114 Evaluation of Extrusion Processing Method and Protein Source on Standardized Amino Acid Digestibility

While the majority of dry complete and balanced foods for pet animals are extruded, the interaction between ingredient matrix and processing methods and stages are poorly understood. Thus, the objective of this study was to determine how the use of plant-based and poultry-based proteins processed under different extrusion condition may affect amino acid digestibility in extruded canine diets using a rooster model. Eight diet formulas were made using chicken (CK), chicken byproduct meal (CM), yellow pea (YP), green lentil (GL), and garbanzo bean (GB) as the primary protein sources. These diets were extruded through a single-screw and a twin-screw extruder. Food samples were collected at various stages of processing (i.e., raw, and after preconditioner, extruder, drier, and coating). Four cecectomized single-comb White Leghorn roosters were used for each diet sample. The roosters were fasted for 26 h and then fed with the treatment diets. The excreta were collected 48 h after feeding. Freeze dried excreta were used to calculate standardized amino acid digestibility (SAAD). For all essential amino acids, a significant interaction (P < 0.05) between diet and processing method was observed. The SAAD of arginine, tryptophan, and methionine were greater than 80% for all diets collected at the end of the extruder. The CK diet supplemented with synthetic taurine and processed through twin-extrusion had 70% to 80% SAAD of histidine, isoleucine, leucine, lysine, phenylalanine, threonine, and valine. Overall, twin-screw extrusion resulted in lower SAAD for all essential amino acids (P < 0.05), except for isoleucine and valine. However, the differences were smaller than 2.5%, and therefore may not negatively impact diet formulation and final product nutrient composition or guaranteed analysis. In addition, the extruded canine diets made with plant-based protein did not have lower amino acid digestibility than those made with animal-based protein.

2014 Dahlberg Award Winner The effects of dietary toughness on occlusopalatal variation in savanna baboons

This study investigates the relationship between dietary toughness and craniofacial variation in two groups of savanna baboons. Standard craniofacial and malocclusion data were collected from a captive, soft-diet experiment group (n=24) and a sample of wild-captured baboons, raised on tougher, natural foods (n=19). We tested the hypothesis that in the absence of normal masticatory stress experienced during the consumption of wild foods, the captive baboons would exhibit higher levels of facial and dental structural irregularities. Principal component analysis indicates separation of the two samples. The soft-diet sample exhibits significantly shorter palates, greater variability in palate position, and higher frequencies of occlusal irregularities that correlate with the shorter palates. Results offer further support that long-term dietary chewing stresses have a measurable effect on adult craniofacial variation.

Evaluation of Yeast Saccharomyces cerevisiae and Algae Chlorella vulgaris as Diet for Rotifer Brachionus calyciflorus

A study was conducted to evaluate the effect of yeast Saccharomyces cerevisiae and algae Chlorella vulgaris on the production of rotifer Brachionus calyciflorus. The Brachionus calyciflorus were cultured using four different types of diets: fresh Chlorella vulgaris (T1), yeast with fresh Chlorella vulgaris (T2), powder Chlorella vulgaris with fresh Chlorella vulgaris (T3) and yeast with powder Chlorella vulgaris (T4). We compared these diets to find out their potentiality on the population growth of Brachionus calyciflorus. The rotifers were cultured under natural environmental condition with continuous artificial aeration. Initial density of Brachionus calyciflorus were 8 individuals ml-1 (ind. ml-1). Water temperature and pH were measured during the culture period. Among the four different diets the fresh Chlorella vulgaris (T1) and it’s yeast combination (T2) gave satisfactory production of rotifer 73±9 and 67±8 ind. ml-1, respectively. However, processing of fresh Chlorella vulgaris to produce powder form declined the production ability of rotifer. The diet sample T3 and T4 containing powdered Chlorella vulgaris produced 48±9 and 25±6 ind. ml-1, respectively. So, the diet in combination of yeast and fresh Chlorella is suggested for the sustainable production of the rotifer Brachionus calyciflorus. DOI: http://dx.doi.org/10.3329/agric.v12i1.19484 The Agriculturists 2014; 12(1) 1-9

Effect of feeding treated peat as a supplement to newborn piglets on the growth, health status and occurrence of conditionally pathogenic mycobacteria

The first purpose of this experiment was to investigate the effect of ad libitum feeding of peat as a supplement to piglets from the age of five days up 23 days of age on their growth performance and health status. The second purpose was to assess the risk of the occurrence of conditionally pathogenic mycobacteria (CPM) in peat treated with ionizing radiation (Group PI) or per acetic acid (Group PP) and fed as a supplement to piglets. In respective experimental periods (at the age of 4, 23, 41 and 67 days), no significant differences in the average body weight between control group (C) and experimental Groups PI and PP were detected. Levels of selected biochemical (total protein, albumin, glucose, cholesterol, Ca, P, Fe and I) and haematological (erythrocytes, leukocytes and immunoglobulin – Ig) parameters of the health status of the piglets from all three Groups C, PI and PP were comparable at the age of 41 and 67 days. Mycobacteria were detected by culture in one diet sample (Mycobacterium intracellulare), in all 10 peat samples (7 M. a. hominissuis isolates, 2 M. intracellulare isolates and 1 M. xenopi isolate) and in 4 samples of biofilm from the drinking water pipeline system in the stables (M. xenopi, M. a. hominissuis, M. gordonae and Mycobacterium sp., one isolate in each). In 15 slaughtered pigs (at 67 days of age), no gross lesions that would give evidence of tuberculosis were found either in lymph nodes or parenchymatous organs. In Group C, mycobacteria were detected in tissues from two piglets (Mycobacterium sp. and M. a. hominissuis), Group PI in four piglets (M. a. hominissuis) and in Group PP in all five piglets (Mycobacterium sp., M. a. hominissuis, M. terrae and M. intracellulare). High positivity for CPM in both types of treated peat caused disseminated infection of the digestive tract of piglets from Groups PI and PP. Based on these results, feeding peat treated with ionisation or per acetic acid may be viewed as risky.

