• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.2
• /
• pp.159-169
• /
• 2016

The goats raised in the barn are usually fed on fresh grass. As dry forage can be stored for long periods in large amounts, dry forage feeding makes it possible to feed large numbers of goats in barns. This review explains the physiological factors involved in suppressing dry forage intake and the cause of drinking following dry forage feeding. Ruminants consume an enormous amount of dry forage in a short time. Eating rates of dry forage rapidly decreased in the first 40 min of feeding and subsequently declined gradually to low states in the remaining time of the feeding period. Saliva in large-type goats is secreted in large volume during the first hour after the commencement of dry forage feeding. It was elucidated that the marked suppression of dry forage intake during the first hour was caused by a feeding-induced hypovolemia and the loss of $NaHCO_3$ due to excessive salivation during the initial stages of dry forage feeding. On the other hand, it was indicated that the marked decrease in feed intake observed in the second hour of the 2 h feeding period was related to ruminal distension caused by the feed consumed and the copious amount of saliva secreted during dry forage feeding. In addition, results indicate that the marked decreases in dry forage intake after 40 min of feeding are caused by increases in plasma osmolality and subsequent thirst sensations produced by dry forage feeding. After 40 min of the 2 h dry forage feeding period, the feed salt content is absorbed into the rumen and plasma osmolality increases. The combined effects of ruminal distension and increased plasma osmolality accounted for 77.6% of the suppression of dry forage intake 40 min after the start of dry forage feeding. The results indicate that ruminal distension and increased plasma osmolality are the main physiological factors in suppression of dry forage intake in large-type goats. There was very little drinking behavior observed during the first hour of the 2 h feeding period most water consumption occurring in the second hour. The cause of this thirst sensation during the second hour of dry forage feeding period was not hypovolemia brought about by excessive salivation, but rather increases in plasma osmolality due to the ruminal absorption of salt from the consumed feed. This suggests the water intake following dry forage feeding is determined by the level of salt content in the feed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.4
• /
• pp.457-463
• /
• 2000

Fifty mid-lactation Holstein cows were used in a six-week feeding trial to study effects of high-forage, high-fat diets on dry matter intake and production performance. Cows were divided into 10 replicates, each consisting of five cows. Each cow was assigned to a control (diet 1) or one of the four experimental diets (high-forage (75%), high-fat (7.5%) (diet 2); high-forage, medium-fat (5%) (diet 3); medium forage (65%), high-fat (diet 4); medium-forage, medium-fat (diet 5)), or a control diet containing about 50% forage and 2% fat. All diets were isonitrogenous (17.7% crude protein). The forage mixture consisted of 20% alfalfa hay, 40% alfalfa haylage, and 40% com silage. Supplemental fat included 80% rumen-protected fat and 20% yellow grease. Dry matter intake was decreased (p<0.01) in cows fed experimental diets (18.4, 20.9, 19.9, and 22.6 kg for cows fed diets 1-4, respectively vs. 27.5 kg for cows fed the control diet). Daily milk production was lower (p<0.05) for cows consuming experimental diets (30.5, 31.3, 31.0, and 32.5 kg for cows fed greater for cows consuming experimental diets (1.74, 1.55, 1.60, and 1.53 kg milk/kg dry matter intake for cows fed diets 1-4, respectively, vs. 1.26 kg milk/kg dry matter intake for cows fed the control diet).

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.3
• /
• pp.341-352
• /
• 2012

In large-type goats that were fed on dry forage twice daily, dry forage intake was markedly suppressed after 40 min of feeding had elapsed. The objective of this study was to determine whether or not marked decreases in dry forage intake after 40 min of feeding are mainly caused by the two factors, that is, ruminal distension and increased plasma osmolality induced thirst produced by dry forage feeding. Six large-type male esophageal- and ruminal-fistulated goats (crossbred Japanese Saanen/Nubian, aged 2 to 6 years, weighing $85.1{\pm}4.89kg$) were used in two experiments. The animals were fed ad libitum a diet of roughly crushed alfalfa hay cubes for 2 h from 10:00 to 12:00 am during two experiments. Water was withheld during feeding in both experiments but was available for a period of 30 min after completion of the 2 h feeding period. In experiment 1, saliva lost via the esophageal fistula was replenished by an intraruminal infusion of artificial parotid saliva (RIAPS) in sham feeding conditions (SFC) control, and the treatment was maintained under normal feeding conditions (NFC). In experiment 2, a RIAPS and non-insertion of a balloon (RIAPS-NB) control was conducted in the same manner as the SFC control of experiment 1. The intraruminal infusion of hypertonic solution and insertion of a balloon (RIHS-IB) treatment was carried out simultaneously to reproduce the effects of changing salt content and ruminal distension due to feed entering the rumen. The results of experiment 1 showed that due to the effects of multiple dry forage suppressing factors when feed boluses entered the rumen, eating rates in the NFC treatment decreased (p<0.05) after 40 min of feeding and cumulative dry forage intake for the 2 h feeding period reduced to 43.8% of the SFC control (p<0.01). The results of experiment 2 indicated that due to the two suppressing factors of ruminal distension and increased plasma osmolality induced thirst, eating rates in the RIHS-IB treatment were, as observed under NFC, reduced (p<0.05) and cumulative dry forage intake for the 2 h feeding period decreased to 34.0% of the RIAPS-NB control (p<0.01). The combined effects of ruminal distension and increased plasma osmolality accounted for 77.5% of the suppression of dry forage intake 40 min after the start of dry forage feeding. The results indicate that ruminal distension and increased plasma osmolality induced thirst are the main factors in the suppression of dry forage intake in large-type goats.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.8
• /
• pp.1069-1085
• /
• 2011

