Cattle and Sheep Nutrition

1. Cattle and Sheep Nutrition

2. Digestion Cattle and sheep: Natural diets primarily plant material. High in fiber (plant cell walls) Animals uniquely adapted to extract energy from fiber: Complex stomachs Rumination

3. Ruminant Digestive System

4. Mouth Mastication: Ruminants initially swallow food without much mastication. Later, food is regurgitated and masticated (rumination) Rumination reduces particle size of fiber and exposes sugars to microbial fermentation.

5. Mouth Saliva Aids bolus formation Moistens feed 160 to 180 liters when a cow chews 6 to 8 hours per day, but less than 30 to 50 liters if rumination is not stimulated (too much concentrate in the diet). No amylase Buffers in the saliva (bicarbonate and phosphates) neutralize the acids produced by microbial fermentation to maintain a neutral acidity which favors fiber digestion and microbial growth in the rumen.

6. Esophagus Tube from mouth to reticulorumen Functions Transports bolus via muscular contractions Downward and upward (rumination)

7. Complex Stomach

8. Reticulum Honeycomb surface Capture and retain dense particles Only particles that are small (< 1-2 mm) and dense (> 1.2 g/ml) move to the omasum.

9. Rumen Largest compartment: 100 to 120 kg of digesting material. Fiber particles remain 20 to 48 hours (bacterial fiber fermentation is slow) Extensive microbial fermentation Bacteria, protozoa, and fungi Population is diet and intake dependent Lined with papillae Increases surface area and absorption

10. Rumen Microbial fermentation produces: 1) volatile fatty acids (VFA): end-products of the fermentation of cellulose and other sugars 2) a microbial mass rich in a high quality protein. VFAs are absorbed through the rumen wall. Used as the major energy source and for the synthesis of milk fat (triglycerides) and milk sugar (lactose). Through belching about 1000 liters of gases per day.

11. Omasum Membranous leaves in lumen Sieve large particles � regulates food passage to abomasum Absorption of water, sodium, phosphorusand residual VFA.

12. Abomasum Glandular stomach Largest compartment prior to rumen development Secretion of strong acids and digestive enzymes. Digestion of feed fractions not fermented in the rumen (some proteins and lipids). Digestion of bacterial proteins produced in the rumen (0.5 to 2.5 kg per day).

13. Unique characteristics of ruminants Young ruminants have no functional rumen � they have reticular or esophageal groove Milk directly from esophagus to omasum Rumen development Stimulated by volatile fatty acids (VFA) Lambs � 8 weeks Calves � 6 to 9 months Rumination Regurgitation and remastication Eructation Emission of fermentation gases

14. Rumen fermentation Advantages Efficient utilization of fibrous feedstuffs Rumen microbes metabolize Hemicellulose and cellulose to VFA (acetate, propionate, butyrate). VFAs are used for energy. Efficient utilization of lower quality protein and NPN Conversion to higher quality microbial protein digested in the abomasum Production of water-soluble vitamins and vitamin K

15. Rumen fermentation Disadvantages Reduced utilization efficiency with higher quality feeds Reduced yield from digestible energy sources High converted to lower quality protein

16. Small Intestine Secretion of digestive enzymes by the small intestine, the liver and the pancreas. Enzymatic digestion of carbohydrates, proteins and lipids. Absorption of some water, minerals and products of digestion: glucose, amino acids and fatty acids.

17. Large Intestine Cecum (fermentation) and large intestine A usually small microbial population ferments the unabsorbed products of digestion. Absorption of water and feces formation.

18. Practical Implications Ruminants can use a greater variety of food sources than non-ruminant animals. The microbes living within the reticulo-rumen allow ruminants to convert fibrous feed (forages, crop residues and industrial by-products) and non-protein nitrogen (ammonia, urea) into highly nutritious and palatable food for humans (milk, meat).  Fibrous feed is necessary for the health of the cow because it maintains rumination and saliva production which are necessary for the proper function of the rumen and to obtain the desired bacterial population within the rumen.

19. Practical Implications A cow can eat forages (low energy feed) and concentrates (high energy feed). Large additions of concentrates to a ration should be gradual (over a period of 4 to 5 days) to allow the population of bacteria in the rumen to adapt to the new diet.  The feces of ruminants are rich in organic matter (undigested microbial debris) and inorganic matter (Nitrogen, Phosphorus and Potassium) that are excellent fertilizers.