Dose–response effects of an antimicrobial peptide, a cecropin hybrid, on growth performance, nutrient utilisation, bacterial counts in the digesta and intestinal morphology in broilers

The aim of the present study was to evaluate the feasibility of an antimicrobial peptide, cecropin A(1-11)-D(12-37)-Asn (CADN), as an alternative to antibiotic growth promoter (AGP) in poultry diets. A total of 1500 14-d-old indigenous male chickens (222 (sd 13) g) were randomly allocated to five groups with five replicate cages of sixty birds each, and fed ad libitum five grower diets and subsequently five finisher diets for 14 d each. The diets were made up by supplementing their basal diets with a CADN liquid sample (CADNL) at 0, 2, 4, 6 and 8 ml/kg, respectively. During the feeding period, a metabolic experiment was carried out to determine the apparent digestibility of diethyl ether extract, nitrogen retention and apparent metabolisable energy of the diet sample fed to each cage of chicks. At the end of the feeding experiment, one chick from each cage was killed for bacteriological, light microscopic and scanning electron microscopic examination of the intestinal villi. CADN had a negative linear, positive quadratic and negative linear effect on feed intake (F), weight gain (G) and feed:gain ratio (F:G), respectively, for the growers; it had a quadratic effect on F, G or F:G for the finishers; it increased nutrient utilisation for both growers and finishers; it decreased aerobic bacterial counts in both jejunal and caecal digesta in a dose-dependent manner; it enhanced intestinal villus heights in a dose-dependent manner and made the duodenum villi of the CADNL8 group at 42 d appear as a netted leaf-like structure. CADN is therefore a possible alternative to AGP in broiler feeds.

The dietary ecology of Australian rodents

Very little systematic information has been collected on the diets of Australian rodents in arid and semiarid regions. The information that is available is restricted generally to short periods of sampling and small sample sizes. Here we review the diets of 15 extant and one extinct species of Australian desert rodents, and provide new results of dietary analyses for (1) Leggadina forresti, Pseudomys desertorand Rattus villosissimus from the Simpson Desert, south-western Queensland, (2) P. albocinereus and P. bolami from the western goldfields of Western Australia, and (3) Notomys alexis, P. desertor and P. hermannsburgensis from the Tanami Desert, Northern Territory. Overwhelmingly, omnivory is the predominant dietary strategy, with most species (11) taking substantial amounts of invertebrate, seed and green plant material. Of the other five species, four can be considered herbivores and one a granivore. Of the four herbivores, however, one is extinct (Leporillus apicalis), one is restricted to an offshore island (Lep. conditor), while another (P. fieldi) is classified as a herbivore from a diet sample of four individuals only. Similarly, P. occidentalis is classified as a granivore on the basis of dietary sampling of two individuals alone. These findings indicate that omnivory, over and above any other dietary strategy including granivory, is predominant among rodents inhabiting Australian deserts.

The dietary ecology of Australian desert rodents

Very little systematic information has been collected on the diets of Australian rodents in arid and semiarid regions. The information that is available is restricted generally to short periods of sampling and small sample sizes. Here we review the diets of 15 extant and one extinct species of Australian desert rodents, and provide new results of dietary analyses for (1) Leggadina forresti, Pseudomys desertorand Rattus villosissimus from the Simpson Desert, south-western Queensland, (2) P. albocinereus and P. bolami from the western goldfields of Western Australia, and (3) Notomys alexis, P. desertor and P. hermannsburgensis from the Tanami Desert, Northern Territory. Overwhelmingly, omnivory is the predominant dietary strategy, with most species (11) taking substantial amounts of invertebrate, seed and green plant material. Of the other five species, four can be considered herbivores and one a granivore. Of the four herbivores, however, one is extinct (Leporillus apicalis), one is restricted to an offshore island (Lep. conditor), while another (P. fieldi) is classified as a herbivore from a diet sample of four individuals only. Similarly, P. occidentalis is classified as a granivore on the basis of dietary sampling of two individuals alone. These findings indicate that omnivory, over and above any other dietary strategy including granivory, is predominant among rodents inhabiting Australian deserts.

Influence of Certain Components of a Chemically Defined Diet on Urinary Excretion of Ultraviolet-Absorbing Compounds

Young [Clin. Chem. 16, 681 (1970)] has recently reported tentative identifications for 12 compounds resolved by anion-exchange chromatography of urine from a subject on a vanilla-flavored synthetic diet. Relative excretion rates for the diet and control periods were also given for several of the chromatographic peaks. We are reporting positive identification of 26 of the resolved compounds and absolute excretion rates for 11 of these. The most significant differences between the diet and control chromatograms are the absence of 5-acetylamino-6-amino-3-methyluracil from the diet sample and the presence of a group of large peaks— including five peaks related to the vanilla flavoring and three peaks derived from 4-aminobenzoic acid—in the diet chromatogram. The 4-aminobenzoic acid derivatives were all acetylated; the chromatogram showed no evidence of un-acetylated products.