as a single dosage (2 L/calf), while NC calves did not receive any diet during the

experimental period. Small intestinal samples (tissue and contents) were collected from three

locations of the small intestine (proximal jejunum, distal jejunum and ileum) at 6 and 12 hours

after birth, following euthanasia. Quantification of bacterial densities (total bacteria,

bifidobacteria, lactobacilli, E. coli) revealed that the feeding of colostrum soon after birth

increased total bacteria density (FC - 1.4±0.7×1010

16S rRNA copy/g of sample, HC -

9.8±3.4×109 16S rRNA copy/g of sample) in calf gut within the first 12 hours compared to NC

(5.3±2.2×108 16S rRNA copy/g of sample). In contrast, the prevalence of lactobacilli was lower

in HC (0.007±0.004%) and FC (0.014±0.008%), comparing to NC (0.031±0.015%). Remarkable

changes in the prevalence of small intestinal tissue-attached bifidobacteria were observed with

the feeding of HC soon after birth, but not that in gut contents. The prevalence of bifidobacteria

was 3.2-fold and 5.2-fold higher in HC (28.6±10.3%) than FC (8.9±2.5%) and NC (5.5±1.5%),

respectively, at 6 hours. The feeding of FC increased the prevalence of tissue-attached

bifidobacteria gradually, reaching the numbers similar to that of HC at 12 hours. Besides, the

feeding of HC decreased the density of E. coli in both tissue and content communities, within the

first 12 hours of life. For example, the prevalence of E. coli in the calf small intestinal tissue was

159-fold and 18-fold higher in NC and FC, respectively at 12 hours compared to that of HC. In

conclusion, the present study reports that the feeding of HC soon after birth enhances the

colonization of bifidobacteria, but diminishes E. coli on small intestinal tissue immediately

postpartum compared to that of FC and NC. Thus, the increase in beneficial bacteria

(bifidobacteria) and decrease in potential pathogens (E. coli) may prevent the decrease diarrhea

in calves fed with heat-treated colostrum.

Characterization of bacterial colonization in hindgut of pre-weaning dairy

calves using quantitative real time-PCR

Song, Y.1, Malmuthuge, N., Steele, M., Guan, L.L.

2

1Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton,

AB，T6G 2P5, Canada.

Email: ysong3@ualberta.ca

The mammalian hindgut is populated with a dynamic bacterial population, which has been

suggested to associate with immune system development and host health. However, prior to this

experiment, the microbial composition in the hindgut of pre-weaned calves had not been studied.

This study aimed to investigate population dynamics of total bacteria, Bifidobacterium, E. coli,

Faecalibacterium prausnitzii and Clostridium cluster XIVa in calf hindgut during preweaning

period. Tissues and digesta samples were collected from the cecum, colon and rectum of 18

Holstein bull calves at day 7 (n=6), day 21 (n=6), and day 42 (n=6), following euthanasia.

Quantitative real time-PCR was used to estimate the copy number of 16S rRNA gene of total

bacteria and selected bacterial groups associated with tissue and digesta. The density of large

intestinal digesta-associated E. coli exhibited two and four-fold higher copy numbers on day 7

compared to that of day 21, and day 42, respectively. Similarly, the density of E. coli attached to

cecum and colon tissue at day 7 was higher compared to day 21, and day 42. In contrast, the

densities of butyrate producing beneficial bacteria Clostridium cluster XIVa and F. prausnitzii in

colon tissue were highest on day 21. This study revealed that the prevalence of bacteria

colonized in the large intestinal communities varied depending on calf age. Thus, detailed

understanding of microbial colonization and their functions in the large intestine requires future

studies based on different sample type and regions.

