BRAHMAN NEWS MARCH 2011 Issue #170
by Felicity Hamlyn-Hill Northern Muster August 2010
Profitable beef businesses of the future will be those that have already started some years earlier to improve the inherent fertility of their herd through monitoring performance, identifying problem areas and making sound management decisions.
For long term profit, breeder performance can be maximised if:
- each cow conceives early in the mating period and calves within an interval of one year or less between calves;
- each cow successfully rears its calf to weaning;
- each calf weaned meets desired weight targets.
Due to the length of the gestation period the average cow must re-conceive within 12 weeks of calving, to produce calves within an interval of one year or less.
| months | |
| Pregnancy (approx 284 days) | 9.3 |
| Calving to cycling (6 weeks) | 1.35 |
| Cycling to conceiving (6 weeks) | 1.35 |
| Total | 12 mths |
To make progress the first step is to measure reproductive performance.
While the ultimate test of a cow’s performance is that she successfully rears her calf to weaning, determining problem areas in is this complex process is more difficult. There a number of reproductive measures that can be used, some of which are listed in the following tables. Level or intensity of management and reproductive history will determine which of these measures are most useful and relevant to the individual business. Producer partners in the Value in Beef project have found that different measures are relevant under different management scenarios with specific objectives and targets. The Cashcow project aims to determine which measures of breeding herd performance are best related to business profit (Fordyce pers comm.). Outcomes from this project will be delivered when the Cashcow research is completed.
Seasonal mating and foetal aging together are paramount for accurate measurement of breeder performance, and for identifying areas for improvement.
Individual NLIS identification is necessary for tracking lifetime performance. Foetal aging 12-13 weeks after bulls have been removed will identify all current pregnancies in seasonally mated herds. With continuous mating, foetal aging will not pick up all pregnancies plus it is harder to define the mating period unless “late” pregnant cows are culled.
MEASURING HEIFER PERFORMANCE
From recent CRC research we know age and weight at puberty are highly heritable. This means genetic progress can be made in these traits.
Once in calf, first calf heifers experience the energy drain of lactating while still growing. This leads to weight loss and failure to re-conceive. However there are those heifers which are more fertile and do re-conceive. These are the heifers that should be producing the breeding females of the future.
MEASURING MATURE COW PERFORMANCE
Body condition at time of calving is a major factor determining a cow’s ability to conceive while lactating. While the ability of a cow to conceive while lactating is influenced by nutrition and mating management (to prevent dry season lactations), we now know this trait is highly heritable. This means genetic progress can be made in female breeding cattle in this trait.
The link between mature cow weights, the average pasture quantity and quality and body condition score is essential when establishing breeding objectives. Remember though that the bulls contribute the most to genetic progress. This is due the number of calves they sire in a lifetime. Objective selection of key traits such as fertility and growth is strongly recommended.
Weaning percentage can be calculated in various ways and this makes it difficult to compare between herds. For consistency it should be: number of calves weaned / number of cows mated to produce those calves (inclusive of pregnancy tested empty females).
Cows which calve regularly are likely to continue to do so. For some producers knowing the percentage of cows calving regularly from year to year is of value in measuring herd performance, and for identifying mothers of future breeders.
Foetal aging will give a profile of the conception pattern, and hence calving pattern. This is useful for determining the percentage of cows conceiving early in the mating period, and whilst lactating. This information is useful in seasonally mated situations where fine tuning performance is the objective. Replacement heifers should be preferentially selected from these early conceiving cows and conversely, calves from late conceiving cows should be considered cash flow.
Cows with long intercalving intervals are not as profitable to the business as cows which conceive early in the mating period and while lactating. By the time empty (and late pregnant) cows can be identified and sold they have represented a cost in pasture consumption, lick consumption, and handling.
Acceptable losses conception to weaning will depend on how extensive and tightly managed the operation is. In extensive situations, some may view greater than 10% losses as unacceptable. Diseases that cause conception and/or pregnancy failure include vibrio, trichomoniasis, leptospirosis, pestivirus and neosporosis.
