Final report for LNE21-432R
Project Information
As sexed semen from proven dairy bulls is becoming more widely used, fewer cattle need to be bred to dairy bulls to produce adequate numbers of high genetic merit replacement heifers. Replacement rates of 20 to 40%, plus a safety margin, leave 40 to 70% of cattle available for crossbreeding with beef semen to produce beef x dairy (BxD) crossbred calves, while maintaining milk production in a herd. These calves have greater potential for growth and result in heavier carcasses with improved carcass characteristics compared with straightbred dairy calves, resulting in increased economic return to the producer. Dairies can increase profits by using sexed dairy semen for replacement heifer production and beef semen to produce BxD for the beef market. However, there is little information on appropriate nutritional management of BxD calves. Given that farms in the Northeast are using beef semen in dairy cows, implementing appropriate feeding strategies in early postnatal life will increase suitability of the BxD carcass for the beef market. Further, our preliminary data indicated that NE producers are interested in adopting this approach but requested additional nutrition, health, and breeding information. We hypothesize that improving postnatal nutrition for BxD calves will improve growth, carcass quality, and economic return. To test this hypothesis, multiparous Holstein dairy cows were bred with beef semen to produce 40 BxD calves. After birth, calves were assigned to one of two milk replacers: control (CON; 26:20 fat:protein milk replacer) or HIGH (32:30 fat:protein milk replacer). At 56 days of age, calves were weaned onto a calf grower (GROWER; 14% protein) or an isonitrogenous, corn silage-based total mixed ration (TMR) to achieve a targeted gain of 3 lb/day. When calves reached 700 lb body weight, they were finished by transitioning to a grain-based diet until slaughter at market weight. At the same time, we surveyed dairies in the Northeast to quantify the number of dairies that are producing BxD calves, determine how they are managing those calves, and what support is required to improve their success. Educational materials were created and presented to producers in a variety of formats, and extension personnel conducted farm visits and consultations with producers. Further, the advisory committee provided feedback on research findings, educational materials, and industry trends. Together, these data are critical to the wide-spread adoption of proper nutritional practices because specific nutritional management schemes to raise BxD calves are currently non-existent and are necessary to increase success and economic return of producers in the NE.
In 2020, Hoard’s Dairyman reported that use of beef semen by dairy producers to generate beef x dairy (BxD) calves had doubled over the past two years, because of an expected increased economic return compared with straightbred dairy calves raised for beef. However, data about management and growth of these animals, especially in the first six months of life is scarce. This study seeks to identify how different nutritional management strategies in early life impact future growth potential. These findings will support profitability of Northeast dairies, increasing returns to the farm and improving carcass quality for the BxD market.
As sexed semen from proven dairy bulls is becoming more widely used, fewer cattle need to be bred to dairy bulls to produce adequate numbers of high genetic merit replacement heifers. Replacement rates of 20 to 40%, plus a safety margin, leave 40 to 70% of cattle available for crossbreeding with beef semen to produce beef x dairy (BxD) crossbred calves, while maintaining milk production in a herd. These calves have greater potential for growth and result in heavier carcasses with improved carcass characteristics compared with straightbred dairy calves, resulting in increased economic return to the producer. Dairies can increase profits by using sexed dairy semen for replacement heifer production and beef semen to produce BxD for the beef market. However, there is little information on appropriate nutritional management of BxD calves. Given that farms in the Northeast are using beef semen in dairy cows, implementing appropriate feeding strategies in early postnatal life will increase suitability of the BxD carcass for the beef market. Further, our preliminary data indicated that NE producers are interested in adopting this approach but requested additional nutrition, health, and breeding information. We hypothesized that improving postnatal nutrition for BxD calves will improve growth, carcass quality, and economic return. To test this hypothesis, multiparous Holstein dairy cows were bred with beef semen to produce 40 BxD calves. After birth, calves were assigned to one of two milk replacers: control (CON; 26:20 fat:protein milk replacer) or HIGH (32:30 fat:protein milk replacer). At 56 days of age, calves were weaned onto a calf grower (GROWER; 14% protein) or an isonitrogenous, corn silage-based total mixed ration (TMR) to achieve a targeted gain of 3 lb/day. When calves reached 700 lb body weight, they were finished by transitioning to a grain-based diet until slaughter at market weight. At the same time, we surveyed dairies in the Northeast to quantify the number of dairies that are producing BxD calves, determine how they are managing those calves, and what support is required to improve their success. Together, these data are critical to the wide-spread adoption of proper nutritional practices because specific nutritional management schemes to raise BxD calves are currently limited to non-existent.
