Ruminal In Vitro Protein Degradation and Apparent Digestibility of Energy and Nutrients in Sheep Fed Native or Ensiled + Toasted Pea (Pisum sativum) Grains

Effects of increasing levels of lasalocid supplementation on growth performance, serum biochemistry, ruminal fermentation profile, in vitro nutrient digestibility, and gas production of growing goats

Introduction

Lasalocid is a feed additive widely used in ruminant nutrition and plays a crucial role in improving livestock productivity, digestibility, immunity, and overall wellbeing. The current study was conducted to investigate the effect of different levels of lasalocid (LAS) supplementation on growth performance, serum biochemistry, ruminal fermentation profile, in vitro nutrient digestibility, and gas production of growing goats.

Methods

A total of 60 growing Aardi male goats with an average body weight of ~17.12 kg (3-month-old) were used for an 84-day trial. Animals were randomly divided into four treatment groups with 5 replicates of 3 goats each. All four groups were provided with a basal diet supplemented with lasalocid (LAS) at 0 (without supplementation; LAS0), 10 (LAS10), 20 (LAS20), or 30 (LAS30) ppm LAS/kg dry matter (DM). Feed intake was measured weekly, and goats were weighed every 2 weeks for an evaluation of the performance parameters. Blood samples were collected for the measurement of biochemical variables. In vitro nutrient digestibility and gas production were evaluated.

Results and discussion

The supplementation of LAS at level 30 ppm/kg DM increased (P < 0.05) the body weight gain and average daily gain without linear or quadratic effect. The serum concentrations of high-density lipoprotein were significantly (P < 0.05) higher in the LAS20 group than in other groups with linear and quadratic effects, while low-density lipoprotein concentration was significantly lower in the LAS20 group than in LAS0 and LAS30 with a linear effect. Different levels of lasalocid supplementation had no effect on the ruminal fermentation profile, in vitro gas production, and nutrient digestibility. In conclusion, the addition of LAS (20-30 ppm/kg DM) to the goat's diet can improve the growth performance and lipoprotein profile.

Feed Clusters According to In Situ and In Vitro Ruminal Crude Protein Degradation

Effective degradation (ED) of crude protein (CP) was estimated in vitro at 0.02, 0.05 and 0.08 h−1 assumed ruminal passage rates for a total of 40 feedstuffs, for which in situ ED was available and used as reference degradation values. For this, the Streptomyces griseus protease test was used. The differences between in vitro CP degradation and the in situ CP degradation values were lowest in legume grains and highest in cereal by-products and barley. The differences between in situ and in vitro ED were expressed using a degradation quotient (degQ), where degQ = (EDin vitro − EDin situ)/EDin situ. Among the tested feedstuffs, eight specific clusters were identified according to degQ for the assumed passage rates. The feedstuffs clustered in an unspecific way, i.e., feedstuffs of different nutrient composition, origin or treatment did not necessarily group together. Formaldehyde−treated rapeseed meal, soybean meal, wheat, a treated lupin, sunflower meal and barley could not be assigned to any of the clusters. Groupwise degradation (range of degQ for assumed passage rates are given in brackets) was detected in grass silages (−0.17, −0.11), cereal by-products together with sugar beet pulp (−0.47, −0.35) and partly in legume grains (−0.14, 0.14). The clustering probably based on different specific nutrient composition and matrix effects that influence the solubility of feed protein and limit the performance of the protease. The matrix can be affected by treatment (chemically, thermally or mechanically), changing the chemical and physical structure of the protein within the plant. The S. griseus protease test had reliable sensitivity to reflect differences between native feedstuffs and treatments (thermally or chemically) that were found in situ. The in situ results, however, are mostly underestimated. The clustering results do not allow a clear conclusion on the groupwise or feed-specific use of carbohydrate-degrading enzymes as pre- or co-inoculants as part of the S. griseus protease test and need to be tested for its potential to make this test more conform with in situ data.

