Calves and Heifers VCSN642

James D. Ferguson, VMD, MS
Section Animal Production Systems
ferguson@vet.upenn.edu

An excellent web site: http://www.calfnotes.com organized by Jim Quigley
                              

Goals: Calve by 22 to 24 months of age and greater than 1200 lbs (large breeds)
	(80% of adult weight)
	First breeding by 13 to 15 months of age >750 lbs (large breeds) (52% adult wt.)
		Puberty at 43% of adult weight
	Average daily gain > 1.58 lbs/day (large breeds)
	Separate from adults in first 6 months of life
	Economical cost of rearing (third biggest expense on farm)
Calves at birth are nonruminants
	Reticulorumen is undeveloped
	Lack sucrase and secrete limited amylase – cannot digest starch well
	Cannot digest plant proteins well
	Cannot digest unsaturated fats well
	Dependent on milk sugars (lactose) and glucose, milk protein, and milk fat
	Liquid diets composed of Milk, milk replacers made from milk, fermented colostrum
	Development of the rumen wall and papillae depend on grain intake
		Muscle development and epithelium development
			Depend on dry feed intake – particularly grain
			Read Calf Note "Development of Rumen Epithelium"
		Substrate – volatile fatty acids (VFA)
			Butyrate>propionate>acetate
			Need grain to ferment to butyrate
			Develops rumen epithelium
		Bacteria needed to produce VFA
			Bacteria ubiquitous in environment
			Early bacteria are aerobic; intake of dry feed changes bacteria to anaerobic population similar to adults by 2 weeks
		Need fresh water to provide ample liquid for the rumen
		Coarse material placed in rumen (hay, sponges) have no effect on development
			dilute solutions of VFA placed in rumen stimulate development
		By 3 weeks of age rumen contractions can be measured if dry grain is offered from 3 days of age; if only milk is offered they are not observed.
		Cud chewing has been observed as early as 7 days of age
		By 2 months (4 to 8 weeks) the calf can be weaned
		By 4 to 6 months the rumen is fully functional
		By 9 months the rumen is same proportion of body weight as adult
Critical at birth: colostrum feeding
	Rich source of IgG (80 to 85%), IgA (8 to 10%), IgM (5 to 12%)
	Vitamin A, D, E
	Enzyme inhibitor trypsin to aid assimilation of immunoglobulins
	Lactoferrin, an iron binding protein which limits growth of bacteria
	Goal: within 4 hours of birth give 4 to 6 quarts (8 to 12 pounds)
		Absorption decreases rapidly after 6 hours of age
		By 12 hours passive transfer is poor due to closure of small intestinal microvilli
	4 quarts of colostrum – volume is more important than measuring quality
		Transfer adequate IgG – 80 to 100 g IgG given orally
			goal >= 10 mg/ml (>10 g/L) IgG in serum of calf
			calf must absorb 36 g of IgG to achieve 10mg/ml
		Consume 80 to 100 g IgG to achieve adequate serum concentrations
		Efficiency of absorption varies with age and ranges from 25% to 65%
		Good quality colostrum has > 60 mg IgG/ml
		Can estimate quality with colostrometer, but more false transfer with measuring and estimating amount to give than just feeding 4 quarts
		Read Calf Note "Colostrum Feeding – How Much is Enough?"

	subtract 1 mg IgG for each degree below 22 oC
	add 1 mg IgG for each degree above 22 oC
	can freeze in zip lock bags, thaw slowly < 110 oF
	One cow – one calf for colostrum feeding

	Quarts colostrum (2 lb/qt)	mortality by 6 months of age
	1.0 to 2.0	15%
	2.5 to 4.0	10%
	4.0 to 5.0	7%

	must force feed 4 quarts to get adequate volume into calf
		2 quarts – 50% of calves will have adequate transfer
		3 quarts – 75% of calves will have adequate transfer
		4 quarts – 90% of calves will have adequate transfer

	IgG in serum and mortality by 2 months of age
Monitor serum total protein as a tool for evaluation in calves >=24 hours of age
	>5.5 gm/100 ml total protein in calf serum (<7.5 g/dl; dehydration>7.5)
	5.0 to 5.5 questionable, <5.0 inadequate

