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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Social determinants of mixed feeding behavior among HIV-infected mothers in Jos, Nigeria

Maru, Sheela Smith-Rohrberg 06 August 2009 (has links)
Mixed feeding confers excess risk of mother-to-child transmission (MTCT) of Human Immunodeficiency Virus (HIV) compared with exclusive breastfeeding (EBF) and exclusive formula feeding (EFF). We undertook a quantitative and qualitative cross-sectional survey to identify the social determinants of mixed feeding among a subset of HIV-infected women enrolled in a MTCT prevention program in Jos, Nigeria. Of the 91 participants, 68(75%) exclusively formula fed, 7(8%) exclusively breastfed, and 16(18%) practiced mixed feeding. Of the mixed feeding women, 7 primarily formula fed and 9 primarily breastfed. Women who primarily formula fed described family pressure as the reason for mixed feeding, whereas women who primarily breastfed indicated insufficient breast milk. In a multivariate analysis, lack of partner support of the feeding decision predicted mixed feeding behavior (OR: 4.2; 95% CI: 1.2-14.9; p=0.03). Disclosure of HIV status was significantly correlated (p<0.001) with partner support. HIV prevention interventions aimed at reducing mixed feeding should encourage supportive partner relationships that facilitate disclosure of HIV status. Attention should also be made to the differing pressures faced by women attempting to exclusively breastfeed and exclusively formula feed.
252

Towards Understanding Feeding Motivation and Management Factors Affecting Feeding Behaviour in Limit-Fed Dairy Heifers

Greter, Angela Marissa 17 December 2012 (has links)
The objective of this dissertation was to determine the feeding motivation of dairy heifers and to determine management factors that contribute to satiety in limit-fed dairy heifers. The first study of this dissertation determined the difference in behavioural patterns between limit-fed and ad libitum-fed dairy heifers so that we may understand how limit feeding diverges from normal behaviour. Limit-fed heifers were found to decrease time spent feeding, consume less DM, and increase their feeding rate across the day in comparison to ad libitum-fed heifers. Additionally, the diurnal patterns of ad libitum-fed heifers were much closer to normal behaviour as they consisted of several short, small meals distributed throughout the day. The next three studies examined the management factors of frequency of feed provision and feed bunk space and how these may impact the behaviour of heifers. Increased frequency of feed provision did result in more distribution of feeding activity throughout the day but also imposed feeding amounts that were likely insufficient to achieve satiety. Heifers fed once daily likely experienced satiety in the short term and did spend the most time feeding throughout the day but the diurnal patterns of these heifers did not allow for expression of normal foraging behaviour. Providing increased feed bunk space did not allow limit-fed heifers to spend more time feeding or impact competition within a pen whereas providing straw alongside of a nutrient-dense TMR did result in more normal diurnal patterns, albeit with an increase in competitive behaviour. There was no interaction found between feed bunk space and frequency of feed provision, indicating that limit-fed heifers must be provided with sufficient bunk space to feed simultaneously. Heifers provided with un-restricted bunk space did gain more and were more feed efficient and less variable in feeding time than heifers given restricted bunk space. Feeding once daily resulted in an increase in competition but also enabled heifers to gain well and to spend more time feeding each day. The remaining studies sought to quantify whether a preference for supplementary feed exists in limit-fed heifers and whether heifers will work, and to what extent, for this extra feed. The results indicated that heifers will consume similar amounts of supplementary long or short straw if provided to them alongside of a limit-fed TMR. The limit-fed heifers do, however, show a clear preference for long straw when offered the choice, suggesting that they find long straw to be more satisfactory for achieving rumen fill and/or meeting their behavioural foraging needs. Heifers were also found to work harder (push more weight), spend less time feeding and ruminating, and consume feed faster when provided a high-concentrate, limit-fed ration than when provided a high-forage, ad libitum-fed ration, suggesting that these animals are experiencing feelings of hunger and may not be physically or behaviourally satisfied. These findings indicate that there are clear behavioural differences between limit-fed and ad libitum-fed dairy heifers. Management factors, such as frequency of feed provision and feed bunk space, may be altered in such a way as to provide some benefit to the animals but are limited in their ability to normalize feeding behaviour and diurnal patterns. Provision of supplemental, long particle low-nutritive roughage (i.e. straw) aids much more in allowing limit-fed heifers to achieve satiety and is considered a desirable resource by the animals, as evidenced through their willingness to work for this supplemental feed. / Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph Production Systems research grant and a Campbell Centre for the Study of Animal Welfare research grant. This project was also supported through contributions from the Canadian Foundation for Innovation (CFI) and the Ontario Research Fund. Angela Greter was supported through NSERC Alexander Graham Bell Canadian Graduate Student scholarship
253

