Dairy nutritionists historically balanced milk cow rations for phosphorus at .45 to .5 % DM of the total ration. New studies have shown a high producing milk cow only requires a diet at .38% DM. Thirty-seven farms were studied to determine and compare P feeding levels in Oregon. The results of the project were then incorporated into educational programs. The average farm studied was over feeding by 18%. Eighty-nine percent of producers surveyed indicated this project increased their understanding of the problem we face as an industry. Approximately 50% of producers participating reduced P feeding on their farm

Downing, Troy

French, Patrick

Higgs, Kathryn

Peters, Amy

English

Clemson University: TigerPrints

The Journal of Extension Volume 45 Number 3 Article 12 6-1-2007 Convincing Oregon's Dairy Industry They Have a Problem with Phosphorus Troy Downing Oregon State University Extension, troy.downing@oregonstate.edu Patrick French Oregon State University Extension, patrick.french@oregonstate.edu Amy Peters Oregon State University Extension, amy.peters@oregonstate.edu Kathryn Higgs Oregon State University Extension, khiggs@oda.state.or.us This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License. Recommended Citation Downing, T., French, P., Peters, A., & Higgs, K. (2007). Convincing Oregon's Dairy Industry They Have a Problem with Phosphorus. The Journal of Extension, 45(3), Article 12. https://tigerprints.clemson.edu/joe/vol45/iss3/12 This Research in Brief is brought to you for free and open access by the Conferences at TigerPrints. It has been accepted for inclusion in The Journal of Extension by an authorized editor of TigerPrints. For more information, please contact kokeefe@clemson.edu. 	 JOEHOME JOURNAL GUIDELINES ABOUT	JOE CONTACT NATIONAL	JOB	BANKCurrent	Issues Back	IssuesJune	2007	//	Volume	45	//	Number	3	//	Research	in	Brief	//	3RIB4Convincing	Oregon's	Dairy	Industry	They	Have	a	Problem	withPhosphorusAbstractDairy	nutritionists	historically	balanced	milk	cow	rations	for	phosphorus	at	.45	to	.5	%	DM	of	thetotal	ration.	New	studies	have	shown	a	high	producing	milk	cow	only	requires	a	diet	at	.38%	DM.Thirty-seven	farms	were	studied	to	determine	and	compare	P	feeding	levels	in	Oregon.	Theresults	of	the	project	were	then	incorporated	into	educational	programs.	The	average	farmstudied	was	over	feeding	by	18%.	Eighty-nine	percent	of	producers	surveyed	indicated	thisproject	increased	their	understanding	of	the	problem	we	face	as	an	industry.	Approximately	50%of	producers	participating	reduced	P	feeding	on	their	farm.	IntroductionHistorical	research	has	shown	a	benefit	in	overall	cow	performance	with	high	levels	of	dietaryphosphorus	(>.45%P).	Some	research	has	suggested	increased	levels	of	phosphorus	increased	drymatter	intake	and	ultimately	increased	milk	yield	(Kincaid,	Hillers,	&	Cronrath,	1981).	Furthermore,Alderman	(1963)	determined	that	deficiencies	in	dietary	phosphorus	decreased	reproductiveperformance	in	dairy	cattle.	For	years	dairy	nutritionists	have	designed	dairy	rations	to	ensureadequate,	if	not	excessive	amounts	of	phosphorus.With	environmental	concerns	building	in	the	country	during	the	1990's,	the	National	ResearchCouncil	(NRC)	conducted	a	re-evaluation	of	the	importance	of	phosphorus	in	dairy	cattle	diets.More	recent	studies	indicated	the	old	recommendation	was	too	high	and	that	something	wasmisleading	or	inaccurate	in	the	older	feeding	studies.	