Economic opportunities for using sexed semen and semen of beef bulls in dairy herds

Abstract

Dairy farmers can increase the number of dairy heifer calves born in their herd by using sexed semen. They can reduce the number of both dairy bull and heifer calves by using beef semen. Long before sexed semen became commercially available, it was believed that it would provide opportunities for increasing genetic level in both herds and populations. In this study, we studied the potential for increasing the genetic level of a herd by using beef semen in combination with sexed semen. We tested the hypothesis that the potential of increasing the genetic level and the overall net return would depend on herd management. To test this hypothesis, we simulated 7 scenarios using beef semen and sexed semen in 5 herds at different management levels. We combined the results of 2 stochastic simulation models, SimHerd and ADAM. SimHerd simulated the effects of the scenarios and management levels on economic outcomes (i.e., operational return) and on technical outcomes such as the parity distribution of the dams of heifer calves, but it disregarded genetic progress. The ADAM model quantified genetic level by using the dams' parity distributions and the frequency of sexed and beef semen to estimate genetic return per year. We calculated the annual net return per slot as the sum of the operational return and the genetic return, divided by the total number of slots. Net return increased up to €18 per slot when using sexed semen in 75% genetically superior heifers and beef semen in 70% genetically inferior, multiparous cows. The assumed reliability of selection was 0.84. These findings were for a herd with overall high management for reproductive performance, longevity, and calf survival. The same breeding strategy reduced net return by €55 per slot when management levels were average. The main reason for the large reduction in net return was the heifer shortage that arose in this scenario. Our hypothesis that the potential for beef semen to increase genetic level would be herd-specific was supported. None of the scenarios were profitable under Danish circumstances when the value of the increased genetic level was not included. A comparable improvement in genetic level could be realized by selectively selling dairy heifer calves rather than using beef semen.

Mating strategies to maximize genetic merit in dairy cattle herds

“…By simulating all possible combinations of excluding cows from producing replacements, nominating top cows to top bulls, and the number of top bulls nominated, we identified that the single biggest factor in improving BrW comes from excluding the lowest BrW cows from producing replacement heifers, similar to the findings of Ettema et al (2017). For each 10% of the bottom cows (based on BrW) excluded from generating a replacement, the average BrW of replacements generated increased by 3.8 to 4.0 BrW regardless of herd structure or bull team used.…”

Bovine sperm sex‐selection technology in Japan

“…This raises the question as to whether sexed semen is beneficial to farm management. Numerous reports have estimated the economic benefits of sexed semen produced by various strategies in many different countries, including the United States, Denmark, Iran, Ireland, and Japan . In general, the use of sexed semen is expected to have a positive effect on the economics of the farms, maintaining replacement heifers and/or the efficiency of expanding dairy herds, resulting in an improved milk yield.…”

Farm characteristics and management routines related to cow longevity: a survey among Swedish dairy farmers

“…One way to extend the average cow longevity is to bring fewer heifers into the herd and therefore to cull fewer cows [ 8 , 15 ]. One management option would be the use of sexed semen with genetically superior cows and inseminating a proportion of the remaining cows with beef semen—which will also improve the farm economy [ 9 ]. It is likely that farms taking breeding advice receive support in these kinds of breeding strategies as genetic improvement is important but does not warrant short cow longevity [ 32 ].…”

“…Herd replacement is the second highest variable cost in a dairy enterprise [ 6 ], and with increased longevity fewer replacement heifers would be required to achieve the same herd output, which would reduce replacement costs [ 3 , 7 , 8 ]. Surplus heifers could instead be sold or a larger proportion of the cows could be inseminated with beef semen [ 9 ]. Furthermore, with increased longevity the mean production of the herd could be higher because a large proportion of the culling decisions are based on production, and also because the proportion of mature cows, which generally produce more milk than young cows, would be increased [ 2 , 3 , 7 , 10 ].…”