Effect of dietary inclusion of Pennisetum purpureum (Napier) grass on growth performance, rumen fermentation and meat quality of feedlot sussex red steers.

The aim of this study was to evaluate the growth performance, fermentation indices and meat quality of Sussex steers fed totally mixed rations that composed of graded inclusion levels of Napier grass (NP). Three experimental diets designated as diet 1 (0.0 g kg-1 NP: Control), diet 2 (300 g kg-1 NP grass) and diet 3 (600 g kg-1 NP) were formulated. Twenty-four male steers aged 8 months with an average body weight of 185.0 ± 30 kg were used. In a completely randomized design, the animals were allocated to the diets and fed for 120 days. Dietary NP inclusion reduced (P < 0.05) the animals' average daily gain and increased the feed efficiency. The steers' daily feed intake and final body weight decreased (P < 0.05) with a 600 g kg-1 inclusion level. The fermentation indices were not affected (P > 0.05) by the inclusion. While the inclusion reduced (P < 0.05) warm muscle temperature, it had no effect (P > 0.05) on carcass dressing percentage, warm and cold initial and ultimate pH. However, 600 g kg-1 inclusion level reduced (P > 0.05) warm and cold carcass weights. Meat physical attributes, moisture characteristics and tenderness were not affected (P > 0.05) by dietary treatments, except for the 7-days aged meat thaw loss, which increased at 600 g kg-1 inclusion level. Inclusion of 300 g kg-1 increased meat protein and fat, but dry and organic matter contents decreased with increasing inclusion levels. Dietary inclusion of NP grass up to 300 g kg-1 in steers' diets improved feed intake, carcass traits and yielded meat high in protein and fat.

Growth performance, nutrient digestibility and carcass characteristics of pigs fed diets containing amarula (Sclerocarya birrea A. Rich) nut cake as replacement to soybean meal.

This experiment evaluated varying levels of Amarula (Sclerocarya birrea A. Rich) nut cake (ANC) on growth performance, nutrient digestibility and carcass characteristics in pigs. Thirty Large White × Landrace (LW × LR) pigs were stratified by weight (average live weight of 20 ± 5 kg) and randomly allocated to the five experimental diets that contained 0 (control), 50, 100, 150 and 200 g ANC/kg DM. Each pig served as a replicate unit, housed individually. The pigs were fed the experimental diets ad-lib once in the morning, allowing a 10% of feed refusal, and had free access to water. Bodyweight, feed intake, average daily gain (ADG) and feed conversion ratio (FCR) were recorded weekly throughout the 56-day trial period. On completion of the growth trial, following a 3-day adaptation, a nutrient digestibility study was conducted over 5 days. Thereafter, pigs were fasted for 12 h, weighed, slaughtered, and carcass samples were collected for analysis. Data on the effects of treatments on growth performance, nutrient digestibility and carcass characteristics were analysed using a two-way ANOVA in randomised blocks and were compared using Student's t-LSD. Feed intake was not affected by dietary treatment, but ADGs were reduced at ANC levels > 150 g/kg, resulting in poor FCR. Protein digestibility was reduced at ANC levels > 150 g/kg, while ether extract and fibre levels increased. Warm and cold carcass weights were lower at ANC levels > 150 g/kg, with improved meat redness and lightness. It was concluded that ANC could replace SBM in the diet of growing pigs at less than 150 g/kg inclusion level.

Effect of replacing soybean meal with marula nut meal on rumen dry matter and crude protein degradability.

