Reproductive Management of Dairy Heifers

Transcription

1 Reproductive Management of Dairy Heifers Associate Professor Department of Dairy Science University of Wisconsin - Madison Heifer Development Age at 1 st Calving = 24 mo Birth 1 st Calving 2 nd Calving Calf Heifer Primiparous Multiparous Nonlactating 1 st Lactation 2 nd Lactation Lactation Age at 1 st calving: 24 mo Puberty (9 mo) Conception (14 mo) Age (months) Optimal age at calving = mo Heifer Development Age at first calving = 32 mo Birth 1 st Calving 2 nd Calving Calf Heifer Primiparous Lactation Nonlactating Age at 1 st $36 to $72 calving: Extra Rearing 32 mo Costs Per Heifer Conception Puberty (9 mo) (23 mo) 1 st Lactation Age (months) Each day calving is delayed beyond 24 months of age costs $1.5 to $3. per heifer 1

2 Heifer Development Age at 1 st Calving = 2 mo Birth 1 st Calving 2 nd Calving Calf Heifer Primiparous Multiparous Nonlactating 1 st Lactation 2 nd Lactation Lactation Age at 1 st calving: 2 mo Conception (11 mo) Age (months) Reducing age at first calving reduces the nonlactating period but results in impaired mammary development and reduction in subsequent milk production Calving Age Influences Subsequent Milk Production Calving heifers at 23 to 24 mo of age is optimal for first lactation milk yields Although heifers can calve at mo of age, they may experience dystocia and metabolic disorders % First Lactation Milk Production Expected Calving Age (mo) Deciding When to Breed Holstein Heifers Breeding Recommendations Age = 13 months Weight = 875 lb (396 kg) Wither Height = 5 in (127 cm) Calving Recommendations Age at first calving = months Weight = 125 lb (567 kg) post-calving Wither Height = 55 in (14 cm) 2

3 Heifer Reproductive Efficiency Poor Reproduction SR=5%; CR=4% Average Age: At 1 st breeding = 14. At conception = 16.4 At 1 st calving = 25.7 Good Reproduction SR=8%; CR=7% Average Age: At 1 st breeding = 14. At conception = 14.7 At 1 st calving = 24. Heifers not pregnant (%) Poor Good Age at conception (mo) Lactating Cows vs. Heifers What is normal for conception rate? Conception Rate, 1998 Minnesota DHI Data Rapnicki P, Stewart S, Eicker S. 21. Proc 4-State Appl Nutr Mgt Conf, La Crosse, WI 12 1 Lactating Cows Herd Count Conception Rate (%) 3

4 Characterization of Holstein Heifer Fertility in the United States Kuhn et al., J. Dairy Sci. 89: ; 26 Herd Count Breedings = 537,938 Heifers = 362,512 Herds = 2, Mean CR: 57% > >8 Conception Rate (%) CR by Service Number Holstein Cows Agri-Tech Analytics; 22-24; 1,68,87 Holstein AI services 35% 3% 3% 31% 31% 29% 28% Conception rate 25% 2% 15% 1% 5% % AI Service Number Effect of AI Service Number on Conception Rate in Heifers Kuhn et al., J. Dairy Sci. 89: ; 26 Conception rate (%) AI Service Number Number of AI (x 1,) 4

5 Reproductive Management Protocols for Dairy Heifers Radiotelemetry HeatWatch Paul M. Fricke, Ph.D. Behavioral Estrus in Holstein Dairy Cattle Based on HeatWatch Lactating Cows Nonlactating Heifers n Standing Events 7.2 ± ± 12.8 Duration of Estrus (h) 7.3 ± ± 6.9 J Dairy Sci 8(Suppl. 1):179; 1997 Paul M. Fricke, Ph.D. 5

6 Hormonal Manipulation of Ovarian Function in Heifers CIDR Inserts GnRH Prostaglandin F 2α PGF Synchronization Protocols (Targeted Breeding System) Treat all heifers and AI those detected in estrus. Retreat remaining heifers after 14 days and AI those detected in estrus. PGF 2α Estrus PGF 2α Estrus PGF 2α TAI (8h) 14 Days 14 Days Paul M. Fricke, Ph.D. GnRH PGF2α GnRH 7 days 56 hours 6

7 Stevenson et al., J. Dairy Sci. 91:3424; 28 PM Fricke, Ph.D. Effect of Treatment on Conception Rate in Dairy Heifers Stevenson et al., J. Dairy Sci. 91:3424; 28 8 Conception rate (%) n=135 n=127 n=14 n=111 CON PGED EDTAI GTAI Cost Analysis Inputs Stevenson et al., J. Dairy Sci. 91:3424; 28 Item Cost ($) Range ($) Increment ($) GnRH per dose PGF 2α per dose CIDR insert Labor per hour Rearing cost (heifer/d)

