Effects of a starch binding agent on in vitro rumen degradability of maize and sorghum starch

The objective of the study was to quantify the potential of a starch binding agent (BioProtectTM) to reduce in vitro rumen starch degradation of maize and sorghum particles that varied in size. Maize and sorghum grain samples were ground through 2-mm sieves with a Wiley mill and subsequently sieved to obtain these sizes: less than 250, 250 - 500, 500 - 1180, and 1180 - 2000 μm (i.e., very fine to coarse). All fractions were analysed separately for starch content. Samples were treated 24 hours before fermentation by spraying BioProtect onto the substrate. Both treated and untreated samples were fermented in vitro for 0, 6, 12 and 24 hours to quantify starch degradability. Rates of degradability (kd) were calculated with a first-order decay model. BioProtect was effective in decreasing starch degradability and rates of degradability for both grains (P <0.0001). The product was more effective with smaller particle size, by reducing starch degradability 17% for the smallest particles as opposed to 7% for the largest particles. A time interaction was observed (P <0.0001), which showed that the highest impact of BioProtect occurred after 12 hours of fermentation for both grains. The starch binding agent resulted in an effective decrease of in vitro starch degradation, but results were affected by particle size and fermentation time. Starch digestion could possibly be shifted to the small intestine with BioProtect

A review of artisanal cheese making: An African perspective

Artisanal cheeses and other fermented milk products have long been part of the diet of African rural communities. Cheese is a source of nutrients that are essential to the development and growth of children in rural areas, where intake of amino acids, vitamin A, vitamin B12, calcium, phosphate, and polyunsaturated fatty acids may be limited. Wara, Karish, Ayib, Takammart, Wagashi, Domiati, and Ras are prominent cheeses of African origin. Artisanal cheese making should be expanded to improve people’s nutritional status at low cost, stimulate the local economy, and empower small-scale farmers. This review firstly gives an overview of artisanal cheese production and consumption, and evaluates opportunities and challenges, while focusing on an African perspective. Secondly, it provides an insight into strategies that could improve cheese making at small-scale level. Possible areas of research and knowledge gaps are highlighted, particularly ways of improving cheese quality and safety

Preweaning milk replacer intake and effects on long-term productivity of dairy calves

AbstractThe preweaning management of dairy calves over the last 30 yr has focused on mortality, early weaning, and rumen development. Recent studies suggest that nutrient intake from milk or milk replacer during the preweaning period alters the phenotypic expression for milk yield. The objective of this study was to investigate the relationship between nutrient intake from milk replacer and pre- and postweaning growth rate with lactation performance in the Cornell dairy herd and a commercial dairy farm. The analysis was conducted using traditional 305-d first-lactation milk yield and residual lactation yield estimates from a test-day model (TDM) to analyze the lactation records over multiple lactations. The overall objective of the calf nutrition program in both herds was to double the birth weight of calves by weaning through increased milk replacer and starter intake. First-lactation 305-d milk yield and residuals from the TDM were generated from 1,244 and 624 heifers from the Cornell herd and from the commercial farm, respectively. The TDM was used to generate lactation residuals after accounting for the effects of test day, calving season, days in milk, days pregnant, lactation number, and year. In addition, lactation residuals were generated for cattle with multiple lactations to determine if the effect of preweaning nutrition could be associated with lifetime milk yield. Factors such as preweaning average daily gain (ADG), energy intake from milk replacer as a multiple of maintenance, and other growth outcomes and management variables were regressed on TDM milk yield data. In the Cornell herd, preweaning ADG, ranged from 0.10 to 1.58kg, and was significantly correlated with first-lactation yield; for every 1kg of preweaning ADG, heifers, on average, produced 850kg more milk during their first lactation and 235kg more milk for every Mcal of metabolizable energy intake above maintenance. In the commercial herd, for every 1kg of preweaning ADG, milk yield increased by 1,113kg in the first lactation and further, every 1kg of prepubertal ADG was associated with a 3,281kg increase in first-lactation milk yield. Among the 2 herds, preweaning ADG accounted for 22% of the variation in first-lactation milk yield as analyzed with the TDM. These results indicate that increased growth rate before weaning results in some form of epigenetic programming that is yet to be understood, but has positive effects on lactation milk yield. This analysis identifies nutrition and management of the preweaned calf as major environmental factors influencing the expression of the genetic capacity of the animal for milk yield