With	this	new	information,	the	NRC	publisheda	new	dietary	phosphorous	recommendation	of	0.38%	of	the	diet,	much	lower	than	the	previousrecommendation	of	0.55%	of	the	diet	made	in	1988	(NRC,	2001).Changing	the	diet	from	one	that	is	overfeeding	phosphorus	to	one	that	meets	the	animalsnutritional	needs	can	have	significant	impacts	on	P	in	the	manure	and	total	P	accumulation	on	thefarm.	Lowering	phosphorus	levels	in	the	diet	from	0.48%	to	0.38%	decreased	the	phosphoruscontent	in	the	manure	by	44%	(Cerosaletti,	Fox,	&	Chase,	2004).	Making	this	feeding	change	willTroy	DowningRegional	Dairy	AgentTillamook,	Oregontroy.downing@oregonstate.eduPatrick	FrenchDairy	NutritionCorvallis,	Oregonpatrick.french@oregonstate.eduAmy	PetersLivestock	and	RangeCoos	Countyamy.peters@oregonstate.eduKathryn	HiggsOregon	Department	of	Agriculturekhiggs@oda.state.or.usOregon	State	University	Extensionreduce	the	load	of	phosphorus	on	dairy	farms	and	allow	for	a	more	manageable	wastemanagement	program.Effective	educational	programs	often	are	ones	that	find	ways	to	involve	learner	participation	andthat	use	statistics	that	students	can	relate	with,	no	matter	whether	your	audience	is	producers,nutritionists,	or	other	Extension	agents.	Conversations	with	leading	dairy	nutritionists	in	2002-03indicated	very	few	had	made	significant	ration	P	changes.	No	nutritionist	in	Oregon	admitted	toreducing	P	levels	in	lactating	cow	diet	down	to	.38%	as	recommended	by	the	National	ResearchCouncil.	Essentially	they	had	nothing	to	gain	by	reducing	phosphorus	to	.38%.	They	argued	a	littleextra	was	"good	insurance."	In	the	spring	of	2003,	a	project	was	developed	to	survey	producerknowledge	of	phosphorus	and	document	phosphorus	feeding	practices.ObjectivesThe	objective	of	this	study	were	to:Access	the	levels	of	phosphorus	in	lactating	and	dry	cow	rations	on	Oregon	dairy	farms.Use	a	written	survey	to	help	understand	the	current	phosphorus	knowledge	of	Oregon	dairyfarmers,	and	use	as	a	teaching	tool	in	follow-up	visits.Document	phosphorus	feeding	practices	on	Oregon	dairies.Use	survey	information	to	engage	producers	in	Extension	programs	and	provide	Oregon	dataas	"real	life"	examples.Work	in	partnership	with	the	dairy	producers	and	their	nutritionists	to	change	current	feedingpractices	in	an	effort	to	alter	levels	of	phosphorus	excreted	while	maintaining/improving	theperformance	of	the	dairy	cows.ProceduresA	field	study	consisting	of	37	Oregon	dairy	farms	was	conducted.	Participating	farms	were	locatedin	the	western	region	of	Oregon	and	were	divided	in	two	regions	based	upon	geographic	location	offarms:	valley	(V)	and	coast	(C).	Valley	comprised	17	farms	residing	in	the	Willamette	Valley.	Theremaining	20	farms	were	located	on	the	coast	of	Oregon	in	Coos	and	Tillamook	counties.	Thesetwo	areas	represent	the	major	dairy	areas	in	Oregon.	In	addition	to	geographic	location,	farmswere	classified	as	either	small	(S)	or	large	(L).	Farms	with	herd	size	smaller	than	the	herd	sizemedian,	for	each	region,	were	classified	as	S.	Likewise,	farms	with	herd	size	larger	than	herd	sizemedian,	for	each	region,	were	classified	as	L.Each	farm	was	visited	on	three	separate	occasions	to	collect	data.	