Nutrient Requirements of the Beef Cow

Transcription

1 Nutrient Requirements of the Beef Cow Dennis Lunn, Ruminant Nutritionist Shur-Gain, Nutreco Canada Inc. 03/04

2 Nutrient Requirements of the Beef Cow Dennis Lunn, Ruminant Nutritionist Shur-Gain, Nutreco Canada Inc. Introduction: Beef cows have different nutritional requirements based on their stage of production. A dry cow in mid-gestation has different nutritional requirements compared to a cow in early lactation supporting a calf. Cows prioritize the nutrients they consume as followed: 1. Maintenance basic metabolic functions 2. Lactation produce milk for the calf 3. Growth weight gain and growth for heifers 4. Reproduction resume estrus and establish pregnancy If the nutritional requirements of one of these are not met then the next one in order will be compromised (i.e. if nutrient requirements for growth or lactation are not met then reproduction will suffer). There are 4 different production stages in the life cycle of the beef cow (Pre-calving, Postpartum, Lactating & Pregnant and Mid-Gestation). The nutritional requirements in each of these stages must be met in order to achieve optimal cow health and production. Most beef producers feed a grassy-type hay and/or pasture as the main forage. Under most situations this will be sufficient when fed along with a mineral to meet the nutrient requirements of the cow. However, during certain times of the year additional energy and protein should be supplemented. Underfeeding cows at certain times of the year could result in poorer cow/calf performance, body condition and reproduction. Pre-Calving Period: The pre-calving period is days prior to calving. The calf is growing very rapidly in the cow and the cow is getting ready for calving. Energy and protein requirements increase by as much as 20% during this period compared to mid-gestation. Cows must be in good body condition during this period in order to have healthy calves and have higher pregnancy rates during the subsequent breeding season. Cows need to be gaining weight at kg/day while heifers need to gain kg/d during this period. Cows deficient in energy and protein during this period will result in: Lighter calf weight Lower calf survival Poorer colostrum production and calf growth Delayed estrus and poorer reproduction 2

3 Ideally, cows should be in condition score of 3 ½ during this period (Appendix 2). Nutritional requirements for cows and heifers are during this period are: Table 1. Pre-Calving Requirements of Mature Cows and Heifers Required Diet Nutrient Density DMI (kg) %TDN NEm % CP % Ca % P (Mcal/d) Mature Cows st Calf Heifers DMI= Dry Matter Intake, TDN = Total Digestible Nutrients, NEm = Net Energy Maintenance, CP = Crude Protein, Ca = Calcium, P = Phosphorus First calf heifers require a higher level of nutrients because they are still growing and have a lower dry matter intake compared to mature cows. The majority of the nutrients can be provided from forages on the farm. Extra energy and protein should be provided to ensure cows produce healthier calves, better quality colostrum and have improved reproduction during the breeding season. It has been shown that cows that are gaining weight during this period had better reproduction. A mineral supplement should also be provided during this period. Vitamin E and selenium are very important. Feeding adequate levels will help reduce the incidence of retained placenta in cows and white muscle disease in calves. Vitamin A supplementation is also necessary. Deficiencies can result in vision problems. Nyctalopia or night blindness can occur with vitamin A deficiencies. Vitamin A is also important for normal epithelial cell development, which affects the linings of various organs in the body. Deficiencies can cause animals to be more susceptible to infectious diseases, diarrhea and the formation of kidney and bladder stones. Vitamin A deficiency can also cause reduced libido and spermatogenesis in bulls and low conception rates, re-absorption of the fetus, abortion and stillbirths in females. Vitamin A is high in growing and freshly stored green forages but is low in mature forages. Late gestation cows are more susceptible to vitamin A deficiency than at any other time. Weather conditions must also be considered prior to calving. Cold temperatures will increase the nutrient requirements of the cow. Temperatures of C will increase energy requirements by 20% while a temperature of 23 0 C increases energy requirements by 40%. Extra energy should be fed during colder weather to meet the cows requirements. With colder temperatures a grain mix or easy grow beef ration would be ideal to increase the energy status of the cow. Postpartum Period: This is the period days after calving and the period with the greatest nutrient demand on the cow. Cows must produce enough milk to support growth for the calf, repair their reproductive tracts from calving, resume estrus cycles, get bred and continue to grow if they are still young animals. If this cow is not fed properly during this period calf growth could be impaired (due to poor milk production) and the cows will lose excess condition. Cows in a negative energy and protein balance postpartum have 3

