How Data Management Improves Dairy Farm Breeding Management

It is well known that for commercially operated dairy farms, the breeding level is a key factor determining farm development, and the breeding level of a dairy farm is affected by many factors. Objective factors include: genetic level, nutritional level, herd health level, and external environment. Subjective factors include: on-site operational skills of breeding staff, whether the breeding process is reasonable, and the execution of the breeding process.

The following is a case study of a large dairy farm improving its breeding level by using the Dairy Star farm management system.

(All images below can be clicked to enlarge)

The 2018 and 2019 full-year milk test records were segmented by days after calving at the time of testing, and the measured individual milk yield corresponding to those days after calving was weighted and averaged to calculate the average milk yield distribution for 2018 and 2019. The farm's milk yield in 2019 increased by 2 kg compared with 2018. The delay in peak lactation of first-lactation cows in 2018 was improved in 2019, and the peak milk of first-lactation cows in 2019 increased by 3 kg compared with 2018, while that of multiparous cows increased by 1.5 kg.

The 21-day pregnancy rate in 2018 and 2019 increased by 4 percentage points (in 2019, there were cows with unknown pregnancy check results in the last 3 estrous cycles, so they were not included in the statistics). The main improvement was reflected in the increase in estrus detection rate, which rose from 56.34% to 69.17%. Practice has proven that when objective factors such as genetics (with no purchased cows in the two adjacent years, the genetic level of the adult cow herd differed little) are nearly the same, how to get more cows to show estrus and be inseminated is the key to improving farm reproduction.

It is recommended that the farm breeding department pay attention to the following processes, so as to find a plan suitable for improving the breeding level of the farm.

Pay attention to stage reproductive progress (21-day pregnancy rate)

Pay attention to the completion of first postpartum insemination and the factors affecting first insemination

Postpartum estrus, insemination, and conception status (VWP=50)

Estrus: the proportion of cows calving in September that showed estrus between 30-85 days postpartum (including cows inseminated during this stage and cows showing estrus signs but not suitable for insemination due to postpartum uterine environment).

Insemination: the proportion of cows calving in September that were actually inseminated between 30-85 days.

Conception: the conception rate of first insemination between 30-85 days for cows calving in September.

Within 85 days postpartum, healthy cows will show obvious or silent estrus under their own hormones or artificial hormone regulation. If the estrus proportion is lower than 95%, it is recommended that the farm consider the following points:

1) Whether insufficient actual dry period/transition period days led to poor body condition at calving, making it impossible for postpartum hormone levels to recover.

2) Whether postpartum diseases affected the first insemination

Fresh cows are prone to diseases (such as metritis, mastitis, metritis, retained placenta, hoof diseases, etc.), resulting in low feed intake, inability to meet the cow's own nutritional needs, and aggravating the danger brought by negative energy balance.

^INegative energy balance, like inflammation, can hinder follicular development and maturation, and this view has been widely recognized. The pathogenesis of low fertility symptoms is very complex. Interference with the hypothalamic-pituitary-gonadal axis can lead to disrupted endocrine signals, thereby causing delayed postpartum ovarian repair in dairy cows. Biochemical parameters associated with negative energy status (such as non-esterified fatty acids (NEFA)) can come into contact with follicular fluid and reduce the developmental competence of oocytes.

3) Whether there are problems with the return-to-estrus cycle

Insemination interval:

1-3 days is re-insemination. A high proportion may be caused by inaccurate estrus identification, follicular cysts, delayed ovulation, and other reasons. It is recommended that the re-insemination proportion be 0. For problem cows, it is recommended to check the details and conduct a specific analysis.

4-17 days is short estrous cycle estrus cows. A high insemination proportion may be due to failed synchronization implementation. It is recommended to keep the short-term insemination proportion within 5%.

18-24 days is the normal return-to-estrus cycle. The recommended reference proportion is above 45%. A low proportion may be due to inadequate observation by personnel in estrus identification, with missed estrus.

25-35 days is abnormal return-to-estrus cows. There are many causes, such as: early embryonic death, missed estrus in short estrous cycle cows, insufficient secretion of the corpus luteum of pregnancy, failed synchronization programs, etc. The recommended proportion is below 10%.

Most of the 36-48 day return-to-estrus cows are cows that returned to estrus after pregnancy check showed open and synchronization treatment, and a small portion are cows whose estrus in the previous estrous cycle was not observed. The recommended proportion is below 25%.

≥48 days indicates that there was unobserved return to estrus and open cows were not handled in a timely manner. The recommended proportion is below 3%.

4) Whether the synchronization process is reasonable

The synchronization processes mostly used on dairy farms mainly include the following two:

• Fresh cows PG PG GnRH PG GnRH TAI;

  Intervals: 14d 12d 7d 56h 16h.

• Open cows GnRH PG GnRH TAI;

  Intervals 7d 56h 16h.

Studies have shown that the conception rate of artificial insemination is 1-3 percentage points higher than that of timed insemination. If the difference is too large, it is recommended to consider whether there are problems with the synchronization process, whether the corpus luteum has not been completely dissolved, or whether synchronization steps have been omitted. It is recommended to try adding one PG injection to the traditional 079 synchronized ovulation protocol, changing it to 0789.

^IIRelated experiments found that for adult cows (not first-lactation cows), the pregnancy rate per insemination of the two-injection group increased by 9.45% compared with the one-injection group (the pregnancy rate per insemination of the two-injection group was 37.6%, and that of the one-injection group was 34.4%). Therefore, adding one PG injection to the ovulation synchronization protocol can increase the pregnancy rate by about 10%, mainly improving the fertility of multiparous cows.

5) Whether the first insemination is timely

The weighted average of 42 and 100 and the average of 69 and 73 are both 71. Looking at the above two figures together, the average days to first insemination is 71 days, which meets the reference value, but the distribution of first insemination is not concentrated enough, which may indicate missed estrus, failed synchronization programs, and issues with first insemination execution standards. It is recommended to periodically analyze cows whose deviation from the average days to first insemination is relatively large.

Pay attention to the timeliness of pregnancy checks and the loss proportion of each pregnancy check

From the above figure, it can be seen that the average first check is 30 days after insemination, the first recheck is 60 days, the second recheck is 178 days, and the pre-dry-off recheck is 219 days. There is a delay in the second recheck. Take the cows reported pregnant this year to analyze the loss proportion. The calculation method is: abortions before each pregnancy check and open cows at pregnancy check / cows pregnant at the previous pregnancy check. Because the first check is too early and its accuracy is low, it is recommended to pay attention to issues such as early embryonic death and pregnancy check accuracy.

Because breeding work involves many interacting links, there are also many influencing factors, so different problems still need specific analysis. I hope the content shared above can provide you with directions for analysis.

Author: Bao Jie, Beijing Xiangzhong Zhimu Technology Co., Ltd.TechnologyExpert

References:

I. MASTITIS and FERTILITY_5_metabolism story_LR by elKe ABBeloos

II. J Dairy Sci. 2015 Dec;98(12):8644-54. doi: 10.3168/jds.2015-9353.