The type of lipid supplement has crucial implications for forage particle size in calf starter diets

Table 3 Least square means for structural growth indicators (cm) in dairy calves fed different alfalfa particle size (small particles vs. long particles) and lipid sources (soybean oil and palm fat) (n = 13 calves per treatment)

Item	Treatments¹				SEM	P-value²
	SP		LP			FPS	Lipid	FPS × Lipid	T	FPS × T	Lipid × T	FPS × Lipid × T
	SBO	PLF	SBO	PLF		FPS	Lipid	FPS × Lipid	T	FPS × T	Lipid × T	FPS × Lipid × T
Body barrel
d 53	112	113	111	112	5.4	0.44	0.78	0.74
d 73	114	115	118	119	6.1	0.039	0.19	0.55
Overall	113	114	114	115	5.8	0.048	0.67	0.71	0.007	0.54	0.093	0.69
Body length
d 53	60.0	59.1	59.8	60.2	0.84	0.99	0.98	0.82
d 73	62.8	63.3	64.2	63.8	0.91	0.55	0.91	0.66
Overall	61.7	61.1	62.2	61.8	0.86	0.50	0.62	0.89	0.003	0.74	0.77	0.44
Heart girth
d 53	98.6	97.2	97.5	99.2	1.19	0.62	0.91	0.14
d 73	105	104	103	107	1.41	0.95	0.26	0.31
Overall	101	101	100	102	1.50	0.78	0.34	0.064	0.001	0.71	0.42	0.94
Withers height
d 53	94.9^ab	92.2^b	90.7^c	96.8^a	1.52	0.84	0.083	0.001
d 73	99.0^ab	96.6^b	96.1^b	100^a	1.93	0.47	0.37	0.003
Overall	97.0^b	94.4^bc	93.6^c	98.7^a	1.85	0.52	0.05	0.018	0.009	0.73	0.48	0.34
Hip height
d 53	90.6	91.2	90.9	93.0	1.13	0.12	0.075	0.22
d 73	94.6	96.5	95.8	96.3	1.28	0.33	0.028	0.21
Overall	92.7	93.8	93.3	94.6	1.30	0.052	0.019	0.85	0.004	0.48	1.00	0.073
Hip width
d 53	19.0	18.3	18.4	18.6	0.78	0.83	0.63	0.44
d 73	20.1	19.8	20.7	20.3	0.80	0.30	0.51	0.79
Overall	19.5	19.0	19.6	19.4	0.73	0.53	0.41	0.73	0.001	0.36	0.88	0.47

¹Treatments: alfalfa hay provided as small particle size supplemented with soybean oil (SP-SBO); alfalfa hayprovided as small particle size supplemented with palm fat (SP-PLF); alfalfa hay provided as long particle sizesupplemented with soybean oil (LP-SBO); alfalfa hay provided as long particle size supplemented with palm fat (LP-PLF)
²Statistical comparisons: Forage particle size (FPS) = small versus long particle sizes; Lipid = soybean oil versus palm fatty acids; FPS × Lipid = interaction between alfalfa hay particle sizes and supplemental lipid; T = time; FPS × T= forage particlesize × time; Lipid × T= lipid source × time; FBS × Lipid × T = forage particle size × lipid source × time
^a–cDifferent small letters indicate differences of a variable within one period (interaction FPS × Lipid; P ≤ 0.05)

ISSN: 2049-1891