In large-type goats that were fed on dry forage twice daily, dry forage intake was markedly suppressed after 40 min of feeding had elapsed. The objective of this study was to clarify whether or not increases in plasma osmolality and subsequent thirst sensations produced by dry forage feeding suppress dry forage intake. Eight large-type male esophageal- and ruminal-fistulated goats (crossbred Japanese Saanen/Nubian, aged 3 to 6 years, weighing $72.3{\pm}2.74$ kg) were used in two experiments conducted under sham feeding conditions. The animals were fed ad libitum a diet of roughly crushed alfalfa hay cubes for 2 h from 10:00 to 12:00 h during two experiments. Water was withheld during feeding in both experiments but was available for a period of 30 min after completion of the 2 h feeding period. In experiment 1, an intraruminal infusion of artificial parotid saliva (RIAPS) in the control replenished saliva lost via the esophageal fistula and an intraruminal infusion of hypertonic solution (RIHS) in the treatment was carried out in order to reproduce the effects of changing salt content due to feed entering the rumen. In experiment 2, the RIHS control was conducted in the same manner as the RIHS treatment of experiment 1. The treatment group consisted of RIHS-with an intravenous infusion of artificial mixed saliva (VIAMS) treatment that was carried out for 3 h to prevent increases in plasma osmolality during feeding. The results of the RIHS treatment in experiment 1 showed that ruminal fluid osmolality increased and then an increase in plasma osmolality was observed. This resulted in the production of thirst sensations and the reduction of cumulative dry forage intake to 43.3% (p<0.05) of the RIAPS control. The results of the RIHS-VIAMS treatment in experiment 2 indicated that ruminal fluid osmolality was the same as the RIHS control but plasma osmolality significantly decreased, and thirst level was markedly reduced. This caused a significant increase of 31.4% (p<0.05) in cumulative dry forage intake in the RIHS-VIAMS treatment compared to the RIHS control. These results indicate that increases in ruminal fluid osmolality during dry forage feeding indirectly suppresses dry forage intake by causing an increase in plasma osmolality and subsequently inducing thirst sensations. The results of the present study suggest that marked decreases in dry forage intake after 40 min of feeding are caused by increases in plasma osmolality and subsequent thirst sensations produced by dry forage feeding.

• Asian-Australasian Journal of Animal Sciences
• /
• v.1 no.3
• /
• pp.157-161
• /
• 1988

To study the effect of moisture content of the diet on drinking behaviour and the amount of water drunk, observations were made on 8 Holstein steers fed either fresh cut forage or first cut hay. The observations were made in a barn with a mean temperature of about $13^{\circ}C$. Drinking occurred mainly within 3 hours after feeding for the steers fed hay, while those fed soilage drank casually. Frequency of drinking (F) was related to the dry-matter concentration (DMC, %) of herbage: F = 0.47 (${\pm}0.09$) DMC - 6.5, $SE={\pm}0.4$, r = 0.86, P<0.01. Intake of drinking water for each 100 kg of live weight (IDW/100kg) for steers fed soilage was related to the dry-matter concentration: IDW/100kg = 0.55 (${\pm}0.06$) DMC - 8.7, $SE={\pm}0.3$, r = 0.94, P<0.01. The intake of water in each drinking period for animals fed fresh forage was curvilinearly related to the drinking frequency; for the hay-fed steers there was a negative linear relationship. When the drinking frequency for steers fed the fresh forage increased to the same as that observed for the hay, water intake in each drinking period was the same as found for the hay-fed steers.

