There are several critical success factors in every suckler beef operation, including managing cow costs, weaning weights and percentage calf crop.
Although the key to profitability in the breeding herd revolves around maximising reproductive efficiency, despite its importance, there is clear evidence that fertility of beef females is declining nationally, with a decrease in calves per cow per year, and an increase in calving interval and age at first calving.
These unfavourable fertility trends need to be tackled at farm level, if the true production potential of the suckler herd is to be realised. The most critical time to influence these factors is just prior to and after calving. Management decisions made during these time periods will greatly influence profitability in all beef cow operations.
Manage the postpartum interval
Infertility occurs when beef cows (1) become pregnant but fail to calve; (2) become pregnant late in the breeding season and fall out of the annual production cycle; or (3) fail to become pregnant during the breeding season.
The latter two causes of infertility are a direct result of the length of the postpartum interval (PPI, the period from calving to first heat). Failure to successfully manage the cow herd through the PPI is one of the major causes of infertility.
To maintain a yearly calving interval, beef females must be managed so that they overcome their postpartum interval (PPI) within 80 to 85 days of calving to allow for a 280- to 285-day gestation. Shortening the PPI is a difficult challenge under the best of conditions.
Several factors influence the length of the PPI, the two primary factors being the nutritional status (both pre-partum nutrition and plane of nutrition post-calving) of the cow and the suckling effect. While the suckling stimulus undoubtedly has a negative effect on cow cyclic activity, cows on a proper nutrition management, in positive energy balance and in adequate body condition, will generally overcome this negative stimulus prior to the breeding season.
Nutritional requirements
Nutrition is probably the easiest way to shorten the PPI. Indeed, nutritional status before calving is more influential on reproductive performance than supplementation following calving. Proper attention to BCS is also crucial to successful reproductive management.
The most critical time period to manage cow nutrition is from six weeks before calving through to six weeks after breeding. During this time period, the freshly-calved cow faces many competing demands. If dietary energy intake is inadequate, the cow’s reproductive performance is limited.
Reproduction is of very low priority when nutrient partitioning is considered and that is why thin cows often don’t rebreed.
For example, the energy required for reproduction and to initiate oestrous cycling after calving is only available after requirements for maintenance, growth, and milk production have been met.
Energy in cattle nutrition is measured in units called UFL, where one UFL is equivalent to 1kg of air-dry barley. Compared to dry cows, the lactating suckler cow rearing one calf requires over 1.5 times greater feed requirement.
Suckler cows with higher milk production also have higher feed requirements (0.45 UFL per litre of milk produced). Typically, cows of the continental beef breeds produce five to eight litres of milk/day indoors and therefore a 600kg cow needs 7.8 to 9.1 UFL per day while maintaining body condition.
Feed management
After calving and during the breeding season, it crucial that the nutrient supplied by the diet meets the needs of the cow. The post-calving diet should be based around five key principles:
Nutrition status of the cow estimated by the BCS at calving.The quality of diet available – silage analysis. Timing of calving. Cow age.Cow type or milk production potential.Taking these factors into account, a number of feed options and management practices are proposed, which, if implemented correctly post-calving, may result in heavier weaning weights and a higher % calf crop without dramatically increasing cow costs.
Diet type: Ad-lib access to moderate- to low-quality grass silage for about four to six weeks after calving, following which cows are turned out onto high-quality grazing pasture.
On a moderate-quality silage diet (62-68% DMD; fairly typical of silage quality this year) the typical suckler cow (600kg) producing five to eight litres will have an energy deficit of between 1.3 and 2.6 UFL per day.
If in appropriate condition at calving, cows can be allowed to mobilise body reserves (0.25 condition score loss or 70 UFL) to make up for this energy shortfall, for a four- to six-week period after calving, provided the cow goes to grass thereafter. The high nutritive value of early spring grass will ensure the rapid recovery of these body reserves.
Applying this feeding strategy has no negative effects on cow fertility or calf performance.
This is the feed regime of choice for most spring-calving operations and should continue to be, given its adequacy in meeting the cow’s reproductive requirements in a cost-effective
manner.
Diet type: Ad-lib access to moderate- to high-quality grass silage. Concentrates will need to be supplemented at 1.5-2.5kg per day (depending on silage quality) up to mating.