Cooperators
- (Researcher)
- (Educator and Researcher)
- (Researcher)
- (Educator and Researcher)
Research
We hypothesize that improving postnatal nutrition for beef x dairy (BxD) crossbred calves will improve growth, carcass quality, and economic return. These data are critical to the wide-spread adoption of proper nutritional practices because specific nutritional management schemes to raise BxD calves are currently non-existent. Further, we seek to understand how dairies in the Northeast states are currently utilizing this approach and generate educational material aimed at increasing their success and economic return.
Experimental Design.
Multi-parous Holstein cows were bred with semen from a Sim-Angus sire to produce 43 BxD calves. At birth, calves were removed from their dam, provided colostrum, and placed in an individual hutch. Calves were fed one of two milk replacers: control (CON; 20:22 fat:protein) or HIGH (32:30 fat:protein) according to manufacturer’s recommendations for the first 56 days of life. Starting at 3 days of age, calf starter (18% protein) was offered to all calves and increased gradually. At 56 days of age, calves were weaned onto a calf grower (COM; 14% protein) or an isonitrogenous, corn silage-based total mixed ration (TMR) to achieve a targeted gain of 3 lb/day. When calves reached 700 lb body weight, they were finished by transitioning to a grain-based diet until slaughter at market weight.
Aim One: Determine the effects of nutritional plane before weaning and type of feed during growing on BxD calf growth. We hypothesized that feeding a high fat, high protein milk replacer before weaning and a grower feed during the grower period would improve calf growth during the growing and finishing periods.
Methods: Calf body weights and measurements [crown rump length (CRL), girth circumference, and hip height] were taken at birth, weekly through day 56 of age, and monthly through finishing. Body weights were used to calculate average daily gain. The number of days on feed to reach the finishing phase (700 lb) and slaughter weight were calculated to determine how early nutrition impacts later growth trajectory. Ultrasound for loin eye area (LEA), back fat (BF) thickness, rib fat thickness (RF) and intramuscular fat (marbling) were performed monthly from one month of age until slaughter weight. Muscle biopsies were collected from the longissimus dorsi muscle at 14 and 56 days of age. Muscle fiber number, cross-sectional area (CSA), and intramuscular fat quantity were determined by immunohistochemistry.
Aim Two: Determine the effects of nutritional plane before weaning and type of feed during grower phase on BxD calf carcass quality and economic return. We hypothesized that feeding a high fat, high protein milk replacer before weaning and a grower feed during the grower period would reduce days to slaughter and improve carcass quality, resulting in greater economic return.
Methods: Animals were slaughtered at a commercial slaughterhouse, where hot carcass weight (HCW), USDA Quality and Yield grade, BF thickness, LEA, and marbling score were collected, and dressing percentage was calculated.
Aim Three: Assess current use and needs of dairies incorporating BxD calves into their operations. Our objective was to survey dairies in the Northeast to quantify how many dairies are producing BxD calves, how they are managing those calves, and what support is required to improve their success.
Methods: We partnered with the Penn State Center for Survey Research (CSR) to send out a robust survey to dairies in the Northeast. Surveys were sent electronically and by mail to approximately 10,000 dairy producers. To reach as broad an audience as possible with the survey, we exhausted contact lists from Extension departments, Beef and Dairy Councils/Promotion Boards/Associations, and the Department of Agriculture in each state. The survey was made available for eight weeks. CSR consolidated the data and provided a methodology report and dataset of survey responses to the research team.