Nutritional effects of big sagebrush (Artemesia tridentata) Nutt. on deer

Smith, Gary Eugene 06 August 1963 (has links)
Graduation date: 1964
254

A study of the effects of infant feeding on the present health of university men a dissertation submitted in partial fulfillment ... Master of Science in Public Health ... /

Finlay, Robert R. January 1932 (has links)
Thesis (M.S.P.H.)--University of Michigan, 1932.
255

A study of the effects of infant feeding on the present health of university men a dissertation submitted in partial fulfillment ... Master of Science in Public Health ... /

Finlay, Robert R. January 1932 (has links)
Thesis (M.S.P.H.)--University of Michigan, 1932.
256

Tubie : Ambulatory tube-feeding, for an active every day life

Sjöblom, Cindy January 2015 (has links)
Background Tube-feeding or nutritional support is a therapy for people who can’t get enough nutrition by eating or drinking. You may need it if you have difficulty swallowing, loss of appetite, are severely malnourished or have inability to absorb nutrients through your digestive system. There are several diagnoses associated with tube-feeding, depending on the persons diagnose and users state the user can be tied to the tube-feeding equipment from 3 to 18 hours a day. In Sweden there are around 1500-3000 adults in need of tube-feeding outside the hospitals.   Method This report is made by Cindy Sjöblom and is an individual student’s work. The project is her dissertation and final project at the two year Masters program Advanced Product Design at Umeå Institute of Design. The project has been executed during 20 weeks the spring 2015. The project is based on the design process which includes the following phases; Research &amp; Analysing, Ideation &amp; Concept’s and Detailing &amp; Visualization. The Research &amp; Analysis phase has included; Product analysis, user interviews &amp; observations, market outlook, anatomical knowledge, problem listing and opportunity findings. The Ideation &amp; Concept’s phase has included; Inspiration, persona creation, creative workshop, sketching, concepts creation, mock-up building, user testing &amp; feedback. The Detailing &amp; Visualization phase has included; 3D modelling, moodboard creation, sketching, final model building, photo shooting, video recording, documentation, presentation and a poster and exhibition stand at Umeå Institute of Design and at Semcon, Gothenburg. Result Tubie is an ambulatory tube-feeding system to facilitate an active everyday life for people in need of enteral nutrition. Tubie consists out of six parts; A nutrition pump and a wireless charging station, a nutrition bag and an external tubing, a wearable waist band and an application for a smart device to be able to control the pump. Unlike traditional enteral nutritions systems, Tubie is designed with a focus on the users in a home environment and their need for a more active lifestyle and discreet usage in social environments. Tubie is simply discreet due to its wearable features that allows the user to wear it underneath the clothing as well as control the pump via a smart device with an adaptable pre-alarm that sounds like any other text message or ring tone.
257

Towards understanding the effect of size variation on the aggressive and feeding behaviours ofjuvenile dusky kob Argyrosomus japonicus (Pisces: Sciaenidae)