4 been shown to have poorer reproduction. Cows and heifers nutrient requirements during this period are: Table 2. Post-Calving Requirements for Mature Cows and Heifers Required Nutrient Diet Density DMI (kg) %TDN NEm % CP % Ca % P (Mcal/d) Mature Cows st Calf Heifers Similar to pre-calving, body condition is extremely critical, as it will effect reproduction. Cows should not be losing body condition during this period! Maintaining a condition score of 3-3 ½ during this period will ensure good reproduction. Cows losing condition during this period have been shown to have poorer reproduction. Mineral supplementation is also critical. Calcium and phosphorus requirements are highest postpartum due to milk production. Supplementing mineral will help ensure the cow gets enough minerals and vitamins. Lactating and Pregnant: This is a period of days after breeding (generally late summer and fall) up to when the calf is weaned. Nutritional requirements are still high; however, energy requirements decrease by 13% and protein requirements by 8% compared to the postpartum period. The cow will still be producing milk for calf growth but if the calf is being creep fed their nutritional requirements from milk will be decreased. Cows are pregnant at this time but fetal growth is very small which at this stage does not require much energy or protein. Heifers are still growing and must be fed adequately to support growth. Nutrient requirements for cows and heifers in this period are: Table 3. Lactating and Pregnant Cow and Heifer Requirements Required Nutrient Diet Density DMI (kg) %TDN NEm % CP % Ca % P (Mcal/d) Mature Cows st Calf Heifers Generally during this period cattle will be on pasture. Pasture alone should be able to support the nutrient requirements of the cow. A mineral supplement should be provided to ensure the cow meets her requirements for minerals and vitamins. Later on in the summer pasture quality will decline. A protein lick block can be used to extend the pasture for the cattle. Hay can also be supplemented during this period to extend the pasture. 4

5 Mid-Gestation: This is the day period immediately after the calves are weaned to days prior to calving. Nutritional requirements are at their lowest during this period due to the cows being dry and the nutrient requirements of the fetus still being small. Energy and protein requirements are 23% and 36% less than during the lactating phase. This is an ideal time to put condition back onto thin cows due to their low nutrient requirements. Separate thin cows and heifers from cows in good condition! Give these thin cows and heifers some extra energy to get body condition back on them. Studies have shown that thin cows will have poorer reproduction compared to cows in good condition. It takes days to increase one body score on a cow. Feeding extra energy during this period allows the time to get cows back into good condition resulting in better reproduction during the breeding season. Ideally cows should be in a condition score of 3 ½ during this period. Heifers still need to gain kg of body weight during this period so a higher energy diet is required to achieve this. Nutritional requirements during this period are: Table 4. Mid-Gestation Nutrient Requirements Required Nutrient Diet Density DMI (lb.) %TDN NEm % CP % Ca % P (Mcal/d) Mature Cows st Calf Heifers During mid-gestation medium quality hay alone will provide the protein and energy needed by the cow. If corn silage is fed it should not be fed free choice. Cows will become too fat! If hay is in short supply crop residues could be used during this period. Straw can make up to 50% of the diet but should be supplemented with hay and grain to meet nutrient requirements. Corn Stover pasture is another option that can be fed. The energy and protein requirements can be met if 2/3 corn stover and 1/3 good quality hay are fed. Most corn stover fields can provide between 1-2 months grazing per cow per acre (i.e. 30 cows on 30 acres for 1-2 months). The ideal time to have cows on a corn stover pasture is right after the field has been harvested. Cows will get the most use out of it at this time. Thin cows should not be fed crop residue diets. There is not enough energy to increase body weight during this period. With feeding any crop residue abomasal impaction could occur. Ensure cows are receiving energy and protein from other sources other than the crop residue. A mineral supplement should be fed during this period in order to provide the cow with enough minerals and vitamins to meet her requirements along with the growing fetus. Feed wastage can be an issue in feeding beef cows. University research has shown that cows can waste up to 43% of their hay! Feeding hay free choice without any feeder structure or feeding hay on the ground causes the most waste. Using a round bale feeder has been shown to reduce wastage by up to 80%. Feed losses would only be about 5-6%. Another way to reduce feed wastage is with the use of a TMR grinder mixer. Minerals and other additives can be added in to ensure cows consume the correct amount. 5