Evaluation of the Nutritive Value and Digestibility of Sprouted Barley as Feed for Growing Lambs: In Vivo and In Vitro Studies

The main objective of this study was to investigate the effects of freshly sprouted barley on the growth of lambs, in addition to its nutritional value and digestibility. In addition, sprouted barley digestibility and rumen fermentation were studied in vitro on a dry matter (DM) basis. A total of 45 three-month-old Awassi lambs were randomly assigned to five treatments of sprouted barley (0, 25, 50, 75, 100%) diets. Bodyweight, weight gain, feed intake and feed efficiency were recorded every two weeks. Nutrient analyses were performed on feed, faecal, and urine samples. DM and non-fibrous carbohydrates were measured. Digestibility of DM, organic matter (OM), and neutral detergent fiber (NDF), as well as gas production, pH value, ammonia-N, and volatile fatty acids (VFAs), were determined in vitro using continuous culture. The results showed that final bodyweight was lower (p < 0.05), while feed intake and the feed-to-gain ratio were increased (p < 0.05) in sprouted barley treatments. Nutrient analysis indicators of sprouted barley treatments (25 to100%) were lower (p < 0.05) for DM, crude protein, acid detergent fiber, lignin and ash, and higher for total digestible nutrients, NDF, fat, phosphorus, zinc, copper, and net energy than the traditional diet. In the in vivo study, the digestibility of nutrients in sprouted barley treatments was improved (p < 0.05), while the diet (sprouted barley 100%) had the lowest digestibility of DM, OM, and NDF compared with the other treatments in the in vitro study. In conclusion, the addition of sprouted barley improved digestibility, and fermentation characteristics, while having a negative effect on growth. Further studies are recommended for optimal growth performance.

The Inclusion of Pea in Concentrates Had Minor Effects on the Meat Quality of Light Lambs

The use of pea (Pisum sativum) has been recommended to replace soybean meal in the diet of ruminants, but it may affect meat quality. The aim of this study was to evaluate the effect of the proportion of pea (0%, 10%, 20% and 30%) in fattening concentrates fed to light lambs for 41 days on carcass colour and on the meat quality. Pea inclusion affected neither the colour of the lamb carcasses nor affected most of the parameters of the meat quality. However, the inclusion of pea affected the cholesterol content, and the 20%pea concentrate yielded meat with greater cholesterol contents than the 30%pea concentrate did (p < 0.05). The inclusion of pea had minor effects on individual FAs but affected the total saturated fatty acids (p < 0.01) and the thrombogenicity index (p < 0.05). A greater total saturated fatty acid content was recorded for the 20%pea concentrate than for the rest of the concentrates, and a greater thrombogenicity index was recorded for the 20% concentrate than for the 10%pea concentrate. The results indicated the viability of the inclusion of pea in the fattening concentrate of light lambs without impairing meat quality, with the 30%pea concentrate being the most suitable to reduce the soya-dependency.

Impact of Microwave Thermal Processing on Major Grain Quality Traits of Linseed (Linum usitatissium L.)

The current study investigated the effects of thermal processing of the microwave technology on nutritive value, crude protein solubility, urease activity and amino acid profile on linseed grains. Samples were treated in a SAMSUNG GE82N-B microwave oven at 450W for 0 (L1), 60 (L2), 180 (L3), 300 (L4), and 420 (L5) seconds, respectively. Microwave treatment for 300 seconds showed a significant (p ≤ 0.05) decrease in activity urease comparing to raw linseed. The raw and treated linseed protein solubility index (PDI) show statistical differences (p ≤ 0.05) between all the treatments compared. High performance liquid chromatography (HPLC) analyses of samples differences in the amino acid composition between controls and experimental treatments showed that amino acids were not significantly affected (p ≥ 0.05), except isoleucine and leucine amino acid (p ≤ 0.05). From the results of the present study, it is possible to identify that the best method for improving linseed quality for animal feed is the application of microwave for 60 second (treatment L2). Our results indicate that microwave thermal processing or micronizing dry thermal processing of grains could be successfully used in large industrial feed production with a short period of time and the improved nutritional parameters of grains, increased shelf-life and the unchanged amino acid profile of treated grains.