Feeding More Often Can Reduce the Severity of SARA and Increase Milk Fat

Yield

K. Macmillan and M. Oba

Department of Agriculture, Food and Nutritional Science, University of Alberta,

Edmonton, AB T6G 2P5, Canada

Previous research reported that cows fed the same diet have a large variation in rumen pH, and

that cows at a higher risk for developing sub-acute ruminal acidosis (SARA) spend more time on

eating following feed delivery, which is also known as slug feeding. The objective of this study

was to determine the effects of feeding frequency on productivity of dairy cows and the severity

of SARA in higher-risk cows. Eight ruminally cannulated lactating cows were fed a high-grain

TMR (35% forage and 65% concentrate) to induce SARA. The study consisted of 2 periods of

21 d each, and half the cows were fed once daily at 0800 h and the other half were fed 3 times

daily at 0800, 1500, and 2200 h in the first period, and cows were assigned to the other treatment

in the second period. In each period, after 16-d of treatment adaptation, ruminal pH was

measured every 30 s over 72 h. Cows were categorized as higher or lower risk to SARA based

on an acidosis index (area of pH < 5.8/ kg DMI), which indicates the severity of SARA

normalized for intake, measured during the 1x treatment for all cows. Four cows had an acidosis

index above 1.0 (3.47 ± 0.36 pH × min/kg) and four cows had an index below 1.0 (0.19 ± 0.33

pH × min/kg), and were categorized as higher-risk and lower-risk cows, respectively. Feeding

behaviour (eating, ruminating, drinking, or lying) was recorded every 5-min over the same 72-h,

and each behaviour was assumed to last 5-min. Behaviour data was summarized in 3 time

periods (0800-1500 h, 1500-2200 h, and 2200-0800 h) to determine when cows spent most of

their time eating. The 3x feeding reduced eating time between 0800-1500 h (99 vs. 145 min; P <

0.01) and increased eating time between 2200-0800 h (76 vs. 43 min; P < 0.01) for both

categories of cows. For the higher-risk cows, 3x feeding reduced severity of SARA (the area

below pH 5.8; 51 vs. 98 pH × min/d; P = 0.05) while it did not affect rumen pH for the lower-

risk cows. There was no difference in milk yield, however 3x feeding increased milk fat yield

(1.22 vs 1.08 kg/d, P < 0.05) for both categories of cows.

Implications: Increased feeding frequency may reduce slug feeding and increase the distribution

of eating throughout the day, leading to reduced severity of SARA in higher risk cows. Our

results suggest that frequent feeding may be a beneficial approach to reduce SARA and increase

milk fat yield.

Feeding Frequency Did Not Affect Hunger Behaviour of Calves on a High

Plane of Nutrition

K. Macmillan, J. McPherson, C. Bench, M. Oba, and M. Steele

Department of Agriculture, Food and Nutritional Science, University of Alberta,

Edmonton, AB T6G 2P5, Canada

Feeding a high plane of nutrition has been shown to decrease hunger-related behaviours in pre-

weaned dairy calves. However, it is not known if feeding a high plane of nutrition at different

feeding frequencies and meal sizes also affects hunger in calves. Ten male Holstein calves were

housed in 1 pen with an automated milk feeder and fed 8L of milk replacer daily. Five calves

were fed 2L 4× per day and the other 5 were fed 4L 2× per day. Behaviour observations occurred

on the same day each week from age 4 – 9 weeks, for a total of 12 hours split into morning (0800

to 1400 h) and evening (1800 to 2400 h) observation periods. In each observation period,

behaviours of each calf were recorded for 1.5 h before and after individual meal times. Four

behaviours (non-nutritive sucking of the feeder nipple, cross sucking, lying and feeder

occupancy) were video recorded continuously with each observation (AM or PM) analyzed

separately for total and mean durations (minutes) as well as frequencies. The automated feeder

recorded daily visits, both rewarded and unrewarded. No treatment effect was observed for lying,

cross sucking, and non-nutritive sucking behaviour (P > 0.05). There was a tendency for 2×

calves to occupy the feeder for a longer time (total duration) than 4× calves (8.30 vs. 6.35 min; P

= 0.07). A significant effect on frequency of feeder occupancy was also observed, where 2×

calves occupied the feeder more often (3.58 vs. 2.44; P < 0.01). Calves fed twice daily also had

an increased number of unrewarded visits to the feeder, both during the observation period (2.82

vs. 1.89; P < 0.05) and for the entire day (17.4 vs. 13.9; P < 0.05).

