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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.
[email protected]; [email protected]
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: [email protected]
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
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: [email protected]
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: [email protected]
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: [email protected]
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: [email protected]
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.