Protection of polyunsaturated fatty acids against ruminal biohydrogenation: Pilot experiments for three approaches

Protected or Unprotected Fat Addition for Feedlot Lambs: Feeding Behavior, Carcass Traits, and Meat Quality

Simple Summary

The use of lipids in ruminant diets aims to increase energy density without affecting the animal’s performance; however, its use can be toxic to the ruminal microbiota, which can be avoided with the use of protected fats. Diets with the inclusion of different fat sources (whole soybean grain, corn germ, calcium salt of fatty acids, and soybean oil) were tested to evaluate the effects of unprotected or protected fats on feeding behavior, carcass characteristics, and quality of the meat of feedlot lambs. The use of calcium salts from fatty acids in feedlot lambs’ diets improves the quantitative and qualitative characteristics of the carcass and meat.

Abstract

This study aimed to evaluate the effect of the inclusion of protected or unprotected fats in the diet of feedlot lambs on feeding behavior, productive characteristics, carcass traits, and meat quality. Forty male Dorper × Santa Inês lambs (22.27 ± 2.79 kg) were randomly assigned to treatments in a completely randomized design. The experimental treatments consisted of five diets: no added fat (NAF), whole soybeans (WSB), calcium salts of fatty acids (CSFA), soybean oil (SO), and corn germ (CG). The total intake of dry matter (DMI) (p < 0.001) and neutral detergent fiber (NDFI) (p = 0.010) were higher in the CSFA and NAF diets. Feeding behavior, morphometric measurements, physicochemical characteristics, and centesimal composition of the Longissimus lumborum muscle were similar between treatments (p > 0.05). The CSFA diet provided higher production (p < 0.05) and better-quality carcasses. The inclusion of fat sources increased the concentration of polyunsaturated fatty acids (p < 0.05). The use of calcium salts of fatty acids in feedlot lambs’ diets provides better quantitative and qualitative characteristics of the meat and carcass.

Effects of rumen-protected oil supplementation on finishing grazing beef cattle

The objective of this study was to evaluate the effects of rumen-protected oil (soybean and palm oil) in supplements for beef cattle during the fattening phase in pastures on the intake and digestibility of nutrients, animal performance, and carcass characteristics. Forty-eight noncastrated male Nellore cattle (15 ± 2 months and 389.5 ± 20 kg of body weight) were used in a completely randomized design to evaluate the following treatments: protein-energy supplement (PES) without rumen-protected oil (control: CO), PES containing palm rumen-protected oil (PRPO), PES containing soybean rumen-protected oil (SRPO), and PES containing a mixture of soybean and palm rumen-protected oil (SPRPO). The study lasted 112 days, and there was a decrease in crude protein intake (P < 0.05) and an increase in ether extract intake (P < 0.05) when rumen-protected oil was included in the supplements. In comparison to the palm rumen-protected oil supplement, the soybean rumen-protected oil supplement promoted a lower average daily gain (ADG) (P < 0.05); however, regardless of the rumen-protected oil source, an increase in the fat thickness of the subcutaneous tissue was observed. In addition, there was no difference in carcass gain (P > 0.05) regardless of oil source. Rumen-protected oil is a tool to increase the finishing of pasture-finished young beef cattle in the dry season.

Effects of flaxseed encapsulation on biohydrogenation of polyunsaturated fatty acids by ruminal microorganisms: feedlot performance, carcass quality, and tissue fatty acid composition

The objective of this study was to evaluate the efficacy of protecting PUFA within ground flaxseed against ruminal biohydrogenation by encapsulating them in a matrix consisting of a 1:1 blend of ground flaxseed and dolomitic lime hydrate (L-Flaxseed). Crossbreed heifers ( = 462, 346 ± 19 kg) were blocked by weight and randomly assigned to pens. Pens were assigned to 1 of 6 dietary treatments in a randomized complete block design. Treatment 1 consisted of a combination of 54.6% steam-flaked corn (SFC), 30.0% wet corn gluten feed, 8.0% roughage, and supplement (0% flaxseed). In treatments 2 and 3, a proportion of SFC was replaced with 3 and 6% flaxseed, respectively; in treatments 4, 5, and 6, SFC was replaced with 2, 4, or 6% L-Flaxseed, respectively. Cattle were fed for 140 or 168 d and then harvested in a commercial abattoir where carcass data were collected. Approximately 24 h after harvest, carcasses were evaluated for 12th-rib fat thickness, KPH, LM area, marbling score, and USDA yield and quality grades. Samples of LM were also obtained for determination of long-chain fatty acid profiles. Cattle that were fed diets with 4 and 6% L-Flaxseed consumed less feed than other treatments ( < 0.05), which adversely affected ADG. Compared with cattle fed 0% flaxseed, cattle in these treatments had lower final BW (18 and 45 kg less for the 4 and 6% L-Flaxseed treatments, respectively), less ADG (0.16 and 0.48 kg/day less for the 4 and 6% L-Flaxseed treatments, respectively), and lower carcass weights, dressing percentages, LM areas, backfat thicknesses, and marbling scores ( < 0.05). The addition of flaxseed or 2% L-Flaxseed did not affect performance or carcass traits ( > 0.05). Supplementation with flaxseed increased ( < 0.05) the concentration of α-linolenic acid (ALA) in meat (0.173, 0.482, 0.743 mg/g for 0, 3, and 6% flaxseed, respectively). Furthermore, proportionate increases in the ALA content of muscle tissue were 47% greater when flaxseed was encapsulated within the dolomitic lime hydrate matrix (0.288, 0.433, 0.592 mg/g for 2, 4, and 6% L-Flaxseed, respectively). Both products showed a linear response in ALA concentration ( > 99%; increases for Flaxseed and L-Flaxseed of 0.095 and 0.140 mg of ALA/g of tissue for each percentage of flaxseed added). This study indicates that a matrix consisting of dolomitic lime hydrate is an effective barrier to ruminal biohydrogenation of PUFA; however, adverse effects on DMI limit the amounts that can be fed.