Implications: In the current study, only visits to the feeder were significantly different between

2× and 4× feeding frequencies. As there were no other differences in hunger-related behaviour in

this study we cannot conclude that 2× calves were hungrier than 4× calves. Our results suggest

that feeding frequency does not affect extent of hunger in pre-weaned calves on a high plane of

nutrition.

Evaluation of whole-crop barley cultivars in western Canada for in vitro fiber

digestibility

M. Oba1, 4

,W. Shi1, V. S. Baron

2, and P. E. Juskiw

3

1Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton,

T6G 2P5, Canada. 2Lacombe Research Centre, Agriculture and Agri-Food Canada, Lacombe, Alberta, T4L 1W1,

Canada

3Field Crop Development Centre, Alberta Agriculture and Forestry, Lacombe, Alberta, T4L W8,

Canada. 4Corresponding Author: Masahito Oba. E-mail: moba@ualberta.ca

High quality forages are able to optimize milk production and thus support the profitability of

dairy producer. Whole-crop barley silage has been widely used as a primaryforage source in

dairy farms in western Canada. However, its quality is highly variable and limited data exists for

effects of cultivars on forage quality. The objective of this study was to evaluate in vitro fiber

digestibility of selected whole-crop barley cultivars. Samples of eight barley cultivars (4

registered lines-‘AC Ranger’, ‘CDC Austenson’, ‘Gadsby’, ‘Vivar’; 4 additional lines-‘FB445’,

‘FB446’, ‘FB447’, ‘FB450’) were collected at 5 locations (Brandon, Hamiota, Lacombe, Roblin,

and Saskatoon) in three replicates in 2013 and 2014.Cultivar had significant effect on the in vitro

30-h fiber digestibility (NDFD). Among the eight cultivars, NDFD ranged from 41.5% to 53.5%,

and ‘Gadsby’(53.5%) had the highest NDFd30, followed by ‘FB450’ (51.7%), ‘AC

Ranger’(50.7%),‘FB446’ (50.5%), ‘CDC Austenson’(49.4%) and ‘Vivar’ (49.4%), ‘FB445’

(46.1%), and ‘FB447’ (41.5%). The NDFD was not different between year 2013 and 2014

(49.1% for 2013 vs. 49.2% for 2014). Starch content of whole-crop barley averaged at 13.2%,

and it was not affected by cultivars or years. As for neutral detergent fiber (NDF) content,

significant differencewas found among cultivars;‘CDC Austenson’ and ‘Gadsby’ (52.8 and

53.8%, respectively) had lower NDF content than ‘FB447’ and ‘FB450’(56.8 and 56.2%,

respectively). In addition, biomass yield averaged at 14,090 and 11,680DM kg/ha for 2013 and

2014, respectively, but it was not affected by cultivars.

Implications: Findings from this study suggest that a significant variation exists in NDF and

NDFD among barley cultivars grown under different environment, and ‘Gadsby’ had low NDF

and highest NDFD among barley cultivars evaluated in the current study.

Effects of plane of nutrition and age on glucose and insulin kinetics and

abomasal emptying in female Holstein Frisian dairy calves fed twice daily

J. A. R. MacPherson1, H. Berends

2, L. N. Neal

2, J. P. Cant

3, J. Martín-Tereso

2, and M. A.

Steele1,4

1Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton,

T6G 2P5, Canada. 2Trouw Nutrition R&D, P.O. Box 220, 5830 AE, Boxmeer, the Netherlands

3Department of Animal Biosciences, University of Guelph, Guelph, N1G 2W1, Canada.