This feeding option covers the early spring-calving cow. To maintain a 365-day calving interval, cows that fall into this scenario will need to be rebred while still indoors and must be offered higher feed levels to ensure good reproductive performance. These cows must be fed to their requirements and cannot tolerate any prolonged feed energy deficit pre-breeding.
On farms where silage quality is poor (<60% DMD), an extra 1-2kg on top of the above feed allocations will be needed to meet the cows’ requirements. Always offer an appropriate mineral/vitamin mix.
Diet type: In all cases, concentrate supplement after calving, until going to grass. Where silage quality is moderate to good, feed 1-2 kg meal and where silage quality is poor, feed 2-3kg meal, daily.
First-calf heifers are a unique management group on suckler farms. They are highly susceptible to calving and reproductive failure unless properly fed and managed. Preferential feeding treatment should always be given to them. The combined effects of growth and first lactation impose a high nutritional demand that is challenging to fulfil.
As such, first-calf heifers cannot be subjected to low-level feeding as inadequate nutrient intake (both pre- and post-calving) has a detrimental effect on subsequent fertility. Additionally, on average, first-calving heifers usually resume cycling 15-20 days longer than mature cows. To overcome the longer PPI in time for the start of the breeding season, farmers are advised to breed heifers to calve three weeks ahead of the main cow herd and also provide these females with the best feed resources available and continuously monitor their progress.
Diet type: Recommendation is to feed moderate- to good-quality silage to appetite, plus 1-2 kg meals daily, until turnout to grass.
Cows calving thin or below the target body condition score tend to have a delayed return to cyclicity. Dietary manipulation in the period immediately before or after calving, or in the breeding season itself, rarely affects a recovery.
In fact, cows calving under condition score 2.0 will be two to three weeks slower going back in calf than cows calving at target condition score. This extra time lengthens the calving interval and makes the 365-day target almost impossible to achieve. Furthermore, the effects of low BCS at calving are only partially reversed by putting cows on a high rising plane of nutrition after calving.
To limit the impact on overall herd fertility, calf removal strategies (on/off suckling) and progesterone-based synchronisation treatments should also be considered to induce cyclicity, especially in cows that have failed to show heat by 60 to 70 days after calving.
There are several critical success factors in every suckler beef operation, including managing cow costs, weaning weights and percentage calf crop.
Although the key to profitability in the breeding herd revolves around maximising reproductive efficiency, despite its importance, there is clear evidence that fertility of beef females is declining nationally, with a decrease in calves per cow per year, and an increase in calving interval and age at first calving.
These unfavourable fertility trends need to be tackled at farm level, if the true production potential of the suckler herd is to be realised. The most critical time to influence these factors is just prior to and after calving. Management decisions made during these time periods will greatly influence profitability in all beef cow operations.
Manage the postpartum interval
Infertility occurs when beef cows (1) become pregnant but fail to calve; (2) become pregnant late in the breeding season and fall out of the annual production cycle; or (3) fail to become pregnant during the breeding season.
The latter two causes of infertility are a direct result of the length of the postpartum interval (PPI, the period from calving to first heat). Failure to successfully manage the cow herd through the PPI is one of the major causes of infertility.
To maintain a yearly calving interval, beef females must be managed so that they overcome their postpartum interval (PPI) within 80 to 85 days of calving to allow for a 280- to 285-day gestation. Shortening the PPI is a difficult challenge under the best of conditions.
Several factors influence the length of the PPI, the two primary factors being the nutritional status (both pre-partum nutrition and plane of nutrition post-calving) of the cow and the suckling effect. While the suckling stimulus undoubtedly has a negative effect on cow cyclic activity, cows on a proper nutrition management, in positive energy balance and in adequate body condition, will generally overcome this negative stimulus prior to the breeding season.
Nutritional requirements
Nutrition is probably the easiest way to shorten the PPI. Indeed, nutritional status before calving is more influential on reproductive performance than supplementation following calving. Proper attention to BCS is also crucial to successful reproductive management.
The most critical time period to manage cow nutrition is from six weeks before calving through to six weeks after breeding. During this time period, the freshly-calved cow faces many competing demands. If dietary energy intake is inadequate, the cow’s reproductive performance is limited.
Reproduction is of very low priority when nutrient partitioning is considered and that is why thin cows often don’t rebreed.
