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Reproductive Performance in Chilean Holstein Dairies by Geographic Region
Our objectives were to compare reproductive indicators from Holstein dairies in the 3 main productive areas of the Chilean Valley and establish benchmarks for the 20% most efficient herds. Data from 24,319 cows and over 70,000 inseminations recorded in DC305, Afi-farm, and Dairy Plan were evaluated from January to December 2013. Data included 30 dairies located in: Central Area (C [5th, 6th, and Metro Regions]; n=12 herds]) in dry lots and free-stall housing; South-Central Area (SC [7th and 8th Regions]; n=6 herds]) with free-stall and grazing systems; and South Area (S [9th and 10th Regions]; n=12]) with free-stall and grazing systems. Analyses were conducted with the MIXED procedure of SAS using herd as the experimental unit. The regions did not differ (P>0.05) by mean (SD) herd size (C=592±315; SC=940±1612; S=989±815), days open in pregnant cows (C=137±19; SC=135±19; S=144±15), days in milk (C=203±17; SC=209±39; S=210±31), and days to first breeding (C=71±5; SC=73±10; S=79±4). Similarly, pregnancy risk (C=19%; SC=17%; S=16%), insemination risk (C=53%; SC=48%; S=46%), all services conception rate (C=37%; SC=37%; S=38%), and removal rate by 60 days in milk (C=7%; SC=7%; S=5%) were not different among regions. The S region had lower (P<0.05) mean (SD) daily milk production in kilograms (25±4) in comparison to the SC (34±5) and C region (36±5). The C region had more (P<0.05) days of voluntary waiting period (51±3) than regions SC and S (48±4 and 47±3, respectively). The 20% most efficient operations based on pregnancy risk ranking had a voluntary waiting period of 52±3 days, mean pregnancy risk of 21%, insemination risk of 56%, and all services conception rate of 40%. They achieved 50% pregnant by day 100 in milk, and mean (SD) days open and days in milk of 126±8 and 184±16, respectively. Conception rates for first insemination (40% vs. 35%) and for the first lactation (44% vs. 37%) were higher (P<0.05) for the 20% most efficient herds. The 3 regions evaluated differed only in milk production level and voluntary waiting period. The most efficient herds had higher pregnancy risk, insemination risk, and conception rates; especially for first insemination and first lactation cows.
Keywords:
Fertility
Reproduction
Estrus