A review of artisanal cheese making: An african perspective

Artisanal cheeses and other fermented milk products have long been part of the diet of African rural communities. Cheese is a source of nutrients that are essential to the development and growth of children in rural areas, where intake of amino acids, vitamin A, vitamin B12, calcium, phosphate, and polyunsaturated fatty acids may be limited. Wara, Karish, Ayib, Takammart, Wagashi, Domiati, and Ras are prominent cheeses of African origin. Artisanal cheese making should be expanded to improve people’s nutritional status at low cost, stimulate the local economy, and empower small-scale farmers. This review firstly gives an overview of artisanal cheese production and consumption, and evaluates opportunities and challenges, while focusing on an African perspective. Secondly, it provides an insight into strategies that could improve cheese making at small-scale level. Possible areas of research and knowledge gaps are highlighted, particularly ways of improving cheese quality and safety

Effects of Saccharomyces cerevisiae, medium and forage type and their interactions on in vitro ruminal fermentation

The objective of this study was to investigate the effects of a live yeast, Saccharomyces cerevisiae CNCM I-1077, at four doses (0, 1×105, 1×106 and 1 × 107 cfu/mL) according to the reducing medium used [Goering-Van Soest (GV), McDougall (MD) or Kansas State (KS)] on in vitro ruminal neutral detergent fibre digestibility (NDFd), rate of digestion of NDF (kd), organic matter digestibility (OMd), dry matter digestibility (DMd), pH as well as volatile fatty acids (VFA) concentration, using two forages (oat hay and wheat straw) with differing chemical composition. The maximum in vitro NDFd, DMd, OMd as well as kd were obtained with dose 1 × 106 cfu/mL, although differences between doses were not always significant. The pH estimates were the lowest with the 1 × 107 cfu/mL dose, but the differences were not all significant; however, 1 × 107 cfu/mL corresponded to significantly lower pH estimates compared to the control and 1×105 (6.51 vs. 6.60 and 6.59, respectively). The decrease in pH was accompanied by an increase in VFA concentrations as the yeast dose increased. The KS medium resulted in the lowest digestibility estimates, pH estimates as well as kd, regardless of yeast dose. The 1 × 106 cfu/mL was the better performing yeast dose in vitro resulting in higher digestibility estimates which indicates the yeasts ability to stimulate the microorganisms within the rumen by beneficially modifying rumen environment, thus promoting microbiota activity. The MD and GV media provide better environments for fermentation than the KS medium, resulting in higher in vitro NDFd, DMd, OMd, pH estimates as well as rate of NDF digestion. The MD and GV are also the media that resulted in more consistent results when analysing the effects of the live yeast. Our data suggest that the in vitro conditions have to be carefully chosen to be able to demonstrate rumen fermentation shifts with the use of live microbial additives

A Survey of Cheese from Small-Scale Artisanal Producers in Western Cape, South Africa

The objective of this study was to assess cow milk cheese from small-scale producers in the Western Cape Province, South Africa. Forty cheeses were selected, and microbiological data of the samples were analyzed with age (1, 3, 6 months), cheese type (Cheddar, Gouda, other), and milk type (raw and pasteurized) as main factors. Rapid sensory characterization was done using the sorting technique. The results indicated that the available cheese types were diverse, with minority (20.0%) in the Gouda group followed by Cheddar (32.5%) and "other" (47.5%). Most of these cheeses (45%) were aged three months and produced using pasteurized milk (92.5%). Five cheese samples did not meet the European Union standards for coliforms, and four samples tested positive for Escherichia coli. Sensory analysis results showed a clear differentiation between mature and young cheese. In conclusion, the current market presents more diverse milder cheeses, and there is a need to follow proper hygiene protocols to reduce cross-contamination