Colostrum replacers (>100 g IgG/dose) or supplements(<100 g IgG/dose) can provide a supplement but are not as adequate as colostrum as a management practice.
	Regulated by USDA Center for Veterinary Biologics
		Must raise serum IgG above 10 mg/ml to be called a replacer
	provide extra IgG as a colostrum supplement
	desireable to have >75 g IgG per dose if used as a colostrum replacer
		many products contain only 30 to 45 g IgG per dose
	sources of  IgG: blood, milk/colostrum, or eggs
	Lifeline™ - serum derived product; absorption 15 to 38%
	Whey products – 25 to30 grams IgG per dose; poor absorption; 5 to 7%
	Freeze dried colostrum products from cows; poor absorption; 5 to 7%
		First Milk;
		Colostrx; 30 g IgG per dose ($8.95/lb)
		Immu Start – 50 g IgG/dose from Grade A dairies
	Calf’s Choice Total (gold, silver, bronze) – colostrum product
		60 g IgG/dose, 100 g IgG/dose, 120 g IgG/dose
		Results have been good with this product
	Efficiency of absorption can be calculated:
		((Blood IgG g/L x plasma volume)/IgG dose) x 100
			1 g/l = 1 mg/ml
		8 g/L x 45 kg x .091 / 100 g x 100 = 32.8%
			8 g/L = IgG concentration in plasma at 24 hours of age
			45 kg = body weight
			.091 = plasma volume as percent of body weight
			100 g = dose of IgG fed orally
	Colostrum can be refrigerated for 1 week before quality declines
	Colostrum can be frozen for up to a year and maintain quality
		Freeze in 1 to 2 liter (quart) lots – zip lock bags work well
			1 to 2 gallon zip lock bags
		Thaw with warm water (<120 oF) or microwave on low power in short periods (< 1minute), pouring off liquid periodically to avoid over heating
	If a cow produces more than 18 lb of colostrum, IgG concentrations will be reduced. Sufficient colostrum has >= 35 g of IgG/L. If colostrum production is greater than 18 lb, concentration of IgG maybe less than this and the colostrum should be fed on days 2 and 3 postcalving.
	Do Not feed bloody colostrum.
	Do Not feed colostrum from Johne’s positive cows
	Failure of passive transfer has consequences:
		Increase in diarrhea, pneumonia, death
		Decreased average daily gain to 180 days of age
		Increased age at first calving
		Decreased first lactation production
		Fewer calves with pneumonia eventually calve
	Causes of failure of passive transfer
	Calves left with dam, unattended, have lower IgG consumption and lower serum concentrations
	too little fed, too late is most common cause
	weak, stressed calf will absorb less as time of absorption decreases
	E. coli organisms can attach to gut walls and inhibit absorption
	Excessive protein intake can decrease absorption
		Super charging colostrum with colostrum replacer

Colostrum Quality
	Formation in last 2 to 4 weeks of gestation
	Adequate dry period necessary > 35 days
	Leakage of milk: IgG drops by 50% from first to second milking
	Age of dam – third lactation and older cows have more IgG in colostrum
Composition of colostrum and milk (from PSU Circular 311, Foley and Otterby, JDS 61:1033, 1978)

		Milking
	Component	1st	2nd	3rd	5/6
	Total solids	23.9	14.1	13.6	12.9
	Fat, %	6.7	3.9	4.4	4.0
	Protein, %	14.0	5.1	4.1	3.1
	Lactose, %	2.7	4.4	4.7	5.0
	Vitamin A, ug/dl	295	113	74	34
	IgG, %	6.0	2.4	1.0	0.1
	IgG content can range from 2% to 23% across cows

	Separate calves into individual hutches or calf kennels
	Ventilation to remove moisture and stale air
		10 cfm/100 lb calf
	Adequate dry bedding: straw, sawdust
	Milk feeding once to twice a day
	Fresh water

What about cold? Thermal neutral zone is 15 to 28 oC (59 to 82 oF) for young calves (<21 days of age)
	By 21 days of age lower critical temperature is 5 oC (41 oF)
	Keep dry and draft free
	Additional energy in milk (feed) needed to support calf
		Below 15 oC (59 oF) need .022 Mcal/kg0.75/oC to maintain body temperature
		Body weight 40 kg: extra milk replacer needed
			Temp 15 oC	0.38 kg milk replacer (.84 lbs)
				0.35 kg milk (0.76 lbs)
			Temp 0 oC	0.50 kg milk replacer (1.11 lbs)
				0.46 kg milk (1.01 lbs)

Young calves need a liquid diet composed of milk, milk replacer, or fermented colostrum
	Esophegeal groove diverts milk to abomasum away from rumen
	Functions to 12 weeks of age

Milk versus milk replacers in calves
	Whole milk has a nutritional content on a dry matter basis of