20. Feeding Sheep Supplying the nutrient needs is the largest single production cost in all types of sheep operations. Goal is to maximize efficiency of converting feed into meat, wool, and milk.

21. Nutrient Requirements Water: Daily consumption in ewes: 0.72 gal in winter to 2.2. gal in summer. Water intake increases with the increased intake of DM, protein, or minerals, the temperature above 70�F, and the stage of production such as during the late gestation and lactation. Sheep can get water from feed, snow & dew, oxidation of feed/metabolic water, as well as drinking water - Thus, depending on the situation, can get by without drinking water!

22. Nutrient Requirements Energy Inadequate energy limits performance of sheep more than any other nutritional deficiency, especially during the late gestation and lactation. Deficiency - Results in reduced growth, fertility, wool quantity & quality, etc. Generally can satisfy the needs with good quality pasture, hay, or silage, but may need supplement (e.g., grains) immediately before & after lambing, conditioning for breeding, and finishing lambs.

23. Nutrient Requirements Protein The amount of protein is more critical than quality, i.e., microbial protein is often adequate. Green pastures provide adequate protein, but if mature or dry may need additional protein. Bypass protein might be beneficial Can use non-protein nitrogen in some instances.

24. Nutrient Requirements Minerals & vitamins In practice, the true "dietary" requirements vary considerably depending on the amount and nature of minerals. Most requirements can be met with under normal grazing and feeding habits, but trace mineral salt is usually fed free choice, and often contain Na, Cl, I, Co, Fe, Mn, and Zn.

25. Nutrient Requirements Although sheep need all the fat-soluble vitamins, normally, the forage & feed supply all the vitamins in adequate amounts. Exceptions: Vitamin A (grazing on dry or winter pasture for an extended period time) vitamin D (under confinement) The B vitamins are synthesized in the rumen, there is no need for supplementation.

26. Feeding Ewes Ewes are the backbone of the sheep enterprise Raise lambs & produce wool. Their nutritional status during the all stages of production is critical for optimum production During pregnancy - Determines the number of lambs born alive, lamb birth weight and survivability. During lactation - Critical for milk production.

27. Feeding Ewes Optimum feeding systems vary based on the system intense feeding of confined sheep supplementation of flocks on range forage. How a ewe should be fed? - Monitor changes inbody weight during lactation. Should lose about 5 to7% during lactation recover this during the post weaning period gain weight appropriately during gestation. Nutritional needs differ depending on the size,body conditions, and levels of production: may be useful to divide the flock into groups of ewes with similar needs?

28. Feeding Ewes - Flushing Flushing: Increase feed intake of ewes prior to and during mating to increase ovulation rate and thus lambing rate. Start about 2 wk before breeding until 2-3 wk into the breeding season. Turn ewes onto a lush, high-quality pasture just prior to breeding, or Supplement � to � lb of grain or pellets/day. Mature ewes respond better than yearlings or fat ewes Expected increase in the lambing rate: 10 to 20%.

29. Feeding Ewes - Gestation Many lamb deaths shortly after birth are due to poor nutrition during gestation With mature (3 to 8 years) ewe: Feed to maintain "normal" weightfrom weaning until about 15 wk ofpregnancy. Pasture and other "field feeds," Harvested feed: hay, haylage, corn or sorghum silage.

30. Feeding Ewes - Gestation Last 6 wk of gestation: About 70% of fetal growth during this phase: critical period! Poor nutrition: Lighter lambs at birth, uneven birth wt in twin & triplets, reduced wool follicle development, lower energy reserves of newborns, etc. Birth wt is a major factor affecting lamb mortality. Need 50 or 75% more feed if bearing a single & twin lambs, respectively. Nutrition during this phase influences milk production after parturition.

31. Feeding Ewes - Lactation A. Nutrient needs - Usually 2 to 3 times maintenance. B. Ewes with twin lambs produce 20 to 40% more milk than those with singles, thus have higher nutrient requirements. C. Milk production: a) Peaks 2 to 3 wks after lambing and then declines b) Ewes produce 3 to 6 + lb milk daily. c) Milk is the total source of nutrients for lambs during the first mo. and a significant proportion for the first 2 mo. D. Wean lambs at 8 wk - More efficient to feed the lamb directly than to feed the ewe to feed the lamb beyond 8 to 10 wk.