INCLUDING WEANER INFORMATION
Other important measures are weaning weight and percentage of calves weaned at the first round. Weaning weight is a component of reduced age of turnoff, necessary for targeting premium markets. Reducing age of turnoff in turn increases the importance of fertility. Most producers would like as many calves as possible weaned at the first round. A significant “spread” of weaners is not as profitable as a tighter spread. A higher percentage of weaners at first round gives cattle a good start for earlier turnoff.
MEASURING PROFITABILITY
A fertile herd makes a significant contribution towards long term profitability. Increased reproductive rates enables greater selection pressure on replacement females and thereby greater opportunity for genetic progress and increased profitability.
Marketing non performers results in short term profitability. To improve long term profitability, the fertility of a herd needs to improve.
One way of measuring the profitability of a herd is to calculate Gross Margin per Adult Equivalent (GM/AE) and Gross Margin/ Breeder. The GM/AE can be compared against other herds and also within the herd (for both male cattle and female cattle). Different classes, or ages of female cattle can be compared. The GMs for groups of females in the breeding herd may range from $30.00 to $150.00 or more. This is ultimately driven by fertility, assuming acceptable survival rates. The weight of weaner produced will impact on male GM, and is also related to female fertility.
The Breeding Edge workshop covers aspects of this article in more detail. If interested contact your local beef officer.
TABLE 1: MEASURING HEIFER PERFORMANCE
| MEASURE (HEIFERS) | PROBLEM AREAS | KEY STRATEGIES |
| Age at joining /age at calving | Age/Weight at puberty | Nutrition, genetics |
| Heifer conception % | Weight at puberty | Nutrition, genetics, disease control |
| 1st calf Heifer conception % | Condition score at calving Weight at calving | Nutrition (inc spike feeding), genetics, early weaning, seasonal mating |
| Mating period/calving spread | Body condition score, sub fertile and infertile bulls | Genetics, bull fertility (BBSE), season |
TABLE 2: MEASURING MATURE COW PERFORMANCE
| MEASURE (HEIFERS) | PROBLEM AREAS | KEY STRATEGIES |
| Conception % | Condition/weight,lactational anoestrus, bulls,reproductive disease | Nutrition, genetics, vaccination, seasonal mating, strategic weaning. |
| Branding % | Foetal and calf losses (disease, genetic defects, cow factors, predators, stress) | Eliminate problem cows (and don’t breed from daughters) Predator control Disease control |
| Weaning % | All of above | All of above |
| Wet cow conception % | Lactational anoestrus, condition/weight | Seasonal mating, nutrition, genetics, genotype |
| Conception pattern (ie % early conceptions in mating period, spread in conception by month) | Bulls (infertile, sub fertile), reproductive diseases, poor nutrition | Bull fertility (BBSE), vaccination (for vibrio, etc) Adjustment to mating times |
| Intercalving interval (ICI) | Condition/weight, anoestrus Bulls, disease | Nutrition, genetics, strategic weaning |
| % losses conception to weaning | Foetal and calf losses | Vaccination, Nutrition, genetics |
| Breeder / Mature cow weight | Mature size vs pasture availability | Breeding Objectives matching environment and animal requirements |
TABLE 3: MEASURING WEANER PERFORMANCE
| MEASURE (HEIFERS) | PROBLEM AREAS | KEY STRATEGIES |
| Average weaning weight (1st round, 2nd round) | Time of calving, low inherent growth rates Nutrition Dry season lactations | genetics, seasonal mating, nutrition (inc spike feeding) |
| Proportion weaners 1st round | Calving creep (later and later calves due to season, disease, and long ICI) | Nutrition, genetics, vaccination, seasonal mating, strategic weaning |
| Weight of calves weaned/cows mated | Time of calving, Low growth Nutrition | All of above |