• Asian-Australasian Journal of Animal Sciences
• /
• v.8 no.2
• /
• pp.107-111
• /
• 1995

An experiment was conducted at Pabna milkshed area under Bathan condition during November, 1992 to February 1993 with 16 milking cows fed legume forage with straw supplementation (treated group) and 8 milking cows fed legume forage only (control group). From the study, the results revealed that supplementation of straw with leguminous diet increases the total dry matter intake (DMI) of 11.83 kg/d/cow for the treated group and 11.53 kg/d/cow for the control group. The average daily legume forage intake was $37.39{\pm}8.67kg/d/cow$ and $49.62{\pm}10.57kg/d/cow$ for the treated and control group respectively and the difference was significant (p < 0.05). The results also exhibited that due to the supplementation of straw, the legume forage intake reduced by 12 kg/d/cow. The forage dry matter intake (DMI) kg/d/cow for the treated and control groups were $6.18{\pm}1.44kg$ and $8.38{\pm}1.95kg$ respectively. The milk production was $8.64{\pm}1.15litre/day$ for the treated group which was significantly (p < 0.05) higher than the control group ($7.74{\pm}1.24litre/day$). The average initial body weight of the supplemented and control groups were $338.06{\pm}39.32kg$ and $329.87{\pm}48.03kg$ respectively. Whereas, the final body weight of supplemented group was $344.33{\pm}35.90kg$ and control group was $330.35{\pm}37.28kg$. It may be concluded that straw supplementation with legumes diet could save legume forage for further use as well as increase milk production.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.37 no.3
• /
• pp.208-215
• /
• 2017

This study was designed to investigate the carryover effects of high-forage to concentrate (F: C) diet in bred heifers on feed intake, feed efficiency (FE) and milk production of primiparous lactating Holstein cows. The experiment was conducted for 589 days (d) from onset of pregnancy through to the end of first lactation. Twenty-four bred heifers (Body weight: $BW=345.8{\pm}45.4kg$ and $15{\pm}1.2mon$ of age) randomly assigned to two groups of 3 pens containing 4 heifers each and fed high forage (HF) diet with F: C ratio of 91.7: 8.3% and low forage (LF) diet with F: C ratio of 77.8: 22.2% throughout the pregnancy period. After calving, lactating cows were fed total mixed ration (TMR) based diet. No differences (p > 0.05) were observed in dry matter intake (DMI) of bred heifers and primiparous lactating cows in both HF and LF groups. The FE of mid-to-late lactation period was higher (p< 0.05) in HF than LF group. However, the HF group showed higher (p < 0.05) milk yield, 4 % fat corrected milk (FCM) and energy corrected milk (ECM) than LF group during the 305 d lactation. The LF group showed higher (p < 0.05) milk fat, crude protein (CP), milk urea nitrogen (MUN), solid not fat (SNF) and somatic cell count (SCC) than HF group. It is concluded that restriction of F: C ratio to 91.7: 8.3% to bred heifers has the potential carryover effects to maintain higher milk yield and FE with no adverse effect on feed intake and milk composition of primiparous lactating Holstein cows.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.9
• /
• pp.1174-1183
• /
• 2010

In goats fed on dry forage twice a day, an esophageal fistula was used to investigate the physiological factors present in the marked suppression of dry forage intake that occurs after 40 min of feeding. The animals used in this study were five large-type male esophageal- and ruminal-fistulated goats. Roughly crushed alfalfa hay cubes with any large remaining chunks removed were used as feed for this research. The study was conducted under both normal feeding conditions (NFC) and sham feeding conditions (SFC). In the NFC control, the esophageal fistulae were closed by plugs and the animals ate dry forage in the normal manner. In the SFC treatment, before starting the experiment the plugs for closing the esophageal fistula were removed and the cannulae for collecting boluses were fitted into the fistulae. Therefore, the esophageal boluses were removed via an esophageal fistula before they entered the rumen. In the NFC control, eating rates sharply decreased in the first 40 min of feeding and were subsequently maintained at low levels. However, eating rates in the SFC treatment remained high after 40 min of the feeding period had elapsed and the goats ate continuously during the 2 h feeding period. In comparison with the NFC control ($1,794{\pm}203.80\;g$/2 h), cumulative dry forage intake in the SFC treatment ($3,182{\pm}381.69\;g$/2 h) was 77.4% greater (p<0.05) upon conclusion of the 2 h feeding period. In the SFC treatment, cumulative bolus output ($6,804{\pm}469.92\;g$/2 h) was about twofold the cumulative dry forage intake due to cumulative salivary secretion volume ($3,622{\pm}104.13\;g$/2 h) upon conclusion of the 2 h feeding period. The result indicates that large amounts of secreted saliva during dry forage feeding act in conjunction with consumed feed to form the ruminal load responsible for ruminal distension. The increased plasma total protein concentrations were higher in the SFC treatment than in the NFC control. However, plasma and ruminal fluid osmolalities increased in the NFC control during and after feeding but were mostly unchanged in the SFC treatment. In comparison with the NFC control ($3,440{\pm}548.04\;g$/30 min), thirst level in the SFC treatment ($1,360{\pm}467.02\;g$/30 min) was 60.5% significantly less (p<0.05) upon conclusion of the 30 min drinking period. The results of the present study indicate that In the second hour of the 2 h feeding period, dry forage intake is regulated by factors produced when boluses enter the rumen.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.8
• /
• pp.1100-1111
• /
• 2011