32. Feeding Ewes - Lactation Not necessary to feed the ewe very much for a day or so after lambing - Important to have plenty of fresh water By day 3, feed (as-fed basis) : 2� - 3 lb each of hay and ground ear corn, 4 - 5� lb hay plus 1 to 1� lb shelled corn, 8 to 10 lb corn silage plus � to 1� lb shelled corn + � lb soybean meal, or 10 lb alfalfa haylage plus 1� lb shelled corn.

33. Feeding Ewes - Lactation Daily feed intakes can be increased by feeding frequently: If the ewe is nursing one lamb, feed once a day, if she is nursing two lambs, twice a day, etc. Splitting the amount fed per day: reduces the potential for acidosis when more concentrates are fed.

34. Feeding Lambs Born with a nonfunctional rumen - need dietary sources of nutrients such as milk and milk replacer. Make sure that a lamb nurses within 1 hr or its chance of survival is limited most lambs nurse within 30 min after birth. Give access to dry feed immediately, some degree of rumen functionality appears within 2 wk or so. With continued consumption of dry feed, milk is no longer essential for good growth by 45 to 60 d of age.

35. Feeding Lambs � Creep Feed Advantages Increased weight gains, especially in twins & triplets - Up to 0.25 lb /d more Can be marketed at younger age - 1 to 2 mo earlier Moving lambs to the drylot earlier allows more ewes on available pasture. Start as soon as possible - set up when lambs are 7 to 10 d of age & on the location where they spend most of their time. Commercially prepared complete creep feeds Cracked, shelled corn, bran, rolled oats, molasses, soybean meal, and high quality, leafy alfalfa hay PLUS a complete supplement top dressed on the corn to provide added CP, Ca, vitamin E, Se, antibiotic, etc.

36. Feeding Dairy cattle

37. Feeding Dairy Calves Commercially, calves need to be separated from mother as soon as possible Health and vigor of calves at birth depend on the nutrition of the cow during the last 60 days of gestation - about 70% of birth wt of the calf during that time. Newborn calves have all the necessary organs of a ruminant digestive system, but their processes are similar to non ruminants. The rumen is not populated with the typical microbes until close to 60 d of age, thus necessary to provide milk/milk replacer in the beginning.

38. Feeding Dairy Calves Newborn calves have all the necessary organs of a ruminant digestive system, but their processes are similar to non ruminants. The rumen is not populated with the typical microbes until close to 60 d of age, thus necessary to provide milk/milk replacer in the beginning. Calf may be left with dam for 24 hr to get colostrum Then placed in a milk or milk replacer feeding program

39. Feeding Dairy Calves Feed milk replacer for about 3 weeks At about 1 week of age offer a starter ration High energy � high protein � low fiber grain mixes Based on corn � Soy bean meal Supplemented with minerals and antibiotics

40. Feeding Dairy Calves

41. Feeding Dairy Calves Milk Feeding Programs Liberal milk system Veal calves Herd replacements Limited milk system Conventional Feed milk, milk replacer, or stored colostrum at 8 to 10% of body wt until they start consuming 2 to 3 lb starter/day, at which time "milk feeding" can be decreased & no milk by 4 to 7 wk of age. Start feeding hay at 1 wk of age

42. Feeding Dairy Calves Milk Feeding Programs Limited milk system Early Weaning Off milk entirely by 1 mo of age - Requires good management practices and early adjustment to starter feeding. Suggested milk feeding program: 4-6, 5-7, and 3-4 lb milk/d for 0-3, 4-24, and 25-31 d of age At the time of weaning, in addition to milk, should be consuming "dry feed" at the rate of 1.5% of BW.

43. Feeding Dairy Calves Give hay at 5 � 10 days of age Limit Silage offerings before 3 months of age because of moisture content

44. Feeding Heifers: 4 to 12 months If heifers are properly introduced to solid feeds before weaning, the growing ration can be changed gradually so that they reach puberty at 15 mo of age. Rumen capacity - Not sufficient for the animal to satisfy the energy need from forages alone, thus feeding some grain is necessary until 1 yr of age. Summer - Pasture, hay and grain mix (3-7 lb/d depending on body size and forage quality Winter - Hay, silage and grain mix (3 -7 lb/d depending on body size and forage quality. The same forage and grain mix used for the milking herd can be used for heifers.