6 Larger cow/calf herds using this method of feeding have been able to pay back for the mixer in a couple of years. Feed Additives: Many different feed additives can be fed to beef cows not only to improve animal health, but to also improve production. Ionophores can be fed anytime of the year. Options include monensin sodium (Rumensin) or lasalocid sodium (Bovatec). Ionophores will reduce the incidence of coccidiosis in cattle. Feeding an ionophore to cows will reduce the number of coccidia eggs being shed leading to a cleaner environment. Calves would be less likely to pick up coccidiosis. If calves are being creep fed, an ionophore could be added to the ration. Not only will it help prevent coccidiosis but also improve feed efficiency and improve weight gain. Ionophores in beef cow diets can also have additional benefits has they alter the population of the rumen bacteria. This will result in improved feed efficiency. On pasture ionophores can reduce the incidence of bloat by reducing rumen gas production and reducing the amount of foam being produced in the rumen. Other additives that can be added include yeast and organic selenium. Yeast will help with fiber digestion in the rumen and improve rumen function. Organic selenium can help with immune function in cows and help prevent white muscle disease in calves. It is most ideal for late gestation/early lactation cows. Organic trace minerals are another option that can be used. Organic zinc has been shown to improve hoof integrity while other organic trace minerals have been shown to improve reproduction. 6

7 TYPICAL PRE-CALVING DIETS Mature Cows and Heifers: Feed Ingredient Hay (8-10% protein) Hay (10-13% protein) Hay (14%+ protein) Hay Corn Silage Feeding Level kg (21-24 lbs.) 2.3 kg (5 lbs) (22-25 lbs.) kg (3-4 lbs.) kg (24-27 lbs.) kg (2-3 lbs.) kg (15-19 lbs) kg (10-15 lbs) kg (2-3 lbs) Typical analysis for forages is in appendix 1. Hay can be fed free choice. Feed according to body condition. Thin cows and heifers need extra energy for improved reproduction, colostrum production and calf viability. Water and salt should be available free choice. 7

8 TYPICAL POST-CALVING DIETS Mature Cows and Heifers: Feed Ingredient Hay (8-10% protein) Hay (10-13% protein) Hay (14%+ protein) Hay Corn Silage Feeding Level kg (23-30 lbs) 2.27 kg (5 lbs) kg (22-28 lbs) 2.3 kg (5 lbs) kg (21-28 lbs) 2.3 kg (5 lbs) kg (18-22 lbs) 7.0 kg (15 lbs) 2.3 kg (5 lbs) Hay can be fed free choice. When cows are on pasture a mineral supplement should be provided to meet the cows mineral and vitamin requirements. Thin cows and heifers should be fed higher levels of in order to improve milk production, body condition and reproduction. Water and salt should be available free choice. 8

9 TYPICAL LACTATING AND GESTATION DIETS Mature Cows and Heifers: Feed Ingredient Good quality pasture Shur-Gain pasture mineral Hay (8-10% protein) Shur-Gain pasture mineral Hay (10-13% protein) Shur-Gain pasture mineral Hay (14%+ protein) Shur-Gain pasture mineral Feeding Level Free Choice kg (28-30 lbs) kg (27-28 lbs) (24-28 lbs) Hay can also be supplemented to extend the pasture. can be used to help extend the pasture season or to improve body condition in thin cows and growing heifers. A complete list of Shur-Gain pasture mineral products is attached at the end of this article. Water and salt should be available free choice. 9