Each	farm	visit	was	scheduledto	be	4-6	weeks	a	part	to	monitor	the	farm	over	time.	Data	collection	included	ration	informationand	feed	samples	for	both	lactating	and	dry	cows,	as	well	as	fecal	and	urine	samples	from	thelactating	and	dry	cows.	Individual	feeds,	fecal	matter,	and	urine	were	then	analyzed	forphosphorus.A	five-page	survey	covering	topics	of	soil	testing	and	commercial	fertilizer	use,	phosphorusknowledge,	and	manure	management	were	issued	to	participating	farmers	on	the	initial	visit.	Themajority	of	the	questions	were	multiple	choice.	However,	a	few	fill-in-the-blank	questions	were	alsoincluded.	The	survey	was	conducted	in	a	manner	that	was	compliant	with	the	regulations	of	theOregon	State	University	Institutional	Review	Board.	This	allowed	producers	to	complete	the	surveyon	a	voluntary	basis,	and	all	results	were	collected	anonymously.	The	survey	was	used	tounderstand	the	current	participant	understanding	of	phosphorus	issues	related	to	manure	and	soilfertility.Results	of	surveys	were	recorded,	and	response	percentages	were	tabulated	for	each	question.	Apoint	system	was	devised	to	measure	the	accuracy	of	responses	for	multiple	choice	and	true-falsequestions.	An	overall	score	for	phosphorus	questions	was	determined	by	summing	the	pointsreceived	for	each	response	within	each	question.	This	score	was	then	divided	by	the	total	numberof	responses	for	that	individual	question.Multiple	lactating	and	dry	cow	diets	existed	on	several	of	the	farms	visited.	Many	of	the	producersgrouped	cows	(i.e.,	according	to	stage	of	lactation	and/or	number	of	lactations)	to	more	closelymeet	nutrient	requirements.	As	a	result	of	grouping	strategies	on	farms,	each	of	the	differing	cowgroup	diets	was	recorded,	and	subsequent	manure	and	urine	samples	were	collected.	On	average,the	number	of	lactating	and	dry	diets	fed	on	farms	was	2	and	1.4,	respectively.	In	most	cases,group	size	was	recorded	or	obtained	from	DHI	records.	Data	were	analyzed	as	repeated	measuresusing	the	mixed	procedure	of	SAS	(1996).ResultsThe	average	herd	size	in	the	study	was	339	cows	and	ranged	from	50	to	1650,	with	an	average	of277	acres	receiving	manure	ranging	from	65	to	1000	acres.	Producers	were	divided	into	groupsbased	on	geographic	region	(V	or	C)	and	herd	size	(S	or	L),	and	characteristics	of	these	groups	aresummarized	in	Table	1.Out	of	the	37	surveys	issued,	a	total	of	34	surveys	were	completed	for	a	92%	response	rate.	Thesurvey	was	modeled	after	a	similar	one	done	in	the	upper	Midwest.	This	survey	was	issued	tofarmers	in	southeastern	Minnesota	and	west	central	Wisconsin.	Similarities	in	questions	betweenthe	original	and	present	survey	allowed	for	comparisons	between	soil	testing	and	commercialfertilizer	use,	P	information,	manure	management,	and	farm	characteristics	between	the	Midwestand	Oregon.	The	results	of	the	survey	and	the	comparison	between	the	Midwest	and	Oregon	wereused	mainly	as	a	talking	point	to	engage	producers	in	Extension	activities.Table	1.Characteristics	of	Participant	Farms		 Coast Valley	 Small Large Small LargeNumber	of	farms 10 10 8 9Herd	size,	cows 101 278 198 800Milk	Yield,	lbs/d 56.5 64.9 77.7 78.3Grazing	(months) 7.8 6.7 4.8 2.4Total	acres	receiving	manure 171 292 209 428Owned 117 181 92 335Rented 55 111 117 93Acres/Cow 1.69 1.05 1.06 0.54Based	upon	the	responses	received	by	the	participating	Oregon	dairy	producers,	it	appears	thatrespondents	were	more	knowledgeable	about	P	information	when	compared	to	the	Midwestproducers.	