	Fat	30%	colostrum   6.7%
	CP	25%	colostrum 14.0%

	Milk replacers typically have a content of:
		20 to 27% CP
		10 to 20% fat

	Read Calf Note "Some Measures of Milk Replacer Quality"
	Traditional milk replacers have contained 20% crude protein and 20% fat (top quality, DM basis)
	Protein should be from milk protein sources
		casein, whey proteins
	Cheaper replacers have 10% fat – problem in cold weather
	Cheaper replacers have soy protein sources
	Egg, plasma proteins, wheat proteins can be substituted for milk proteins

	Production of milk proteins for use in milk replacers
	Sources are from cheese production (whey proteins) butter industry (casein and whey proteins)
	(source: http://www.merricks.com/tech_milkreplacerguide.html)

	Fat sources are often lard or grease of swine origin or animal fats
		Milk fat is 95 to 97% digestible
		Lard and choice white grease are 88 to 96% digestible
		Coconut oil is 92 to 96% digestible
		Palm oil is 92 to 96% digestible
	Carbohydrate in milk is lactose; lactose is high in whey protein sources
		Milk replacer should contain 40 to 45% lactose on a DM basis;
			(milk is 39% lactose)
		Acceptable carbohydrate sources in calves are lactose, dextrose, glucose, and galactose. Starch and sucrose are not acceptable.
		Traditionally liquid is fed at 8 to 10% of body weight in two feedings/day up to 4 to 5 days of age and then can be fed once a day
			The MR added to water is 1% of body weight at birth
			Fixing this amount to 1% of birth weight encourages starter intake
				Liquid milk – 2 quarts twice a day (8 lbs of milk/day)
				Milk replacer – 1.1 lb powder plus 7 lb water in two feedings
				Fermented colostrum – 5 to 6 lbs 2 to 3 lbs water
		Milk has higher CP and fat on a DM basis (30% fat, 25% CP) but is expensive unless waste milk is used
			pasteurized milk for biosecurity reasons
			145 oF for 30 minutes
			161 oF for 15 seconds
			201 oF  for 0.1 seconds
How?  Nipple bottle, nipple bucket, open bucket
	Options: MR, waste milk, whole milk, or fermented colostrum
	Fermented colostrum: collect 6 to 10 milkings
		Clean trash cans, plastic, covered; ferments in 10 to 14 days
		Room temperature (60 to 80 oF is ideal)
		One cup butter milk, stir once a day (propionic acid1%, acetic acid, .7%)
		Feed 2 to 1 with warm water, 8 to 12 lbs/day diluted mixture
		10% of body weight (6 lb oF for 30 minutes colostrum, 3 lb water 90 lb calf)
		Use within a month
How long on milk (liquid)? 4 to 8 weeks
	When consuming 1.5 to 2 lb starter two to three days in a row
Traditional program: liquid feeding
	First three days – feed colostrum from dam
		8% to 10% of body weight/ divided in two feedings
	After day three to 42 to 56 days of age:  8% to 10% of body weight whole milk
		1 lb of milk replacer in 7 lbs water
	Day three offer starter free choice
	Offer water free choice
	First seven days, feed BID
	After seven days may feed SID
Dry starter
	Offer free choice from 7 days of age, put some in mouth to encourage to eat Fresh daily
	Wean when consuming 1.5 to 2 lb/day for 2 to 3 consecutive days
	Maximum 4 to 5 lbs/day starter consumption
	Palatable, coarse, 18 to 20% protein, 7 to 8% molasses
Should hay be offered?
	Good quality hay may be offered – alfalfa or grass
	VFA’s stimulate rumen papillae development
	Concern if a lack of “scratch factor’ rumen parakeratosis may develop
		Parakeratosis has not always been associated with reduced growth
	Coarse starters are preferred versus fine textured starters
	Not clear how much benefit to hay offered to calves on liquid
Rapid growth program – first 3 to 6 months grow at 1.8 to 2.0 lb/day
	Typical growth rates are 0.3 lb/day on conventional program!
	Newer goals – grow more rapidly with higher protein MR to increase lean tissue deposition. Taller, leaner calves
	Double birth weight by 56 days of age
		40 kg to 80 kg (88 lbs to 176 lbs, 1.57 lb/day gain)
		Rapid growth try to achieve rates of 1.8 to 2.0 lb/day
	Pasteurized milk or milk replacer with 25% to 28% CP with 15% to 20% fat (costs $8 to $10 more per 50 lb/bag)

	1.5% body weight = 650 g DM/day		2 to 7 days of age
		1.5 lb MR in 11 lb water
	2.0% of body weight = 1.0 kg DM/day		8  to 42 days of age
		2.2 lb MR
		Offer starter free choice
	1.0% of body weight = .5 kg DM/day		43 to 50 days of age
	Feed starter only		50 to 57 days of age
	Move to super hutch		58 days of age