4Corresponding Author: Michael A. Steele. Telephone: +1(519) 400-6556. Fax: +1(780) 492-

4265. E-mail: masteele@ualberta.ca

Current dairy calf nutrition research is focusing on feeding calves an elevated plane of pre-

weaning nutrition (~8 L milk replacer/day or 20% birth weight), over conventional feeding (~4 L

milk replacer/day or 10% birth weight). A common concern when feeding an elevated plane of

nutrition over two large meals (4 L) a day is that it has been hypothesized to decrease insulin

sensitivity. The objective of this study, was to investigate how pre-weaning plane of nutrition

and age can impact insulin and glucose kinetics, as well as abomasal emptying rate, in calves fed

twice a day. Twelve female Holstein-Frisian calves were randomly assigned to an elevated plane

of nutrition (HIGH; 8 L/d, 1.2 kg milk replacer/day; n = 6) or a low plane of nutrition (LOW; 4

L/d, 0.6 kg milk replacer/d; n = 6). All calves received 4 L of colostrum over two meals (1 and 6

hours after birth), then were directly transferred to their assigned feeding plans until they were

stepped-down from milk by 50% during week 7 and weaned on week 8. Milk replacer (24% CP,

18% CF) was fed at 150 g/L twice daily and all calves had ad libitum access to pelleted calf

starter, chopped wheat straw, and water. Jugular catheters were placed in calves at 4, 7, and 10

weeks of age to measure: 1) Pre-weaning postprandial plasma glucose and insulin response, as

well as abomasal emptying rates by adding acetaminophen (150 mg/kg BW0.75

) as a blood

marker to the morning milk replacer; 2) Pre- and post-weaning insulin response to high plasma

glucose levels by conducting a glucose tolerance test (GTT) consisting of an infusion of 540 mg

of glucose per kg of BW0.75

via the jugular catheter. Statistics were determined using SAS Proc

Mixed for repeated measures and any data not normally distributed was transformed

logarithmically. The postprandial plasma insulin was greater (P < 0.05) in HIGH calves

compared to LOW due to the larger meal size, however there was no difference in postprandial

glucose concentrations between treatments or across ages indicating adequate control of

glycaemia for both groups. This was further demonstrated by the abomasal emptying rate of the

milk replacer meal being slower (P < 0.05) in HIGH calves compared to LOW, indicating that

emptying rate is slowed when larger meal sizes are fed and may be used as a means to maintain

stable blood glucose levels. In addition, there were no differences in GTT kinetics (P > 0.05)

between the HIGH and LOW dairy calves across ages, indicating no decrease in insulin

sensitivity. Findings from this study suggest that feeding dairy calves a HIGH milk replacer diet

in two meals per day does not negatively affect glucose and insulin kinetics.

Effects of feeding frequency and age on glucose and insulin kinetics in

Holstein calves fed an elevated plane of milk replacer nutrition

J. A. R. MacPherson, J. Haisan, S. Pletts, and M. A. Steele1

Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton,

T6G 2P5, Canada. 1Corresponding Author: Michael/Steele; E-mail: masteele@ualberta.ca

There is evidence that feeding elevated planes of nutrition (~8 L milk replacer/day) in two large

meals per day disrupts metabolic and endocrine function, leading to a decrease in insulin

sensitivity and disturbed glucose metabolism in dairy calves. The objective of this study was to

investigate how feeding an elevated plane of milk replacer (MR) nutrition pre-weaning, at

different feeding frequencies, could influence glucose and insulin kinetics both pre- and post-

weaning. Ten male Holstein calves (42.2 kg ± 1.8 initial body weight) were blocked by body

weight and randomly assigned to 2 treatments whereby calves were offered 8 L of milk replacer