A Survey of Cheese from Small-Scale Artisanal Producers in Western Cape, South Africa

The objective of this study was to assess cow milk cheese from small-scale producers in the Western Cape Province, South Africa. Forty cheeses were selected, and microbiological data of the samples were analyzed with age (1, 3, 6 months), cheese type (Cheddar, Gouda, other), and milk type (raw and pasteurized) as main factors. Rapid sensory characterization was done using the sorting technique. The results indicated that the available cheese types were diverse, with minority (20.0%) in the Gouda group followed by Cheddar (32.5%) and "other"(47.5%). Most of these cheeses (45%) were aged three months and produced using pasteurized milk (92.5%). Five cheese samples did not meet the European Union standards for coliforms, and four samples tested positive for Escherichia coli. Sensory analysis results showed a clear differentiation between mature and young cheese. In conclusion, the current market presents more diverse milder cheeses, and there is a need to follow proper hygiene protocols to reduce cross-contamination

Predicting the growth and feed intake of Boer goats in a feedlot system

This research sought to develop a mathematical model to predict the growth and feed intake of Boer goat kids destined for slaughter. Data were collected from castrated kids that were housed in individual pens and fed diets that varied in energy content (11.3, 12.0, and 12.7 MJ metabolizable energy (ME)/kg feed). Growth and feed intake were monitored weekly for 20 weeks, from the time that the kids weighed 22.2 ± 3.5 kg until they were slaughtered at 48.3 ± 0.8 kg. The linear equation (bodyweight = 0.202 age – 5.241 (R2 = 0.84)) was found to predict the growth of kids between 126 and 266 days old. Correlations between expressions of intake and bodyweight were evaluated, cumulative feed intake and bodyweight being most highly correlated (r = 0.93). Linear models were developed to predict cumulative feed intake from bodyweight for goats fed each diet. Regression coefficients were compared between diets, with the slope of the equation for goats on the low energy diet (6.74 ± 0.25) being greater than that of the medium (5.80 ± 0.23) and high energy diets (5.82 ± 0.23). This indicates that goats on the medium and high energy diets gained weight more efficiently than those on the low energy diet. The results from this study can be used by goat producers to predict the growth and intake of goats and determine the ideal feedlot finishing period for optimal productivity.______________________________________________________________________________________Keywords: cumulative intake, dietary energy, modellin

Variability of indigestible NDF in C3 and C4 forages and implications on the resulting feed energy values and potential microbial protein synthesis in dairy cattle

Estimation of indigestible neutral detergent fibre (iNDF) is necessary for accurate and precise predictions of feed energy values and potential microbial protein from digested NDF in the rumen. Due to lengthy laboratory procedures, iNDF has been estimated using the formula ADLÃ?2.4 (iNDF2.4). The relationship between iNDF and acid detergent lignin (ADL) is more variable, across and within forage species. The purpose of our study was then to assess the variability of iNDF and respective implications on ration fine-tuning for dairy cattle. Sixty forages, including grasses, maize silages and lucerne hays, were fermented in vitro from 0 to 240 hours. Residual NDF of the fermented samples were obtained at 0, 6, 12, 24, 36, 48, 72, 96, 120, 144, 216 and 240 h, with the last value assumed to represent iNDF (iNDF240).This was used to obtain the potentially digestible NDF fraction (pdNDF). Rates of digestion of pdNDF were obtained assuming a first order decay. Simulations with the Cornell Net Carbohydrate and Protein System (CNCPS v 6.1, 2012) were done to evaluate the effects of the different estimated iNDF and NDF rate of digestion (kd) on energy and microbial protein estimations, assuming the requirements of a high-yielding lactating cow and a standard TMR with at least 50% forage. Results were dependent on the amount of forage and respective NDF and ADL. The iNDF240 values resulted between 1% and 136% higher than the iNDF2.4 values. The reduced pdNDF pool resulted in both lower cell wall linked protein in the rumen and microbial protein of around 5 to 165 g, and, as a consequence, on a total decreased metabolizable protein for milk. Use of iNDF240 showed consistently lower metabolizable energy (ME) between 2 and 10 MJ/day, compared to when using iNDF2.4. The improved metabolizable protein (MP) and ME values would result in 0.3 to 3.2 kg/d less milk when using iNDF2.4. This research demonstrates how points later in the fermentation curve, even if not biologically relevant for the cow, result in a more accurate and precise estimation of the rate of NDF digestibility. Indigestible NDF estimated at 240 h would give better predictions of rumen parameters in models like the CNCPS and better fine-tuning in dairy cow diets, especially when using high forage and/or NDF rations.http://www.sasas.co.zaam201