Babane, Siviwe Elvis January 2018 (has links)
Many studies have been conducted on the effect of size-grading in other fish species. However, there is a paucity of scientific information on the effects of size variation on cannibalism of juvenile dusky kob. Thus, a study focusing on the effect of size variation on juvenile dusky kob aggressive and feeding (browsing) behaviours was conducted. Three separate groups of hatchery-reared juvenile dusky kob of were obtained from Oceanwise (Pty) Ltd for use in a series of three experimental trials. In all trials, juvenile fish of the same age were size-graded and the COV-value was used to determine the size variation. The focal fish (largest fish) was exposed to groups of fish with different size variation for 30-min. behavioural observations before and after feeding in randomised trials. The first experimental trial (Chapter 2) quantified the effect of increasing size variation and observation time on the aggressive and browsing behaviours of juvenile dusky kob. On average, juvenile dusky kob weighed 3.60 ± 0.68 g fish-1 and measured 5.8 ± 0.41 mm. Each focal fish was observed (a) before feeding in the morning, (b) 2 h after feeding, (c) 6 h after feeding and (d) 12 h after feeding. Fish increased browsing behaviours (averaging 6.60 ± 0.56) and decreased intimidating aggressive behaviours (18.60 ± 1.39) 12 h after feeding. Other aggressive behaviours occurred but did not differ between observation times. Aggressive and browsing behaviours positively correlated with size variation variables, predominantly, 12 h after feeding. An average frequency of 19 chases were observed positively correlated with size variation, followed by average frequencies of 17 body bites and browses, and 11 tail bites per 30 min. Some behaviours including average frequencies of 0.2 chases, 4 tail bites, 2.4 intimidating and 0.3 browsing behaviours negatively correlated with the size variation, generally closer to the last meal. These preliminary observations thus showed that fish have become hungry approximately 6-12 h after feeding and substituted certain behaviours for others as time after feeding passed and as size variation increased. The second experimental trial (Chapter 3) consisted of the observations further testing the relationship between aggressive behaviours and size variation of juveniles of dusky kob averaging 0.43 ± 0.27 g fish-1. The focal fish was exposed to groups of fish of four size variation (COV) treatments for observations before and 12 h after feeding. Aggressive behaviours positively correlated with size variation both before and 12 h after feeding. An average frequency of 437 body bites positively correlated more often with COV, followed by average frequencies of 365 intimidating behaviours and 199 tail bites per 30 min., respectively, before and 12 h after feeding. The least often exhibited aggressive behaviours averaged 26 chases while positively correlating with size variation on the times specified. An average frequency of 311 intimidating behaviours before and after feeding including average of 28 tail bites after feeding negatively correlated with size variation. This may relate to shift of behaviours depending on the needs and capacity of the fish. Apparently, aggressive fish can change its behaviour as a function of COV-values rather than the mean size of the other fish. The third trial (Chapter 4) investigated the effect of the aggressor’s (focal fish) size in relation its aggressive and browsing behaviours to other fish (non-focal fish). Juvenile fish used for this trial, on average, weighed 30 ± 7.63 g fish-1. Aggressive and browsing behaviours were observed in four treatments of a) high COV and mean weight below, b) low COV and mean weight less, c) high COV and mean weight equivalent to and d) low COV and mean weight higher than that of the focal fish. Increased frequencies of aggressive and browsing behaviours per 30 min. occurred in treatment A, sharing similar frequencies in treatment C, compared to the other treatments (B and D) which shared certain frequencies. The intimidating behaviours predominated, followed by browsing, body bites, chases and tail bites, respectively. The results of the overall study suggest that the time passed after feeding and increasing size variation and differences facilitated aggressive and browsing behaviours in juvenile dusky kob. Dusky kob showed increasing aggressive behaviours as early as in the first two weeks after hatching, averaging 0.43 ± 0.27 g fish-1 with the frequency correlating with size differences. Consistent size-grading technique in the same-age fish should be used to manage size variation associated with aggressive behaviours. The period of about 4-6 h after feeding may explain the noticeable increased aggressive and browsing behaviours. Thus, fish should be fed immediately before or after evacuation of their guts to maintain less-aggressive behaviours of juvenile dusky kob. Fish generally increased aggressive and browsing acts before and long time after feeding than closer to after feeding. The study has provided the fundamental scientific groundwork for fish farmers and future researchers can further explore size variation, time after feeding and gut evacuation rate as critical components of aggressive behaviours. The scientific knowledge of aggressive and cannibalistic behaviours has essential application in farming management to achieve improved survival and growth rates in juvenile fish.
258

Qualidade da dieta de escolares do município de São Paulo / Diet s quality of school children in São Paulo