	Calf Starter	22 to 24% CP with high quality sources
		1.1 Net energy mcal/lb dm
		10 to 15% lipid
		17 to 19% NDF (soy hulls, citrus pulp, beet pulp)
	Fat content of milk replacer can depress starter intake; therefore MR with 15% fat may be preferable except in cold weather. If do not consume sufficient starter, rumen will not develop adequately and calves will stall at weaning.
	Increase costs $40 to 50/calf

Other additives in MR and/or starter:
	Vitamin A, D, E; 20,000 to 30,000;  5,000; 20 to 100 IU/lb, respectively
	B vitamins in starter
	Calcium and phosphorus in starters (.60%, .40%, respectively)
	Trace mineral supplements in starters
	Iron (100 to 150 ppm); selenium (0.10 ppm)
	Coccidiostat	deccox can be added to milk
		Bovatec, Deccox, or Rumensin can be included in starter
	Antibiotics	oxytetracycline or neomycin
A typical calf starter can be composed of
	Cracked Corn	52.0%
	Rolled oats	20.0%
	Soybean meal	20.0%
	Molasses, liquid	5.0%
	Limestone	1.0%
	Dicalcium Phosphate	0.25%
	TM salt	0.20%
	Animal fat	1.50%
	Vitamin supplement	0.05% (plus coccidiostat)
Postweaning – socialize with super hutch or group pen
	4 to 8 calves/group (2 to 4 months of age)

	calf starter: 4 to 5 lbs per calf
	forage; hay good quality, grass or legume - free choice
	some recommend high group TMR
	others hold off on high moisture feeds until 4 months of age
	avoid poor ventilation
	extreme differences in size

after 3 months of age, calves can be placed on a “grower” grain
	generally lower in CP than a starter
	fed up to 6 months of age
			starter	grower
	Cracked Corn		52.0%	55%
	Rolled oats		20.0%	15%
	Soybean meal		20.0%	20%
	Molasses, liquid		5.0%	7%
	Limestone		1.0%	2%
	Dicalcium Phosphate		0.25%	1%
	TM salt		.20%	.5%
	Animal fat		1.50%	-
	Vitamin supplement		0.05%	0.05%
		A	3,000 IU/lb	2,000 IU/lb
		D	500 IU/lb	400 IU/lb
		E	15 IU/lb	10 IU/lb
	<------plus coccidiostat------>
	Read Calf Note "Coccidiostats in Calf Starters"
	Group within 200 lb of each animal – don’t want large size discrepancy

	what do you see in this picture?
Hutches – good But what do you see here?
	Heifers managed in a group pen
	Heifers managed in group pens similar to “kennels”
	modified Virginia style system
	Calf kennels
Heifers after weaning:
Time and cost to raise a Holstein Heifer from 180 kg (400 lbs) to 360 kg (800 lb)

Group	ADG KG/D	TOTAL COST, $	TIME TO GAIN 180 KG	COST/D $/D	TOTAL FEED COST, $	TOTAL COST/KG $/KG	FEED/DAY $/D	FEED/KG $/KG
1	0.37	491	488	1.00	225	2.69	0.46	1.23
2	0.46	419	396	1.06	205	2.31	052	1.12
3	0.59	340	305	1.11	177	1.87	0.58	0.97
4	0.85	262	214	1.22	149	1.43	0.70	0.82
5	1.1	264	172	1.53	172	1.46	1.00	0.95

	Issues on growth and development

Prepubertal growth concerns:
	Excessive energy intake can impact on mammary development by decreasing ductal tissue development. Ductal tissue provides the framework for further development of secretory cells. Gains over ?  Danish work >.60 kg/day
Mammary Growth
	Phases of growth
		Isometric - same rate as body: birth to 3 months
			10-12 m to 3 months of gestation
		Allometric - faster than rate of body: 3 months of age to 10-12 months
			3 months of gestation to calving

Growth curves for average and top herds	Average daily gains 0.7 kg/day (1.54 lb/day)
Clost to .7 kg (1.54 lb/d)	Until last two months prior to calving

Size at calving is important
	Body weight at calving and milk production
	408 kg =   900 lb	add milk
	466 kg = 1025 lb	300 kg
	600 kg = 1320 lb	600 kg
	646 kg = 1421 lb	700 kg
	681 kg = 1498 lb	800 kg
	>1150 lb body weight sufficient
	Small heifers – dystocia risk

