the effect of body condition score change 15 days prior to calving on lactation curve and production...

The effect of body condition score change 15 days prior to calving on lactation curve and production parameters in grazing dairy cows in Ireland

M.R. Sheehy*1,2, F.J. Mulligan1, M.A. Crowe1, S.P.M. Aungier1, and A.G. Fahey3

1School of Veterinary Medicine, University College Dublin, Ireland 2Devenish Nutrition Ltd., Belfast, Northern Ireland

3 School of Agriculture & Food Science, University College Dublin, Ireland

Introduction

• The transition period extends from 3 weeks before to 3 weeks after calving

• It is the most critical period of the lactation– Nutrition and energy balance– Production–Metabolic Health Issues

• Economic and welfare implications

Introduction

INPUTS OUTPUTS

ENERGY BALANCE

Energy balance can be assessed during transition by body condition score change

Previous StudiesHave been concerned with the implications of cows reaching target BCS at various stages of lactation

However, little is known about the effect of BCS change immediately pre-calving on the lactation characteristics of the

dairy cow

Stage Body Condition ScoreDry off 2.75 – 3.00 Calving 3.00 – 3.25 Breeding Minimum 2.75150 to 250 days in milk 2.75 – 3.00

(Mulligan, 2012)

Objective

To determine if change in BCS in the last 15 days before calving has an affect on subsequent lactation characteristics

Materials and Methods• Commercial Irish dairy farm

• 98 Spring-calving Holstein-Friesian cows

305 day yields

Milk (kg) 9125Fat (kg) 331Protein (kg) 298Fat (%) 3.62Protein (%) 3.27SCC (‘000 per ml) 308Calving Interval (days) 445

Treatments

MAIN LOSSParity 1 N 23 8

∆ BCS 0 -0.28

Parity 2 N 12 15∆ BCS 0 -0.25

Parity 3 N 20 20∆ BCS 0 -0.32

MAIN – cows that maintained BCS 15 d prior to calving

LOSS – cows that lost BCS 15 d prior to calving

Body Condition Scoring

• 1 to 5 BCS scale (Edmonson et al., 1989)

• Same trained researcher every 2 weeks• Eliminate inter-observer variation

Dairy Cow BCS

Body Condition Score (BCS) Records Analysis

Milk Sampling

• Cows milked at 0700 and 1600 h daily

• Milk was sampled every two weeks– Mid infrared spectrophotometry – Milk, fat, and protein yields– Fat, protein, and lactose concentrations

• Energy Corrected Milk (KirchgeBner 1997)(Milk yield x 0.3246) + (Fat yield x 12.86) + (Prot yield x 7.04)

Lactation Curve Modelling

• Woods Incomplete Gamma Function (Woods, 1967)

• Non-linear function

• y(t) = atbe-ct

– t = time– a = estimate of initial milk yield– b= rate of increase until peak production– c = rate of decrease after peak production

Curve ShapeShape Parameter Curve Shape description

b c

C1 + - Standard lactation curve

C2 + + Continuous increase

C3 - - Continuous decrease

C4 - + Inverted lactation curve

a

b

c

Lactation Curve Characteristics

• Initial milk yield (a)

• Rate of increase to peak yield (b)

• Rate of decline after peak yield (c)

• Lactation persistency (p)

• Time at which peak yield is attained (Tm)

• Peak yield (Ym)

Statistical Analysis

Yijkl = BCS + Ci + Tj + Pk + TPjk + TCij + PCki+ eijkl Yijkl = lactation curve characteristics of the lth cow in ith calving month,

the jth treatment, and the kth parity, BCS = covariate of BCS on d -15Ci = the ith calving month of Jan, Feb, Mar, or Apr

Tj = the jth treatment of MAIN or LOSS

Pk = the kth parity of 1, 2, or ≥ 3

TPjk = the interaction of the jth treatment and the kth parity

TCij = the interaction of the jth treatment and the ith calving month

PCij = the interaction of the kh parity and the ith calving month

eijkl = random residual error

Results: Milk (kg)MAIN LOSS Significance

Parity 1 Parity 2 Parity 3 Parity 1 Parity 2 Parity 3 T P T × P

Milk

a 20.75(2.34)