Barbara Grassi Prado 31 July 2014 (has links)
INTRODUÇÃO: O hábito alimentar dos escolares pode ser influenciado por características sociodemográficas e do ambiente, seja escolar, doméstico oufora do lar e a valiar o consumo de alimentos do escolar em diferentes locais,pode fornecer informações sobre a qualidade dos alimentos ofertados em cada local. O Índice de Qualidade da Dieta Revisado (IQD -R) é um instrumento apropriado, pois, analisa a qualidade dos alimentos consumidos, comparando - os com as recomendações brasileiras. OBJETIVO: descrever a qualidade da dieta de escolares utilizando o IQD - R. MÉTODOS: Trata-se de um estudo transversal realizado com escolares de 7 a 10 anos de duas escolas municipais de São Paulo. Foram coletadas informações socioeconômicas, de estado nutricional e de consumo alimentar, por meio da aplicação de três recordatórios de 24h. A qualidade da dieta foi avaliada pelo método IQD-R. RESULTADOS:A média do IQD-R foi de 64,6 pontos e a maioria dos escolares apresentou dieta que necessita de modificação. Os componentes que apresentaram menores escores foram cereais integrais e sódio, e os maiores escores foram observados nos óleos, carnes, ovos e leguminosas, e cereais totais. As meninas apresentaram maior consumo de frutas e menor consumo de carnes, ovos e leguminosas, e sódio. O menor consumo de sódio esteve associado ao maior nível de escolaridade da pessoa de referência da família e maior número de refeições diárias. Escolares que consomem café da manhã possuem maior consumo de vegetais e de leite e derivados. O maior consumo de refeições em casa esteve associado com o menor consumo de gordura saturada e calorias provenientes de gordura sólida e açúcares de adição (Gord_AA), além de ser fator de proteção para uma melhor qualidade da dieta. Escolares que consumiram refeições fora do lar, apresentaram maior consumo de cereais integrais e Gord_AA. CONCLUSÃO: A análise da qualidade da dieta dos escolares mostrou que estes não consomem os alimentos e nutrientes conforme a recomendação brasileira. O maior número de refeições em casa é considerado como fator de proteção para uma melhor dieta quando comparado ao maior número de refeições fora do lar, por isto, ações de educação alimentar e nutricional devem ser direcionadas aos escolares, com intuito de reduzir o consumo de alimentos industrializados e fora do lar. Além disto, a presença do nutricionista nas unidades produtoras de alimentos e na regulamentação da produção dos alimentos industrializados, pode auxiliar na elaboração de cardápios saudáveis, em que se incluem os cereais integrais, frutas e hortaliças, utilizando-se o aproveitamento integral dos alimentos, modos de preparo com menos gordura, como as preparações cozidas, assadas e grelhadas, redução na quantidade de sal de adição e da utilização de alimentos industrializados. / INTRODUCTION: the feeding habits of school children can be influenced by sociodemographic characteristics and environment, whether school, home or outside the home. To assess food intake school among children in different settings can provide information about the quality of food offered at each lo cation. The Healthy Eating Index 2005 (HEI - 2005) is an appropriate tool, for assessing the quality of food consumed, comparing them with Brazilian recommendations. OBJECTIVE: to describe the diet quality of school children by means of the HEI - 2005. METHODS : this was a cross - sectional study of school children 7 - 10 years of two public schools in São Paulo. Information on socioeconomic and nutritional status was collected, as well as, food consumption by the application of three 24 - hour records. The diet quali ty was assessed by HEI - 2005 method. RESULTS: the mean HEI - 2005 score was 64.6 points and most children presented a diet needing improvement. The components that had lower scores were whole grains and sodium, and higher scores were observed for oils, meats, eggs and beans, and total cereals. Girls had higher consumption of fruits and lower consumption of meat, eggs and beans, and sodium. The lowest sodium intake associated with parents higher level of education and increased number of daily meals. School ch ildren who consumed breakfast had higher consumption of vegetables and milk. The increased consumption of meals at home was associated with lower intake of saturated fat and calories from solid fats and added sugars (SoFAAS), in addition to being a protect ive factor for a better diet quality. School children that consumed meals outside the home had higher intake of whole grains and SoFAAS. CONCLUSION: The assessment of diet quality of school children showed that they do have a food intake that meets Brazili an recommendations . The more meals at home is regarded as a protective factor for a better diet when compared to more meals outside the home, thus, shares of food and nutrition education shall be directed to the school children, in order to reduce the cons umption of processed foods and outside the home. Furthermore, the presence of a nutritionist in food producing units and the regulation of the production of processed foods, can help to develop healthy menus, where whole grains, fruits and vegetables are i ncluded, using the full utilization of food, modes of preparation with less fat as cooked, baked and grilled preparations, reduction in the amount of added salt and the use of processed foods.
259