Goals to strive for:
	Heifers can be freshened at 22 - 24 months
		reduced total cost of rearing
		increased milk produced per day
	ADG >.7 kg/d and less than 1.0 kg/d
		1.54 lbs/d to 2.2 lbs/d
Pitfalls to avoid:
	1. Too high NDF in animals <175 kg
		Excessive forage in ration of young animals
	2. Imbalance in absorbed protein and energy
		particularly on silage based diets
	3. Decrease in ADG in late pregnancy
		> 150 days of gestation

	Assessing ADG
	Weigh tape a group of heifers Put data into a spreadsheet Calculate slope by age
	Too young, maybe too small
	Milk production will be reduced

Feeding after 4 months of age
	2 to 4 months	3 to 5 lbs of grain mix; 2 lbs of hay
	4 to 6 months	2 to 4 lbs of grain, corn silage and haylage and reduction in hay
	6 to breeding	high forage ration
		High haylage is preferable to corn silage to keep from fattening
	Pregnancy to two months prior to calving high forage ration, little grain is needed
	Two months to calving	higher grain diet and less forage as pregnancy requirements
		Increase and dry matter intake decline

Some terminology used in NRC for growth
	Shrunk body weight (SBW) = 96% of body weight
	SBW = animal weight after an overnight fast-no feed or water
	Empty body weight (without ingesta) = 85.5% of body weight
	= 89.1% of SBW
	SBW is used to calculate NEm requirement
	NEm is the fasting heat production
	SBW is used to determine the amount of net energy available for growth in the diet, after computing that needed for NEm
	Gain is then reported as shrunk weight gain
		Empty body weight is used to develop equations to predict the energy required for shrunk weight gain because net energy requirements are a function of of the proportion of fat and protein in the empty tissue gain.
		Empty body gain is 96% of shrunk weight gain
	Why all this adjustment – as an animal grows, they are bigger and can eat more. As they eat more, the intestinal tract increases in volume of ingesta. Therefore live weight gain is confounded by increases in intestinal weight, which is not skeletal gain or body tissue gain. Shrunk and empty weight gain adjust for intestinal gain.
Composition of Gain
	Height and weight are strongly correlated, which makes it possible to describe growth with linear measurements. However, animal growth cannot be directly used to compute energy and protein requirements for growth.
		1. net energy for gain (NEg) is defined as energy content of tissue deposited during growth
			a. it is a function of the proportion of fat and protein in empty body gain and this changes with age or size relative to mature body  size.
			b. the percentage of protein diminishes and the percentage of fat  increases in the empty body as the animal matures. “Chemical” maturity occurs when weight gain contains little additional protein.
		2. most of the height – weight relationships are from Holstein cows and relationships differ in different breeds. Because chemical composition varies depending on mature size and gender, body composition may differ among animals for similar weights. Body weight needs to be scaled to account for these differences.
			a. scaling is done by coparing weight to a standard reference weight, the weight at which skeletal development is complete and empty body fat is 25% with a BCS of 3.0 (1 to 5 scale)
			b. mature weights of cattle vary from 400 kg to 680 kg (882 to 1500, lb)
Equations used to make size scaling adjustments
	Equivalent shrunk body weight (EQSBW) = SBW x (478/MSBW)
	RE, Mcal = 0.0635 x EQEBW0.75 (retained energy)
		EQEBW = 0.891 x EQSBW
		0.0635 x (0.891xEQSBW)0.75
		0.0635 x (0.891xSBWx(478/MSBW))0.75
		0.0635 x (0.891x0.96xBWx(478/MSBW))0.75
		The average Holstein has a mature BW of 677 kg (SBW=650 kg)
			1493 lb (SBW = 1433 lb)
	Net Protein in gain is calculated
		NP, g/d = SWG x (268 – (29.4 x (RE/SWG))
			SWG = ADG x .96 shrunk weight gain
			Empty body gain is = shrunk weight gain
	Absorbed protein requirement is calculated from the NP
		MPgrowth =  NP / (.834 – (EQSBW x .00114))
		MPgrowth =  NP / (.834 – ((BW x 478/(677)) x .00114))
		Efficiency of protein utilization from young calves to first lactation animals for growth decreases from 79% at 50 kg of body weight to 29% at 500 kg of body weight
	Prediction of gain from diet
		Energy available for gain after maintenance energy is met is calculated as follows:
			SWG = 13.91 x NEgdiet0.916 x EQSBW-0.6837
			SWG = 13.91 x NEgdiet0.916 x (BW*478/MBW)-0.6837

Maintenance requirement = 0.086*SBW0.75
	Deposition of energy and protein as body weight increases