Link to this article: http://journals.cambridge.org/abstract_S000335610000177XHow to cite this article: M. Kaim, Y. Folman, H. Neumark and W. Kaufmann (1983). The effect of protein intake and lactation number on post-partum body weight loss and reproductive performance of dairy cows. ABSTRACTIn three experiments 250 high-yielding dairy cows were fed for 18 weeks after parturition either a low-protein (LP) diet containing 150 to 160 g crude protein per kg or a high-protein (HP) diet containing 190 to 200 g crude protein per kg. In all three experiments cows were fed an average of 2-6 to 2-9 kg crude protein per day on the LP diet and 3-3 to 3-7 kg crude protein per day on the HP diet. Inclusive of maintenance, crude protein intake was, on average, 71 to 83 g crude protein per kg milk on the LP diet and 84 to 112 g crude protein per kg milk on the HP diet.Protein intake did not affect the post-partum decrease in body weight; however, cows in their 4th and later lactations lost significantly more weight than cows in their 2nd and 3rd lactations (P < 0-01). Number of lactation did not affect the levels of rumen fluid ammonia or plasma urea, but older cows had significantly higher milk yields than younger ones. In all the experiments the first oestrus was observed, on average, between 38 and 43 days after parturition. The first insemination was carried out, on average, between 69 and 75 days after calving. Protein intake or age did not affect the intervals between parturition and the first observed oestrus or insemination. Proportional conception rates of cows fed the LP and HP diets were 0-566 and 0-431, respectively (P < 005). Conception rates of cows in their 2nd and 3rd lactations were 0-582 and 0-515 for cows on the LP and HP diets, respectively, whereas conception rates of cows in their 4th and later lactations were 0-526 and 0-288, respectively (P < 0-02). Within the HP-fed group the difference in conception rate between cows in their 2nd and 3rd lactations and those in their 4th and later lactations was also significant (P < 0-01). The proportion of cows pregnant 126 days after parturition was 0-786 and 0-645 for cows fed the LP and HP diets, respectively (P < 0-05). The proportion of cows in their 2nd and 3rd lactations which were pregnant, was 0-792 and 0-702 for cows of the LP and HP groups, respectively. Pregnancy rates for cows in their 4th and later lactations were 0-769 and 0-515 in the LP and HP groups, respectively (P < 005).
NEUMARK et a1.-AMINES etc. I N SILAGES 487 diagnosing the cause of poor growth and low crop yield in the absence of visible deficiency symptoms (a condition sometimes encountered in the field) if the cause of the poor growth is nutritional.Silages from different sources were arranged into two groups according to their palatability for cattle, and assayed for their amine, aldehyde and keto-acid content. A correlation between tryptamine content and palatability was established. None of the assayed amines per se was found to have a direct influence upon appetite, although histamine enhanced the appetite-depressing action of formaldehyde. Only formaldehyde, but not acetaldehyde or butyraldehyde, was found to exert a strong influence upon the appetite of ruminants.Electrophoretic analyses were made on acetic acid-extracts of flour milled from five varieties of Hard Red Winter wheat grown a t six locations. The electrophoretic experiments were performed in phosphate buffer, pH 3.0, r/z 0.05. Differences were found in the distribution of the protein components and the protein content for locations of growth as well as for varieties. This also applies to the amount of protein extractable by acetic acid and that remaining after dialysis. The long-mixing flours had less glutenin-gliadin than the short-mixing flours. The better-quality flours (which also required longer mixing) also contained more of the salt-soluble proteins.
SummaryTwo experiments were conducted with eight rams in a latin-square design of four treatments with different lucerne hay (LH): maize grain (MG) ratios: 100:0, 80:20, 50:50 and 20:80. In Expt 1 the amount of food offered was restricted to 1 kg/day. In Expt 2 the rams were offered 1·5 kg/day, which was about the maximum amount the animals in the 100% LH treatment were able to consume. Animals were kept on each treatment for 4 weeks; during the final 8 days the faeces were oollected and weighed for each animal and analysed for dry matter, organic matter (OM), crude fibre and δCThe values of δC in LH, MG and different faeces samples were used for direct determination of LH and MG digestibilities of mixed diets in the different treatments.The increase of MG in the ration and the decrease of LH improved the digestibility of total OM. The effect of MG was more pronounced at the low than at the high level of consumption. At the low level of intake, an increase in the amount of MG in the ration did not affect the digestibility of LH, and MG digestibility was close to the extrapolated value. At a food intake level 1·5 times that of Expt 1, the addition of grain to more than 50 % of the ration caused a marked depression in digestibility of LH.Results of the δC method were discussed in comparison with calculated values of LH and MG digestibilities and with whole ration crude-fibre digestibility.
It was recently found by Neumark, Bondi & Volcani (1964) that the quantity of silage eaten by sheep was reduced when fermentative products such as formaldehyde, formic acid and histamine were present in the silage. The inference was drawn that these undesirable products were responsible for the low consumption of such silages. It was also found (Neumark, unpublished work) that the introduction of solutions of formic acid and histamine via a stomach tube into the rumen of sheep depressed the quantity of food subsequently eaten. The taste of silages cannot be eliminated as a reason why sheep are reluctant to eat them when they contain formic acid and histamine, but even so, these experiments show that the substances have an effect in the stomach or systemically which are sufficient to depress appetite.The experiments reported here were designed to see whether the effects of formic acid and histamine could be attributed to peripheral effects in the stomach or to systemic effects. They indicate that an area between the cardia and the fundic area of the abomasum is sensitive to formic acid and that histamine, when it is effective, is so by the wellknown systemic effects it produces. EXPERIMENTALFour clun forest wethers (nos. 174, 265, 34 and 70) were used for all experiments. These animals were maintained on 350 g chopped hay with 100 g flaked maize which was given twice daily at 8 a.m. and 4 p.m. The animals under normal circumstances ate their food within 30 min of receiving it.The average 'eating time' for sheep 174 and 265 was found to be 24 min and 23 min 40 s respectively, calculated from twenty-seven observations. The maximum 'eating time' was 27 min 30 s and the minimum was 21 min.Surgical. Sheep 174 and 265 were both fitted with an ebonite rumen cannula. Sheep 265, 70 and 34 were later fitted with abomasal cannulas.Procedures. Solutions were given either directly into the rumen via the rumen cannula or by stomach tube (sheep 174 and 265). In intitial experiments the stomach tube was passed into the rumen to an unknown depth. In order to standardize the procedure, radiographs were taken of the sheep with the stomach tube filled with a suspension of barium sulphate and the length of tube needed to place the orifice at the region of the cardia was measured. It was found that 72-73 cm of stomach tube, measured from the incisor teeth, was needed to reach the cardia.In experiments in which solutions were run into the anterior rumen or reticulum via a rumen cannula, a flexible copper wire was introduced into the lumen of the dosing tube so that it could be passed forwards over the anterior pillar.Solutions introduced directly into the abomasum were introduced through the abomasal cannula to the region of the omasal orifice or caudally into the pyloric part of the abomasum.Intravenous infusions were made with sterile solutions from a 'Braun Constant flow' infusion pump through polyvinyl tubing inserted into the jugular vein. The duration of the infusions was 5 min. All infusions into the stomach or into the jugular...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.