When	asked	about	the	P	levels	in	manure	and	grass	crops,	60%	of	the	Oregonrespondents	answered	correctly,	compared	to	a	40%	correct	response	rate	from	the	participatingMidwest	producers.	Oregon	respondents	also	had	more	knowledge	of	the	rate	at	which	P	movesthrough	the	soil.	However,	when	asked	about	the	effect	of	excessive	soil	P	on	the	environment,only	12%	of	Oregon	respondents	answered	correctly.	Overall,	this	survey	was	an	excellenteducational	tool	to	engage	producers	in	conversations	about	phosphorus.Table	2	illustrates	the	levels	of	phosphorus	feeding	as	well	as	fecal	and	urine	phosphorus	levels.Participating	Oregon	dairy	producers	were	feeding	0.40%	P	(DM	basis)	to	lactating	dairy	cattle.Based	upon	milk	production	records,	a	typical	farm	should	feed	0.34%	P	(NRC,	2001).	Phosphoruslevels	in	diets	studied	were	18%	higher	than	currently	recommended.	In	comparison	to	a	Virginiafield	study,	Oregon	producers	are	feeding	less	P.	This	study	reported	dietary	P	content	of	lactatingcow	rations	was	0.49%	(Sink,	Knowlton,	&	Herbein,	2000).Table	2.Levels	of	P	for	Diet,	Feces,	and	Urine	for	Lactating	and	Dry	Cows	Stage	of	LactationRegion Herdsize SE PC1 V2 S3 L4 	 Region HerdsizeLactatingDiet	P	(%	DM) 0.41 0.39 0.40 0.40 0.01 0.12 0.76Fecal	P	(%	DM) 0.87 0.97 0.89 0.95 0.04 0.08 0.27Urine	P	(mg/dl) 2.22 2.94 2.13 3.04 0.66 0.41 0.30DryDiet	P	(%	DM) 0.30 0.32 0.30 0.32 0.01 0.42 0.46Fecal	P	(%	DM) 0.77 1.02 0.88 0.91 0.07 0.01 0.71Urine	P	(mg/dl) 1.40 2.05 1.52 1.94 0.26 0.08 0.251C	=	Coast.2V	=	Valley.3S	=	Small.4L	=	Large.Dietary	P	levels	of	lactating	diets	between	region	(P	=	0.12)	or	herd	size	(P	=	0.76)	did	not	differ.	Adifference	between	feeding	levels	of	dietary	P	within	herd	size	was	expected	because	L	herds	aremore	apt	to	use	professional	services,	such	as	nutritionist,	compared	to	S	herds.	In	addition,	Vherds	were	expected	to	have	lower	dietary	P	due	to	more	consistent	rations	since	C	herds	grazemore	often.Average	fecal	P	from	all	lactating	cow	samples	was	0.92%	(DM	basis).	The	overall	mean	for	urinaryP	was	2.58	mg/dl.	These	data	were	similar	in	P	concentration	of	both	manure	and	urinary	P	asreported	in	a	previous	study	(Wu,	Satter,	Blohowiak,	Stauffacher,	&	Wilson,	2001).	Interestingly,although	P	intake	is	similar	for	region	and	herd	size,	the	fecal	P	output	was	greater	(P	=	0.08)	for	Vherds,	resulting	in	a	lower	apparent	digestibility.Our	project	showed	on	average	we	were	over	feeding	P	by	18%.	Some	on	the	study	wereoverfeeding	by	as	much	as	100%.	At	18%,	the	average	farm	in	our	study	needs	an	additional	100acres	to	apply	manure	in	an	agronomic	fashion.	Some	farmers	have	easily	made	reductions,	whileothers	are	finding	some	of	the	feedstuffs	they	are	using	are	inherently	high	in	P,	making	thereduction	more	difficult.The	fact	that	they	are	looking	at	P	in	their	feedstuffs	and	attempting	to	reduce	imports	is	really	amajor	success.	In	a	survey	of	producers	who	were	part	of	this	project,	100%	that	responded	saidthis	project	helped	them	understand	the	challenges	of	over	feeding	P	on	their	farm,	and	89%indicated	this	project	improved	their	understanding	of	the	problem	we	face	with	phosphorus	as	anindustry.	