Aim 1: At days 49 and 56 of age, female calves fed the control milk replacer (CON) were 7 to 17% lighter than CON and male and female calves fed the high energy milk replacer (BIG; P≤0.05). BIG calves tended to have 14% larger muscle fiber cross-sectional area than CON calves at 8 wk of age. No significant differences were observed for rib eye area or backfat thickness on ultrasound at 2 or 8 weeks of age (P≥0.38). Thus, feeding a milk replacer with a protein and fat content similar to beef cow milk improves BxD calf growth compared with a milk replacer containing less protein and fat. Grower diet did not have significant effects on calf body weight, hip height, or average daily gain during the grower period, or days to 318 kg. The grower diet was associated with differences in both crown-rump length and heart-girth, with calves on the silage-based diet having larger heart-girths at four and seven months of age and calves on total mixed ration having larger crown-rump lengths from three to nine months of age. At 17 mos of age, cattle fed the BIG milk replacer and a silage-based diet were heavier than cattle fed a CON milk replacer (regardless of grower diet). At slaughter, there were no significant differences in rib or back fat thickness due to milk replacer or grower diet, but animals fed a silage-based grower diet tended to have greater rib eye area at 17 months of age. Pre-weaning data are presented in Carter et al., 2024, Translational Animal Science (https://doi.org/10.1093/tas/txaf005).
Aim 2: After finishing, there was a milk replacer x grower x age interaction for body weight (P = 0.015) where at 14 months of age, BIG-COM and BIG-TMR cattle were heavier than CON-COM cattle (P < 0.04). At 16 months of age, BIG-COM cattle were heavier than CON-COM (P < 0.01). At 17 months of age, BIG-COM cattle were heavier than CON-TMR (P = 0.04) and CON-COM (P < 0.01) cattle. There was an age effect on rib fat thickness (P < 0.01), back fat thickness (P < 0.01), and IMF (P < 0.01) but no other main or interaction effects (P > 0.05). There was a grower x age interaction on rib eye area (P = 0.02), where at 15 months, COM cattle tended to have smaller rib eye area. There was a grower x age interaction on crown rump length (P = 0.03) where at 10 months of age, TMR cattle were longer than COM cattle (P = 0.05). Carcass characteristics were assessed on a subset of 32 cattle. There were no observed differences in hot carcass weight, dressing percentage, rib eye area, back fat thickness, or percentage of kidney, pelvic, and heart fat based on milk replacer or grower diet (P > 0.08) at slaughter at 17 months of age.
Aim 3: Working with the Penn State CSR, we distributed our survey to dairy producers across the Northeast. Paper and electronic surveys were sent to mailing lists in each state, through cooperative extension and beef and dairy producer boards. The survey was also advertised on social media. We received 617 survey responses. The Penn State CSR consolidated the data and provided a data set of responses. The data are published in Felix et al., 2023, Translational Animal Science (https://doi.org/10.1093/tas/txad038).
Feeding increased nutrition during the pre-weaning period improved pre-weaning growth, which resulted in heavier cattle at slaughter but did not significantly affect other carcass attributes. During the grower period, feeding a silage-based diet appeared to support greater muscle growth. Providing sufficient energy to BxD crossbred cattle early in life supports future growth, with potential returns to the producer at slaughter. While not a specific aim of the current study, distinct "types" of cattle were observed (more similar to dairy cattle or more similar to beef cattle), which may have impacted the outcomes of the study and is an area of need for future research. Producers should carefully consider early life nutrition strategies that support adequate pre-weaning growth to increase the opportunities for additional return at slaughter.
Education & Outreach Activities and Participation Summary
Educational activities:
Participation Summary:
Two journal articles were published (Survey of the use of beef semen in dairy herds in Pennsylvania and nearby states, T L Felix et al., Translational Animal Science, Volume 7, Issue 1, 2023, txad038, https://doi.org/10.1093/tas/txad038 and Effects of milk replacer composition on growth and development of beef × dairy crossbred calves, Rachel E Carter et al., Translational Animal Science, Volume 9, 2025, txaf005, https://doi.org/10.1093/tas/txaf005). The Master's student working on the project successfully graduated and is employed in an agricultural industry.
Results have been shared at the American Society of Animal Science annual meeting (2023) and the Northeast American Society of Animal Science sectional meeting (2022).
Results and impacts of the study were shared with participants at the Florida Ruminant Nutrition Symposium, the PA Dairy Summit, and a Balchem webinar.
Note that individual information on participants was not collected.
Learning Outcomes
We did not collect these data.
Project Outcomes
The project allowed a working collaboration between faculty and students at Penn State University and the University of Connecticut. This has continued as the student on the project graduated and has remained in contact with the faculty involved in the project as she has become employed.