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

Table 4 Least square means for blood metabolites and insulin concentration in dairy calves fed starters containing alfalfa hay with different particle sizes (small vs. long particles) with different lipid supplements (SBO vs. PLF, both 2.5% DM basis) (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
Glucose, mg/dL
d 53	97.8^ab,B	94.2^b,B	89.9B^c,C	109.0^aA	5.09	0.26	0.029	0.003
d 73	64.1^D	72.9^CD	69.2^CD	76.6^C	3.53	0.25	0.056	0.88
Overall	81.0^ab	83.4^b	79.5^c	93.7^a	4.94	0.104	0.004	0.036	0.008	0.98	0.90	0.024
BHB, mmol/L
d 53	0.12^b,CD	0.11^b,CD	0.08^c,D	0.15^a,C	0.03	0.908	0.077	0.009
d 73	0.25^B	0.33^A	0.31^AB	0.35^A	0.05	0.157	0.028	0.466
Overall	0.19	0.22	0.19	0.25	0.04	0.188	0.017	0.495	0.003	0.22	0.26	0.052
Total protein, g/dL
d 53	7.22	7.16	7.12	7.28	0.057	0.970	0.818	0.606
d 73	6.96	7.11	6.61	6.56	0.049	0.127	0.814	0.695
Overall	7.08	7.14	6.86	6.92	0.061	0.195	0.736	0.985	0.036	0.18	0.92	0.51
Triglyceride, mg/dL
d 53	56.1	43.0	60.1	56.3	1.98	0.14	0.14	0.43
d 73	33.5	26.3	28.0	30.2	0.79	0.83	0.51	0.21
Overall	44.8	34.7	44.0	43.1	1.07	0.25	0.10	0.17	0.006	0.18	0.35	0.96
Cholesterol, mg/dL
d 53	103	107	109	116	6.5	0.29	0.43	0.86
d 73	74.6	70.1	80.2	76.2	4.23	0.35	0.51	0.64
Overall	72.3	105	78.1	112	5.98	0.15	0.91	0.87	0.001	0.93	0.30	0.94
Blood urea nitrogen, mg/dl
d 53	24.2	22.9	24.7	21.8	1.34	0.69	0.035	0.43
d 73	16.5	18.2	17.8	16.8	1.02	0.94	0.88	0.27
Overall	20.4	20.6	21.3	19.4	1.17	0.87	0.23	0.18	0.002	0.87	0.13	0.69
Insulin, IU/L
d 53	8.16^b,B	7.41^b,BC	6.63^c,C	9.65^a,AB	0.614	0.357	0.006	0.001
d 73	9.96^AB	11.1^A	10.2^A	10.9^A	0.900	0.910	0.038	0.79
Overall	9.0^b	9.26^b	8.36^c	10.3^a	0.893	0.554	0.012	0.001	0.007	0.55	0.88	0.009

¹Treatments: alfalfa hay provided as small particle size supplemented with soybean oil (SP-SBO); alfalfa hay provided as small particle size supplemented with palm fatty acids (SP-PLF); alfalfa hay provided as long particle size supplemented with soybean oil (LP-SBO); alfalfa hay provided as long particle size supplemented with palm fatty acids (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 particle size × 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)
^A−DDifferent capital letters indicate differences of a variable across periods (interaction FPS × Lipid × T; P ≤ 0.05)

ISSN: 2049-1891