22.53(2.75)

24.54(2.23)

16.18(3.53)

17.79(2.67)

21.04(2.16)

<0.05 NS NS

c -0.005Aa

(0.0005)-0.006(0.0004)

-0.006B

(0.0004)-0.007b

(0.0007)-0.006(0.0005)

-0.007(0.0005)

<0.10 NS NS

tm 56.24ACc (4.35)

45.79B (4.20)

43.51D (3.63)

48.99d (6.04)

46.72 (4.07)

44.47 (3.12)

<0.10 NS NS

Ym 35.82CE (1.21)

40.33D (1.42)

46.02F (1.24)

34.06E (1.74)

39.77EF (1.31)

44.36F (1.06)

NS <0.01 NS

Results: Fat (kg)MAIN LOSS Significance

Parity 1 Parity 2 Parity 3 Parity 1 Parity 2 Parity 3 T P T × P

Fat kg

P 6.62a (0.10)

6.41 (0.19)

6.42 (0.14)

6.15b (0.23)

6.44 (0.16)

6.33 (0.14)

NS NS NS

tm 42.66 (6.12)

45.72 (8.11)

53.38c (5.78)

40.71 (12.12)

40.70 (6.99)

34.79d (5.87)

NS NS NS

Ym 1.11E

(0.04)1.34F

(0.06)1.33F (0.04)

1.25 (0.09)

1.24A (0.05)

1.37B

(0.05)NS <0.05 NS

305 Day Production YieldsMAIN LOSS Significance

Parity 1 Parity 2 Parity 3 Parity 1 Parity 2 Parity 3 T P T × P

Milk (kg)

7573.51CE (240.35)

8352.29DE (284.42)

9329.21F (232.48)

6873.65E (362.43)

8445.86AF (276.44)

9126.74BF (224.38)

NS <0.01 NS

Fat (kg)

238.89E (16.24)

276.53C (20.58)

330.65DF (16.48)

248.65 (25.59)

272.14 (19.10)

298.88 (16.11)

NS <0.01 NS

Prot(kg)

238.03E (6.69)

269.32CF (7.92)

294.40DF (6.47)

218.80E (10.09)

266.03EF (7.69)

294.21F (6.25)

NS <0.10 NS

SCC (,000)

108.57A (63.41)

157.62 (58.62)

252.60aB (48.37)

164.89C (88.61)

247.99 (59.04)

369.12bD (45.65)

<0.05 <0.05 NS

Summary

• Overall– MAIN significantly greater initial milk yield (a) than LOSS– MAIN significantly lower SCC than loss– LOSS cows tended to reach peak milk yield sooner– LOSS cows tended to have a faster rate of decline post peak

• Parity 1– MAIN took longer to reach peak milk yield– MAIN lower rate of decline post peak milk yield– MAIN more persistent fat yield curve

• Parity 3– MAIN took longer to reach peak fat yield– MAIN had lower somatic cell count

Conclusion

• Ideal lactation curve– Cows that reach peak milk and component yields

slowly and remain persistent– More beneficial to the cows’ metabolic and health

status (Solkner and Funchs, 1987)

• Therefore MAIN parity 1 and parity 3 cows had improved lactation curve characteristics compared to LOSS parity 1 and parity 3

Thank you for your attention

The effect of body condition score change 15 days prior to calving on lactation curve and production parameters in grazing dairy cows in Ireland

M.R. Sheehy*1,2, F.J. Mulligan1, M.A. Crowe1, S.P.M. Aungier1, and A.G. Fahey3

1School of Veterinary Medicine, University College Dublin, Ireland 2Devenish Nutrition Ltd., Belfast, Northern Ireland

3 School of Agriculture & Food Science, University College Dublin, Ireland

Lactation Curve Characteristics• Initial milk yield (a)

• Rate of increase to peak yield (b)

• Rate of decline after peak yield (c)

• Lactation persistency (p)– p = -(b+1)*ln(c)

• Time at which peak yield is attained (Tm)– Tm =b/c

• Peak yield (Ym)– Ym = a(b/c)be-b