45. Feeding Heifers: 12 months to calving Sufficient rumen capacity to meet their nutrient needs from good quality forages. Should be gaining 1.5 to 1.8 1b per day. Feed grain mix only when/if forages are poor or limited in amount. Summer - Use pasture and (or) hay, and feed 2 to 8 lb of grain mix if necessary depending on the body size. Winter - Hay and silage, and feed 2 to 8 lb of grain mix if necessary depending on body size. Free-choice minerals (Ca, P, & salt, and trace minerals if feeding poor forages).

46. Feeding Heifers: 12 months to calving To breed at 15 mo, heifers should weigh 550 (Jerseys) to 800 lb (Holstein and Brown Swiss) Should gain about 1.75 lb/day from birth Growing heifers use available nutrients in an irreversible order: 1) Daily maintenance, 2) growth, and 3) ovulation and conception. Avoid over-conditioning to avoid impairment of the reproductive efficiency, and also reduced milk production because of fatty deposits in the udder. Management techniques for early conception "Flushing" - Increase the intake of all the nutrients to heifers with appropriate age. "Bypass protein" - Use during the first breeding period

47. Feeding Heifers: bred heifers Breeding to 60 days before the expected calving date Aim for growth, avoid excess fat deposition, especially in the udder. Last 60 days of gestation Start feeding a grain mix and increase gradually to adapt heifers to high grain intake needed for lactation after calving. By doing so: Can adjust the rumen population to increase microbes that ferment the specific feeds in the "lactation" ration. Can increase nutrient intake to increase body reserves necessary to support early lactation . . . plus own growth. Can provide for the increased demand for nutrients because of the rapidly developing fetus.

48. Feeding for Milk Production Systems used in the US depend on geographic area and availability of feedstuffs: Pasture system - "Traditional" system is continuing in areas of sparse human population. Drylot systems with minimum roughage and higher quantities of less bulky feeds such as concentrates - Being used in areas surrounding some of the larger cities.

49. Feeding for Milk Production Dairy cows consume a lot of feed/nutrients to achieve today's expected milk production Feed represents about 50% of the total production costs. The feeding program can determine the productivity of lactating dairy cows & profitability About 75% of the differences in milk production between cows is determined by environmental factors, with feed making up the largest portion. At peak production, may require 3 to 10 times as much as protein & energy vs late gestation, but the cow's appetite usually lags behind her nutritional needs.

50. Feeding for Milk Production The lactation and Gestation Cycle

51. Feeding for Milk Production The lactation and Gestation Cycle Milk production increases rapidly and reaches peak 6-8 wk after calving. Feed intake lags behind production, i.e., maximum DM intake does not reach until 12 to 15 wk after calving. Body reserves - Make up differences in the need & supply by mobilizing body stores. Often loose 90 to 135 kg of body wt

52. Forages The cow cannot consume enough forage to meet her nutrient needs during lactation Allowed to consume all the forage at their will, then may not have enough room left to consume necessary grains to meet the energy needs of high milk production Limit forage intake to 1.75 to 2.0% of boy wt Increase forage intake by feeding several times/day and providing a variety of forages

53. Concentrates Mixture of grains, mill feeds, protein supplements and minerals

54. Concentrates The kind of mixture to feed varies with the kind of forage fed (e.g., a high-protein mix will be needed with a low-protein forage), availability, and cost. The amount of concentrate fed depends on: Amount of forage consumed Amount of milk produced Composition of the milk produced

55. Concentrates Limit the concentrates to a maximum of 60% of the diet Higher levels of concentrate affect VFA profile and milk fat content

56. Phase Feeding Program Feeding periods/phases can be divided into four or five Phase 1: First 10 wk of lactation. Peak milk production - body stores are used to make up deficits in the nutrient intake. Phase 2: 10 to 20 wk or so of lactation. Maximum DM intake, and the intake is in balance with the needs Phase 3: The intake exceed the needs. The period to restore body reserves for the next lactation. Phases 4 & 5 - Dry period, and can be considered as only one phase: Phase 4 - Most of the dry period, and replete body reserves & regenerate secretory tissues for the next lactation. Phase 5 - The last 1 to 3 wk of prepartum. Start increasing grain intake to prepare the rumen for the increased nutritional demands

57. Phase Feeding Program Peak milk production (Phase 1) 1) Bring cows into peak milk production as soon as possible after calving Feeding slightly more grain than recommended until there is no increase in production & then adjusting the amount of grain accordingly. 2) Milk production increases rapidly, peaking at 6 to 8 wk after calving. 3) The most critical period for a dairy cow is from parturition until peak milk production: a) Objective for this phase is to increase feed intake as rapidly as possible! b) Increase grain intake 1 to 2 lb per day after calving to meet the energy needs. c) Avoid excessive grain (> 65% total DM) and maintain 17 to 19% acid detergent fiber in diet to reduce rumen disorders.