Effects of dietary energy level and intake of corn by-product based diets on newly received growing cattle

Spore, Tyler J. January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Dale A. Blasi / Four pen studies and one digestibility trial were conducted to evaluate the effects of energy level and intake of corn by-product based diets on newly received growing cattle. In Exp.1 there were four diets where one was offered for ad libitum intake and formulated to supply 0.99 Mcal NEg/kg DM (0.99/100) and the other three treatments were fed at 95, 90, and 85% of the ad libitum treatment and to supply 1.10 (1.10/95), 1.21 (1.21/90), and 1.32 Mcal NEg/kg DM (1.32/85), respectively. ADG was unaffected by treatment (P = 0.32). However, G:F increased linearly with increasing energy and decreasing intake level (P < 0.01). In Exp. 2, a digestibility trial was conducted to study diets from Exp. 1. Ruminal propionate linearly increased with increasing dietary energy and decreasing intake (P < 0.01). Total tract DM digestibility increased linearly with increasing energy and decreasing intake (P < 0.01), whereas passage rate decreased (P < 0.01). Experiment 3 validated results from Exp. 1 feeding the 1.10/95 treatment at 2.40% of BW daily and the 1.32/85 treatment at 2.2% of BW daily and studied a DNA-immunostimulant (Zelnate, Bayer Animal Health, Shawnee Mission, KS). Zelnate had no effect on parameters measured. ADG was not different between energy treatments (P = 0.75), but efficiency was greater for the 1.32/85 treatment (P = 0.03). Experiment 4 was designed to observe effects of the 1.32 Mcal NEg/kg DM diet fed at four intake levels of 1.9, 2.2, 2.5, and 2.8 % of BW daily. ADG increased linearly with increasing intake (P < 0.01), however G:F was not affected (P = 0.98). In Exp. 5 a factorial design was employed to evaluate the effects of two by-products; wet corn gluten feed and wet distiller’s grains plus solubles, and two levels of corn processing; whole corn or dry-rolled corn. Final ADG and G:F were not affected by by-product, corn processing, or their interaction (P > 0.30). Additionally, animals and diets from Exp. 1 were used to study effects on antibody production, acute phase protein response, stress, and immunocompetency of healthy and morbid cattle. Diet had no effect on the parameters measured (P > 0.10). A quadratic response to time (P < 0.01) was detected for haptoglobin, titers for bovine viral diarrhea type 1 (BVD-1), and infectious bovine rhinotracheitis (IBR). Haptoglobin was highest on d 14, and close to baseline levels by d 27. Titer levels for BVD-1 and IBR were higher on d 14, and significantly higher on d 27. Titers for bovine viral diarrhea type 2 (BVD- II) responded linearly (P < 0.05) to time with the highest levels on d 27. Haptoglobin was elevated in morbid animals compared to healthy pen mates (P < 0.05). Titer levels for BVD-I and IBR were higher in healthy animals (P < 0.01). Fecal cortisol was higher on arrival than on d 14 (P < 0.05). In summary, high-energy limit-fed diets based on corn by-products do not affect health and are more efficient than when roughage-based growing diets are fed.
260

Replacing maize with barley in concetrates fed to jersey cows grazing on kikuyu/ryegrass pasture