8 Cost Analysis Stevenson et al., J. Dairy Sci. 91:3424; 28 $1 Program Cost Cost per Pregnancy $85 $8 $6 $5 $55 $4 $42 $3 $29 $4 $34 $2 $ CON PGED EDTAI GTAI PM Fricke, Ph.D. Synchronization Systems Fricke et al., 23 Pursley & Wiltbank, 1995 Moreira et al., 21 PM Fricke, Ph.D. Conception rates after AI to estrus or Ovsynch and timed AI Heifers vs. Cows Conception (%) Study n Control Ovsynch Lactating Cows Lactating Cows Virgin Heifers * *Differs from Control, P <.1 8

9 Connie Cordoba Experimental Design Lactating Cows Grazing System Ovsynch (n=114) GnRH (5 μg) PGF 2α GnRH (25 mg) (5 μg) Timed AI (Day ; May 19, 2) Bulls Introduced (June 1, 2) day AI breeding period Tail Paint (n=114) Reproductive Performance 1 st AI service Cordoba & Fricke, J. Dairy Sci. 85: ; 22 Item Ovsynch Tail Paint Method of AI Timed AI AI at estrus AI submission rate (%) 1. a (114/114) 84.2 b (96/114) Mean d of AI. 12. ±.6 Conception rate (%) 27.3 a 47.3 b (3/11) (43/91) a,b Within a row, percentages with different superscripts differ (p<.1) 9

10 Frequency Distribuation of AI Cordoba & Fricke, J. Dairy Sci. 85: ; 22 Number of Cows Tail Paint Ovsynch Day of Breeding Period Ovsynch cows with low P 4 at 2 nd GnRH Cordoba & Fricke, J. Dairy Sci. 85: ; 22 P 4 -class n Anovular % (no) CR % (no) Return to AI % (no) LLL 5 8. (4). () 6. (3) HLL 28. () 14.3 a (4) 71.4 (2) LHL (8) 39.4 b (13) 27.3 (9) HHL 23. () 43.5 b (1) 3.4 (7) Σ (12) 3.3 (27) 43.8 (39) a,b Different superscripts denote significant contrasts (p<.5) HLL Cows (n=28) Proestrus at 1 st GnRH injection Low High Conception rate = 14.3% 2% of HLL cows returned to AI service during the AI breeding period on d 14 to 17 Lo w G Initial Heat Estrus P TAI (d ) G Return AI Service (d 14 to 17) Estrus

11 Three Follicular Waves Progesterone Follicular Size Ovulation 9 21 Two Follicular Waves Progesterone Follicular Size Ovulation 1 21 Day After Ovulation 22 Heifer Field Trial Results 11

12 Experimental Design Nonlactating Holstein dairy heifers GPG + Tail Chalk (n=175) GnRH (1 μg) PGF 2α GnRH + TAI (25 mg) (1 μg) 6 8 Once-daily estrus detection and AI based on tail chalk 42-day AI breeding period Tail Chalk (n=17) Effect of GPG vs. Tail Chalk Rivera et al., J. Dairy Sci. 87:251; 24 Interval to 1 st AI (d) CR Treatment n Mean Min Max % (no.) GPG * ± (67) TAI 144 (82%) 8. ± (55) Estrus before TAI 31 (18%) 5.2 ± (12) Tail Chalk ± (8) Overall ± (138) *Differs from Tail Chalk (p<.1). Four Factors Influence Conception Rate: Female Fertility X Bull Fertility X PR/AI = Accuracy of Heats X AI Efficiency 12

13 Effect of AI technician Rivera et al., J. Dairy Sci. 87:251; 24 Technician Treatment % (no./no.) % (no./no.) % (no./no.) GPG 2. (12/6) 25. (6/24) 53.8 (49/91) Tail Chalk 3.2 (16/53) 33.3 (12/36) 62.6 (52/83) Overall 24.8 a (28/113) 3. a (18/6) 58. b (11/174) a,b Within a row, percentages with different superscripts differ Survival curve of days to first AI Rivera et al., J. Dairy Sci. 87:251; 24 GnRH (1 μg) GPG (n=96) Rivera et al., J. Dairy Sci. 88:957; 25 PGF2α (25 mg) GnRH +TAI (1 μg) 6 Days 2 Days GnRH (1 μg) GPG + CIDR (n=94) PGF2α (25 mg) GnRH +TAI (1 μg) CIDR 6 Days 2 Days 13

