Table 3.

Effect of lipid supplementation to lactation diets on the change in subsequent wean-to-estrus interval (WEI) and subsequent farrowing rate^a,b

					Normal temperatures		High temperatures
Study	Referencec	Sows, nd	Sourcee	Level	Δ WEI, d	Δ Farrowing rate, %	Δ WEI, d	Δ Farrowing rate, %
1	[42]	64	Animal fat	10	−3.2		8.3*
2	[43]	52	Dried-fat	10	2.4	0.7
3	[24]	112	Corn oil	10	2	2.4
4	[30]	36	Soy oil	5	0.2*
5	[31]	84	A-V blend	2			1.4	10.0*
				4			1.3	14.1*
				6			1.2	7.2*
6	[32]	55	A-V blend	2				13.2*
				4				4.2
				6				13.2*
			CWG	2				11.6*
				4				5.8
				6				13.9*

^aSummary of the results from 6 published studies from 1983 to 2012 that were not included in previous reviews and reported on supplemental dietary lipids in lactating sows diets

^bImprovement of lipid supplementation relative to lactation diets containing no added lipids

^cReferences are presented in chronological order

^dn refers to the number of observations per treatment

^eAnimal-vegetable blend (A-V blend), choice white grease (CWG)

*P < 0.05