In situ rumen degradability of dry matter (DM) and crude protein (CP) in ruminant diets composed of graded inclusion levels of marula nut meal (MNM) as a protein source to replace soybean meal were evaluated. The five diets denoted as diet 1 (0.0 g kg-1 MNM: control), diet 2 (45.5 g kg-1 MNM), diet 3 (91.7 g kg-1 MNM), diet 4 (138.4 g kg-1 MNM), and diet 5 (185.9 g kg-1 MNM) were tested. Three cannulated mid-lactating Holstein cows were used to incubate triplicate subsamples of each diet for 2, 4, 8, 16, 24, and 48 h in polyester bags. The soluble fractions of DM and CP increased (P < 0.05) with increasing levels of MNM (138.4-185.9 g kg-1 MNM). However, the insoluble but degradable fractions of DM and CP increased (P < 0.05) with decreasing levels of MNM (45.5-0.0 g kg-1 and 91.7-0.0 g kg-1 MNM, respectively). While the degradation rate of fraction and the effective degradability of DM increased (P < 0.05) with decreasing levels of MNM (91.7-0.0 g kg-1), those of CP increased with increasing levels of MNM (138.4-185.9 g kg-1 MNM) in the diet. These results suggest that dietary inclusion of MNM up to 91.7 g kg-1 in ruminant diets can provide undegradable protein to be absorbed in the small intestines and used for metabolic function, while an inclusion of up to 185.9 g kg-1 can be degraded in the rumen for microbial protein synthesis.

Dietary enzyme addition on the growth performance and carcass characteristics of pigs fed diets containing avocado oil cake silage.

Avocado oil cake (AOC) was mixed with dried grape pomace and sugarcane molasses and ensiled for 90 days. A total mixed ration containing 5% AOC silage was formulated and top dressed with Axtra® XB enzyme at 0, 2.5 and 5%. The experimental diets were fed to 24 (8 pigs/diet) Large White × Landrace (LW × LR) cross pigs (± 22-kg live weight). Growth performance data was recorded for 60 days, after which the pigs were adapted to chromic oxide mixed diet for 3 days, whereby faeces were collected for 5 days after to determine nutrient digestion. Following nutrient digestion, pigs were fasted for 12 h, weighed and slaughtered. Carcass samples were collected and analysed for meat quality. Dietary addition of enzyme increased (P < 0.05) dry matter intake and nutrient digestibility, but did not affected (P > 0.05) feed conversion ratio and average daily gain. Carcass characteristics were not affected (P > 0.05); however, small and large intestine weight and length were increased (P < 0.05) with enzyme inclusion in feed. Dietary treatments did not affect (P > 0.05) the colour and cooking quality of the meat. Enzyme addition was worth in the growth performance and nutrient digestion but did not affect the carcass characteristics and meat quality of pigs.

Nutrient evaluation and ruminal degradation of dry matter and protein from amarula (Sclerocarya birrea), macadamia (integrifolia) and baobab (Adansonia digitata L.) oilcakes as dietary supplements for ruminants.

Inadequate availability of feed ingredients significantly contributes to reduced animal production. Nutritional evaluation of feed ingredients for potential use in feed ration is key. Triplicate samples of oil extraction by-products viz.: amarula (Sclerocarya birrea), macadamia (integrifolia) and baobab (Adansonia digitata L.) oilcakes were analysed for proximate, mineral and amino acids content. To determine the in situ rumen degradability of dry matter (DM) and crude protein (CP) from the oilcakes, polyester bags were used to incubate triplicate subsamples of each oilcake in the ventral rumen of each of the three cannulated mid-lactating Holstein cows for 2, 4, 8, 16, 24, or 48 h. Amarula oilcake (AOC) had higher (P < 0.05) CP, ether extract and essential amino acid content than macadamia (MOC) and baobab (BOC) oilcakes. Fibre fractions were higher (P < 0.05) in MOC and BOC than in AOC. While calcium (Ca) and potassium (K) concentrations were high (P < 0.05) in MOC and BOC, phosphorus (P) concentration was high (P < 0.05) in AOC. The effective degradability of DM and water-soluble, rapidly degradable fractions of DM and CP were high (P < 0.05) in AOC. Insoluble but degradable fraction of CP was high (P < 0.00) in BOC and effective degradation of CP was high (P < 0.05) in AOC and BOC. The AOC with its high CP, EE and essential AA can be used as both protein and energy source for ruminants. Seemingly, MOC and BOC can be used as supplements for fibre as well as Ca and K in ruminant diets. Hence, these non-conventional oilcakes have the potential to partially replace conventional oilcakes in ruminant diets. Evaluation of growth performance, nitrogen digestion and carcass characteristics in ruminants fed diets containing the AOC, BOC and MOC are recommended.