Lehmann, Maryna January 2004 (has links)
The aim of the first study was to determine if barley could replace maize as an energy source in concentrates fed to dairy cows grazing on kikuyu/ryegrass pasture without affecting the milk production, milk composition, or cause metabolic disorders. Sixty Jersey cows, in early to mid lactation were randomly allocated to one of five treatments (n = 12) based on feeding concentrates with different ratios of maize to barley, ranging from 100:0, 75:25, 50:50, 25:75 and 0:100, respectively. Concentrates contained 12 MJ ME kg -1 and 130g CP kg-1 DM and cows were fed 3 kg (as-is) concentrate after each milking for a period of 42 days (14-day adaptation and 28-day measurement). Cows strip-grazed the irrigated kikuyu/ryegrass pastures (15.7 ± 1.8 percent DM; 20.2 ± 4.3 percent CP; 44.7 ± 3.5 percent NDF). Milk weights were recorded daily and milk samples collected weekly and analyzed for milk fat and protein content. Body condition score and live weight were recorded at the start and end of the experimental period. Data of all the studies were subjected to a one-way ANOVA. Daily milk yield, FCM, MUN, milk fat yield, milk fat percent, protein yield, protein percent, live weight change, or body condition score change were not affected by treatment and values were 15.8 kg, 17.2 kg, 14.9 mg dl-1, 0.72 kg, 4.56 percent, 0.59 kg, 3.77 percent, 6.67 kg, and 0.15 BCS; 15.6 kg, 17.4 kg, 15.2 mg dl-1, 0.73 kg, 4.3 percent, 0.57 kg, 3.71 percent, 1.33 kg and 0.04 BCS; 17.2 kg, 17.9 kg, 15.2 mg dl-1, 0.74 kg, 4.36 percent, 0.63 kg, 3.71 percent, 0.33 kg and 0.08 BCS; 15.6 kg, 16.4 kg, 15.5 mg dl-1, 0.67 kg, 4.33 percent, 0.60 kg, 3.83 percent, -1.46 kg and 0.11 BCS; and 15.0 kg, 16.0 kg, 15.5 mg dl-1, 0.67 kg, 4.57 percent, 0.57 kg, 3.85 percent, 8.86 kg, and 0.05 BCS, respectively for the cows fed 100:0, 75:25, 50:50, 25:75 and 0:100 maize to barley ratio concentrate. According to these results, barley can replace maize without significantly affecting the milk production or milk composition. None of the cows presented any visible symptoms of acidosis. As it was clear from the results in the first study that maize could replace barley the aim of study 2A was therefore focused on determining the effect of feeding different levels of such a barley-based (2.4, 4.8 or 7.2 kg cow-1day-1) concentrate, on milk production, milk composition and live weight change of Jersey cows on kikuyu/ryegrass pasture (23.1 ± 2.95 percent DM, 11.1 ± 0.11 percent CP, 60.8 ± 0.58 percent NDF). Forty-five Jersey cows (early- to mid lactation), were randomly allocated to one of three treatments (n = 15) involving different levels of concentrate (12 MJ ME and 130g CP kg-1 DM) feeding for a period of 42 days (14-day adaptation and 28-day measurement). Milk weights were also recorded daily, and milk samples collected weekly, and analyzed for milk fat and protein. Body condition score and live weight were recorded at the start and end of the experimental period. The results of this study indicated that increasing the concentrate level from 2.4 to 4.8 and 7.2kg cow-1day-1 did not increase the milk yield (14.0 kg, 15.2 kg, 14.4 kg; P = 0.19). The FCM production increased from 15.8 to 17.5kg (P = 0.04) as the concentrate level increased from 2.4 to 4.8kg cow-1day-1. Increasing the concentrate from 4.8 to 7.2kg cow-1day-1 did not result in a significant increase in FCM. The milk protein percent increased significantly from 3.4 - 3.6 percent when the concentrate feeding level was increased from 2.4 to 7.2kg cow-1day-1. The MUN levels were 17.09 mg dl-1, 16.03 5 mg dl-1, and 16.36 mg dl-1 for the 2.4, 4.8 and 7.2kg cow-1day-1 concentrate levels, respectively. This is well within the recommended MUN levels (12 – 18 mg dl-1) indicating that sufficient protein was fed to cows. Increasing the concentrate level from 4.8 to 7.2 kg cow-1day-1 did not increase production, probably due to a higher pasture substitution rate. Supplementing large quantities of rapidly fermentable grains, such as barley, can suppress rumen pH and may have a negative effect on the rate and extent of fibre digestion in the rumen. Therefore the aim of study 2B was not only to determine the effect of feeding different levels of a barley-based concentrate, on milk production, milk composition and live weight change, but was also to determine the effect of a low (4.8 kg cow-1day-1) versus