Table 13.

Average fixed effects of Improvest [immunologically castrated barrows (IC)– physically castrated barrows (PC) and gilts] on loin quality¹

Item	IC	Gilt	PC	Effect IC vs. Gilt	Effect IC vs. PC	SED2	P-value
pH	5.59	5.55	5.60	−0.04	0.01	0.05	0.60
Instrumental color3
L*	48.52	48.03	48.25	−0.49	−0.27	0.90	0.69
a*	6.89	6.75	7.13	−0.14	0.24	0.46	0.31
b*	3.67	3.59	3.79	−0.08	0.12	0.45	0.72
Subjective quality4
Color	2.83	2.93	3.01	0.10	0.18	0.25	0.24
Marbling	1.74a	1.59a	2.07b	−0.15	0.33	0.22	< 0.01
Firmness	2.52a	2.53ab	2.72b	0.01	0.20	0.14	< 0.01
Loin composition
Moisture, %	74.61a	74.33ab	74.12b	−0.28	−0.49	0.50	0.02
Fat, %	2.01a	2.08ab	2.39b	0.07	0.38	0.31	0.03
Drip loss, %	2.78ab	3.14b	2.56a	0.36	−0.22	0.28	0.04
Cook loss, %	21.04	21.11	20.73	0.07	−0.31	1.36	0.83
WB Shear force, kg5	2.92	–	2.91	–	−0.01	0.08	0.82

¹Sources include Pauly et al. (2009), Boler et al. (2011a, 2012, and 2014), Lowe et al. (2014, 2016b), Tavárez et al. (2014, 2016), Harris (2014), and Elsbernd et al. (2016).

²Greatest reported.

³Minolta Colorimeter, D65 illuminant. L*, greater value indicates a lighter color; a*, greater value indicates a redder color; b*, greater value indicates a more yellow color.

⁴Evaluated according to National Pork Producers Council standards for color and marbling (NPPC, 1999) and firmness (NPPC, 1991).

⁵Warner-Bratzler shear force was conducted on chops aged 14 to 21 d postmortem.

^a,bMeans within row lacking common superscripts differ (P < 0.05).