For example, the energy required for reproduction and to initiate oestrous cycling after calving is only available after requirements for maintenance, growth, and milk production have been met.
Energy in cattle nutrition is measured in units called UFL, where one UFL is equivalent to 1kg of air-dry barley. Compared to dry cows, the lactating suckler cow rearing one calf requires over 1.5 times greater feed requirement.
Suckler cows with higher milk production also have higher feed requirements (0.45 UFL per litre of milk produced). Typically, cows of the continental beef breeds produce five to eight litres of milk/day indoors and therefore a 600kg cow needs 7.8 to 9.1 UFL per day while maintaining body condition.
Feed management
After calving and during the breeding season, it crucial that the nutrient supplied by the diet meets the needs of the cow. The post-calving diet should be based around five key principles:
Nutrition status of the cow estimated by the BCS at calving.The quality of diet available – silage analysis. Timing of calving. Cow age.Cow type or milk production potential.Taking these factors into account, a number of feed options and management practices are proposed, which, if implemented correctly post-calving, may result in heavier weaning weights and a higher % calf crop without dramatically increasing cow costs.
Diet type: Ad-lib access to moderate- to low-quality grass silage for about four to six weeks after calving, following which cows are turned out onto high-quality grazing pasture.
On a moderate-quality silage diet (62-68% DMD; fairly typical of silage quality this year) the typical suckler cow (600kg) producing five to eight litres will have an energy deficit of between 1.3 and 2.6 UFL per day.
If in appropriate condition at calving, cows can be allowed to mobilise body reserves (0.25 condition score loss or 70 UFL) to make up for this energy shortfall, for a four- to six-week period after calving, provided the cow goes to grass thereafter. The high nutritive value of early spring grass will ensure the rapid recovery of these body reserves.
Applying this feeding strategy has no negative effects on cow fertility or calf performance.
This is the feed regime of choice for most spring-calving operations and should continue to be, given its adequacy in meeting the cow’s reproductive requirements in a cost-effective
manner.
Diet type: Ad-lib access to moderate- to high-quality grass silage. Concentrates will need to be supplemented at 1.5-2.5kg per day (depending on silage quality) up to mating.
This feeding option covers the early spring-calving cow. To maintain a 365-day calving interval, cows that fall into this scenario will need to be rebred while still indoors and must be offered higher feed levels to ensure good reproductive performance. These cows must be fed to their requirements and cannot tolerate any prolonged feed energy deficit pre-breeding.
On farms where silage quality is poor (<60% DMD), an extra 1-2kg on top of the above feed allocations will be needed to meet the cows’ requirements. Always offer an appropriate mineral/vitamin mix.
Diet type: In all cases, concentrate supplement after calving, until going to grass. Where silage quality is moderate to good, feed 1-2 kg meal and where silage quality is poor, feed 2-3kg meal, daily.
First-calf heifers are a unique management group on suckler farms. They are highly susceptible to calving and reproductive failure unless properly fed and managed. Preferential feeding treatment should always be given to them. The combined effects of growth and first lactation impose a high nutritional demand that is challenging to fulfil.
As such, first-calf heifers cannot be subjected to low-level feeding as inadequate nutrient intake (both pre- and post-calving) has a detrimental effect on subsequent fertility. Additionally, on average, first-calving heifers usually resume cycling 15-20 days longer than mature cows. To overcome the longer PPI in time for the start of the breeding season, farmers are advised to breed heifers to calve three weeks ahead of the main cow herd and also provide these females with the best feed resources available and continuously monitor their progress.
Diet type: Recommendation is to feed moderate- to good-quality silage to appetite, plus 1-2 kg meals daily, until turnout to grass.
Cows calving thin or below the target body condition score tend to have a delayed return to cyclicity. Dietary manipulation in the period immediately before or after calving, or in the breeding season itself, rarely affects a recovery.
In fact, cows calving under condition score 2.0 will be two to three weeks slower going back in calf than cows calving at target condition score. This extra time lengthens the calving interval and makes the 365-day target almost impossible to achieve. Furthermore, the effects of low BCS at calving are only partially reversed by putting cows on a high rising plane of nutrition after calving.
To limit the impact on overall herd fertility, calf removal strategies (on/off suckling) and progesterone-based synchronisation treatments should also be considered to induce cyclicity, especially in cows that have failed to show heat by 60 to 70 days after calving.
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