(150g/L; 26% CP, 18% CF) per day in two (2x; meal size 4 L) or four (4x; meal size 2 L)

feedings via an automated feeding system. Calves were gradually stepped down by 1 L MR/d

from week 7 until weaning on week 8 (0 L) and remained in the study until week 11. Water was

offered ad libitum while intakes of MR and starter (19% CP, 4.7% CF) were recorded daily and

body weight weekly. Blood samples were also collected weekly before the 10:00 am meal and 2

hours afterwards. Jugular catheters were placed on week 4, 7, and 10 of the study and remained

for ~72 hours for postprandial and glucose tolerance test (GTT) blood sample collection. The

GTT consisted on a glucose infusion via the jugular catheter at a concentration of 540 mg of

glucose per kg of BW0.75

. Statistics were determined using SAS Proc Mixed for repeated

measures and any data not normally distributed was transformed logarithmically. Calf final body

weights, starter intake, and metabolizable energy intake did not differ (P > 0.1) between

treatments. Postprandial insulin tended to differ (P = 0.09) by treatment across ages with 2x

calves having higher insulin concentrations compared to 4x due to the difference in meal sizes.

However, there where no differences (P > 0.1) between treatments and age for postprandial

glucose concentrations demonstrating similar glycemic control by both treatments. Weekly

plasma glucose and insulin concentrations taken before and after the 10:00 am meal decreased (P

< 0.1) overall as calves aged, indicating no impaired glucose and insulin kinetics with age.

Additionally, there was no interaction effect between treatments and age observed for any of the

measured parameters (time to maximum concentration, maximum concentration, area under the

curve (AUC240), basal concentration, or change in concentration) for the GTT, suggesting that

feeding frequency in this study had no effect on insulin sensitivity. These findings suggest that

feeding 8 L/d at a frequency of 2x or 4x are both viable feeding methods that do not compromise

insulin and glucose kinetics.

The effects of feeding a high- or low-plane of nutrition pre-weaning on growth

and starter intake of group-housed calves.

J. Haisan1, M. Oba

1, D. J. Ambrose

1, 2 and M. A. Steele

1

1Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton,

T6G 2P5, Canada 2Agriculture and Forestry, Government of Alberta, Edmonton, T6H 5T6

While positive effects on growth have been shown when calves are fed more milk, there is little

information on the impact of this feeding strategy on starter intake of group-housed calves fed

from an automated calf feeder. The objective of this experiment was to determine the effects of

milk level, when fed through an automated calf feeder, on starter intake of group housed calves.

Twenty-six female Holstein calves were fed four 2-L feedings of colostrum in the first 2 d after

birth before being offered pasteurized whole milk and randomly assigned to either a HIGH

(10L/d; n=12) or LOW (5L/d; n=14) plane of nutrition. All calves were allowed 2.5L of milk per

meal until d 48 when a 10-d weaning transition began, where milk was reduced by 10% per day,

resulting in all calves being weaned at d 58. Calf starter and water were provided ad libitum

starting on d 3 to d 70. Calves were housed in individual pens for the first 21 ± 3 d and fed using

the Calf Rail system before moving to a group pen where they were fed through an automated

calf feeder. Individual starter intake was measured via an automated system on a daily basis from

d 25 to 70, and weekly body weights (BW) were taken from birth to d 70. Blood samples were

taken in the first week of life and no differences were observed in serum protein (P = 0.95) or

immunoglobim concentration (P = 0.37) between treatments. Birthweight of calves was not

different between the treatment groups. Pre-weaning average daily gain was greater for HIGH

than LOW (0.90 vs. 0.65 kg/d; P <0.01), however no difference was seen post-weaning. Prior to

the weaning transition (d 42-48) starter intake was less in calves on the HIGH than LOW plane

of nutrition (569 vs. 1083 g/d, P<0.01, respectively). However, average starter intake over the

10-d weaning transition period was similar between both groups (P=0.27). Post-weaning (d 58-

70), starter intake was not different between HIGH versus LOW (3188 vs. 2723 g/d; P = 0.11).

These results indicate that feeding more milk pre-weaning may suppress starter intake, however,

the effect is not carried post-weaning and growth is not compromised.