Effects of starch sources varying in particle sizes on ruminal fermentation, nutrient flow, starch digestibility, and lactation performance of dairy cows

Cereal grains are the predominant starch source (SS) for dairy cows; however, starch digestibility varies greatly depending on source, grain processing, and potentially interactions between these factors. The objective was to study the effects of the interactions between SS, and particle sizes (PS) on ruminal fermentation, nutrient flow, starch digestibility, and lactation performance of dairy cows. Four ruminally cannulated multiparous Holstein cows were used in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Two SS (corn or sorghum) used in this study were either finely or coarsely ground (using a 1- or 4-mm screen sieve). Digesta flow was quantified using the reticular sampling technique, applying the triple-marker method. Data were analyzed using the GLIMMIX procedure of SAS version 9.3 (SAS Institute Inc., Cary, NC, USA). For ruminal pH, data were analysed with time as repeated measure. There were no interactions between SS and PS on production or intake, flow, and digestibility of nutrients. Dry matter intake was greater for the corn diet compared to the sorghum diet (25.15 vs. 21.98 kg/d), which consequently affected nutrient intake, however, PS did not affect intake. Milk yield was not affected by SS; however, it was greater for cows fed fine grains than cows fed coarser grains (25.32 vs. 23.16 kg/d). Milk fat and milk protein were not affected by SS or PS. Interactions (SS x PS) were observed for ruminal pH, reticular pH, and volatile fatty acids (VFA) concentrations but not for ruminal NH3-N concentration. Ruminal and reticular pH were greater for sorghum when coarsely ground and the total VFA concentration was decreased, compared to coarse corn and fine sorghum; however, coarsely grinding corn did not affect ruminal or reticular pH nor VFA concentration. Acetate concentration was lower for corn when finely ground; however, finely grinding sorghum did not affect acetate. Decreasing PS increased ruminal digestibility of starch (87.18% vs. 83.43%), reduced the flow of starch to the reticulum (0.79 vs. 0.96 kg/d) but decreased neutral detergent fiber digestibility in the rumen (30.23% vs. 34.88%). Although SS were differently affected by processing, the effects of PS on production, intake, flow, and digestibility of nutrients were observed regardless of the SS. Furthermore, the effects of decreasing PS on pH and VFA concentrations were more pronounced in sorghum compared to corn.Lay Summary Starch digestibility varies greatly depending on starch source (SS), grain processing, and potentially interactions between these factors. Four ruminally cannulated lactating Holstein cows were fed a total mixed ration that varied in SS and particle sizes (PS) to evaluate the interactions between SS and PS on ruminal fermentation, nutrient flow, starch digestibility, and lactation performance of dairy cows. There were no interactions between SS, and PS on production, intake, flow, and digestibility of nutrients; however, interactions were observed for ruminal pH, reticular pH, volatile fatty acids (VFA) concentrations, and in some VFA molar proportions.Decreasing grain particle size increased ruminal digestibility, reducing starch flow to the reticulum but also decreased ruminal neutral detergent fiber degradability. Reducing grain particle size improves starch utilization regardless of the starch source (sorghum or corn) for lactation dairy cows