10 TYPICAL MID-GESTATION DIETS Mature Cows and Heifers: Feed Ingredient Hay (8-10% protein) Shur-Gain beef cow mineral Hay (10-13% protein) Shur-Gain beef cow mineral Hay (14%+ protein) Shur-Gain beef cow mineral Hay Corn Silage Shur-Gain beef cow mineral Feeding Level kg (22-26 lbs) kg (21-24 lbs) kg (20-22 lbs) kg (15-16 lbs) 4.5 kg (10 lbs) Hay can be fed free choice. If crop residues are being fed make sure that hay is also fed to meet the cows energy and protein requirements (along with a mineral). For thin cows and heifers 2-5 pounds of can be fed to add additional body weight. Water and salt should be available free choice. 10

11 Shur-Gain Products Designed for the Cow/Calf Operation Shur-Gain Easy Grow HF Beef Ration. This product is to be fed at a rate of kg/head/day (2-5 lbs) and is ideal for improving body condition of thin cows and heifers and increasing milk production in the nursing cow. Shur-Gain Easy Grow Beef Ration. This product is to be fed at a rate of kg/head/day (2-5 lbs) and is ideal for improving body condition of thin cows and heifers and increasing milk production in the nursing cow. Shur-Gain Beef Cow Premix (Plain or Medicated). This mineral is designed to be fed to beef cows to meet their mineral and vitamin requirements under medium to high quality forage conditions. It can be fed at a rate of 100 g/head/day. Rumensin can be added as an aid in the prevention of coccidiosis in cattle. Shur-Gain Fresh Start Beef Cow Mineral. This mineral is designed for the late gestation/early lactation beef cow. It contains organic selenium and higher levels of vitamin E to improve immune function in cows and calves. It also contains organic trace minerals to improve animal performance. It can be fed at 100 g/head/day. Pasture Mineral Beef Premix. This mineral is designed for pasture-based diets to meet mineral and vitamin requirements. Expected intake would be 100 g/h/d. Free-Choice Pasture Mineral (with Bovatec). This mineral is designed for pasturebased diets to meet mineral and vitamin requirements and designed for the prevention of coccidiosis. Expected intake is 100 g/h/d. Optimizer Mineral. This mineral is designed to be fed free choice on a pasture-based diet to meet mineral and vitamin requirements. It has been designed to withstand the elements of weather (i.e. rain). Expected intake is 100 g/h/d. Custom Beef Cow Mineral. This mineral is designed to be fed to beef cows to meet their mineral and vitamin requirements. It contains a high level of salt to improve mineral intake. Expected intake is 150 g/h/d. TMV Salt for Cattle. This mineral is designed to be fed to beef cows to meet their mineral and vitamin requirements under high quality forage conditions. Expected intake is 50 g/h/d. Pasture Mate Beef Cow Mineral. This mineral is designed for pasture-based diets to meet mineral and vitamin requirements. It contains chelated zinc to improve animal performance. Expected intake is 100 g/h/d. 11

12 Appendix 1. Typical Forage Analysis (% DM) Forage %TDN NEm (Mcal/kg) CP Ca P Brome Hay (Mid Bloom) Brome Hay (Mature) Timothy Hay (Mid Bloom) Timothy Hay (Full Bloom) Alfalfa Hay (Mid Bloom) Alfalfa Hay (Mature) Red Clover Hay Corn Silage Pasture (Spring) Pasture (Summer) Pasture (Fall) Wheat Straw NRC Nutrient Requirements of Beef Cattle, 1996 Appendix 2. Body Condition Scoring of Beef Cattle Score 1: Short ribs feel sharp. Tail head has no fat. Hip bones, tail head and ribs are easily seen. Score 2: Short ribs feel rounded rather than sharp. There is some tissue over the tail head and hip bones. Individual ribs no longer visible. Lack of fill in brisket region. Score 3: Firm pressure is needed to feel the short ribs. Fat can be felt around the tail head. Score 4: Can no longer feel short ribs with firm pressure. High degree of fat over ribs and tail head. Brisket starting to fill out. Score 5: Short ribs completely buried by fat. Tail head and hip bones are almost buried in fat. Animal has blocky appearance and difficulty moving. 12