Interrelationships between sex and dietary lysine on growth performance and carcass composition of finishing boars and gilts1

Abstract

The main goals of this study were to determine whether boars and gilts respond differently to the standardized ileal digestible lysine to net energy ratio (SID Lys:NE) and model the response to optimize growth performance. A total of 780 finishing pigs, 390 boars and 390 gilts (Pietrain NN x (Landrace x Large White), with an initial individual body weight of 70.4±9.2 for boars and 68.7±8.0 kg for gilts, were used in a 41 day dose-response experiment. Pens (13 pigs/pen) were randomly allocated to a dietary treatment (2.64, 3.05, 3.46, 3.86, 4.27 g SID Lys/Mcal NE) by block and sex, with six replicates per treatment and sex. Two isoenergetic diets (2,460 kcal NE/kg), representing the extreme SID Lys:NE, were formulated and then mixed. Pigs were individually weighed at day 0, 22 and 41, when the experiment finished. The differential effect of SID Lys:NE on growth performance and carcass composition between sexes was analyzed with orthogonal polynomial contrasts to compare the linear and quadratic trends in each sex. In addition, broken-line linear (BLL) models to optimize average daily gain (ADG), including average daily feed intake (ADFI) as a covariate, were fitted when possible. As expected, boars had a greater ADG and feed efficiency (G:F) (P < 0.001) than gilts, but there was no evidence of differences in ADFI (P = 0.470). Increasing SID Lys:NE had a greater linear impact on boars ADG (P = 0 .087), G:F (P = 0.003) and carcass leanness (P = 0.032). In contrast, gilts showed a greater linear increase in SID Lys intake per kg gain (P < 0.001) and feed cost per kg gain (P = 0.005). The best fitting BLL models showed that boars maximized ADG at 3.63 g SID Lys/Mcal NE (95% CI: [3.32-3.94]), although another model with a similar fit, compared with the Bayesian information criterion, reported the optimum at 4.01 g SID Lys/Mcal NE (95% CI: [3.60, 4.42]). The optimum to maximize ADG for gilts was estimated at 3.10 g SID Lys/Mcal NE (CI 95%: [2.74, 3.47]). Thus, the present study confirmed that boars and gilts have a different linear response to SID Lys:NE, explained by the greater protein deposition potential of boars. Likewise, BLL models indicated that boars require a higher SID Lys:NE to maximize ADG from 70-89 kg. These results suggest that split feeding of finishing boars and gilts could be beneficial in terms of both performance and cost return.

The Indigenous Prestice Black-Pied Pig Breed Differs from a Commercial Hybrid in Growth Intensity, Carcass Value and Meat Quality

“…Our findings are in accordance with other studies [5,23] where a significantly higher growth intensity was found in barrows than in gilts. For example, following the same breeding principles and age of pigs at slaughter, Peinado et al [23] reported a higher ADG in barrows than in gilts, by 113 g. However, in a significant number of studies, the differences in growth intensity between sexes are not so pronounced, in fact, they are often negligible, which suggests that this characteristic can differ depending on various factors, such as breeding systems, feeding strategies as well as genetic effects [24][25][26].…”

Quelles stratégies alimentaires pour couvrir les besoins nutritionnels des porcs mâles entiers et/ou immuno-castrés et pour réduire les risques d’odeurs de verrat dans la viande ?

“…Cela conduit à recommander pour les ME une formulation à 0,94 g LYS DIS /MJ EN en période de croissance (soit + 16 %) et à 0,81 g Lys DIS /MJ EN en période de finition (soit + 14 %). Aymerich et al (2020) concluent à une augmentation proche du besoin, + 17 % pour les ME par rapport aux femelles (0,91 vs. 0,75 g LYS DIS /MJ EN).…”

Strategies to Meet Nutritional Requirements and Reduce Boar Taint in Meat from Entire Male Pigs and Immunocastrates

“…Quiniou et al [ 26 ] estimated that the standardized ileal digestible (SID) lysine requirement is 0.1 g/MJ NE greater (grower period: 0.94 vs. 0.81 g/MJ NE; finisher period: 0.81 vs. 0.71 g/MJ NE) for entire males than for surgical castrates throughout the growing-finishing phase ( Figure 2 ). Aymerich et al [ 27 ] found a 17% greater SID lysine requirement for entire males (0.91 vs. 0.75 g SID/MJ NE) than for female pigs, especially in the finisher period. Interestingly, Moore et al [ 28 ] hypothesized that entire males might use the available amino acid more efficiently for growth compared to female pigs.…”