14 Survival to first service Rivera et al., J. Dairy Sci. 88:957; 25 Effect of GPG vs. GPG + CIDR Rivera et al., J. Dairy Sci. 88:957; 25 Treatment Item GPG GPG + CIDR AI to estrus before TAI 23.9 (23/96). (/94) Heifers receiving TAI 76. (73/96) 1. (94/94) CR (3 d) to estrus 26.1 (6/23) - CR (3 d) to TAI 29.1 (28/96) 31.9 (3/94) Effect of AI technician Rivera et al., J. Dairy Sci. 88:957; 25 Technician Treatment % (no./no.) % (no./no.) % (no./no.) GPG 8. (2/25) 8.3 (2/24) 51.1 (24/47) GPG + CIDR 13.6 (3/22). (/24) 56.2 (27/48) Overall 1.6 a (5/47) 4.2 a (2/48) 53.7 b (51/95) a,b Within a row, percentages with different superscripts differ 14

15 5-day Heifer CIDR Synch protocol Thatcher et al, unpublished PGF 2α PGF Synch (n=12) PGF 2α GnRH +TAI GnRH 14 days CIDR Synch (n=127) PGF2α (AM/PM) 6 hours GnRH +TAI CIDR 5 days 3 days Conception rate (32 d) of dairy heifers to TAI after PGF Synch or CIDR Synch Thatcher et al. Unpublished Conception rate (%) Treatments do not differ statistically n=12 n=127 PGF Synch CIDR Synch CIDR Synch comparing 1 vs. 2 doses of PGF Thatcher et al., Unpublished CIDR Synch GnRH PGF2α GnRH +TAI CIDR 5 days 3 days 15

16 Conception rate (32 d) of dairy heifers to TAI after CIDR Synch using 1 vs 2 doses of PGF Thatcher et al. Unpublished Conception rate (%) Treatments do not differ statistically n=98 n=11 1 x PGF 2 x PGF Semen Sexing X-chromosome has 4% more DNA Sperm stained with dye & sorted by laser 85% accuracy Many sperm are damaged or wasted Can sort 8-1 straws of semen per hour Commercial Application of Sex-Sorted Semen in Holstein Heifers DeJarnette et al., J. Dairy Sci. 91:459; 28 (Abstr.) 49 herds from Jan, 25 to Jan. 28; 41,398 sexed semen AI services. Sexed semen resulted in ~45% CR and ~9% female calves in Holstein heifers. Conception rate (%) % of Conv. Conventional 53.8 Sex-Sorted % of Conv % of Conv. 1st 2nd 3+ AI service number 16

17 Use of Sexed Semen on Wisconsin Dairy Farms Ryan Sterry, UW-Extension Polk County Denise Brusveen, UW-Extension Sauk County Kent Weigel, Department of Dairy Science, UW-Madison Paul Fricke, Department of Dairy Science, UW-Madison 28 Board of Regents of the University of Wisconsin System, doing business as the Division of Cooperative Extension of the University of Wisconsin-Extension Survey Administration Conducted Winter 7-8 Administered by UW- Extension county faculty 2 questions Three general response categories Never used Used, but not currently Currently using 347 responses (37 Dairy, 38 Heifer Growers) How was survey distributed? Phone 1% Meeting 85% Farm Visit 7% Mail 7% 28 Board of Regents of the University of Wisconsin System, doing business as the Division of Cooperative Extension of the University of Wisconsin-Extension Experience with Sexed Semen Dairy Farms (n=39) Heifer Growers (n=38) Currently Using 39% Never Used 53% Currently Using 63% Never Used 29% Discontinued 8% Discontinued 8% 28 Board of Regents of the University of Wisconsin System, doing business as the Division of Cooperative Extension of the University of Wisconsin-Extension 17

18 Source of Sexed Semen (n=168) Other 1.8% Semex 1.8% Multiple 12.5% ABS 9.5% Select Sires 46.4% Accelerated 14.9% Genex 1.7% Alta 2.4% 28 Board of Regents of the University of Wisconsin System, doing business as the Division of Cooperative Extension of the University of Wisconsin-Extension 16 6% Age of Heifers at First Breeding - Only Beltsville Conventional (n=119) 17 3% Don t Use 18+ 7% 3% 15 23% 13 or less 17% 14 41% 16 6% Sexed (n=118) % 2% 15 22% Don t Use 4% 14 34% 13 or less 3% 28 Board of Regents of the University of Wisconsin System, doing business as the Division of Cooperative Extension of the University of Wisconsin-Extension Services for Using Sexed Semen - Beltsville 6 5 Heifers Cows % of Farms st 2nd 3rd 4th 28 Board of Regents of the University of Wisconsin System, doing business as the Division of Cooperative Extension of the University of Wisconsin-Extension 18

19 On the Web: Department of Dairy Science University of Wisconsin - Madison 19