58. Phase Feeding Program Peak milk production (Phase 1) 3) The most critical period for a dairy cow is from parturition until peak milk production: d) Extra dietary protein permits more efficient use of body fat for milk production because cows are usually losing body weight. e) Feed more ruminally undegradable protein source (i.e., bypass protein) for high-producing cows in early lactation. Limit urea to 0.2 to 0.4 lb/day - urea is utilized less efficiently when total ration protein level is high. Increasing the energy density of the ration may help cows meet the energy requirement - Feed 1 to 1.5 lb of added fat per day may increase energy intake while maintaining adequate fiber intake. Buffers such as Na bicarbonate alone or in combination with Mg oxide may be beneficial during the early lactation - Aid in maintaining ruminal pH, which minimizes acidosis, reduce digestive upsets, and result in increased DM intake.

59. Phase Feeding Program Peak dry matter intake (Phase 2) 1) To maintain peak milk production, should achieve maximum DM intake as early in lactation as possible - 12 to 14 wk 2) With maximum DM intake: a) Can minimize the negative nutrient balance experienced during the early lactation. b) A conception rate is greater for ones in positive energy balance 3) Maximum DM intake will likely to reach 3.5 to 4% of body wt for most cows a) Grain intake may reach 2�% of cow's body wt, and forage intake (DM) should be at least 1-1�% of cow's body wt to maintain rumen function and milk-fat test. b) Should feed forages and grain several times daily. c) High-producing cows (i.e., > 70 lb 4% FCM) should be fed only natural protein and not urea

60. Phase Feeding Program Mid to late lactation (Phase 3) 1) Easiest phase to manage? - Milk production is declining and the nutrient intake exceeds the needs. Also, the cow is pregnant at this phase. 2) Keep in mind that young cows are still growing - i.e., Nutrient requirements for growth are 20% of the maintenance requirements for 2-yr-olds and 10% maintenance for 3-yr-olds. 3) Match grain intake to milk production 4) NPN is well utilized, use urea (0.4 to 0.5 lb/cow/day) to reduce feed costs. 5) Feed extra nutrients, if needed, to replace any body tissue lost during the early lactation - Cows are more efficient in replacing body tissue while lactating than during the dry period, but avoid over-conditioning.

61. Phase Feeding Program Dry period & bred heifers (Phases 4 & 5) 1) Cows need a short dry period as rest to prepare for the next lactation - The optimum dry period would be 6 to 8 wk! a) Shorter that 40 d? - Not enough time for udder regeneration, thus may reduce the production rate. b) Longer than 60 d? - Do not increase the production, and may result in excess body condition & calving difficulties. 2) Bred heifers a) Nutrient needs are slightly higher vs dry cows of similar size - Still growing! b) Good-quality hay can provide all the nutrient needs during the early gestation. c) Need some grains along with forages during the last 3 to 4 mo of gestation to support growth & provide nutrients for fetus. d) As with dry cows, should be in good condition but not too fat at calving. 3) Quality of forage may not be as critical during the dry period, but cows need sufficient feed to support both the unborn calf and to meet body reserves not replaced in the previous period.

62. Phase Feeding Program Dry period & bred heifers (Phases 4 & 5) 4) Nutrient needs can be met with only forages and no grain, but may be fed up to 4 to 6 lb of grain per day (0.5% of body wt) depending on the condition. 5) "Fat cow syndrome" - Feeding high levels of corn silage or grains may cause excess fat deposits in the liver region: a) "Fat cow syndrome" - Characterized by high blood lipids & fatty livers. b) May result in calving difficulties, displaced abomasum, ketosis, and other. c) Less likely to have problems with hay and (or) haylage vs corn silage. 6) About 2 wk before calving, increase grain feeding so cows are consuming 12 to 16 lb grain/day at calving (1% of body weight). a) Helps cows get accustomed to high grain intake needed after calving, and can reduce the occurrence of ketosis during lactation. b) Best to increase the amount of grains gradually, which may minimize the chance for milk fever