a high (7.2 kg cow-1day-1) level of barley-based concentrate supplementation on ruminal DM and NDF degradability of Westerworld ryegrass sampled from the pastures that these cows were grazing on. Sixty Jersey cows (early- to mid lactation), were randomly allocated to one of three treatments (n = 20) involving different levels of concentrate feeding. Concentrate (12 MJ ME, 130g CP kg-1 DM) was fed at 2.4, 4.8 or 7.2 kg cow-1day-1 for a period of 74 days (14-day adaptation and 60-day measurement). These cows stripgrazed irrigated kikuyu/ryegrass pastures (14.7 ± 4.37 percent DM, 25.1 ± 1.53 percent CP, and 44.4 ± 2.58 percent NDF) at a daily pasture allocation of 10 kg DM cow-1. Milk weights were recorded daily and milk samples collected weekly and analyzed for milk fat and protein. Body condition score and live weight were recorded at the start and end of the experimental period. Twelve Jersey cows, fitted with ruminal cannulae, were randomly allocated to two of the three treatments in the production study and received either 2.4 or 7.2 kg cow-1 day-1, of the same barley-based concentrate, in a two-period crossover design. These cows strip-grazed the same irrigated kikuyu/ryegrass pastures as the sixty cows in the production study. Each period consisted of 21 days for adaptation and seven days for data collection. Rumen liquor samples were collected every 4 hours within a 24-hour cycle and repeated once. Rumen pH was measured immediately, recorded, and the supernatant fluid preserved and frozen, pending VFA analysis. The in situ nylon bag technique was used to determine DM and NDF degradation and dried samples of Westerworld ryegrass pasture were incubated for 0, 4, 8, 12, 20, 30, 48, 72 and 96 hours. The data were fitted in the non-linear model p = a + b (1-exp-ct) (Ørskov & McDonald, 1979). Daily milk production, fat corrected milk, milk fat yield and milk fat percent were not affected by treatment and values were 17.3 kg, 18.4 kg, 0.76 kg and 4.42 percent; 19.0 kg, 20.0 kg, 0.82 kg and 4.35 percent; and 18.1 kg, 19.1 kg, 0.79 kg and 4.37 percent for the 2.4, 4.8 and 7.2 kg cow-1 day-1 concentrate treatments, respectively. Milk protein percentage of cows on the 7.2 kg concentrate cow-1 day-1 was significantly higher than that of cows on 4.2 kg concentrate cow-1 day-1 feeding level. Live weight increased significantly as the level of concentrate feeding increased and values were 17.9 kg; and 28.9 kg on the 2.4 and 7.2kg concentrate treatment, respectively. There was a significant increase in the live weight of cows that were fed 7.2 kg cow-1 day-1 (as-is) in comparison to those cows that were fed 2.4 kg concentrate cow-1 day-1 (as-is). This may have resulted from more nutrients being partitioned to live weight gain rather than milk production. No further response in milk production was observed when concentrate daily feeding was increased from 4.8 to 7.2 kg cow-1 day-1. It is postulated that the higher concentrate allowance resulted in a higher substitution rate and lower DMI intake from pasture. 6 There was no significant decline in the rumen pH (6.2 ± 0.4 and 6.2 ± 0.5) when the concentrate level was increased from 2.4 to 7.2 kg cow-1 day-1 (as-is). The total VFA (118.1 ± 45.9 and 139.4 ± 45.6 mmol L-1) and isovalerate (0.009 ± 0.07 and 0.248 ± 0.52 mmol L-1) increased significantly when the concentrate was increased from 2.4 to 7.2 kg cow-1day-1. No other rumen parameters were affected by treatment. Ruminal DM and NDF degradability of the Kikuyu/ryegrass pature were not affected by the level of concentrate supplementation. An increase in the concentrate level from 2.4 to 7.2 kg cow-1day-1 did not reduce degradability of either DM (94.67 ± 5.97, 94.49 ± 5.09; P = 0.919) or NDF (92.15 ± 8.69, 94.4 ± 11.73; P = 0.451), respectively. Results of rumen parameters and PD values were within the range reported by Bargo et al., (2003), viz. pH 5.76 – 6.29, NH3-N concentration 8.7 – 32.2 mg dl-1, total VFA concentration 90.3 - 151.4 mmol L-1 and PD values 89.5 – 93.5 % reported by Bargo et al. (2003). According to these authors, there is no simple relationship between any amount of the concentrate supplemented, and the ruminal pH and concentrate feeding only affects the in situ ruminal digestion of pasture when it is fed, at quantities higher than 8 kg DM cow-1day-1 (Bargo et al., 2003).

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