Two experiments under sham feeding conditions were conducted to determine whether or not ruminal distension brought about by feed boluses entering the rumen is a factor in the marked suppression of feed intake after 40 min of feeding. In experiment 1, a comparison was made between the intraruminal insertion of a water filled balloon (RIB) treatment and normal control (non-insertion of a balloon, NIB). In experiment 2, saliva lost due to sham feeding conditions was replenished via an intraruminal infusion of iso-osmotic artificial saliva. A comparison of dry forage intake was then conducted between the intraruminal replenishment of iso-osmotic artificial saliva and insertion of a balloon (RRIAS-RIB) treatment, and the intraruminal replenishment of iso-osmotic artificial saliva and non-insertion of a balloon (RRIAS-NIB) control. In experiment 1, eating rates in the RIB treatment 30 min after the commencement of feeding tended to be lower than those in the NIB control. In comparison with the NIB control, cumulative dry forage intake in the RIB treatment was 29.7% less (p<0.05) upon conclusion of the 2 h feeding period. The secreted saliva weight in the NIB control and the RIB treatment during the 2 h feeding period was 53.2% and 60.9% total weight of the boluses, respectively. In experiment 2, eating rates in the RRIAS-RIB treatment 30 min after the commencement of feeding was significantly lower (p<0.05) than those in the RRIAS-NIB control. Cumulative dry forage intake in the RRIAS-RIB treatment was a significant 45.5% less (p<0.05) compared with that in the RRIAS-NIB control upon conclusion of the 2 h feeding period. The secreted saliva weight in the RRIAS-NIB control and the RRIAS-RIB treatment during the 2 h feeding period was 54.1% and 64.2% total weight of the boluses, respectively. The level of decrease in dry forage intake in the RRIAS-RIB treatment of experiment 2 was larger than that in the RIB treatment of experiment 1. In the present experiments, due to the sham feeding conditions, the increases in osmolality of ruminal fluid and plasma, and a decrease in ruminal fluid pH which are normally associated with feeding were not observed. The results indicate that the marked decrease in feed intake observed in the second hour of the 2 h feeding period is related to ruminal distension caused by the feed consumed and the copious amount of saliva secreted during dry forage feeding.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.8
• /
• pp.1127-1132
• /
• 2000

Forty yearling Tswana sheep and goats (20 sheep and 20 goats) of both sexes were used in a feeding trial conducted in Botswana College of Agriculture (B.C.A) Content Farm in Gaborone for three months. The animals were randomized into four treatment groups of five animals per species balancing for weight and sex such that average initial weights were not statistically different. The sheep and goats were individually housed and fed under a common roof. All the animals were fed on Lablab purpureus L. as a protein supplement which was 40% of the ration. In addition to L.purpureus L. the control groups of both species were fed on 60% Cenchrus ciliaris L. as basal diet. The other three treatment groups were fed on different forages namely; sorghum forage (Sorghum sudanense (Piper) Stapf), millet forage (Pearl millet, Pennisetum typhoides (Burm.) Stapf and Hubb.) and veldt grass mainly Urochloa mosambicensis (Hack.) as basal diet (60%). Water was provided individually to all the animals on ad lib. basis. Daily intakes of feed and water were recorded and weighing of the animals was done every two weeks. The collected data were analysed statistically for differences. Average daily weight gain by Tswana sheep was significantly different (p<0.05), sheep fed on millet forage had a higher daily weight gain $(120.24{\pm}8.91g)$ compared with sheep fed on veldt grass $(92.86{\pm}6.94g)$. Treatment effects on daily total DM intake by sheep were significant, the control group (C. ciliaris L.) had higher intake $(705.77{\pm}10.22g)$ and those fed on sorghum forage had the least intake $(668.10{\pm}10.70g)$. There was no significant difference (p>0.05) in the average daily weight gain by Tswana goats and it was 84.52, 73.81, 83.33 and 78.57 g for goats fed on C. ciliaris L., sorghum forage, millet forage and veldt grass respectively. Average daily total DM intake by goats was 655.27, 652.64, 650.07 and 650.94 g for C. ciliaris L., sorghum forage, millet forage and veldt grass respectively. Feed conversion efficiency was 8.00, 8.98, 7.93 and 8.34 for goats fed on C. ciliaris L., sorghum forage, millet forage and veldt grass respectively and were not significantly different (p>0.05).