Approximately	50%	made	changes	in	the	feeding	program	to	reduce	P	levels	in	theirration.The	results	of	this	project	have	been	used	in	many	fashions	to	educate	the	rest	of	Oregon's	dairyindustry	of	this	issue.	A	survey	of	nutritionists	at	one	workshop	indicated	72%	planned	on	reducingP	feeding	levels	on	dairies	they	work	with.SummaryBefore	this	project,	dairymen	were	placing	their	trust	in	their	nutritionists	to	balance	their	rationsfor	them.	Dairy	nutritionists	had	no	incentive	to	reduce	phosphorus	overfeeding,	and	many	did	notappreciate	the	magnitude	of	the	problem	they	were	helping	to	create.	Data	from	this	project	havebeen	shared	with	both	the	dairy	operators	and	nutritionists	and	has	changed	the	way	both	viewthe	problem.Often	it	is	difficult	to	stimulate	changes	in	behavior	through	traditional	workshop	and	newsletterteaching	methods.	This	project	is	an	example	of	how	data	gathered	from	dairies	throughout	thestate	could	be	used	as	the	basis	of	an	effective	Extension	education	program.	We	have	known	foryears	that	data	generated	locally	is	very	powerful	when	working	with	local	audiences,	but	thecredibility	and	influence	it	can	have	in	an	educational	program	like	this	one	continues	to	supportthis	idea.ReferencesAlderman,	G.	(1963).	Mineral	nutrition	and	reproduction	in	cattle.	Vet.	Record.	75:1015-1018.Cerosaletti,	P.	E.,	Fox,	D.	G.,	&	Chase,	L.	E.	(2004).	Phosphorus	reduction	through	precision	feedingof	dairy	cattle.	J	Dairy	Sci.	87:2314-2323.Kincaid,	R.	L.,	Hillers,	J.	K.,	&	Cronrath,	J.	D.	(1981).	Calcium	and	phosphorus	supplementation	ofrations	for	lactating	cows.	J.	Dairy	Sci.	64:754-758.National	Research	Council.	(2001).	Nutrient	Requirement	of	Dairy	Cattle	(7th	Rev.	Ed.)	Natl.	Acad.Sci.,	Washington	D.C.SAS	User's	Guide:	Statistics,	Version	8	Ed.	1999.	SAS	Inst.,	Inc.,	Cary,	NC.Sink,	S.	E.,	Knowlton,	K.	F.,	&	Herbein,	J.	H.	(2000).	Economic	and	environmental	implications	ofoverfeeding	phosphorus	on	Virginia	dairy	farms.	J.	Anim.	Sci.	78	(Suppl.	2):	4.Wu,	Z.,	Satter,	L.	D.,	Blohowiak,	A.	J.,	Stauffacher,	R.	H.,	&	Wilson,	J.	H.	(2001).	Milk	production,estimated	phosphorus	excretion,	and	bone	characteristics	of	dairy	cows	fed	different	amounts	ofphosphorus	for	two	or	three	years.	J.	Dairy	Sci.	84:1738-1748.Copyright	©	by	Extension	Journal,	Inc.	ISSN	1077-5315.	Articles	appearing	in	the	Journal	become	the	property	of	theJournal.	 Single	 copies	 of	 articles	may	 be	 reproduced	 in	 electronic	 or	 print	 form	 for	 use	 in	 educational	 or	 trainingactivities.	Inclusion	of	articles	in	other	publications,	electronic	sources,	or	systematic	large-scale	distribution	may	bedone	only	with	prior	electronic	or	written	permission	of	the	Journal	Editorial	Office,	joe-ed@joe.org.If	you	have	difficulties	viewing	or	printing	this	page,	please	contact	JOE	Technical	Support©	Copyright	by	Extension	Journal,	Inc.	ISSN	1077-5315.	Copyright	Policy

Convincing Oregon\u27s Dairy Industry They Have a Problem with Phosphorus

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Convincing Oregon\u27s Dairy Industry They Have a Problem with Phosphorus

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